Is Diabetes Genetic?

Is Diabetes genetic?  A lot of people are concerned about this.  They wonder if they will get the disease, or if their parents, brother, sister or some other close relative is diabetic. They also worry about their children, if they are have diabetes themselves.  No answer is conclusive, but some diabetes is genetically caused or passed along.

Since diabetes  involves genetic factors, it can be classed as a genetic disorder. However, that does not imply that it is a hereditary disorder, or that genes alone are the cause of it.   While genes play an important role in diabetes, there are some environmental factors too. Children of diabetic patients may not necessarily be diabetic. To understand how this complex interplay works, we have a few facts below.

Is Diabetes Genetic? –  Look at the Types of Diabetes

Diabetes results from deficiency of, or improper utilization of, insulin — a hormone synthesised by beta cells of the pancreas. This hormone is responsible for breaking down carbohydrates or sugar, protein, and fat in the body. Deficiency or improper use of this hormone results in increased levels of glucose and lipids in the blood. There are two main types of Diabetes.

Type 1 diabetes is also known as juvenile diabetes, and it occurs more commonly in children and young adults, and accounts for 5 to 10 percent of all diabetes cases.  Type 2 diabetes is often classed as a lifestyle disease and it usually occurs in middle age and is the commoner variety, responsible for 90 to 95 percent of diabetes cases.

Both type 1 and type 2 are caused by a combination of genetic and environmental risk factors. A child may inherit the genes for diabetes from a parent, but whether or not he or she has diabetes depends on the presence of certain environmental conditions, as well.

Is Diabetes Genetic?   If not How Do You Get Diabetes, and Why?

Type 1 diabetes is characterized by destruction of cells in the pancreas, thereby producing little or no insulin. The development of the disease is triggered by a few environmental factors in those who are genetically susceptible. The most important trigger is viral infection. Early weaning of infants from breast-feeding and cold climates are thought to be other triggers. Studies in twins and first degree relatives of individuals with type 1 diabetes, show some relation to, but do not favour a strong correlation with genetics.

In type 2 diabetes, the pancreas synthesises insulin in very little amounts and/or if adequate amounts of insulin are produced, the body is not able to properly utilize it.  This is known as insulin resistance. Type 2 diabetes develops because of genetic and environmental factors. It has been shown to have a strong genetic component, in studies conducted on first degree relatives of individuals with type 2 diabetes, as well as studies in twins.

A family history of diabetes i.e. genetic predisposition, increases the chances of developing diabetes.  Whether or not the person actually develops the disease actually depends to  a greater degree on environmental risk factors. These include:

Obesity
Lack of exercise
Older age (around 45 years, or middle age)

Less important environmental risk factors are high triglycerides, low HDL (good) cholesterol, smoking, hypertension, and polycystic ovary syndrome. Also, children are more likely to develop type 2 diabetes if the mother is diabetic, rather than if the father is. If both parents have diabetes, the chances of a child getting diabetes are much higher.

What Can Happen If You Have Diabetes?

Patients may be asymptomatic for years. Those who are symptomatic usually have excessive thirst, excessive urination, increased hunger, fatigue or tiredness, frequent infections, or new-onset blurred vision. All forms of diabetes have very serious effects on health. Both type 1 and type 2 are associated with the same long-term complications.

Diabetic patients, if undiagnosed or inadequately treated, develop various acute and chronic, vascular and non-vascular complications leading to irreversible disability and death. Acute complications include diabetic ketoacidosis, hyperglycaemic hyperosmolar state,  and hypoglycaemia, all of which may result in potentially serious complications if not promptly diagnosed and treated.

Long-term complications of diabetes include heart disease, blindness, cataracts, glaucoma, kidney disease, nerve damage (diabetic neuropathy is commonest), stroke, diarrhoea, sexual dysfunction, foot ulcers, infections, non-traumatic amputation of the lower limb and skin changes.  Social, psychological and financial burdens are other implications of the disease.

Can We Prevent Diabetes?

It is not possible to prevent Type 1 diabetes. However, it is possible to delay or prevent Type 2 diabetes by leading a healthy lifestyle. This includes a healthy diet and adequate exercise and weight loss. Exercise helps by controlling weight and improves glucose and fat utilization, which decreases the risk of type 2 diabetes.

Treatment:

Diabetes is a chronic disease requiring lifelong treatment. There is virtually no permanent cure for diabetes. In cases of Type 1 diabetes, lifelong insulin therapy is the only available treatment. The treatment of patients with type 2 diabetes should include diet, lifestyle modifications (exercise, smoking cessation), good glycaemic control (with oral hypoglycaemic agents and/or insulin) and lipid modifying drugs.

A well-balanced, nutritious diet (medical supervised nutrition therapy) and exercise remain the fundamentals in treatment of Type 2 diabetes mellitus. Those who have symptoms not controlled by diet and exercise are put on oral hypoglycaemic agents. About 30% to 40% patients are shifted from oral agents to insulin.

Current and Future Role of Genetics in Diabetes

It is hoped that individuals at high risk for type 1 and type 2 diabetes can be identified through genetic testing, before the onset of the disease. In the near future, the genes responsible for increasing the risk of developing all forms of diabetes will likely be known. All this may be greatly helpful in predictive genetic testing for diabetes, and thus be beneficial in the prevention and management of the diseases.

 In a nutshell:

Diabetes is usually caused by a combination of genetic and environmental risk factors

• Genetics and development of diabetes have weak association to type 1 diabetes, and a stronger association to type 2 diabetes.
• In cases of type 2 diabetes, environmental factors have an even stronger influence than genes on whether or not the individual will actually develop the disease, and healthy diets and active lifestyles will be most beneficial in preventing or delaying diabetes and its complications.

The question is diabetes genetic will be best answered in the near future by genetic testing studies, when the genes for all types of diabetes are decoded.