Prediabetes and risk of stroke and its subtypes by hypertension status.

Abstract

This study aimed to investigate whether the relationship of prediabetes with the risk of stroke and its subtypes differed among individuals with or without hypertension. This prospective study included 85,763 participants without diabetes or a history of stroke at the baseline from the Kailuan study (2006). Prediabetes was defined as a fasting plasma glucose concentration between 5.6 and 6.9mmol/L. We performed multiplicative and additive interaction analyses to assess the interaction effect between prediabetes and hypertension on the risk of incident stroke. We found that 47.13% of all participants had no prediabetes or hypertension, 11.45% had prediabetes alone, 30.12% had hypertension alone, and 11.31% had both prediabetes and hypertension at baseline. During a median follow-up period of 11.05years, we documented 3972 events of incident stroke. We found that hypertension modified the relationship of prediabetes with total stroke and ischaemic stroke (p for interaction <0.05). After adjustment for potential confounders, prediabetes was significantly associated with the risk of total stroke (hazard ratio [HR] 1.33, 95% confidence interval [CI] 1.18-1.52], p for interaction=0.0147) and ischaemic stroke (HR 1.33, [95% CI 1.16-1.54], p for interaction=0.0413) among participants without hypertension, but not among participants with hypertension. However, no interaction effect of the association between prediabetes and hypertension was observed on the risk of haemorrhagic stroke. Hypertension modified the association between prediabetes and risk of total and ischaemic stroke. Prediabetes was associated with an increased risk of total and ischaemic stroke only in the non-hypertension population.