The risk of metabolic syndrome after gestational diabetes mellitus - a hospital-based cohort study

Abstract

Background: Women with gestational diabetes mellitus (GDM) are at an increased risk of developing metabolic syndrome (MetS) after delivery. Recently, the prevalence of both GDM and MetS has increased worldwide, in parallel with obesity. We investigated whether the presentation of MetS and its clinical features among women with previous GDM differs from that among those with normal glucose tolerance during pregnancy, and whether excess body weight affects the results.

Methods: This hospital-based study of two cohorts was performed in Kanta-Häme Central Hospital, Finland. 120 women with a history of GDM and 120 women with a history of normal glucose metabolism during pregnancy, all aged between 25 and 46 were enrolled. They all underwent physical examination and had baseline blood samples taken. All 240 women were also included in subgroup analyses to study the effect of excess body weight on the results.

Results: Although the groups did not differ in body mass index (BMI; p = 0.069), the risk of developing MetS after pregnancy complicated by GDM was significantly higher than after normal pregnancy, 19 vs. 8 cases (p = 0.039). Fasting glucose (p < 0.001) and triglyceride levels (p < 0.001) were significantly higher in women affected. In subgroup analysis, cardiovascular risk factors were more common in participants with high BMI than in those with previous gestational diabetes.

Conclusions: The risk of MetS was 2.4-fold higher after GDM than after normal pregnancy. Cardiovascular risk factors were more common in participants with high BMI than in those with previous GDM. Multivariate analysis supported the main findings. Weight control is important in preventing MetS after delivery.

Keywords: Body mass index; Body weight excess; Cardiovascular risk factors; Gestational diabetes mellitus; Metabolic syndrome.

Figure 1

Pack-years of smoking in the GDM and control groups. Pack-years of smoking differed significantly (p = 0.012) between women with a previous history of GDM vs. women unaffected. The median in both groups was zero, because the majority were non-smokers. The mean (±SD) number of pack-years in the GDM group was 3.1 (±6.1) and in the control group, 1.6 (±4.4).

Figure 2

Lifetime weight loss, fasting glucose and alanine transaminase in the subgroups. A: Median (minimum, maximum) lifetime weight loss among obese (BMI ≥ 27) GDM women was 20 (0, 116) kg, among obese control women 20 (0, 100) kg, among non-obese GDM women 8 (0, 100) kg and among non-obese control women 0 (0, 70) kg. B: Median (minimum, maximum) fasting glucose levels among obese GDM women 5.6 (4.6, 7.9) mmol/L, among obese control women 5.2 (4.4, 6.2) mmol/L, among non-obese GDM women 5.4 (4.6, 9.8) mmol/L and among non-obese control women 5.2 (4.5, 6.1) mmol/L. C: Median (minimum, maximum) alanine transaminase levels among obese GDM women 21 (10, 122) U/L, among obese control women 17 (9, 53) U/L, among non-obese GDM women 16 (9, 48) U/L and among non-obese control women 16 (9, 82).

Figure 3

HDL cholesterol, LDL cholesterol and triglyceride levels in the subgroups. A: The median (minimum, maximum) HDL cholesterol level among obese (BMI ≥ 27) GDM women was 1.4 (0.8, 2.7) mmol/L, among obese control women 1.4 (1.0, 2.4) mmol/L, among non-obese GDM women 1.5 (0.8, 2.3) mmol/L and among non-obese control women 1.5 (1.1, 2.7) mmol/L. B: The median (minimum, maximum) LDL cholesterol level among obese GDM women was 3.1 (2.0, 5.3) mmol/L, among obese control women 3.0 (1.7, 4.8) mmol/L, among non-obese GDM women 2.6 (1.6, 4.2) mmol/L and among non-obese control women 2.7 (1.6, 3.8) mmol/L. C: The median (minimum, maximum) triglyceride level among obese GDM women was 1.2 (0.4, 4.4) mmol/L, among obese control women 0.9 (0.5, 2.0) mmol/L, among non-obese GDM women 0.8 (0.4, 3.5) mmol/L and among non-obese control women 0.6 (0.4, 1.8) mmol/L.