At 28 weeks of pregnancy, Surekha Patil (name changed) from Pabal village in Shirur tehsil of Pune district knows she has to report to the Diabetes Research Centre at KEM hospital in Pune on Tuesday for a glucose tolerance test and a gynaecological evaluation.
This is no routine check for 22-year-old Surekha. She has been monitored since birth as part of an ambitious Pune Maternal Nutrition Study that has spanned three generations of participants in the last 25 years. Surekha is accompanied by her mother who is among the first generation of participants in the study that was launched in 1993.
Research by Chittaranjan Yajnik, head of the Diabetes Research Centre at KEM hospital, showed that mothers with low Vitamin B12 and excess folate levels (level of folic acid) predispose their babies to adiposity and insulin resistance that are key risk factors for diabetes.
That landmark research helped in explaining why diabetes was so widely prevalent in India, even among malnourished populations, when, globally, the disease was very commonly associated with obesity.
“We showed that the ‘small and thin’ Indian babies were ‘fatter’ than the Europid babies and the risk of future diabetes was present at birth itself. Evidence also showed that the role of maternal micronutrient nutrition for the baby’s growth was crucial,” Yajnik told The Indian Express.
It was these results that led Yajnik’s team to embark upon the Pune Maternal Nutrition Study. Twenty five years later, it has led to pioneering ideas in the field of fetal programming.
“Nutritional programming as a basis of Developmental Origins of Health and Disease (DOHaD) is here to stay, although there is a long way to go. Observational research and animal models have taught us a lot, but real success will depend on successful interventions to promote inter-generational health and reduce the burden of disease,” says Yajnik.
The first stage of the study that began in 1993 included 814 women from six villages in Pune district. Between 1994 and 1996, a total of 770 of these women delivered babies. The weight and size of these babies were monitored every six months.
Their insulin resistance was observed at the age of six, 12 and 18 years. These children were followed up by social workers who ensured that they did not drop out of the study, Pallavi Yajnik, wife Chittaranjan Yajnik and administrator at the Centre, said.
The observations showed that children born to mothers with high homocysteine and low vitamin B12 levels had lower birth-weight and higher insulin resistance.
“These findings can have important implications in controlling diabetes and heart disease epidemic in the country,” Dr Yajnik said.
By 2012, the research team had been following up on 577 children born to the mothers of the 1993 cohort. They started providing them Vitamin B12 supplements in order to reduce the future diabetes risk in their own offspring.
Till December last year, 107 of this group of 577 had given birth to children, forming the third generation of subjects under observation. The newly born babies will now be studied for various metabolic parameters as the researchers have stored the babies’ cord blood, placenta and other samples at the unique bio-bank. The researchers are waiting for this third-generation sample size to grow up to 200 before doing data analysis.
“We have been successful in monitoring three generations so far, retained the study participants, got consent from the in-laws after the girls got married to continue in the study and now their babies will be assessed. Dietary patterns are being analysed and other physical changes are being documented. Counselling is provided for each participant and once we record a total of 200 deliveries the data will be further analysed,” Pallavi Yajnik said.
Chittaranjan Yajnik said it had been a difficult but rewarding journey so far. “We have more than 90 per cent follow-up rates and have documented the nutritional and socioeconomic transition in the society. The unique bio-bank has samples stored for measurements of DNA, RNA, metabolites, hormones, and so on. This will be a unique legacy for future investigators,” he said.
Yajnik’s centre now collaborates with researchers Indian Institute of Science Education and Research (IISER) in Pune, Centre for Cellular and Molecular Biology (CCMB) in Hyderabad and Indian Institute of Science (IISc) in Bangalore.