Poster Presentation Australian Diabetes Society and the Australian Diabetes Educators Association Annual Scientific Meeting 2017

POSTER DISCUSSION: Relationship between glycated haemoglobin (HbA1c) and acute stroke risk: a systematic review and meta-analysis (#300)

John P. Mitsios 1 2 3 , Elif I. Ekinci 1 2 , Gregory P. Mitsios 1 , Leonid Churilov 1 3 , Vincent Thijs 1 2 4
  1. (The) University of Melbourne, Melbourne
  2. Austin Health, Melbourne
  3. The Florey Institute of Neuroscience & Mental Health, Melbourne
  4. Stroke Division, The Florey Institute of Neuroscience & Mental Health, Melbourne

INTRODUCTION:

Diabetes Mellitus is a major risk factor for ischaemic stroke. Rising HbA1c levels are strongly associated with the development of microvascular diabetes complications. We investigated the relationship between rising HbA1c levels and stroke risk, a macrovascular complication.

 

METHODS:

We conducted a systematic review with meta-analysis of observational cohort and nested case-control cohort studies assessing the association between rising HbA1c levels and stroke risk (including ischaemic stroke risk) in adults (≥18yo) with and without type 1 or type 2 diabetes. Random-effects model meta-analyses were used to generate covariate-adjusted hazard ratios (HR) for outcomes assessed.

 

RESULTS:

We identified 36 articles fulfilling our entry criteria of which 29 articles, involving a total of 532 779 participants, were used in meta-analyses and sensitivity analyses. Compared to non-diabetes range HbA1c (<5.7%), American Diabetes Association pre-diabetes range HbA1c (5.7%-6.5%) increased risk of first-ever stroke with a HR (95% CI) of 1.19 (0.87,1.62) and diabetes range HbA1c (≥6.5%) increased risk of first-ever stroke with a HR (95% CI) of 2.15 (1.76,2.63).

For every 1% HbA1c increment (or equivalent), the HR (95% CI) for first-ever stroke risk was 1.12 (0.91,1.39) in non-diabetes cohorts and 1.17 (1.09,1.25) in diabetes cohorts. When limited to studies only examining first-ever ischaemic stroke, HR (95% CI) were 1.49 (1.32,1.69) and 1.24 (1.11,1.39) for non-diabetes and diabetes cohorts respectively.

 

CONCLUSIONS:

The current meta-analytical results suggest that rising HbA1c levels, even in the pre-diabetes range, are associated with higher first-ever ischaemic stroke risk in populations with and without diabetes. This relationship appears to be restricted to diabetes populations when other subtypes of stroke (ischaemic, haemorrhagic and undifferentiated) are included in outcome measurement. These results present a novel quantifiable risk relationship between first-ever stroke and HbA1c which may assist primary prevention of stroke through improved risk stratification.