Obesity fuels blood glucose spikes in nondiabetic pregnant women

Obesity raises glycaemic level in pregnant women even if they have normal findings on a glucose tolerance test (OGTT), a recent study has found.

Researchers conducted an observational, longitudinal study including 10 pregnant women (median age 32 years) who were obese and 10 controls (median age 33.5 years) who were normal weight. Between gestational weeks 24 and 28, all participants were normoglycaemic according to an OGTT. All women were subjected to continuous glucose monitoring (CGM).

CGM data found that before breakfast, glucose levels in the obese group was significantly higher than that in controls (82.02±11.06 vs 77.77±10.55 mg/dL; p<0.01). The same was true 2 hours after breakfast (93.48±18.74 vs 87.31±13.13 mg/dL; p<0.001). No such between-group difference was reported for 1 hour after breakfast and for the rest of the day.

Nevertheless, overall daytime (93.08±18.30 vs 87.58±15.40 mg/dL; p<0.001) and night-time (84.73±16.31 vs 79.35±15.76 mg/dL; p<0.001) glucose levels were significantly raised in the obese group. Similarly, the areas under the curve for day, night, and 24-hour glucose levels were all significantly greater in obese pregnant women (p<0.001 for all).

Notably, mixed linear models showed that obesity had a significant and independent impact on night-time glucose levels (p<0 .001), but not on daytime (p=0.25) concentrations.

“[T]he present study demonstrated that continuously assessed blood glucose levels were higher in obese pregnant women without gestational diabetes mellitus than in nonobese pregnant women and this effect was more evident at night. Additional studies may lead to the better understanding of this metabolic alteration and its possible correlation with adverse neonatal outcomes,” the researchers said.