Longitudinal changes in insulin sensitivity and beta cell function between women with and without a history of gestational diabetes mellitus

Abstract

Aims/hypothesis: The aim of the study was to compare longitudinal changes in insulin sensitivity (SI) and beta cell function between women with and without a history of gestational diabetes mellitus (GDM).

Methods: The prospective follow-up cohort included 235 parous non-diabetic Mexican-American women, 93 with and 142 without a history of GDM. The participants underwent dual-energy x-ray absorptiometry, OGTTs and IVGTTs at baseline and at a median of 4.1 years follow-up. The baseline values and rates of change of metabolic measures were compared between groups.

Results: At baseline, women with prior GDM (mean age 36.3 years) had similar values of SI but higher percentages of body fat and trunk fat (p ≤ 0.02), a lower acute insulin response and poorer beta cell compensation (disposition index [DI]) (p < 0.0001) than women without GDM (mean age 37.9 years). During the follow-up, women with GDM had a faster decline in SI (p = 0.02) and DI (p = 0.02) than their counterparts without GDM, with no significant differences in changes of weight or fat (p > 0.50). Adjustment for baseline age, adiposity, calorie intake, physical activity, age at first pregnancy, additional pregnancies and changes in adiposity during follow-up increased the between-group differences in the rates of change of SI and DI (p ≤ 0.003).

Conclusions/interpretation: Mexican-American women with recent GDM had a faster deterioration in insulin sensitivity and beta cell compensation than their parous counterparts without GDM. The differences were not explained by differences in adiposity, suggesting more deleterious effects of existing fat and/or reduced beta cell robustness in women with GDM.

Fig. 1

Changes in (a) S_I and (b) beta cell compensation (DI from the IVGTTs; DI=S_I×AIR) in women with (solid line) and without (dashed line) a history of GDM at baseline. Data are geometric means and 95% CI at baseline and at the median follow-up time for each group after adjustment for age, age at first pregnancy, baseline percentage body fat, total calorie intake and level of physical activity