Type 1 Diabetes (Nursing)

Learning Outcome

  1. Recall the cause of Type 1 diabetes
  2. Describe the presentation of type 1 diabetes
  3. List the complications of type 1 diabetes
  4. Summarize the treatment of type 1 diabetes


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, mineral metabolism, and growth. Importantly, the insulin allows glucose to enter muscle and adipose cells, stimulates the liver to store glucose as glycogen and synthesize fatty acids, stimulates the uptake of amino acids, inhibits the breakdown of fat in adipose tissue, and stimulates the uptake of potassium into cells. People with T1DM require life-long insulin replacement therapy. Without insulin, diabetic ketoacidosis (DKA) develops and is life-threatening.[1][2]

Nursing Diagnosis

  • Increased thirst and hunger
  • Dry mouth
  • Frequent urination
  • Weak
  • Blurred vision
  • Confused
  • Numbness and tingling
  • Anxiety
  • Wounds healing slowly
  • Diaphoresis


In T1DM, there is the immune 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 with a strong link with specific HLA (DR and DQ) alleles, especially DRB103-DQB10201 and DRB 10401-DQB10302H. Multiple other genes contribute to heritability, as well. The risk of developing T1DM with no family history is approximately 0.4%, while the offspring of an affected mother is 1% to 4%, the offspring of an affected father is 3% to 8%, and the offspring of both affected parents is as high as 30%. In monozygotic twins, the risk of developing T1DM in the first ten years of diagnosis of the first twin is 30%, with a lifetime risk of around 65%.[3][4][5]

The presence of circulating pancreatic autoantibodies suggests that the individual is at risk for or has developed T1DM. These antibodies include islet cell cytoplasmic antibodies (ICA), antibodies to insulin (IAA), glutamic acid decarboxylase (GAD65), insulinoma-associated 2, or protein tyrosine phosphatase antibodies (IA-2), and zinc transporter8 (ZnT8). The greater the number of detectable antibodies and the higher their titers, the greater the risk of developing T1DM.

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 with 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 reducing childhood exposure to infectious agents leads to the lack of proper immune system development. Dietary factors have also been examined as potential triggers. One study showed an increased development of islet autoimmunity with cow’s milk-protein consumption in study participants with low to moderate-risk HLA-DR genotypes but no significant increased risk in those with a high-risk genotype.

Risk Factors

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 people with diabetes. In the United States, there are an estimated 1.24 million people with T1DM, which is expected to grow to 5 million by 2050. Between 2001 and 2009, there was a 21% increase in the prevalence of T1D in those 20 years of age or younger. The most common age of presentation is between the ages of 4 to 6 and early puberty (10 to 14 years). 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, where there is the lowest reported incidence. In the United States, the highest rate of T1DM is seen in non-Hispanic whites, affecting both females and males almost equally.[6][7]


In the initial outpatient visit, obtaining a complete medical, surgical, social, and family history is important. History of prior diabetes education, including monitoring of blood glucose and ketones, proper administration of insulin, recognition/treatment of hypoglycemia, education on nutrition, sick-day rules, and foot care, should also be obtained. Particular attention should be paid to prior treatment, current medication, and history of acute (hypoglycemia including severe episodes and episodes of DKA) and chronic (skin disorders, dental problems, retinopathy, macular edema, neuropathy, kidney disease, cardiovascular disease, peripheral arterial disease, stroke, foot ulcers) diabetic-related complications.

Clinicians should measure height, weight, and blood pressure. The thyroid should be palpated, as patients with T1DM are at increased risk of developing autoimmune thyroid disease. The skin should be examined, especially at insulin injection or infusion sites. If lipodystrophy is evident, they should be educated on the importance of varying injection sites. The heart, chest, and abdomen should also be examined. A foot exam examines pedal pulses, deformities, pre-ulcerative lesions, ulcerations, calluses, and onychomycosis. It is also important to test vibratory and protective sensations with a 10-g monofilament exam to look for peripheral neuropathy. A screen for depression (for example, PHQ-2/PHQ-9) is also recommended annually.


HbA1c is recommended every 3 to 6 months. The HbA1c reflects glycemic control over the previous 2 to 3 months. There should also be a yearly lipid profile, liver function tests, spot urine albumin to creatinine ratio, serum creatinine, GFR, and TSH. These tests could be repeated more frequently if the previous results were abnormal. It is also important to remember that patients with T1DM are at an increased risk of developing other autoimmune diseases, such as autoimmune thyroid disease, primary adrenal insufficiency, celiac disease, and vitiligo. Screening for these disorders should be considered when appropriate.[8][9][10]

Medical Management

All patients with T1DM require insulin therapy. Multiple daily insulin injections (MDI) using a basal/bolus insulin regimen or continuous subcutaneous insulin infusion through an insulin pump are the preferred treatment. The patient’s weight in kilograms is multiplied by 0.5 to 0.6 units to calculate the initial total daily insulin dose (TDD) in an adult. In general, 40% to 50% of the total daily dose comprises the patient’s long-acting insulin needs. The other half approximates the daily short-acting insulin that needs to be given before or with meals. Dosing is modified based on many factors, including diet and physical activity. Adjustments can also be made based on self-monitoring of blood glucose or continuous glucose monitoring results. When possible, patients should be taught carbohydrate counting and instructed to use an insulin-to-carbohydrate ratio that approximates the grams of carbohydrates that will be covered by one unit of insulin. A carbohydrate-consistent diet is helpful if carbohydrate counting is not realistic due to poor numeracy or other reasons. Patients should be taught which foods contain carbohydrates and benefit from meeting with a dietician. It is also recommended to calculate a correction factor, which can be initially estimated using the formula 1800 divided by the TDD. This estimates the fall in blood glucose for every 1 unit of insulin given. This number will need to be adjusted per subsequent glucose monitoring results.[11][12]

It is important to note that insulin requirements vary across the lifespan and under specific circumstances. For example, larger insulin doses are normally required during puberty, pregnancy, when steroids are given, and with the development of obesity. Individuals need less insulin when they are engaged in aerobic exercise and during the “honeymoon period.” The honeymoon period occurs soon after diagnosis when there is a temporary recovery of beta-cell function.

Multiple types of insulin can be used for diabetes management. Rapid-acting insulin (lispro, aspart, glulisine) will generally have an onset in 10 to 30 minutes, peak in 30 to 90 minutes, and have a duration of 3- to 5 hours. Insulin aspart injection is more rapidly acting. Short-acting insulin (regular insulin) has an onset in 30 minutes to 1 hour and peaks in 2 to 4 hours with a duration of 6 to 8 hours. Intermediate insulin (NPH, NPL) will have an onset in 1.5 to 4 hours, peaks around 4 to 10 hours, and with a duration of 12 to 18 hours. Long-acting insulin is often given once a day (glargine, degludec) or 1 to 2 times daily (detemir). Glargine does not have a peak and lasts approximately 20 to 24 hours. U-300 glargine lasts more than 24 hours, and degludec has a longer duration of action, up to 42 hours. When MDI is used, the patient will ideally use rapid insulin with each meal and for hyperglycemic correction and long-acting basal insulin. If using insulin pump therapy, a continuous infusion of rapid-acting insulin will be used.

Blood glucose readings should be monitored throughout the day. Patients should check their blood glucose pre-meals, 2 to 3 hours post meals (when adjusting prandial dosing), before bedtime, and when they suspect hypoglycemia. It is beneficial to check a 2 am to 3 am glucose reading if the morning glucose value is high to determine the underlying cause of hyperglycemia. It is important to educate patients about the symptoms of hypoglycemia, which include diaphoresis, tachycardia, lightheadedness, confusion, visual changes, and tremors. 15 to 20 g of glucose should be given orally for blood glucose levels below 70 mg/dl. Patients should then recheck their blood glucose 15 minutes later and consume a snack once the value has normalized to prevent a recurrence. Glucagon should be prescribed for emergency use when patients have a severe hypoglycemic episode and are unable to consume carbohydrates by mouth.

Continuous glucose monitors (CGM) are extremely useful tools for people with T1DM. Sensors are inserted into the subcutaneous tissue and measure interstitial glucose levels, which are transmitted to a receiver and displayed in real time. One can examine trends and use alarms to prevent serious hypoglycemia episodes. There are continuous glucose monitoring systems (CGMs) that transmit glucose readings every 5 minutes and can alarm the patients if readings are too high or too low or if there is a rapid change in glucose value (thresholds set by the patient). These CGMs can communicate with insulin pumps. Readings from certain CGM sensors can be transmitted to smartphones and can be shared with relatives, friends, or caregivers. Other sensors communicate with insulin pumps, providing a hybrid artificial pancreas. Another CGM is a less expensive option worn for ten days at a time. This “flash” CGM records glucose readings every 15 minutes, does not have an alarm feature and uses a “reader” (a device the user scans over the site of sensor placement) to visualize recent glucose readings and trends. All these devices make it easier to monitor glucose values throughout the day. Users examine trends and are provided with vital information to guide insulin therapy and food intake to help avoid wide glycemic variation.

In addition to insulin therapy, diet, and physical activity, individuals with T1DM should generally have an annual eye exam by an eye care specialist. Those with foot deformities, neuropathy, a history of foot ulcers, or peripheral arterial disease should see a podiatrist, be educated in proper foot care/footwear, and be evaluated for orthotics if necessary. Other specialists, such as psychologists, nephrologists, and cardiologists, may also be needed.

More advances in T1DM management can be expected soon. “Closed-loop” systems are anticipated in which CGMs directly communicate with insulin pumps and automatically direct insulin infusion rates. Research is also being conducted on islet cell transplantation. Individuals who receive islet-cell transplantation require immunosuppressive therapy, and many islets do not have a long lifespan. Encapsulated islets unrecognizable by the immune system would obviate the need for immunosuppressive therapy and are a promising future therapy. These and other research initiatives give hope to the increasing number of youth and adults with T1DM that a cure is in their future.

Nursing Management

  • Monitor blood sugar and use a sliding scale to treat high levels of glucose
  • Educate patient about diabetes
  • Examine feet and skin and teach patient foot care
  • Educate the patient on foot protection
  • Monitor vitals
  • Teach the patient about insulin self-injections and how to perform fingersticks
  • Encourage annual visits to the dentist, ophthalmologist, cardiologist, and neurologist
  • Teach the patient about hypoglycemia and how to manage it
  • Teach the patient about nutrition and the importance of exercise
  • Urge the patient not to smoke and to abstain from alcohol

Outcome Identification

Type 1 DM is associated with high morbidity and mortality. Close to 50% of patients will develop a serious complication over their lifetime. Some will lose eyesight, and others will develop end-stage renal disease. The prognosis is good for those who make it past the first 20 years. However, the disease has no cure, and with time, the patient may develop premature coronary artery disease, neuropathy, foot ulcers, and vision loss.

Maintaining euglycemia for a lifetime is associated with severe anxiety and depression; for many patients with type 1 diabetes, the quality of life is poor.

Coordination of Care

Type 1 diabetes is a systemic disorder with diverse presentations and very high morbidity; for this reason, the condition is best managed by an interprofessional team of healthcare professionals.

Type 1 diabetes is a serious disorder with very high morbidity and mortality. Over the long term, the vast majority of patients with this disorder will develop blindness, adverse cardiac events, end-stage renal disease, neuropathy, and in some cases, premature death. Data indicate that those patients who manage to control their blood sugars without developing severe complications tend to have a good quality of life.

The patient must be screened for foot, eye, and eye complications at each visit. Appropriate referrals need to be made before disease occurs in these organs. A diabetic nurse should educate the patient on self-insulin injection and how to perform fingerstick tests for blood glucose level monitoring.

Social workers should be involved in the care to ensure that the patient has adequate support and finances for treatment. Communication with the interprofessional team should be prompt to ensure no patient is denied treatment. With assurance and guidance, many patients with type 1 diabetes can live a good quality of life.[13][14][15]

Health Teaching and Health Promotion

As stated above, patient compliance with their medications, follow-up with specialists, and patient education is critical in preventing complications. At every patient encounter, the pharmacist, nurse, and clinicians should emphasize the importance of blood glucose control, long-term complications, and management goals. The patient should be encouraged to modify their lifestyle to reduce the risk of complications. In addition, all people with diabetes should be made aware of the signs and symptoms of hypoglycemia and ways of managing it. Patients should be educated about available resources and the benefits of joining support groups. A dietitian should educate the patient about foods that can be consumed, and the nurse should educate the patient on blood glucose monitoring at home.

Risk Management

Call the clinician if:

  • Fever
  • Unstable hemodynamics
  • No urine output
  • Acute vision loss
  • Chest pain
  • Confused
  • Low or high blood sugars
  • Presence of ketones in the urine
  • Altered mental status

Discharge Planning

The critical factor in preventing complications is patient compliance with their medications and follow-up with specialists and educators. Patients need to understand their disease, how to monitor glucose, and the importance of medication compliance. At each follow-up visit, the patient needs to be screened for complications to the foot, eyes, and eyes. Appropriate referrals need to be made before disease occurs in these organs. A home care diabetic nurse should educate the patient on self-insulin injection and how to perform fingerstick tests for blood glucose level monitoring.

Pearls and Other issues

Type 1 diabetes is a systemic disorder with diverse presentations and very high morbidity; for this reason, the condition is best managed by an interprofessional team of healthcare professionals.

Type 1 diabetes is a serious disorder with very high morbidity and mortality. Over the long term, the vast majority of patients with this disorder will develop blindness, adverse cardiac events, end-stage renal disease, neuropathy, and in some cases, premature death. Data indicate that those patients who manage to control their blood sugars without developing serious complications tend to have a good quality of life.

Article Details

Nurse Editor

Chaddie Doerr

Article Author

Jessica Lucier

Article Editor:

Ruth S. Weinstock


3/3/2023 12:48:00 PM



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