Parental transmission of type 2 diabetes mellitus in a highly endogamous population

To determine the parental transmission of diabetes mellitus (DM) and evaluate its influence on the clinical characteristics.

This was a cross sectional study. The survey was carried out in urban and semi-urban primary health care centers. Of the 2400 registered with diagnosed diabetes, 1980 agreed and gave their consent to take part in this study, thus giving a response rate of 82.5%. Face to face interviews were conducted using a structured questionnaire followed by laboratory tests. DM was defined according to the World Health Organization expert group. A trained nurse performed physical examinations and measurements.

Of the study population, 72.9% reported a family history of DM. Family history of DM was significantly higher in females (54.2%; P = 0.04) and in the age group below 30 years (24%; P < 0.001). The prevalence of diabetes was higher among patients with a diabetic mother (25.4% vs 22.1%) and maternal aunts/uncles (31.2% vs 22.2%) compared to patients with a diabetic father and paternal aunts/uncles. Family history of DM was higher in patients of consanguineous parents (38.5%) than those of non-consanguineous parents (30.2%). The development of type 2 diabetes mellitus (T2DM) complications was higher in patients with either a paternal or maternal history of DM than in those without. No significant difference was observed in the metabolic characteristics of patients with/without family history of DM except for hypertension. Complications were higher in diabetic patients with a family history of DM.

The present study found a significant maternal effect in transmission of T2DM. Family history is associated with the increased incidence of diabetes.