CVD risk factors and later diabetes diagnosis don't appear to blame, leading to calls for early intervention and ongoing monitoring in these women.
Women who had gestational diabetes are at a higher risk of heart and brain problems long term, highlighting the need for early intervention in high-risk women and ongoing monitoring of women who develop the condition.
While the link between gestational diabetes and cardiovascular disease has been shown previously, this study suggests the elevated risks aren’t due to conventional cardiovascular risk factors or the later development of diabetes in women’s lives.
The systematic review and meta-analysis of 15 studies of almost nine million women found that women with a history of gestational diabetes mellitus had a 72% greater risk of developing cardiovascular diseases and a 40% increased risk of cerebrovascular diseases compared to those without the condition.
Specifically, there was a 40% increased risk of incident coronary artery diseases, 74% increased risk of myocardial infarction, 62% increased risk of heart failure, 127% increased risk of angina pectoris, 87% increased risk of cardiovascular procedures, 49% increased risk of stroke, 49% increased risk of ischaemic stroke and 28% increased risk of venous thromboembolism.
“Women with a history of gestational diabetes mellitus are at substantially higher risk of future cardiovascular and cerebrovascular diseases,” the authors wrote in the BMJ.
“This excess risk cannot be solely attributed to conventional cardiovascular risk factors, which were partially mediated by subsequent diabetes.
“Our results highlight the need for early intervention in women at high risk of gestational diabetes mellitus, and for continued monitoring of women with a history of gestational diabetes mellitus after pregnancy,” they noted.
The risks remained even after the researchers adjusted for ethnicity, sociodemographic features, education, conventional cardiovascular and cerebrovascular risk factors and subsequent diabetes diagnosis.
“The precise mechanisms of how gestational diabetes mellitus contributed to increased risk of cardiovascular and cerebrovascular diseases remains unknown,” the authors said.
They pointed to previous research that suggested around one quarter of the cardiovascular risk among women who had gestational diabetes could be explained by those women later developing diabetes. However, the current study accounted for this, suggesting the links could be explained by endothelial changes and dysfunction, which could be accelerated in women who had obesity and dyslipidaemia, in women who had gestational diabetes.
Meanwhile, another study published in the BMJ on women with gestational diabetes found that a healthy lifestyle reduced the chances of type 2 diabetes by up to 90%.
“This study highlights the important public health opportunity for the prevention of type 2 diabetes in this high-risk population,” the authors of that study said.
The prospective cohort study of 4300 women with gestational diabetes found that adherence to optimal levels of key modifiable risk factors such as healthy weight, high-quality diet, regular exercise, moderate alcohol consumption and no smoking significantly reduced the likelihood of developing type 2 diabetes – and that there was a dose-response relationship.
Researchers analysed almost three decades of data from the Nurses’ Health Study II, which included repeated measurements of weight and lifestyle factors.
They found that the number of optimal modifiable risk factors maintained was inversely related to the incidence of type 2 diabetes. Individuals with optimal levels of all these factors were significantly less likely to develop the condition compared with participants who did not meet these standards.
“Participants who had optimal levels of all five modifiable factors after the index pregnancy had a more than 90% lower risk for developing type 2 diabetes compared with those who did not have any,” the authors wrote.
“Importantly, the lower risk … was evident even among high-risk women who were overweight or obese or who had higher genetic susceptibility.”
While maintaining a healthy BMI was an important consideration, adopting the four additional modifiable factors resulted in a reduction in disease incidence by up to 60%, even when optimal weight control could not be achieved.
“A key message of the study was that for women with a history of gestational diabetes mellitus, incremental increase in the number of optimal modifiable risk factors was associated with a dose-dependent reduction of type 2 diabetes risk, even among those who were overweight or obese,” the authors wrote.