Abstract 143: Baseline Pre-Diabetes Boosts Future Stroke Risk

Abstract

Background: Recent national US estimates indicate that up to 35% of adults have pre-diabetes. Pre-diabetes is defined as impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT), and has been associated with modest increase of cardiovascular events. However, the role of pre-diabetes in conferring greater stroke risk is unsettled. Furthermore, it is not clear what impact recent lowering of the IFG threshold of pre-diabetes diagnosis (from 110 to 100 mg/dL) has had on this relationship. Objective: To conduct a systematic review and meta-analysis to - 1} investigate the magnitude and direction of the relation of pre-diabetes with stroke risk, 2} evaluate whether this relationship varies based on IFG threshold or inclusion of IGT criteria in the diagnosis. Methods: We searched PUBMED and EMBASE. We included studies that prospectively collected data within cohort studies or clinical trials, assessed stroke, had follow-up of at least one year, and reported estimates of the multivariate adjusted relative risk and 95% confidence interval for stroke associated with pre-diabetes. We combined data using the inverse variance approach. Results: The final primary analysis included 16 prospective cohort studies comprising 767,813 participants. In 9 publications with information about IFG (100 to 125 mg/dL), the summary estimate did not show increased risk of stroke (RR 1.08, 0.94 to 1.23, P=0.26) ( Fig 1). In 6 publications with information about IFG (110 to 125 mg/dl), the summary estimate showed increased risk of stroke (RR 1.21, 1.02 to 1.44, P=0.03). In 11 publications with information about IGT (140 to 199 mg/dL) or combination of IFG/IGT, the summary estimate showed increased risk of stroke (RR 1.24, 1.10 to 1.39, P=0.0003) ( fig 2). Conclusion: Baseline pre-diabetes, defined by fasting glucose 110-125 mg/dL or combination of IGT/IFG certainly raises future stroke risk. However, the current IFG definition (100-125 mg/dL) is not associated with increased stroke risk. Given the high prevalence of pre-diabetes, randomized trials to evaluate the efficacy of blood sugar lowering therapies in persons with this condition are warranted, but may need to focus on persons with IFG 110-125 mg/dL or a combination of IGT/IFG.