The prevalence of prediabetes and obesity among adolescent school children in Chennai has risen sharply over the past 17 years, according to a new study that compared data collected in 2023 with a similar survey conducted in 2006. Researchers say the findings point to worsening metabolic health among children and could foreshadow a growing burden of type 2 diabetes and cardiovascular disease in young adults.

Published in Diabetes & Metabolic Syndrome: Clinical Research & Reviews, the study analysed 954 students aged 12 to 19 years from government and private schools catering largely to low- and middle-income families in Chennai. Their findings were compared with data from 1,080 students surveyed using the same methodology in 2006.

The prevalence of impaired fasting glucose (IFG), a prediabetic state, increased from 3.1% to 28.1% among girls and from 3.5% to 26.4% among boys over the study period. Children surveyed in 2023 also had higher body mass index (BMI), waist circumference, systolic blood pressure and fasting blood glucose levels than those assessed in 2006. More students also reported a family history of diabetes.

Metabolic risk

“This study essentially reports a rise in metabolic dysregulation and cardiovascular risk factors among adolescent schoolchildren in Chennai over a 17-year period,” said Nanditha Ramachandran diabetologist, Dr. A. Ramachandran’s Diabetes Hospitals, Guindy, and the study’s first author.

The increase in obesity was reflected not only in BMI but also in waist circumference, indicating a rise in abdominal obesity, which is associated with a greater risk of insulin resistance and cardiometabolic disease. Girls also continued to have higher body fat percentages than boys.

Prediabetes burden

The researchers noted that the actual prevalence of prediabetes may be higher than the study estimates.

Priscilla Susairaj, research scientist, India Diabetes Research Foundation and Dr. A. Ramachandran’s Diabetes Hospitals, Guindy, co-author, said the study measured only fasting blood glucose because collecting post-glucose blood samples from schoolchildren was not logistically feasible before school hours.

“As a result, we could assess impaired fasting glucose but not impaired glucose tolerance (IGT). Had IGT also been measured, the overall prevalence of prediabetes may have been even higher,” she said.

Early warning

Ambady Ramachandran, Chairman, A. Ramachandran’s Diabetes Hospitals, Guindy, and co-author, said

“ We have also recently reported that the prevalence of type 2 diabetes is rising more rapidly among adults below 40 years than among older adults. ” he said.

The proportion of children with three or more risk factors also increased over the study period.

Published - August 01, 2026 12:12 am IST