Insulin resistance profile among siblings of type 2 diabetes mellitus (preliminary study).

Aim: to obtain prevalence of insulin resistance among siblings of subjects with type 2 DM and their metabolic abnormality profiles as measured by their BMI, waist circumference (WC), blood pressure, glucose intolerance, concentration of triglyceride, HDL cholesterol, and uric acid.

Methods: a preliminary, cross sectional study conducted among 30 siblings from seven type 2 DM subjects under medical treatment in Dr. Cipto Mangunkusumo Hospital and other places where the subjects lived. Those subjects underwent interviews, physical examination including weight, height, abdominal circumference, blood pressure and laboratory examinations including glucose tolerance test, fasting insulin, triglycerides, HDL cholesterol and uric acid level. Data processed to obtain body mass index (BMI), homeostasis model assessment of insulin resistance (HOMA-IR) and HOMA-IR cut-off, which is determined based on 75 percentile. The criteria of hypertension, dyslipidemia, central obesity and hyperglycemia are based on Asian modification NCEP/ATP III criteria for metabolic syndrome. Hyperuricemia is diagnosed based on uric acid level >7mg/dl in men and >6 mg/dl in women.

Results: the prevalence of insulin resistance among siblings of type 2 DM in this study is 26.67% with the proportion in each family varies from 0% to 75%. The most metabolic component found in this study is central obesity (56.7%), followed by hypertension (46.7%), decreased HDL cholesterol level (26.6%), hyper-triglyceridemia (26.6%) and hyperglycemia (20%). As many as three-quarters of subjects with insulin resistance have BMI >25 kg/m2. Among subjects with insulin resistance, all have central obesity, half of them have hypertension, decreased HDL cholesterol level and hyper-triglyceridemia. While hyperglycemia is found in 37.5% subjects.

Conclusion: the prevalence of insulin resistance among siblings of type 2 DM in this study was 26.67% with the proportion in each family varies between 0-75%. Central obesity is the most metabolic component commonly found.