Gestational Diabetes May “Unmask” Pre-existing CVD Risk

Cardiovascular health (CVH) prior to pregnancy appeared to be associated with an increased risk for gestational diabetes (GD) and cardiovascular disease (CVD) later in life, according to a study published recently in JAMA Cardiology.

In addition, the study found that “GD mediated a very small proportion of the association between prepregnancy CVH and coronary artery calcium [CAC] outcomes.”

According to the researchers, “these results emphasize the importance of prepregnancy CVH as a target to prevent both GD and subclinical CVD and suggest that GD is largely a marker of poor underlying CVH that is unmasked during pregnancy.”

This prospective study was nested within a larger CARDIA study, which researchers conducted at four US centers among women with at least one singleton birth. Included patients had no prepregnancy diabetes, available prepregnancy CVH data, and available CAC data from a 15- to 25-year follow-up.

The study included 1,052 women, 47.6% of whom self-identified as Black. Participants with low or moderate prepregnancy CVH were more likely to self-identify as Black, have less education, and have a history of previous live birth.

GD was diagnosed in 7.5% of study participants, with higher rates in those with low or moderate prepregnancy CVH compared with high CVH (8.8% vs. 6.3%). Participants with GD were also more likely to have any CAC (25.3% vs. 15.1%) and had shorter time to CAC (11.7 vs. 13.8 years) compared with those without GD.

The researchers found that GD mediated 6% of the association between prepregnancy CVH and incident CAC. GD did not mediate the association between prepregnancy CVH and time to CAC.

“This study demonstrated a strong direct effect representing a 1.7-fold higher incidence of CAC and 15% relative reduction in time to CAC among those with low or moderate CVH compared with high CVH, regardless of GD status,” the researchers wrote. “These findings suggest that GD may largely unmask preexisting CVD risk.”