ANN/THE STAR – Women with a history of diabetes in pregnancy (gestational diabetes) can still reduce their chances of developing type 2 diabetes by adopting a healthy lifestyle, finds a study published on September 21 (2022) in The BMJ medical journal.
The results show that women who adhered to five key lifestyle factors – healthy weight (ie body mass index, or BMI), high-quality diet, regular physical activity and not smoking – had a 90 per cent lower risk of the disorder, compared with women who did not adhere to any.
This remained true even among those who were overweight or obese (if they adhered to the other lifestyle factors), or were at greater genetic risk of type 2 diabetes.
It’s widely known that a healthy lifestyle is associated with a lower risk of developing type 2 diabetes in generally healthy middle-aged populations.
But less is known about whether this also applies to high-risk women with a history of gestational diabetes, and if obesity status or genetic risk of type 2 diabetes influence this association.
Gestational diabetes develops when the body can’t produce enough insulin to control blood sugar levels during pregnancy.
To fill in these research gaps, researchers evaluated the associations of adherence to optimal levels of the five modifiable risk factors, with the risk of developing type 2 diabetes among these women at high risk.
Their findings are based on data for 4,275 women with a history of gestational diabetes mellitus from the Nurses’ Health Study II, which conducted repeated measurements of weight and lifestyle factors over 28 years of follow-up.
The researchers also assessed whether these associations changed according to obesity status or underlying genetic susceptibility for type 2 diabetes.
Over an average 28 years of follow-up, 924 women developed type 2 diabetes.
After taking into account other major diabetes risk factors, the researchers found that participants who had optimal levels of all five modifiable factors after the index pregnancy had a more than 90 per cent lower risk for developing type 2 diabetes, compared with those who did not have any.
Each additional optimal modifiable factor was associated with an incrementally lower risk of type 2 diabetes.
For example, women with one, two, three, four and five optimal levels of modifiable factors, compared with none, had a six per cent, 39 per cent, 68 per cent, 85 per cent and 92 per cent lower risk respectively. And these beneficial associations were consistently seen, even among women who were overweight or obese, or who had higher genetic susceptibility to type 2 diabetes.
This is an observational study, so it can’t establish cause, and the researchers acknowledge that the data relied on personal reports, which may have affected accuracy.
What’s more, the study included predominantly healthcare professionals of European ancestry, so the results may not apply to individuals of other racial or ethnic groups, or socioeconomic groups.
However, strengths include use of data from a large study with repeated measurements of health-related and behavioural risk factors, which helps to better capture long-term lifestyle habits and reduce measurement error and misclassification.
As such, the researchers said their study “highlights the important public health opportunity for the prevention of type 2 diabetes in this high-risk population”.