Background: Data of studies focusing on the trends of adiposity indices among women with prior gestational diabetes mellitus (GDM), are limited and controversial. The aim of this study was to compare overtime trends of adiposity indices in women with and without history of GDM, using data of the long term longitudinal population-based Tehran-Lipid and Glucose-Study (TLGS).
Methods: A total of 3395 eligible women aged (20-50 years), including 801 women with prior history of GDM and 2594 non-GDM controls were recruited from among Tehran-Lipid and Glucose-Study participants. Generalized estimating equations were applied to assess the time trend of adiposity indices including obesity, central obesity, body mass index (BMI), lipid accumulation product index (LAP), visceral adiposity index (VAI) and a body shape index (ABSI) in women with prior GDM and the non-GDM groups after further adjustment for age and BMI.
Results: Median follow-up years for the GDM and non-GDM groups were 12.12 and 11.62 years, respectively. Women with GDM at initiation had worse adiposity indices than their healthy counterparts. While overall odds of obesity in women with prior GDM were significantly higher those of the non-GDM groups (OR: 1.35; 95% CI, 1.03-1.7; P = 0.03), both these groups overtime revealed a positive trend in obesity (P trend < 0.001), an incremental trend which was less pronounced in GDM women (OR: 0.87; 95% CI, 0.80, 0.95; P interaction = 0.001). Women with prior GDM had higher odds of central obesity, compared to non-GDM groups (OR: 1.44; 95% CI, 1.06-1.96; P = 0.02) and showed a significant an incremental trend overtime for both groups (P trend < 0.001 for both) without statistically significant interaction in terms of their GDM status (P interaction = 0.134). Mean VAI in women with prior GDM was significantly higher than the non-GDM group (19.7, 95%CI: 6.24, 33.15, P = 0.004), although both groups overtime experienced a negative trend (- 10.9, 95%CI: -13.1, - 2.1, P < 0.001); the GDM group showed a higher decrease in VAI (mean changes: -6.62; 95% CI, - 11,-2.1; P interaction = 0.001). However overtime there was a positive trend in LAP and ABSI among both women with and without prior-GDM, though the mean changes were less obvious in women with prior GDM.
Conclusion: Women with prior GDM gained better control of their adiposity than non-GDM women. Nevertheless the increasing numbers of individuals with GDM and uncontrolled adiposity indices, require prompt attention be paid to the issue.
Keywords: Adiposity indices; Gestational diabetes; Obesity; Tehran lipid and glucose study (TLGS); Trend.