Diabetes Mellitus Type 1

Original Editors - Collen Nalley and Abbye Senn  from Bellarmine University's Pathophysiology of Complex Patient Problems project.

Top Contributors - Abbye Senn, Colleen Nalley, Vidya Acharya, Lucinda hampton, Rachael Lowe, Elaine Lonnemann, Kim Jackson, Evan Thomas, WikiSysop, Fasuba Ayobami, Amanda Ager and Alexandra Stead  

Definition/Description

Type 1 diabetes mellitus (T1DM) is an autoimmune disease that leads to the destruction of insulin-producing pancreatic beta cells.

Insulin is an essential anabolic hormone that exerts multiple effects on glucose, lipid, protein, and mineral metabolism, as well as growth. The main functions of Insulin are as follows; it

• facilitates uptake of glucose by muscle and adipose cells,
• signals liver to store glucose as glycogen and synthesize fatty acids,
• stimulates the uptake of amino acids,
• supresses the breakdown of fat in adipose tissue, and
• stimulates the uptake of potassium into cells.

A life-threatening condition called diabetic ketoacidosis can occur without insulin production. People with type 1 diabetes mellitus have to rely insulin replacement therapy for effective lifelong management.

(T1DM) can result in serious vascular complications and neuropathies and can be a major cause of cardiovascular disease and strokes. It is also the leading cause of end-stage renal (kidney) disease, non-traumatic amputations in the lower extremity, and new cases of blindness..

Image 1: Overview of possible symptoms of diabetes

Etiology

In T1DM, there is autoimmune destruction of the beta cells in the pancreatic islets over months or years, causing an absolute deficiency of insulin. Although the exact etiology of T1DM is still unknown, researchers believe there is a genetic predisposition.

Image 2: 3D medical animation still of Type 1 Diabetes showing lower amount of insulin production in a diabetic patient.

• In those at risk, it is generally believed that a virus or other environmental factors trigger the autoimmune beta-cell destruction. Some studies have found an increased development of T1DM in children born to a mother that had Coxsackievirus or another Enterovirus during pregnancy.
• Environmental toxins have also been postulated to play a role. The hygiene hypothesis suggests that improved sanitation relates to the increased development of autoimmune-mediated disorders. It is proposed that the reduction of childhood exposure to infectious agents leads to the lack of proper immune system development.
• Dietary factors have also been examined as potential triggers

Epidemiology

T1DM is one of the most frequent chronic diseases in children but can start at any age. There has been a steady increase in the incidence and prevalence of T1DM, representing approximately 5% to 10% of all people with diabetes.

• In the United States, there are an estimated 1.24 million people with T1DM, and that number is expected to grow to 5 million by 2050.
• Worldwide, there is also a considerable geographic variation in incidence. The highest reported incidences are in Finland and other Northern European nations with rates approximately 400-times greater than those seen in China and Venezuela.

Characteristics/Clinical Presentation

Overview of the most significant possible symptoms of diabetes

Symptoms for type 1 diabetes can include:

• Extreme thirst
• Frequent urination
• Sudden unexplained weight loss
• Extreme fatigue and weakness
• Blurred vision
• Nausea and vomiting
• Constant hunger

Associated Co-morbidities

• Neuropathy
• Nephropathy
• Retinopathy
• Cardiomyopathy
• Hypoglycemia
• Diabetic ketoacidosis
• Diabetic foot disease
• Amputation

Diagnostic Tests

Diagnostic Criteria:

• Fasting plasma glucose (FPG) ≥ 126 mg/dl on two different days
• A1C Levels≥ 6.5 % on two separate occasions (but must be confirmed by FPG)
• Oral glucose tolerance test ≥ 200 mg/dl

Other Information:

• FPG >100mg/dl is a risk factor for future diabetes
• A1C is a measure of how diet, exercise, and/or medication/insulin have been controlling glucose over a period of time 
• Normal FPG= 80-120 mg/dl
• Want to keep A1C levels below 7%
• If A1C is >10% requires medical attention immediately

Management

Patients with T1DM have several challenges including managing daily symptoms, learning to monitor glucose, gaining knowledge about their condition, developing self-control and coping with the psycho-social problems such as risk of depression and social rejection and needing to change their lifestyle. Health care professionals play a crucial role in addressing patients' requirements, assisting them in adapting to life with the disease, and helping to prevent secondary complications.

The aim of diabetes management is to keep blood glucose levels as close to the target range as possible, between 4 to 6 mmol/L (fasting). However, the ranges will vary depending on the individual and an individual’s circumstances. Maintaining glucose level at the optimum range requires a balance between food intake, physical activity and medication. Too high blood glucose could result in hyperglycaemia or ketoacidosis. Blood glucose levels that are too low, could result in hypoglycaemia. Monitoring of blood glucose is needed throughout the day and even at night. Keeping blood glucose levels on target will help prevent both short-term and long-term complications.

Physical Therapy Management

Engaging in physical activity can effectively help manage diabetes. Exercises help improve weight, enhance insulin sensitivity, reduce the need for medication and insulin dosage, and prevent vascular complications associated with diabetes.Despite the benefits, many young people with type 1 diabetes (T1D) may be reluctant to engage in regular exercise. A significant barrier to exercises are lack of knowledge about how to safely manage blood glucose levels before, during, and after physical activity, low motivation, lack of time, limited access to facilities, effect of physical activity on blood glucose levels (recurrent hypoglycemia, hyperglycaemia), negative body image, fear of hypoglycemia, stigma of having diabetes, parental hesitancy.

Physiotherapists play a crucial role in primary care teams for diabetes management and possess essential skills to assist individuals with diabetes in participating in physical activity. Thoughtful goal-setting promotes safe and sustainable exercise program and the goals may include improved fitness, body composition, weight management, social inclusion, better glycemic control, exercise performance, and clarifying these goals will help direct appropriate strategies.

Regular exercise has many benefits and is strongly advised for individuals with type 1 diabetes to prevent cardiovascular complications. Exercise guidelines from the American College of Sports Medicine (ACSM) and the American Diabetes Association (ADA) recommend at least 150 minutes of moderate to vigorous aerobic exercise per week, plus resistance training on 2–3 non-consecutive days (1–3 sets of 10–15 repetitions at 50–75% of 1 repetition maximum across 8–10 multijoint exercises). However, more than 60% of people with type 1 diabetes do not meet these recommendations. According to this guidelines,

• Children and adolescents with T1DM should be encouraged to achieve the recommended 60 minutes of moderate to vigorous intensity of physical activity every day.
• There is an increased risk of hypoglycemia during, shortly after, and up to 24 h after exercise due to increased insulin sensitivity.
• History of severe hypoglycemia in the preceding 24 h is a contraindication to exercise.
• High glycemic index carbohydrates should be available to prevent and treat hypoglycemia during all forms of physical exercise
• Monitoring of blood glucose is essential during and after exercise
• Wide range of insulin adjustment and nutrition strategies are needed to maintain the glucose level in the exercise range of 5.0– 15.0 mmol/L or 90–270 mg/dl and prevent exercise induced hypoglycemia
• Avoid exercise if patient has fluctuating or high blood glucose levels (i.e. fasting blood glucose levels greater than 14 mmol/L and urinary ketones) as it elevate blood glucose and increase ketone production
• Screening for reflexes, sensation in feet, questions about neuropathic symptoms, foot ulcers, calluses, etc should be performed

Exercises

Aerobic exercise has been shown to decrease glucose levels both during the activity and in the post-exercise period. Resistance exercise have demonstrated beneficial glycemic control in patients with TIDM. Resisted exercises offers distinct advantages for managing exercise-induced hypoglycemia in individuals with type 1 diabetes. Results of a study shows that resistance exercise resulted in much smaller declines in blood glucose during exercise than aerobic exercise and it was also associated with relatively stable early postexercise glucose concentration. Combined aerobic and resistance training has shown greater benefits than either modality alone. 6-week HIIT was found to be safe in people with T1DM with no severe hypoglycemia reported, it is also effective in improving well-being and exercise adherence in the previously inactive T1DM population . Short bursts of high-intensity activitiess (sprints or high-intensity intermittent training), whether performed alone or combined with moderate aerobic exercise, produce smaller glucose declines during exercise and up to two hours post-exercise

It is important to note that the blood glucose response to exercise and physical activity varies greatly among individuals with T1DM. This response depends on several factors, including the type of exercise, timing, intensity, and duration, necessitating adjustments in exercise routines to accommodate individual responses.

Important considerations for maintaining glucose stability and avoid exercise related hypoglycemia:

• Engaging in prolonged, low-to-moderate intensity aerobic activities are associated with an increased risk of hypoglycemia often requiring a reduction in insulin dosage and/or an increase in carbohydrate intake to prevent hypoglycemia.
• In contrast, short-duration, high-intensity aerobic or anaerobic activities can help maintain glucose levels during exercise or may even cause early post-exercise hyperglycemia.
• Sprinting raises blood glucose, which may reduce the risk of hypoglycemia. Maximal 10-second sprints before or after moderate-intensity exercise or frequent short sprints (4 s sprints every 2 min) during exercise are more effective than continuous moderate activity in maintaining glucose levels.
• Research indicates that resistance training or high-intensity interval training (HIIT) is most beneficial when performed during the times of day when a person is more likely to experience hypoglycemia, typically in the afternoon or evening because HIIT provides the enhanced blood glucose stability. On the other hand, continuous aerobic exercise is recommended in the morning. There is natural increase in blood glucose levels during that period, offering additional protection against the risk of hypoglycemic episodes.
• Exercise-related hyperglycemia can be managed by a conservative insulin correction dose of 50% of the usual amount, administered immediately after exercise or an aerobic cool-down session, can help reduce post-exercise high blood sugar levels.

Target level for blood glucose range:

Before exercise, blood glucose should ideally be between 90 and 250 mg/dL (5.0 and 13.9 mmol/L)

• <90 mg/dL: Give 15-30 g carbohydrate snack and retest glucose levels 15 minutes later

• 90-250 mg/dL: safe exercise levels; proceed with treatment 

• 250-300 mg/dL: Test blood ketones (do not exercise if moderate amount of ketones present);Delay exercises until glucose levels are <250 mg/dL.

• >300 mg/dL= stop exercise immediately. (Delay exercise; administer insulin and wait until glucose decreases below 250 mg/dL)
• Taking care of feet: Ulcers or other lesions on the feet are a serious danger for people with diabetes. It is important to avoid foot damage especially for middle-aged and elderly people. Always inspect your feet before and after exercise. Avoid exercise that causes stress to the feet (e.g. running). Exercise which poses minimal weight or stress on the feet is ideal such as riding an exercise bike or brisk walking in good footwear. Wear comfortable and well-fitting shoes.
• Watch for confused, lethargic state or change in mental status in DM patient - have patient do finger stick check for glucose levels if available and immediately refer to physician. If patient has an insulin pump, diabetic ketoacidosis (DK) can occur quicker if there is an interruption in insulin delivery. Monitor patient carefully for excess perspiration, increased motion at pump site, and temperature during exercise.  Watch for signs and symptoms of life threatening conditions: Hyperglycemia, Diabetic Ketoacidosis; Hypoglycaemia
  

Prognosis

Diabetic foot ulcer

T1DM has been associated with high morbidity and mortality compared with the general population. However, over recent years, the introduction of diabetes technologies, insulin therapies, improved glycaemic control, and effective management of metabolic risk factors such as hypertension and dyslipidaemia, early screening for microvascular and macrovascular complications,have led to substantial improvements in both morbidity and mortality outcomes. Yet, mortality in people with T1DM remains elevated relative to the non-diabetic population ( 2- to 5-fold higher mortality than those without diabetes) Nearly half of individuals with T1DM may develop a major complication over their lifetime. Common complications include diabetic retinopathy leading to vision loss and diabetic nephropathy progressing to end-stage renal disease. For patients who survive beyond the first two decades after diagnosis, the long-term prognosis improves with appropriate management.

However, since the disease has no definitive cure, affected individuals remain at increased risk of premature coronary artery disease, peripheral neuropathy, foot ulcers, and progressive visual impairment. Maintaining euglycemia for a lifetime is also associated with severe anxiety and depression; for many patients with type 1 diabetes, the quality of life is poor. See Diabetes HRQOL