1. What is naturally occurring insulin?
After a person eats, the digestive tract breaks carbohydrates down into glucose which then enters the bloodstream. In a person without diabetes, the pancreas responds by producing the hormone insulin which enables glucose to enter the body’s cells to provide energy. The main function of insulin is to regulate glucose levels in the blood within a narrow range.
2. What is insulin-dependent diabetes?
If there is a defect in producing insulin (Type 1 diabetes) or an issue using it efficiently plus sometimes a defect in producing insulin (Type 2 diabetes), glucose levels rise when a person eats because there is not enough insulin to move the glucose into the body’s cells. Elevated blood glucose levels can lead to complications that may affect the eyes, kidneys, nerves, heart, and blood vessels. There is no cure, so patients must maintain good control of blood glucose levels to monitor their status and determine insulin doses.
3. What are the goals of insulin therapy in people with diabetes?
The ultimate goal is to maintain blood glucose levels in the desired range to help prevent diabetes complications. For people with Type 1 diabetes, insulin therapy is essential to replace the insulin the body is unable to make itself. For some people with Type 2 diabetes, insulin is needed if other treatments have not kept glucose levels within the desired range.
4. How common is diabetes in the U.S.?
The latest U.S. statistics are for 2018 when about 10.5% of the population (34 million people) had diabetes. Within this number were 7.3 million people who had diabetes but who had not yet been diagnosed. The percentage of adults with diabetes increased with age, reaching 27% among those aged 65 years or older. In terms of insulin use, 5.2% of all U.S. adults with diagnosed diabetes (1.4 million people) reported having Type 1 diabetes and using insulin.
5. What are the risk factors for diabetes?
Type 1 diabetes: It is thought to be caused by an immune reaction (the body attacks itself by mistake). Known risk factors include: (a) family history (parent, brother, or sister with Type 1 diabetes) and (b) younger age.
Type 2 diabetes: Prediabetes (blood glucose levels are higher than normal, but not high enough to be diagnosed as diabetes); overweight; age 45+ years; parent or sibling with Type 2 diabetes; physically active less than 3 times a week; diabetes during pregnancy; non-alcoholic fatty liver disease; and ethnic origin African American, Hispanic/Latino American, American Indian or Alaska Native.
6. What are the symptoms of diabetes?
The Centers for Disease Control and Prevention (CDC) lists the following symptoms as possible with diabetes: thirst and/or hunger; unintended weight loss; frequent urination, often at night; blurry vision; numb or tingling hands or feet; fatigue; very dry skin; sores that heal slowly; and more frequent infections than usual.
Type 1 diabetes: Type 1 diabetes is a lifelong condition and there is no cure. There are no known ways to prevent it. Symptoms can develop in weeks or months and can be severe. Type 1 generally appears in young people (children, teens and young adults) but can happen at any age. People with Type 1 diabetes may also have nausea, vomiting, or stomach pain.
Type 1 diabetes presenting as diabetic ketoacidosis: Some people with Type 1 diabetes are not aware of their condition and first present with very high blood sugars. Symptoms may include: deep, rapid breathing; flushed face; fruity breath odor; nausea and vomiting, including the inability to keep down fluids; dry skin and mouth; and stomach pain.
Type 2 diabetes: As described above but people may have few or no symptoms.
7. How is diabetes diagnosed?
Diabetes is diagnosed via using one or more of the following blood tests:
- Fasting blood glucose level: 126 mg/dL (7 mmol/L) or higher at two different times
- Random (non-fasting) blood glucose level: 200 mg/dL (11.1 mmol/L) or higher (confirmed with a fasting test)
- Oral glucose tolerance test: Glucose level is 200 mg/dL (11.1 mmol/L) or higher 2 hours after drinking a sugar drink supplied by the laboratory
- Hemoglobin A1C: 6.5% or higher
8. How is insulin used to treat diabetes?
General recommendations from the American Diabetes Association 2021:
- Most people who need insulin will receive multiple daily injections of prandial (related to a meal) and basal insulin or continuous subcutaneous insulin infusion.
- Most people should use rapid-acting insulin analogs to reduce hypoglycemia risk.
- People should receive education on how to match prandial insulin doses to carbohydrate intake, premeal blood glucose, and anticipated physical activity.
Overview of the types of insulin:
- Long-, ultralong- or intermediate-acting insulins (these work for 8-40 hours, depending on the type): Examples are glargine (Lantus, Basaglar, Toujeo), detemir (Levemir), degludec (Tresiba) and NPH (Humulin N, Novolin N, Novolin ReliOn Insulin N).
- Rapid or short-acting (work for 2-4 hours, and begin to work much faster than long-acting or intermediate-acting insulins do): Examples are aspart (NovoLog, Fiasp), glulisine (Apidra), lispro (Humalog, Admelog) and regular (Humulin R, Novolin R).
9. What is involved in regular testing of blood glucose?
People on insulin regularly self-monitor their blood glucose levels based on their insulin regimen. This may include testing when fasting, before meals and snacks, at bedtime, before exercise, when low blood glucose is suspected, after treating low blood glucose up to the point where blood glucose is normal, and before and during critical tasks such as driving.
Increasingly, people with diabetes monitor their glucose levels using a continuous glucose monitoring device. Use of the technology should be determined by a person working with their health care team.
Long-term glucose control is monitored using A1C testing – a blood test ordered by a physician. For people who have stable glucose control, A1C testing twice a year is suggested by the American Diabetes Association. Four times a year is suggested for people with changes in medication or where their diabetes is not considered stable. Regarding results, an A1C goal for many nonpregnant adults of 7% (53mmol/mol) without significant hypoglycemia is considered appropriate. In some cases, lower levels may be acceptable and even beneficial if they can be achieved safely without significant hypoglycemia or other adverse effects of treatment. More relaxed A1C goals may be sought where the harms of treatment are greater than the benefits and for patients with limited life expectancy.
American Diabetes Association (ADA). Standards of medical care in diabetes – 2021 abridged for primary care providers. Clin Diabetes. 2021 Jan;39(1):14-43. Available at: https://clinical.diabetesjournals.org/content/diaclin/39/1/14.full-text.pdf
Centers for Disease Control and Prevention (CDC). National diabetes statistics report 2020. 2020 Feb. Available at: https://www.diabetesresearch.org/file/national-diabetes-statistics-report-2020.pdf
Langendam M, Luijf YM, Hooft L, et al. Continuous glucose monitoring systems for type 1 diabetes mellitus. Cochrane Database Syst Rev. 2012 Jan 18;1(1):CD008101. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6486112/pdf/CD008101.pdf
Mayo Clinic. Diabetes treatment: Using insulin to manage blood sugar. 2019 Jul. Available at: https://www.mayoclinic.org/diseases-conditions/diabetes/in-depth/diabetes-treatment/art-20044084
Medline Plus. Type 1 diabetes. 2021 Jul. Available at: https://medlineplus.gov/ency/article/000305.htm