According to a study, women of South Asian heritage may be more prone to develop gestational diabetes due to the same complicated genetics that raises their risk of developing type 2 diabetes. The study’s findings were published in the journal eLife. The discovery might lead to new methods of identifying women who would benefit from diabetes prevention measures during pregnancy.
People of South Asian heritage are more likely to acquire type 2 diabetes. Women of African origin are also twice as likely as women of European descent to acquire gestational diabetes during pregnancy. However, it is unclear why South Asians are at a higher risk of these two illnesses.
“Only a handful of studies have looked at how genetic and environmental factors interact in gestational diabetes in South Asian women,” says lead author Amel Lamri, a research associate at McMaster University and Population Health Research Institute (PHRI) in Ontario, Canada. “None have looked at how the genes associated with type 2 diabetes may interact with environmental factors to contribute to gestational diabetes in South Asian women.”
Lamri and colleagues investigated the link between genes linked with type 2 diabetes, environmental variables, and gestational diabetes to bridge this gap. They investigated whether genetic patterns associated with type 2 diabetes risk were also associated with gestational diabetes in 837 and 4,372 South Asian women who took part in the SouTh Asian BiRth CohorT (START) and Born in Bradford (BiB) studies, respectively.
The researchers used a polygenic risk score to quantify an individual’s hereditary risk of acquiring type 2 diabetes based on the number of risk alleles they had. The researchers discovered that South Asian women with higher polygenic risk scores for type 2 diabetes had a greater chance of gestational diabetes; each incremental rise in the score was linked with a 45% increase in the likelihood of acquiring this illness.
When the researchers looked at the risk of gestational diabetes at the population level, they discovered that having a polygenic risk score in the top one-third explained 12.5% of the risk among South Asian women. A family history of type 2 diabetes plus a polygenic risk score in the top third explained 25% of the risk of developing gestational diabetes.
“These findings reveal that a higher polygenic risk score for type 2 diabetes and a family history of diabetes are substantially and independently related with gestational diabetes in women of South Asian heritage,” Lamri added.
The researchers also investigated if environmental variables influenced these genetic risk factors. In both trials, the majority of the environmental factors they investigated (with the probable exception of body mass index and food quality) did not significantly increase the risk of diabetes during pregnancy. However, the authors cautioned that the studies may not have been big enough to identify more minor environmental impacts, and that further research is needed to validate the modulatory effects they detected.
“Our results support the idea that type 2 diabetes and gestational diabetes share a common genetic background,” concluded senior author Sonia Anand, the Michael G. DeGroote Chair in Population Health, and a senior scientist at PHRI, McMaster University, and Hamilton Health Sciences. “If future studies confirm our results, this information may help identify which women would benefit most from interventions to help prevent diabetes during pregnancy.”
