Bone mineral density changes in gestational diabetic pregnancies-a longitudinal study using quantitative ultrasound measurements of the os calcis.

To compare the maternal bone mineral density (BMD) changes in gestational diabetic and non-diabetic pregnancies using quantitative ultrasound measurements of the os calcis, BMD measurements were performed at the os calcis in early pregnancy before 20 weeks and in the late third trimester after 36 weeks, using a Hologic Sahara Clinical Bone Sonometer system. Random glucose screening and direct oral glucose tolerance testing were used to diagnose gestational diabetes mellitus (GDM) according to World Health Organization criteria, which was then treated according to a standard protocol. In a cohort of 480 patients, there were 96 gestational diabetic patients (14 GDM and 82 with impaired glucose tolerance). The mean BMD loss was higher in diabetic patients compared with controls (0.038 vs. 0.025 g/cm2, p = 0.048). A regression model of all pregnancies showed that higher fat accumulation was related to lower BMD loss, but diabetic status was not in the equation. Within diabetic pregnancies, lower initial BMD values, higher fat accumulation and higher early-pregnancy body mass index were associated with lower BMD loss. While gestational diabetic women had higher BMD loss than non-diabetic women, this was apparently secondary to other anthropometric factors rather than due directly to the gestational diabetic state.