LISBON – Women with a history of gestational diabetes had an overall 50% higher risk for cardiovascular events later in life, and the risk was doubled among overweight women, based on the results of a large, population-based, case-control study in Sweden.
Gestational diabetes is associated with increased risk for type 2 diabetes later in life. The relationship between gestational diabetes mellitus (GDM) and cardiovascular disease has been less well studied.
Also, this appears to be the first analysis to adjust for possible confounders. The increased risk for cardiovascular disease among women with previous GDM was significant among women with body mass indexes (BMIs) of at least 25 kg/m
Moreover, hypertension and smoking during pregnancy were stronger risk factors for later cardiovascular disease than was GDM. “Preventive strategies after pregnancy might need to be individualized depending on each woman's characteristics and risk profile,” said Dr. Erik Schwarcz, an endocrinologist and senior physician at University Hospital Orebro, Sweden.
Cases in the study, which used data from Swedish National Healthcare Quality registers from 1991 through 2008, were 4,590 women who died of cardiovascular disease or had a first cardiovascular event – ischemic heart disease, ischemic stroke, peripheral arterial disease, or atherosclerosis – and who gave birth to at least one child during the study period. Each of those women was matched with about five age-matched controls – total 22,398 – who did not have cardiovascular disease and who gave birth during the same year.
At the time of the cardiovascular event, the cases' mean age was 41 years (range 19-61), with a mean of 9 years between the pregnancy and the event. There were 130 deaths among the 2,660 cases, compared with 2 in the 13,357 controls. Ischemic heart disease and stroke were the most common diagnoses, affecting 56% and 35%, respectively.
A history of GDM was present for 2.4% of the cases, compared with 1.2% of the controls, a significant difference. Also significantly increased among the cases were chronic hypertension (2.1% vs. 0.3%), smoking (35.3% vs. 18.1%), non-Nordic ethnicity (14.1% vs. 11.5%), mean BMI (25.4 vs. 23.9 kg/m
After adjustment for hypertension, smoking, BMI, parity, education level, and ethnicity, all of the risk factors remained significant except for non-Nordic ethnicity, with odds ratios of 1.50 for GDM, 5.15 for chronic hypertension, and 2.24 for smoking. Using a BMI of 20-25 as the referent, a BMI of 25-29 gave an odds ratio of 1.32, while a BMI of 30 or greater doubled the risk (OR, 2.00).
Dr. Schwarcz disclosed that he has received lecture fees and has conducted clinical trials for Sanofi-Aventis, Novo-Nordisk, and AstraZeneca.