Genes And Lifestyle Together Drive Obesity Risk: AIG Report

Hyderabad: Genes and lifestyle together contribute to the obesity risk among Indians, according to a multi-cohort genomic study led by AIG Hospitals in Hyderabad and published in ‘Scientific Reports’ from the Nature portfolio.

The research analysed participants with Indian ancestry from the UK Biobank alongside an India-recruited cohort that was genomically profiled at the AIG Hospitals. Using a DNA analysis tool called the ‘SNP microarray platform’, investigators examined hundreds of thousands of genetic variants across the genome and constructed polygenic risk scores to quantify inherited susceptibility to obesity.

Participants were stratified into different genetic risk categories and assessed against composite lifestyle measures that included diet, physical activity and smoking behaviour. The study found a graded rise in obesity risk when polygenic risk scores — which reflect inherited susceptibility to obesity — combined with unfavourable lifestyle patterns.

The statistical interaction between genetic susceptibility and lifestyle was significant in the larger cohort and showed similar directional trends in the Indian cohort, according to the study.

An analysis of participants by age suggested that lifestyle influences may be particularly important among younger individuals with higher inherited risk. This, according to the study, indicated that there was a window for early intervention to prevent obesity and related risks.

Dr D. Nageshwar Reddy, Chairman of AIG Hospitals, said Indians were known to develop insulin resistance, fatty liver disease and cardiovascular complications at lower body mass index levels when compared to the Western populations. “Obesity is polygenic, influenced by thousands of variants. But inherited risk does not operate in isolation. Modifiable exposures still matter,” he said.

Dr Rakesh Kalapala, director of the Centre for Obesity and Metabolic Therapy, explained that polygenic risk scores aggregated the small effects of multiple obesity associated variants, meaning that several smaller factors would combine to increase the risk of obesity. “Two individuals with similar weight may have very different metabolic trajectories depending on their genetic architecture and lifestyle,” he explained.

Researchers noted that lifestyle measures were self-reported and that the India-recruited cohort in the study required expansion. They stressed that early screening, monitoring waist circumference and blood markers, and starting preventive action in early adulthood rather than waiting for overt disease, would help mitigate the growing obesity crisis.