Benefits of Implementation of Insulin Pump in People with Type 1 Diabetes: 10 Case Reports

Abstract

Ten people with type 1 diabetes (T1D), aged 28 to 57 years, with a duration of diabetes from 8 months to 47 years, attending an urban diabetes center, were retrospectively observed to assess the effects of intensive insulin treatment using continuous subcutaneous insulin infusion (insulin pump) for a period ranging from 2 months to 30 years, controlled either by glucometer-strips systems or using sensors for continuous glucose monitoring (CGM). Retinopathy, neuropathy, and nephropathy were present in some of them. An assessment of changes in HbA1c, body mass, insulin requirements per day (INS/d), blood pressure, lipoproteins, and estimated glomerular filtration rate (eGFR) was used to determine treatment efficiency. In conclusion, a combination of adequate education, long-term therapy with an insulin pump, and early implementation of CGM appear to be the optimal approach to T1D management, resulting in improved diabetes control and/or enhanced quality of life for the users.

1. Introduction

According to American Diabetes Association (ADA), immune-mediated diabetes, also known as “insulin-dependent diabetes,” caused by cellular-mediated auto-immune destruction of the pancreatic β-cells, accounts for 5–10% of diabetes, making it the major of the two subcategories of type 1 diabetes. Islet cell autoantibodies and autoantibodies to GAD (glutamic acid decarboxylase, GAD65), insulin, the tyrosine phosphatases islet antigen 2 (IA-2) and Ia-2β, and zinc transporter 8, represent autoimmune markers. Only a minority of people with diabetes fall into the second subcategory, idiopathic T1D, with no evident β-cell autoimmunity, higher susceptibility to ketoacidosis, and permanent insulinopenia [1, 2]. The ADA’s clinical practice recommendations in “Standards of Medical Care in Diabetes—2022” state that the ideal HbA_1c concentration should be lower than 53 mmol/mol (7%) as it correlates to a 50–76% decrease in microvascular complications (retinopathy, neuropathy, and diabetic kidney disease), development, and progression [3]. However, for many people with T1D, despite the availability of the latest innovative technology in insulin therapy, achieving the recommended target remains challenging [4, 5, 6].

When considering methods of treatment, insulin pumps should be made accessible to all people with insulin-deficient diabetes, nonetheless, specific circumstances, desires, and needs of the patient should be brought into account [6, 7]. Offering the latest available technology to all patients is one of many priorities in our hospital, including sensor-augmented pumps from Medtronic MiniMed in T1D.

The latest MiniMed 780G (Figure 1) system, the successor to MiniMed 640G and 670G, is equipped with advanced hybrid closed-loop (AHCL) [8, 9, 10]. The AHCL system is composed of CGM and an insulin pump. The continual administration of self-adjusting basal insulin delivery and correctional boluses every 5 minutes is based on glycemia measured in real-time. This may prevent hypoglycemia, while also making it safe, effective, and more comfortable to use [5, 8, 9, 10, 11]. Even CGM alone has proven to be more effective than manual self-monitoring with a glucometer [12, 13, 14]. Insulin delivery via this system represents a near-physiological mechanism; it mimics endogenous insulin secretion to the extent of minimal need for manual user intervention [15, 16, 17, 18]. For optimal results, in the traditional “Manual mode,” the number of saccharides should be entered and the bolus calculator (“bolus Wizard”) may be used as an advisor. In the “Smart Guard” mode the user needs to enter only the number of saccharides [9, 18]. The CareLink system creates person-related graphs (Figure 2) depicting CGM, saccharide intake, and insulin infusions, providing an organized overview for the user and their healthcare provider. Time in range (TIR) is the amount of time spent in target glycemia, represented as a percentage, in the course of defined period.

Figure 1.

Insulin pump MiniMed 780G: the SmartGuard mode showing glycaemia 7.4 mmol/l (on the left), and time in range (TIR) 89% (on the right).

Figure 2.

This CareLink graph depicts two shaded areas of data: blue and orange, each area representing information about glycemia from a date range (A and B), (see left corner). The black dotted line in the middle represents average glycemia from the last date range (A). The darker shaded blue area represents 25–75% of all sensor readings, meaning this is where the majority of glucose readings have been. The remainder of the data is in the 0–90% range presented within the solid blue line. Data from the date range (B) are colored orange behind the blue plot. This report should be reviewed with one’s healthcare professional to see progress from the last visit or the last device settings change [19]. The internet address specified for each user is www.carelink.minimed.eu.

Figure 3.

Anna’s absolute values of HbA_1c, BM, and INS/d since her first pump D (Dahedi Elektroniks) was implemented. Insulin pump H-tron (1994–2008) was followed by pumps paradigm (without CGM). Since the therapy with a sensor-augmented insulin pump MiniMed 780G with SmartGuard auto mode was applied in 2022, there is a subtle improvement in HbA_1c concentration (red box). See also red box in Figure 4.

Figure 4.

Anna’s relative values of HbA_1c, BMI, and INS/d from 1993 to 2022 indicate an extended period of HbA_1c at 30% above the norm with slight fluctuation and a 10% decrease within 1 year after CGM implementation. Over the entirety of 29 years, BMI remains stable in the high 80s and low 90s. There is no difference in INS/d before and after MiniMed 780G. D – Dahedi Elektroniks, P – Paradigm, M – MiniMed.

Based on previous data, the algorithm may predict glycemia and the body’s reaction to insulin delivery. Therefore, it can be expected that with a longer period of use comes better control of glycaemic targets. Some other factors that play a role in optimal results include; correct application and fixation of the cannula and infusion set; turning off insulin delivery when taking off the pump (for example during showers, sports, and sex). At night, the algorithm controls glycemia according to the automatic basal rate, regardless of evening glycemia. This enables users to stay in range without any active intervention for the duration of their sleep [18]. Anyone using the technology should be well informed on how AHCL algorithms work, and most importantly how to use it to get the maximum benefit out of it [20].

2. Case reports

To demonstrate different challenges and aspects of insulin pump therapy, four men and six ladies were chosen out of 20 people with T1D registered in an urban diabetes center. They were 28 to 57 years old (y/o), with a duration of diabetes from 8 months to 47 years, and insulin pumps were implemented for a period ranging from 2 months to 30 years.

Each of the following case reports consists of a Focus (the reason for demonstration); a short Medical history; a Current goal (an objective for further management); a Table with important clinical and laboratory parameters; two Figures: a graph with absolute values illustrating the progress of HbA_1c, BMI, and INS/d in time; a graph with relative values, where 100% of HbA_1c, BMI, and INS/d corresponds to the highest value of a respective physiological range. Later, the effectiveness of the pump was assessed based on clinical and laboratory parameters as well as its subjective impression on the user.

Providing the user with the proper knowledge, skills and attitudes ensure the possibility that the health benefits, convenience, and comforts that the AHCL algorithm offers are utilized to their full potential. Therefore, everyone was familiarized with: physiological insulin function, prandial boluses, basal rate, the effects of physical activity, nutrition, energy intake and expenditure, and how all the above effects the parameters of therapeutic efficiency (HbA_1c, body mass, glycemia, and INS/d) [21]. Additionally, they were taught how to use glucometer-strips system for self-monitoring (such as Calla, Galileo Glu/Ket, Contour plus, and ambulatory glycaemic profiles), insulin pens, and most importantly, insulin pumps. Specifically, this entails refilling the insulin reservoir, catheter insertion and replacement in 3-day intervals, sensor insertion, entering saccharide information before and during meals, and overall maintenance of the pump. Education on the insulin pump was provided after implementation either within a two-week hospitalization period or in an outpatient alternative mode.

2.1 Case report Anna

Focus: 30 years lasting management of T1D using various insulin pumps, and eventually improved quality of life along with a subtle reduction in HbA_1c after the sensor-augmented insulin pump, MiniMed 780G, was implemented.

History: At 9 years of age (1975), Anna (today 57 y/o) was admitted to the emergency department for a hyperglycaemic coma. Based on history, clinical, and laboratory findings, T1D was diagnosed. From 1975 to 1983, treatment was done with animal insulin consisting of insulin delivery by a glass syringe and a blunt metal needle. At that time self-monitoring was not available apart from a urinalysis. Anna’s description of her medical care from 1983 to 1991 is vague. In 1992, she was referred to a diabetes center and received MADI (manual insulin dispenser) [22]. In 1993, she obtained her first glucometer, which Anna describes as a milestone in her life as a person with T1D. In 1993, she obtained her first insulin pump (Dahedi Elektroniks), which reduced the INS/d day from 34 to 29 IU. Next, the pump Dahedi was replaced by a pump H-Tron V100, Disetronic (1994–2008). In 1996, she became pregnant with twins. Both children (boy and girl) were born on January 10, 1997, healthy, by planned Cesarean section (indicated by a breech position of one of the children) with body mass at births of 2.6 and 2.7 kg. In the following period of 25 years, Anna’s clinical condition was stable. She performed intensive selfmonitoring (SMPG) using glucometer-strips system 5 to 12 times a day and adopted the insulin boluses according to plasma glucose, food, and exercise. In 2009 insulin pump Paradigm 722 was implemented, followed by Paradigm Veo 554. In 2010, hypothyroidism was diagnosed and treated further on.

In 2021, the hybrid insulin pump MiniMed 780G was put in motion. Anna has been continuously employing the SmartGuard mode (Figures 3 and 4). The important clinical and laboratory findings can be seen in Table 1. Current TIR: 89%.

Parameters	Units	Refer	1.12.1994	26.10.2004	13.07.2012	29.04.2015	21.09.2022
T1D duration	Years	N/A	19	29	37	40	47
Heart rate	BPM	60–90	76	—	72	78	72
Blood pressure	Torr	<130/85	110/70	—	125/70	150/80	168/89
fvS-glucose	mmol/	3.3–5.5	—	—	5.6	6.7	8.8
fvS-C-peptide	pmol/l	>300	—	500	<300*	—	—
fvS-GADA	kU/I/	0–5	—	—	0.2	—	—
fvS-HDL	mmol/l	1.2–2.7	1.26	1.74	2	1.84	2.12
fvS-LDL	mmol/l	1.2–2.6	4.19	2.23	2.72	2.83	3.25
fvS-TAG	mmol/l	0.5–1.7	1.53	1.9	0.91	0.6	0.8
fvS-creatinine	μmol/l	< 108	—	—	78	67	69
eGFR	ml/s	1.0–1.3	—	—	1.15	—	1.55
fvS-CRP	mg/l	< 10	—	—	0.7	0.6	0.7

Table 1.

Anna’s clinical and laboratory parameters over 28 years.

fvS – fasting venous serum, *since 2004 repeated five times.

Current goal: To reduce LDL below 2.6 mmol/l and HbA_1c below 50 mmol/mol without hypoglycemia, therapy of hypoglycemia with glucagon; screening for macroangiopathy (Table 1).

2.2 Case report Betty

Focus: influence of pregnancy on HbA_1c, INS/d, and BMI in a lady with T1D using a pump without CGM, and effects of hybrid MiniMed 780G implemented after pregnancy.

History: Betty (today 33 y/o) was diagnosed with T1D at the age of 14 years in September 2004 in pediatric department of regional hospital. She was immediately treated by means of an insulin pen with insulin aspart and detemir, a maximum dose of insulin was 20 IU/d. In 2007, insulin pump Animas was implemented as the main form of insulin therapy. In 2015 the pump Animas was replaced by MiniMed 640G. In the course of the first pregnancy, a decrease in HbA_1c and marked increase in INS/d could be seen. She gave birth to a boy (delivery July 8, 2015 by Cesarean section, 4.48 kg, 54 cm). The parameters from August 31, 2015 demonstrated improved compensation (lower values of HbA_1c), however, the amount of insulin per day was nearly doubled (Table 2, Figures 5 and 6). Betty had a second pregnancy in 2019 (delivery November 1, 2019 by Cesarean section, girl 4.75 kg, 53 cm). During this second pregnancy, there was an apparent decrease in HbA_1c concentration and an increased supply of exogenous insulin (161 IU/d). To explain these similar changes in HbA_1c and INS/d it is worth noting that placenta is permeable to glucose but impermeable to insulin [23, 24]. Therefore, the insulin from fetal pancreas may create new fetal adipose tissue by converting the glucose crossing through placental barrier from mother’s plasma. These pathways may result in fetal macrosomia (which is a known complication associated with raised HbA_1c concentration in the last trimester of pregnancy). Only a minority of pregnant women were able to optimize their glycemic control. This makes CGM and hybrid insulin pumps all the more favorable for treatment during pregnancy [25, 26]. However, Betty could receive the hybrid pump MiniMed 780G as late as in April 2021. Current TIR: 96% (January 5, 2023).

Figure 5.

Betty’s absolute values of HbA_1c, BMI, and INS/d from 2015 to the last check-up. The Animas insulin pump was implemented in 2007. The two peaks on the blue line (INS/d) in the years 2015 and 2019 correlate to Betty’s pregnancies when the insulin dosage nearly doubled and lowered HbA_1c, indicating better metabolic control. Pregnancy is symbolized by yellow stars. The last two check-ups show high INS/d (110 U/d) and increased body mass with no sustainable effect on HbA_1c (red box).

Figure 6.

Betty’s relative values of HbA_1c, BMI, and INS/d from 2015 to 2022. HbA_1c has exceeded the desired reference value for a long period of time, which is illustrated by all the red percentages. Two peaks, with 275% (=110 IU/d) value INS/d during her first pregnancy in 2015, and 403% (=161 IU/d) value INS/d during her second pregnancy in 2019 (yellow stars). The last two check-ups show high insulin delivery and increased BMI with no sustainable effect on HbA_1c (red box). TIR was 62% (February 9, 2022).

Parameters	Units	Refer	21.4.2014	12.10.2016	30.4.2019	16.12.2020	10.06.2022
T1D duration	years	N/A	9	12	14	16	18
Heart rate	BPM	60–90	94	89	98	94	97
Bl. pressure	Torr	<130/85	130/80	140/85	121/82	134/95	175/97
fvS-glucose	mmol/	3.3–5.5	9.9	7.0	9.0	6.0	6.8
fvS-C-peptide	pmol/l	>300	—	—	—	<7	—
fvS-GADA	kU/I/	0–5	—	—	—	33	—
fvS-HDL	mmol/l	1.2–2.7	1.29	2.04	1.55	1.17	1.17
fvS-LDL	mmol/l	1.2–2.6	2.89	3.53	2.7	3.31	3.31
fvS-TAG	mmol/l	0.5–1.7	1.26	0.88	2.7	1.39	1.39
fvS-creatinine	μmol/l	< 108	47.1	58	48	65	59
eGFR	ml/s	1.0–1.3	—	—	—	1.9	1.93
fvS-CRP	mg/l	< 10	1.9	1.8	7.9	3.6	5.1

Table 2.

Betty’s clinical and laboratory parameters over the last 8 years.

fvS – fasting venous serum.

Current goal: examine the methods for managing her increased appetite, management of hyperlipoproteinemia, hypertension, and hypoglycemia; selfmonitoring of ketones.

2.3 Case report Clark

Focus: continuously increased INS/d, and body mass along with near-optimal HbA_1c concentration and hypoglycaemia when using insulin pump without CGM and followed by hybrid pump with SmartGuard.

History: At 20 years of age, Clark (today 46 y/o) was diagnosed with T1D. Education and treatment by means of insulin pen and multiple daily injections resulted in improvement in clinical and laboratory findings. Clark was compliant and had no problem adjusting to the insulin boluses according to meals and physical exercise at that time. In 2009, Clark received his first insulin pump. In 2013, insulin pump Paradigm Veo (without CGM) was implemented and, in 2017, replaced with MiniMed 640G. INS/d was high (routinely adopted according to intake of saccharides), but otherwise no other issues, in clinical and laboratory parameters (Table 3 and Figures 7 and 8). In 2022 a hybrid insulin pump MiniMed 780G was introduced. Since that time Clark had troubles with his adaptation to the new algorithms dealing with saccharide ratio and insulin boluses. For example: after eating a roll for breakfast that contains 25 g of saccharides and noticing that the pump gives him only one unit of insulin, he would enter additional saccharides that he did not consume, until it would give him 2.5 units of insulin as he was used to. (Essentially ignoring that the pump gives him exactly what he needs at that moment.) This approach resulted in reoccurring hypoglycemia followed by increased food intake and growing body mass. Therefore, lower insulin doses resulting in reduced risk of hypoglycemia, lower body mass, and lower HbA_1c may be reached provided Clark creates a deeper understanding of the algorithm behind MiniMed 780G. At the time he is able to manage MiniMed 780G. Current TIR: 87% (January 5, 2023).

Figure 7.

Clark’s absolute values of HbA_1c, BM, and INS/d show relatively constant values of HbA_1c and INS/d over 9 years of time, while his body mass changed within a range of 88 kg and 98 kg. Treatment with an insulin pump was initiated in 2009. Followed by the insulin pump Paradigm Veo 554 implemented in April 2013, MiniMed 640G in April 2017, and MiniMed 780G in January 2022. Using CGM could potentially improve HbA_1c concentration with a lower number of insulin units needed.

Figure 8.

Clark’s relative values of HbA_1c, BMI, and INS/d from 2013 until the last check-up. Red values of INS/d in columns indicate the overuse of insulin to lower glycemia. Nevertheless, there is an apparent difference between the needed insulin dose during the use of the Paradigm Veo 554, MiniMed 640G, and MiniMed 780G.

Parameters	Units	Refer	21.05.2014	02.05.2015	05.09.2018	29.01.2020	23.11.2022
T1D duration	years	N/A	17	18	21	23	25
Heart rate	BPM	60–90	68	73	81	76	87
Blood pressure	Torr	<130/85	120/70	120/80	133/89	149/96	164/99
fvS-glucose	mmol/	3.3–5.5	4.9	6.4	5.3	7.5	4.9
fvS-C-peptide	pmol/l	>300	—	30	—	—	—
fvS-GADA	kU/I/	0–5	—	32.5	—	—	—
fvS-HDL	mmol/l	1.2–2.7	1.6	2.07	1.63	1.42	1.85
fvS-LDL	mmol/l	1.2–2.6	3.2	2.52	3.42	1.92	1.91
fvS-TAG	mmol/l	0.5–1.7	0.6	0.76	0.92	1.62	0.86
fvS-creatinine	μmol/l	< 108	90	121.6	95.7	83.6	77.7
eGFR	ml/s	1.0–1.3	—	—	—	1.7	1.7
fvS-CRP	mg/l	< 10	0.1	0.5	0.2	0.2	0.5

Table 3.

Clark’s clinical and laboratory parameters from the diagnosis of T1D over the last 8 years.

fvS – fasting venous serum.

Besides T1D, Clark also has hyperlipoproteinemia (diagnosed in 2014), treated with rosuvastatin, and unstable hypertension.

Current goal: reeducation on the use of MiniMed 780G with SafeGuard mode: input of saccharides, temporary targets, reassurance that the pump delivers the optimal doses without manual intervention, and management of high blood pressure and hypoglycemia.

2.4 Case report Daniel

Focus: long-term inadequate compensation during therapy by insulin pump with an improvement after switching to a hybrid pump with CGM and SmartGuard.

History: Daniel (today 51 y/o) was diagnosed with T1D in 2000. Primarily, he experienced polydipsia (drinking almost ten liters per day). Upon examination, glycemia was 30 mmol/l. Insulin therapy was initiated, however, glycated hemoglobin HbA_1c (70 mmol/mol) and unexpected hypoglycemia (twice a month) persisted. After 13 years (December 3, 2013), Daniel was given the Paradigm Veo 554 insulin pump (without CGM). Despite this, glycated hemoglobin showed no improvement. He was diagnosed with retinopathy in his left eye in 2015. It was recommended to regularly measure glycemia and learn to recognize hypoglycemia. The implementation of continuous monitoring with a new hybrid insulin pump MiniMed 780G made this easier and showed immediate improvement in glycated hemoglobin and a decrease in INS/d (Figures 9 and 10).

Figure 9.

Daniel’s absolute values of HbA_1c, BM, and INS/d over 9 years. Since he has been diagnosed with T1D in 2000, he has been treated with insulin by delivering it via an insulin pen. His first insulin pump, Paradigm Veo 554, was implemented on December 3, 2013. Laboratory values were constant until the application of a sensor-augmented insulin pump in September 2022, when the HbA_1c concentration decreased alongside a lower insulin dosage is needed (red box).

Figure 10.

Daniel’s relative values of HbA_1c, BMI, and INS/d from 2013 to 2022. Red values of HbA_1c indicate a long-lasting period in which the respective parameters exceeded the upper limit of the reference range. HbA_1c was constant until the application of a sensor-augmented insulin pump (MiniMed 780G) in September 2022, when the HbA_1c concentration decreased (to 148% = 62 mmol/mol) alongside a lower insulin dosage (78% = 31 IU/d) needed (red box).

When asked to compare Paradigm Veo to the latest MiniMed 780G, which he started using in September of 2022, he stated that it is easy to work with especially thanks to its ability to connect to a mobile phone. Besides T1D, Daniel is also treated for hypertension (ramipril), nephropathy with interstitial and glomerular damage, hypercholesterolemia (rosuvastatin), and neuropathy (Table 4). In 2021, he developed a dental defect. Daniel received a glucometer Galileo Glu/Ket, in order to use it in circumstances such as vomiting, nausea, fever, etc. Namely, some of these symptoms were recently present without apparent explanation. Current TIR: 87% (January 5, 2023).

Parameters	Units	Refer	29.11.2013	07.05.2015	04.05.2018	28.04.2021	05.10.2022
T1D duration	years	N/A	13	15	18	21	22
Heart rate	BPM	60–90	—	64	74	79	86
Blood pressure	torr	<130/85	—	130/80	161/105	147/88	157/98
fvS-glucose	mmol/	3.3–5.5	10.9	21.7	13.7	7.0	6.2
fvS-C-peptide	pmol/l	>300	Neg.	30	—	—	—
fvS-GADA	kU/I/	0–5	14	17	—	—	—
fvS-HDL	mmol/l	1.2–2.7	1.22	1.66	1.27	1.55	1.58
fvS-LDL	mmol/l	1.2–2.6	2.62	3.9	2.24	2.42	1.97
fvS-TAG	mmol/l	0.5–1.7	2.95	1.06	1.8	1.23	0.76
fvS-creatinine	μmol/l	< 108	69.6	67.4	64	71.9	62.4
eGFR	ml/s	1.0–1.3	—	—	—	1.73	1.81
fvS-CRP	mg/l	< 10	3.3	0.6	0.4	1.4	4.5

Table 4.

Daniel’s clinical and laboratory parameters over 9 years.

fvS – fasting venous serum.

Current goal: education in the use of the glucometer Galileo Glu/Ket as means of measurement of glycemia and ketone bodies, management of hypertension, and regular dental and eye exams.

Parameters	Units	Refer	11.2.2014	21.09.2016	20.07.2020	14.04.2021	21.09.2022
T1D duration	Months	N/A	0	32	78	87	104
Heart rate	BPM	60–90	64	88	84	67	80
Blood pressure	Torr	<130/85	130/70	130/70	156/86	136/89	135/80
fvS-glucose	mmol/	3.3–5.5	5.6	6.8	9.5	7.8	7.5
fvS-C-peptide	pmol/l	>300	258	—	142	—	—
fvS-GADA	kU/I/	0–5	47	—	12	—	—
fvS-HDL	mmol/l	1.2–2.7	1.3	1.3	1.3	1.2	1.4
fvS-LDL	mmol/l	1.2–2.6	4.2	3.6	2	2.7	2.8
fvS-TAG	mmol/l	0.5–1.7	0.9	1.4	0.8	0.9	0.9
fvS-creatinine	μmol/l	< 108	71.1	65.2	79.3	80.5	84.9
eGFR	ml/s	1.0–1.3	—	—	—	1.71	1.65
fvS-CRP	mg/l	< 10	0.4	0.3	1.2	0.6	0.7

Table 5.

Edward’s clinical and laboratory parameters over 8 years from the diagnosis of T1D in 2014 to the last check-up.

fvS – fasting venous serum.

2.5 Case report Edward

Focus: insulin pump implementation in 2014 led to post-initial remission until 2018, which was followed by an increase in HbA_1c, body mass, and IU/d needed.

History: Edward (today 46 y/o) was diagnosed with T1D at 27 years of age, in 2014. The diagnosis was made based on the abrupt onset of clinical symptoms such as polydipsia, polyuria, fatigue, and eventually loss of body mass (2 kg/month). He was given insulin in the form of Novopen (insulin aspart and detemir). After 6 weeks, an insulin pump, Paradigm Veo (Figure 11), was implemented while doing intensive self-monitoring of plasma glucose (SMPG) using glucometer Contour plus. Initially, Edward was skeptical about the insulin pump; due to his physical activity and sports, he was not sure if the pump would be an obstruction during his activities (Table 5). After education, when seeing the last parameters (Figures 12 and 13), he agreed to try MiniMed 780G.

Figure 11.

Paradigm Veo 554 and a subcutaneous cannula on the front of the thigh.

Figure 12.

Edward’s absolute values of HbA_1c, BM, and INS/d reflect a rapid decrease in HbA_1c (from 73 mmol/mol to 37 mmol/mol) after insulin therapy was started with an insulin pen. After the implementation of an insulin pump, Paradigm Veo 554, in April 2014, HbA_1c concentration continued to decrease even further while fewer insulin units were needed for better compensation. After the year 2018 (red box), INS/d started to increase alongside HbA_1c, which may be due to the end of supposed post-initial remission period that lasted about 4 years (2014-2018).

Figure 13.

Edward’s relative values of HbA_1c, BMI, and INS/d illustrate long-lasting satisfactory metabolic compensation. The most recent result shows an increase in both HbA_1c from 86–114% and INS/d from 58–119% (red box). His BMI varies between 61% and 68% of its reference range.

Current goal: acknowledging Edward’s reluctance as valid, while also motivating him to use CGM, as his worsening compensation can be attributed to the lack thereof.

2.6 Case report Fiona

Focus: insulin pump implementation can result in subjective improvement, without effect in laboratory parameters.

History: The first signs of T1D appeared in 2014 so Fiona (today 48 y/o) was treated with an insulin pen for 15 months. The HbA_1c concentration has been increasing during this treatment, thus the insulin pump MiniMed 640G was implemented and she was trained in selfmonitoring on glucometer-strips system Contour (Figure 14). Up until the beginning of the year 2017, her clinical and laboratory findings were improving. Since then, her HbA_1c concentration has been increasing (Table 6, Figures 15 and 16). The reason for this rise is multifactorial: difficult life situations, struggling to keep a constant regime of glycemia monitoring, etc. Fiona is satisfied with the insulin pump as it improved the quality of her everyday life; she does not need to prick herself a few times per day as she works on shifts. Fiona is not convinced to use CGM, although she is aware of insufficient compensation and low frequency of self-monitoring: two times per day, sometimes only once a week. Her glycemia is mostly high, and she is afraid to deliver an additional bolus because of an unpleasant experience with hypoglycaemia.

Figure 14.

Glucometer Contour plus one showing glycaemia 4.3 mmol/l. Box with test strips (on the right).

Figure 15.

Fiona’s absolute values of HbA_1c, BM, and INS/d from 2014 to 2022. HbA_1c concentrations were increasing during the treatment with an insulin pen, thus insulin pump MiniMed 640G was implemented. The last seven values show a systematic increase in HbA_1c, which is a result of a lack of compensation.

Figure 16.

Fiona’s relative values of HbA_1c, BMI, and INS/d over an 8-year-long period. All red HbA_1c digits illustrate long-term unsatisfactory results with average values 190% of the reference range, although more insulin could be used for better correction. Her BMI has fluctuated between 88 and 93% of the upper limit of its reference range.

Parameters	Units	Refer	06.10.2014	15.06.2016	15.07.2019	18.10.2021	9.11.2022
T1D duration	Months	N/A	1	21	58	85	98
Heart rate	BPM	60–90	62	66	70	60	105
Blood pressure	torr	<130/85	120/80	161/72	116/82	138/90	149/101
fvS-glucose	mmol/	3.3–5.5	—	8.4	14.7	10.3	11.9
fvS-C-peptide	pmol/l	>300	235	—	—	—	—
fvS-GADA	kU/I/	0–5	>250	>250	—	—	—
fvS-HDL	mmol/l	1.2–2.7	1.9	2.18	1.83	1.78	2.03
fvS-LDL	mmol/l	1.2–2.6	2.03	3.15	2.18	2.8	3.39
fvS-TAG	mmol/l	0.5–1.7	0.8	0.4	0.58	0.76	0.71
fvS-creatinine	μmol/l	< 108	52.9	60	56	56.3	56
eGFR	ml/s	1.0–1.3	—	—	1.77	1.77	1.76
fvS-CRP	mg/l	< 10	0.9	1	1.8	1.7	1.5

Table 6.

Fiona’s clinical and laboratory parameters from T1D start over 8 years.

fvS – fasting venous serum.

Parameters	Units	Refer	12.08.2021	29.11.2021	16.02.2022	25.05.2022	16.11.2022
T1D duration	months	N/A	4	8	11	14	19
Heart rate	BPM	60–90	104	104	104	107	110
Blood pressure	torr	<130/85	152/94	152/94	152/94	155/92	131/87
fvS-glucose	mmol/l	3.3–5.5	6.2	—	5.1	4.6	4.5
fvS-C-peptide	pmol/l	>300	632	—	>600	—	—
fvS-GADA	kU/l	0–5	58.8	—	—	—	—
fvS-HDL	mmol/l	1.2–2.7	1.16	—	1.04	1.04	1.16
fvS-LDL	mmol/l	1.2–2.6	3.31	—	2.75	2.75	3.31
fvS-TAG	mmol/l	0.5–1.7	1.4	1.38	1.63	1.63	1.4
fvS-creatinine	μmol/l	< 108	78.6	79	68.9	77.9	78.6
eGFR	ml/s	1.0–1.3	1.99	—	1.99	1.89	1.87
fvS-CRP	mg/l	< 10	1.1	—	4.7	0.5	0.7

Table 7.

George’s clinical and laboratory parameters from the diagnosis of T1D over 14 months.

fvS – fasting venous serum.

Current goal: to motivate Fiona to use CGM.

2.7 Case report George

Focus: growing body mass and INS/d in a man using SmartGuard mode and TIR 100%.

History: George (today 32 y/o) was diagnosed with T1D in April 2021 and treated with insulin via an insulin pen, immediately resulting in an initial decrease in HbA_1c. By September of the same year, a hybrid insulin pump MiniMed 780G was implemented. George is compliant and has been achieving excellent compensation in terms of HbA_1c and time in range (TIR). However, instead of entering data about the amount of consumed saccharides, which would have allowed the pump to automatically infuse the right insulin dose, tailored to his metabolism, glycemia, and remaining function of beta-cells, he has been entering the order for a bolus in insulin units (Figure 17). This order tends to be less effective, resulting in higher insulin intake and a gradual increase in body mass (Figures 18 and 19). Even though the conversion of saccharides to IU could be appropriate for the use of an insulin pen or pump without AHCL, it lowers the efficiency of pumps with AHCL. Current TIR: 100% (November 16, 2022).

Figure 17.

CareLink Statistics: A comparison between date range A (blue) and B (orange). Progress between both date ranges, blood glucose (BG), insulin usage, and saccharides consumed (Table 7).

Figure 18.

George’s absolute values of HbA_1c, BM, and INS/d over 19 months illustrate the initial rapid correction of HbA_1c (from 120 to 51 mmol/mol) after initiation of insulin treatment by insulin pen. Later, there is sufficient HbA_1c control, at the expense of the high insulin delivery, up to 50 IU/d (red box), and thus an increase in body mass (from 94 to 104 kg). HbA_1c concentration was not measured on August 29, 2022.

Figure 19.

George’s relative values of HbA_1c, BMI, and INS/d over 19 months. Rising BMI (up to 129%) is probably due to an increase in INS/d (to 125% of the upper limit of its reference range), highlighted in the red box, which enables glucose to enter cells through the insulin-dependent glucose transporter GLUT4 [27]. His HbA_1c concentration is under control. HbA_1c concentration was not measured on August 8, 2022.

Current goal: adequate education about the correct use of the hybrid pump when using the SmartGuard mode and management of hypertension and hyperlipoproteinemia.

2.8 Case report Helen

Focus: swift correction of HbA_1c attributed to immediate insulin treatment and implementation of hybrid insulin pump MiniMed 780G 3 weeks after T1D diagnosis.

History: Helen’s (today 53 y/o) issues began when she experienced blurry vision while on holiday. In combination with losing 8 kg over 2 weeks, polydipsia and polyuria led her to seek out medical attention with reason to suspect diabetes. Helen was diagnosed with T1D on September 23, 2021; her HbA_1c concentration was 115 mmol/mol. She began treatment with an insulin pen (28 IU/d). After three weeks (October 10, 2021), Helen was indicated to implement the insulin pump MiniMed 780G with a reduced total insulin dose per day (20 ID/d), (Figures 20 and 21). She claims that it took her approximately one week to fully understand how to use the insulin pump, how to connect sensor Guardian 4, and how to switch the manual or SmartGuard mode. When asked to compare insulin treatment by means of pen vs. pump, Helen prefers the insulin pump unhesitatingly for its comfortability and lesser frequency of multiple needle pricks.

Figure 20.

Helen’s absolute values of HbA1c, BM, and INS/d over 12 months show a decrease in HbA1c concentration after the initiation of insulin therapy, when using an insulin pen at the beginning for 24 days, and followed by MiniMed 780G (manual/SmartGuard mode).

Figure 21.

Helen’s relative values of HbA_1c, BMI, and INS/d over 12 months show a rapid HbA_1c decrease after the initiation of insulin therapy. BMI values indicate an irregular, subtle fluctuation in the range of no larger than 6%. Considering the alternative use of manual/SmartGuard/manual mode, changes in INS/d, body, HbA_1c, and increased satisfaction with the pump one can assume gradual but adequate metabolic compensation based on successful education and flexible management of the hybrid insulin pump.

The biggest challenge for Helen, considering using the pump, is visiting the pool area. Helen called the Medtronic helpline to get information on how to make her summer holiday more comfortable and stay well compensated at the same time. At the time, she was told that her insulin pump is waterproof for up to 24 hours and that the sensor with a transmitter is water resistant for up to 30 minutes. According to Medtronic, although MiniMed 780G is waterproof, it is recommended to remove it before bathing or swimming, because the wear and tear that comes from regular use can increase the risk of water damage [8]. Besides T1D, there is hypertension, transient atrial fibrillation, treated hypothyroidism, and hyperlipoproteinemia in her medical history (Table 8). Current TIR: 75% (December 14, 2022).

Parameters	Units	Refer	29.09.2021	12.01.2022	21.06.2022	29.09.2022	14.12.2022
T1D duration	Months	N/A	0	4	9	12	15
Heart rate	BPM	60–90	84	79	82	73	75
Blood pressure	Torr	<130/85	150/96	146/92	149/93	123/81	149/73
fvS-glucose	mmol/	3.3–5.5	16.6	6.3	6.6	5.3	6.5
fvS-C-peptide	pmol/l	>300	166	—	—	—	—
fvS-GADA	kU/I	0–5	>250	—	—	—	—
fvS-HDL	mmol/l	1.2–2.7	0.82	1.24	1.12	1.27	1.14
fvS-LDL	mmol/l	1.2–2.6	3.23	3.05	2.67	2.82	3.34
fvS-TAG	mmol/l	0.5–1.7	1.81	0.94	1.18	0.92	0.8
fvS-creatinine	μmol/l	< 108	52.1	52.4	56.7	62.1	57.2
eGFR	ml/s	1.0–1.3	1.76	1.75	1.7	1.65	1.69
fvS-CRP	mg/l	< 10	3.4	1.2	0.7	1	1.8

Table 8.

Helen’s clinical and laboratory parameters from the diagnosis of T1D over 15 months.

fvS – fasting venous serum.

Parameters	Units	Refer	16.04.2022	29.06.2022	15.08.2022	02.11.2022	—	—	—
T1D duration	Months	N/A	0	2	4	7	—	—	—
Heart rate	BPM	60–90	—	—	82	86	—	—	—
Blood pressure	Torr	<130/85	—	—	114/63	124/81	—	—	—
fvS-glucose	mmol/	3.3–5.5	13.67	6.3	—	5.4	—	—	—
fvS-C-peptide	pmol/l	>300	420	—	—	—	—	—	—
fvS-GADA	kU/I	0–5	>250	—	—	—	—	—	—
fvS-HDL	mmol/l	1.2–2.7	1.35	1.53	—	1.32	—	—	—
fvS-LDL	mmol/l	1.2–2.6	5.09	3.4	—	3.36	—	—	—
fvS-TAG	mmol/l	0.5–1.7	0.9	1	—	0.84	—	—	—
fvS-creatinine	μmol/l	< 108	72.7	69.9	—	60.7	—	—	—
eGFR	ml/s	1.0–1.3	1.75	1.76	—	1.85	—	—	—
fvS-CRP	mg/l	< 10	1.9	0.6	—	0.5	—	—	—

Table 9.

Isabella’s clinical and laboratory parameters from the diagnosis of T1D over 6 months.

fvS – fasting venous serum.

Current goal: to reduce HbA_1c below 42 mmol/mol, management of hypertension and hyperlipoproteinemia, and monitoring of ketones by means of Galileo Glu/Ket.

2.9 Case report Isabella

Focus: a person who found professional care shortly after the first signs of T1D and received hybrid insulin pump MiniMed 780G within 6 weeks.

History: Isabella (today 38 y/o) experienced a long period of illness before presenting with hyperglycemia on Easter in 2022. Due to her untimely diagnosis before a four-day-long holiday, she was given only an insulin pen (28 IU/d), glucometer Galileo Glu/Ket, and short instructions via mobile phone. Within 10 days, detailed education was initiated and, ultimately, in 6 weeks, she was given an insulin pump MiniMed 780G, to which she adapted and has shown exemplary cooperation (Figures 22–24).

Figure 22.

There are two modes shown in the CareLink graph: SmartGuard mode (00,00–19,45) and manual mode (19,45–00,00), depicted by the gray area. In SmartGuard mode, pink waves represent basal insulin over the span of four meals (orange boxes) and insulin boluses are indicated by purple drops. Manual mode: the basal rate is indicated with a pink descending line, and glycemia is measured manually. Current TIR: 93% (red box) (Table 9).

Figure 23.

Isabella’s absolute values of HbA_1c, BM, and INS/d show rapid glycemic control (from 86 to 44 mmol/mol) after the beginning of insulin therapy. For the last 6 months, we see a stable amount of insulin (12 INS/d) requirement, decreasing body mass, but slightly rising HbA_1c.

Figure 24.

Isabella’s relative values of HbA_1c BMI, INS/d show apparent glycemic control after the beginning of insulin therapy, currently, with INS/d 12 IU, that is, 30% of upper limit of its reference range. HbA_1c decreased to nearly half of its previous concentration from period with insulin pen. There is also a slight decrease in BMI. This highlights the impact of swift implementation of MiniMed780G as well as continuous education on postinitial remission of insulin secretion.

Current goal: to continue education, reduce HbA_1c below 42 mmol/mol, management of hypoglycemia, and hyperlipoproteinemia; monitoring ketones (Galileo Glu/Ket).

2.10 Case report Jane

Focus: implementation of MiniMed 780G 5 months after T1D diagnosis.

History: Jane (today 28 y/o) was initially diagnosed with gestational diabetes during her third pregnancy. Till delivery (in the 34th week, November 22, 2021, girl, 1840 g, 43 cm) she was treated with insulin detemir 8 IU/d. Discharged without any antidiabetic medication [28]. In April 2022, she started to experience polydipsia, polyuria, nausea without vomiting, and anorexia with a loss of 10 kg in body mass. On May 31st, 2022 she was admitted to hospital and diagnosed with T1D (HbA_1c 146 mmol/mol), put on insulin aspart, and trained in selfmonitoring by means of glucometer-strips system Galileo Glu/Ket (Figure 25). Although it was questionable if Jane would adapt well to having an insulin pump, the implementation of MiniMed 780G on October 31, 2022 at an out-patient clinic (with a basal insulin rate of 12.35 IU/d) proved to be a reliable method of therapy (Table 10, Figures 26 and 27).

Jane expected difficulties in learning how to use the pump, however, today is satisfied with the device. Continuously on SmartGuard, current TIR: 91% (January 5, 2023).

Figure 25.

Strips for glucose (on the left) and beta-hydroxybutyrate (in the middle) glucometer Galileo Glu/Ket showing glycaemia 5.7 mmol/l (on the right).

Figure 26.

Jane’s absolute values of HbA_1c, BM, and INS/d over 6 months showed an intense decrease in HbA_1c concentration, an overall stable body mass, and a slight fluctuation in INS/d. After the implementation of a sensor-augmented insulin pump, MiniMed 780G, on October 31, 2022, the INS/d decreased from 25 IU/d to 17 IU/d while maintaining the same HbA_1c concentration (see the red box).

Figure 27.

Jane’s relative values of HbA1c, BMI, and INS/d from June 2022 to December 2022. Since the beginning of treatment, HbA1c decreased from 348% of the upper limit of the acceptable value to 171%, and although insulin requirement was increasing, it was still in the reference range. Post implementation of a sensor-augmented insulin pump, MiniMed 780G, the trend of rising required insulin declined to 43% of physiological insulin needs.

Current goal: to continue the management of T1D, hypoglycemia, and ketosis.

Parameters	Units	Refer	01.06.2022	14.07.2022	17.10.2022	16.12.2022	—	—	—
T1D duration	months	N/A	0	1	4	6	—	—	—
Heart rate	BPM	60–90	82	96	99	101	—	—	—
Blood pressure	Torr	<130/85	110/78	105/69	126/85	122/72	—	—	—
fvS-glucose	mmol/	3.3–5.5	10.6	7.8	—	5.6	—	—	—
fvS-C-peptide	pmol/l	>300	263	—	—	264	—	—	—
fvS-GADA	kU/I	0–5	>250	>250	—	—	—	—	—
fvS-HDL	mmol/l	1.2–2.7	1.09	1.63	—	1.77	—	—	—
fvS-LDL	mmol/l	1.2–2.6	2.41	2.02	—	2.00	—	—	—
fvS-TAG	mmol/l	0.5–1.7	1.98	1.09	—	0.63	—	—	—
fvS-creatinine	μmol/l	< 108	52.4	52.7	—	66.3	—	—	—
eGFR	ml/s	1.0–1.3	2.09	2.08	—	1.93	—	—	—
fvS-CRP	mg/l	< 10	—	0.5	—	0.5	—	—	—

Table 10.

Clinical and laboratory parameters of Jane from T1D start over 6 months.

fvS – fasting venous serum.

3. Discussion

In this chapter, 10 people with T1D using insulin pumps were observed from a clinical and laboratory medical perspective. Eight of them were given a pump during hospitalization and the remaining two had their pump implemented at an outpatient clinic. When being given an insulin pump, their subjective needs, and opinions were considered.

The case reports are arranged according to the duration of treatment with an insulin pump from 29 years to 2 months. Each case report represents a unique progression, with specific individual complications, and challenges for the insulin pump user, educator, physician, and other members of the diabetes team. All subjects were given the appropriate knowledge, skills, and attitudes during a systematic education. It was shown that the insulin pump did not pose a hindrance to their occupation and everyday life. MiniMed 780G is used by eight individuals, while two are still not convinced to use CGM.

Anna’s collected data demonstrates glycemic control without drastic fluctuations. She has been treated with insulin pumps the longest and has tried out several different devices. After being provided with the newest technology in CGM, her compensation improved even further. This trend is not unlike the one observed with Daniel, where there was a noticeable increase in control after implementing AHCL.

Betty’s case report was apparent in her lack of glycemic control, despite having an insulin pump, even during pregnancy, which is likely the cause of the elevated body mass at birth in her children. In contrast, Jane, who previously had gestational diabetes, developed T1D as late as 6 months after delivery and had favorable results after the implementation of the insulin pump.

Another common issue encountered was a lack of understanding and “trust” in the AHCL algorithm. Clark tended to deliver extra boluses to achieve the dose he was used to, instead of allowing the pump to function how it was supposed to. Similarly, George, instead of entering data about the number of saccharides he consumed, has been entering the order for a bolus in insulin units. In both scenarios, the increased insulin worsens the risk of recurrent hypoglycemia.

The case reports of Clark, George, Fiona, and Edward highlight the importance of systematic education on the use of CGM, saccharide ratio, and SmartGuard.

Helen, Isabella, and Jane are comparable in the identification of diabetes symptoms, pursuit of medical attention, almost immediate implementation of a hybrid insulin pump, successful education, and metabolic compensation (probably due to “honeymoon recovery” of endogenous insulin secretion). Ideally, swift implementation should be the standard of care for any person with T1D.

4. Conclusions

Presented case reports imply that the hybrid insulin pump, supported with a professional education program, appears to be an effective first option for insulin substitution in people with insulin-deficient diabetes, nonetheless, specific circumstances, desires, and needs of a person with T1D should be brought into account.

Acknowledgments

We extend our sincerest gratitude to the Department of Internal Medicine II - Gastroenterology and Geriatrics at the University Hospital Olomouc, and the Department of Physiology at the Faculty of Medicine and Dentistry, Palacký University Olomouc, Czech Republic, as well as to Bc. Hana Zálešáková, MUDr. Blanka Doubravová, Ondřej Cienciala, and Bc. Marie Libichová (diabetes educator). Furthermore, we would like to express our special thanks to Tereza Nezvalová, Rachel, Petr, and Laura Novákovi, Dhanuka Sammu, Jakub Olejko, and Viktória Molnárová for their unwavering support.

Dedication

This chapter is dedicated to the memory of professor MUDr. Antonín Mores (1908-1997), in tempore Head, Department of Pediatrics, Faculty of Medicine, Palacký University Olomouc, for his empathy for all children and introduction of liberalized diet for boys and girls with T1D [29].

Antonín Mores