Pre-pregnancy overweight overtakes gestational diabetes as a risk factor for subsequent metabolic syndrome

Gestational diabetes mellitus (GDM) is associated with an increased risk of subsequent diabetes and metabolic syndrome (MS). The independent significance of overweight, often associated with GDM, is controversial. This study was aimed to investigate the prevalence of MS and carotid intima-media thickness (CIMT) values in normal and overweight women with previous insulin-treated GDM and control without GDM 19 years after the index pregnancy.

The study group consisted of 61 women with prior GDM and 55 controls who gave birth in Oulu University Hospital between 1988 and 1993. These women were further divided into subgroups according to pre-pregnancy BMI (<25 or ≥25 kg/m(2)). In 2008-2010, anthropometrics and blood pressure were measured, blood samples were taken, and an oral glucose tolerance test was performed to investigate the components of MS. CIMT was measured by Doppler ultrasound.

Total prevalence of MS was 62% in the GDM group and 31% in the control group (P=0.001); it was highest (86%) in GDM women with pre-pregnancy overweight. CIMT was significantly thicker (0.67 vs 0.56 mm, P=0.007) and more often abnormal (71.7 vs 45.3%, P=0.004) in the GDM group compared with the controls. In logistic regression analysis, the strongest factor predicting MS in the whole study population was pre-pregnancy overweight.

Pre-pregnancy overweight was the strongest predictive factor for later MS, whereas GDM indicated increased risk of subsequent diabetes and subclinical atherosclerosis. The risk of MS was highest when both of these factors were present.