Context:
Gestational diabetes mellitus (GDM) affects postpartum glucose metabolism and future risk of type 2 diabetes. Pregnancy and GDM are related to disturbed circadian rhythms and sleeping, which are determined by genetic variations in genes such as
Melatonin receptor 1B
(
MTNR1B
).
Objective:
We prospectively assessed whether the circadian rhythms related
MTNR1B
genotype was related to on 1-5 years of postpartum glycemic changes among women with a history of GDM, and whether gestational weight gain modified such associations.
Design:
The established circadian rhythms-associated
MTNR1B
genetic variant (rs10830963) was genotyped in 1025 Chinese women with a history of GDM. Body weight and glycemic traits during and after pregnancy were longitudinally collected.
Results:
The frequency of
MTNR1B
rs10830963 was not different among the three categories of gestational weight gain (inadequate, adequate, and excessive). We found women carrying different
MTNR1B
genotype showed distinct postpartum changes in 2-h glucose (OGTT) – 0.36, 0.20, and -0.19 mmol/L per additional copy of the G allele in women with inadequate, adequate, and excessive gestational weight gain, respectively (
p
for interaction=0.028). The corresponding changes in fasting glucose were 0.14, 0.13, and 0.01, though the modification effects of gestational weight gain on the genetic association was marginal (
p
for interaction= 0.067).
Conclusions:
Our findings suggest that gestational weight gain may modify the circadian rhythms related
MTNR1B
genetic variant on long term glycemic changes, highlighting the significance of gestational weight management in diabetes prevention among women with GDM.
Excessive gestational weight gain prior to glucose screening and the risk of gestational diabetes: a meta-analysis
