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How does family history affect the risk of type 2 diabetes mellitus?

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An anatomical illustration of the human pancreas shows its location near the stomach and intestines, a detailed cross-section highlighting ducts and the islet of Langerhans, and an inset of pancreatic tissue histology with labeled alpha, beta, and delta cells. — diabetes mellitus The islets of Langerhans are responsible for the endocrine function of the pancreas. Each islet contains beta, alpha, delta, and pancreatic polypeptide (PP) cells that are responsible for the secretion of pancreatic hormones. Beta cells secrete insulin, a well-characterized hormone that plays an important role in regulating glucose metabolism.

Type 2 diabetes mellitus has a significant genetic component, and family history plays a clear role in an individual's risk of developing the condition.1

The likelihood of developing the disease increases based on the number of parents affected:
* Approximately 7 to 14 percent of individuals with one parent who has type 2 diabetes will also develop the condition.1
* This risk rises to 45 percent if both parents are affected.1

Furthermore, genetic susceptibility is often observed in identical twins, who show a higher concordance for type 2 diabetes than for type 1. However, it is important to note that this genetic predisposition may not be expressed unless other factors, such as excess body fat or obesity, are present. While family history is a key indicator of risk, lifestyle interventions—including maintaining a healthy weight through diet and exercise—are highly effective in preventing or delaying the onset of the disease in high-risk individuals.12