Aims: Our aim was to evaluate the uptake of postpartum screening, the prevalence and the risk factors for glucose intolerance in women with a recent history of gestational diabetes mellitus (GDM). Methods: All women with a history of GDM are advised to undergo a 75g oral glucose tolerance test (OGTT) around 6 - 12 weeks postpartum. Indices of insulin sensitivity (the Matsuda index and the reciprocal of the homeostasis model assessment of insulin resistance, HOMA-IR) and an index of beta-cell function, the Insulin Secretion-Sensitivity Index-2 (ISSI-2) were calculated based on the OGTT postpartum. Multivariable logistic regression was used to some factors. Results: Of all women (135) who received an OGTT postpartum, 42.2% (57) had glucose intolerance (11.8% impaired fasting glucose, 24.4% impaired glucose tolerance and 6.0% both impaired fasting and impaired glucose tolerance) and 1.5% (2) had overt diabetes. Compared to women with a normal OGTT postpartum, women with glucose intolerance and diabetes were older (32.5 ± 4.3 vs. 30.8 ± 4.8 years, p = 0.049), were more often obese (34.5% vs. 17.3%, p = 0.023). In the multivariable logistic regression, an EM background [OR = 2.76 (1.15 - 6.62), p = 0.023] and the HbA1c level at the time of the OGTT in pregnancy [OR = 4.78 (1.19 - 19.20), p = 0.028] remained significant predictors for glucose intolerance postpartum. Women with glucose intolerance and diabetes postpartum had a similar insulin sensitivity [Matsuda index 0.656 (0.386 - 1.224) vs. 0.778 (0.532 - 1.067), p = 0.709; HOMA-IR 0.004 (0.002 - 0.009) vs. 0.064 (0.003 - 0.007), p = 0.384] but a lower beta-cell function compared to women with a normal OGTT postpartum, remaining significant after adjustment for confounders [ISSI-2 1.6 (1.2 - 2.1) vs. 1.9 (1.7 - 2.4), p = 0.002]. Conclusions: Glucose intolerance is very frequent in early postpartum in women with GDM these women have an impaired beta-cell function. Nearly one third of women did not attend the scheduled OGTT postpartum and these women have an adverse risk profile. More efforts are needed to engage and stimulate women with GDM to attend the postpartum OGTT.
Impaired fasting glycaemia vs impaired glucose tolerance: similar impairment of pancreatic alpha and beta cell function but differential roles of incretin hormones and insulin action
