Glucose tolerance in pregnancy and the long-term risk of cardiovascular disease

BackgroundStudies demonstrate an association between high but non-diabetic blood glucose levels and cardiovascular morbidity and mortality. Pregnancy alters glucose metabolism and results in a continuum of glucose tolerance, it is not known whether this continuum is associated with a continuum of risk of CVD in later life.ObjectivesTo examine the long-term risk of CVD associated with the continuum of maternal glucose tolerance.ParticipantsNine hundred and seventeen participants assessed during pregnancy and followed over 20 years.MeasurementsSmoking behaviour, BMI at index pregnancy and follow-up, and gestational HbA1c.Main OutcomeRequiring medication for hypertension and CVD, and hospital admissions for CVD as ascertained by record linkage over 20-year period.ResultsFifty-one women had a history of CVD, 85 women had hypertension and 17 women (2.3%) were admitted for CVD. There was a significant increase in the risk for CVD, hypertension and hospitalisation for CVD across the quartiles of gestational HbA1c after adjustment for known risk factors. This increased risk reached statistical significance in the highest quartile although confidence intervals were wide.ConclusionSub-clinical HbA1c during pregnancy was associated with a dose-related increase in the presence of medication and hospital admission for CVD. The magnitude of these effects is of note.