Low birth weight linked to diabetes

Hyderabad: Babies born to diabetic Indian mothers have a higher risk of obesity and diabetes than those born before the mother became diabetic , said Prof C.S. Yajnik, director of the diabetes unit at the King Edward Memorial Hospital and Research Centre in Pune, who delivered the 41st Gopalan Oration Award lecture on Friday at the National Institute of Nutrition (NIN).

Once a fetus is exposed to adverse intrauterine environment, it is transferred to many generations. If the baby is female, even the third generation is impacted as the ova are developed in the fetus stage itself of the diabetic mother. 

Furthermore, the smaller of identical twins will have a higher risk of diabetes. He added that the ideal time for interventions is during pre and periconceptional stages and intrauterine period.

An average western type 2 diabetes patient is in his 60s and considerably obese by BMI criteria but Indian diabetic patients are much younger and thinner, and though not obese by BMI criteria they are centrally obese (higher waist-hip ratio). Over years, the age at diagnosis has fallen and gestational diabetes is on the rise, he said.

Dr.Yajnik said, "We soon found that lower birth weight Indian children had higher glucose and insulin concentrations. Our findings provided a possible explanation for the paradoxical situation that India shares the distinction of being the world’s capital of low birth weight on the one side, and as the capital of diabetes on the other. When we studied these children a few years later, another interesting fact emerged: the worst risk for diabetes and heart disease was in children who were born small but had grown big; the mismatch in growth was detrimental. The life course evolution of diabetes had started unfolding."

The professor observed in his Pune Maternal Nutrition Study, "For a given birth weight, the skinfolds of Indian babies were larger than those of English babies, the cord blood concentrations of insulin and leptin were higher and adiponectin lower in Indian babies. We described a ‘thin-fat’ Indian baby and showed that the body composition of Indians is laid down in utero and that the risk for future NCDs is evident in the cord blood."

It appears that multigenerational under nutrition and recent rapid socio-economic and nutritional transition has added a component of fetal over nutrition to the story and it is observed that in urban Indians, it is a mixture of under and over-nutrition driven fetal programming of diabetes. He added that short legs are a risk factor for diabetes. The height chart was flat for Indians from 1830-1980 while EU gained 15 cm due to under nutrition and environmental changes. Only after 1980 did Indians gain in height. In 1990 Kerala and Tamil Nadu had crude prevalence of diabetes in adults aged 20 years or older, but by 2016, the percentage change in prevalence increased significantly in BIMARU states.

While the textbook model of type 2 diabetes includes genetic susceptibility and precipitation by affluent lifestyle including dietary excess, physical inactivity, psychosocial stress, etc, more than hundred genetic variants have been associated with type 2 diabetes but more than a decade after the description of the human genome, there is little contribution of genetics to prevention or day to day management of diabetes. He said that there is need to investigate modifiable susceptibility  factors.