Impact of consanguinity on cardio-metabolic health and other diseases: findings from an Afro-Indian tribal community

Numerous anthropological reports have indicated consanguineous marriage in populous Asian countries, but the overall impact of first cousin marriage on survival and health of specific communities has rarely been reported. The aim of the study was to estimate risks for various complex diseases in the progeny of consanguineous parents. A cross-sectional study was conducted among 222 women among Siddis, a particularly vulnerable tribal group in the state of Gujarat, India, who are Sunni Muslims by faith. The Siddis are not part of the original Negrito element of India. They are descendants of Africans from Northeast and East Africa who were brought to India as slaves, soldiers, or servants. The degree of consanguinity between each female and her spouse and the degree of consanguinity between their parents and proband’s grandparents were recorded with the help of pedigrees. The results showed that the rate of consanguinity in the present generation was 49 % ( N = 109), higher than preceding generations. A significant association was observed between women’s age, educational level, occupational status, consanguineous parents, and consanguinity. Socioeconomic status and consanguinity showed U-shaped associations. Nearly three times odds for cardio-metabolic risks (2.65 odds ratio (OR) for heart diseases, 2.44 OR for diabetes mellitus, and 2.62 OR for hypertension) have been contracted in the progeny of consanguineous marriage in the parental generation. The risk of cardio-metabolic diseases is higher in offspring of consanguineous couples, and there is a significant increase in the prevalence of common adult diseases.