Diabetes mellitus, or diabetes, is a chronic disease caused by absent or insufficient insulin production. The American Diabetes Association recognizes many types of diabetes; however, two types are seen most frequently. Type 1 diabetes is often diagnosed in children. Insulin production cannot occur because the body's immune system attacks the cells within the pancreas that produce insulin. Type 2 diabetes, diagnosed in children and adults, develops when there is not enough insulin to keep blood sugar levels within normal range. Diabetes is associated with a variety of biological, lifestyle and even psychological factors.
Race
A major study called the Nurses' Health Study, which has been ongoing for decades, examines a variety of health-related conditions and risk factors. This study, which examines the relationship between race and Type 2 diabetes, found that certain ethnic groups are at increased risk for developing this disease. Specifically, those of Asian, Hispanic or African-American descent have been found to be more likely to develop Type 2 diabetes, as compared to white people.
Genetics and Family History
Several types of evidence suggest that genetics play a significant role in diabetes. For instance, according to Dr. David McCulloch and Dr. Paul Robertson, writing in the medical reference UpToDate, identical twins of patients with Type 1 diabetes have a 50 percent risk of themselves developing the disease. Non-twin siblings of patients with Type 1 diabetes have a 5 percent elevated risk. Family history also plays a role in the development of Type 2 diabetes. Having a first-degree relative, such as a mother or father, with Type 2 diabetes increases the risk that the patient will develop this disease as well.
Besides the evidence based on family histories, a variety of genes appear to be involved in the development of type 1 diabetes. Two particular gene combinations, or genotypes, have been found to be especially high risk: over 90 percent of patients with type 1 diabetes have either the genotype called "DR3-DQ2" or the one called "DR4-DQ8." These genes are involved with the ability of autoantigens--parts of one's own body that are incorrectly presented to the immune system as a "foreign body" that must be destroyed--to bind the immune system cells. If the immune system cells cannot bind these autoantigens, the development of type 1 diabetes is less likely, because the immune systems will not begin to attack the body's own pancreatic cells.
Depression
Drs. Lynne Levistky and Madhusmita Misra, summarizing the results of five different studies, write in UpToDate that children with Type 1 diabetes must also learn to deal with the emotional impact of managing a chronic disease. Specifically, the results of these studies have found that children and teenagers with Type 1 diabetes are at higher risk for depression compared to children and teenagers who do not have Type 1 diabetes. Patients with Type 2 diabetes are also at risk. A patient education pamphlet by the American Diabetes Association, the American College of Cardiology and the Preventive Cardiovascular Nurses Association reports that patients with diabetes are twice as likely to develop depression. Other studies find that the risk is less than this. However, regardless of specific numbers, there seems to be a link between Type 2 diabetes and depression. Because depression can cause a variety of complications--including not being able to manage the treatment for diabetes--it's important that patients who are experiencing symptoms such as changes in sleep, a sad or depressed mood, and changes in activity level see a doctor. If depression is the reason, treatment with medications, counseling or a combination of the two may help.
Exercise
Perhaps the most important aspect of lifestyle-related or social/environmental aspects of diabetes care is that of exercise. Exercise can benefit both types of diabetes patients. In patients with Type 2 diabetes, exercise can help with weight loss, improve insulin sensitivity and reduce the risk for heart-related complications, which are common in patients with diabetes. Furthermore, as Dr. David McCullogh reports in UpToDate, exercise may help prevent the onset of Type 2 diabetes in patients who are at risk for developing the disease. In patients with Type 1 diabetes, the issue is not insulin sensitivity, so this benefit is less crucial. However, because exercise does increase insulin sensitivity, patients who exercise regularly may find they're able to reach their target level of blood sugar with less insulin than they were using before they began regular exercise. In addition, the cardiovascular benefit is important. Patients with Type 1 and Type 2 diabetes are at risk for cardiovascular complications, and exercise may help reduce this risk.
References
- "Diabetes Care;" Ethnicity, Obesity, and Risk of Type 2 Diabetes in Women: a 20-year Follow-up Study; I. Shai et. al.; July 2006
- "UpToDate;" Risk Factors for Type 2 Diabetes Mellitus; D. McCulloch and R.P. Robertson; May 2010
- "Clinical Diabetes;" Diagnosis, Classification, and Lifestyle Treatment of Diabetes; M. Fowler; March 2010
- "Recognizing and Handling Depression for People with Diabetes;" American Diabetes Association; 2004
- "UpToDate;" Complications and Screening in Children and Adolescents with Type 1 Diabetes Mellitus; L. Lynn and M. Misra; May 2010
