The Role of Prestroke Glycemic Control on Severity and Outcome of Acute Ischemic Stroke

Background/Aim. Relatively few studies have investigated the association of prestroke glycemic control and clinical outcome in acute ischemic stroke (IS) patients, regardless of presence of diabetes mellitus (DM). The aim of this study was to investigate the importance of prestroke glycemic control on survival, stroke severity, and functional outcome of patients with acute IS. Methods. We performed a retrospective survival analysis of 501 patients with IS admitted to Sahlgrenska University Hospital from February 15, 2005, through May 31, 2009. The outcomes of interest were acute and long-term survival; the stroke severity (NIHSS) and the functional outcome, mRS, at 12 months. Results. HbA1c was a good predictor of acute (HR 1.45; CI, 1.09 to 1.93, ) and long-term mortality (HR 1.29; CI 1.03 to 1.62; ). Furthermore, HbA1c >6% was significantly correlated with acute stroke severity (OR 1.29; CI 1.01 to 1.67; ) and predicted worse functional outcome at 12 months (OR 2.68; CI 1.14 to 6.03; ). Conclusions. Our study suggests that poor glycemic control (baseline HbA1c) prior to IS is an independent risk factor for poor survival and a marker for increased stroke severity and unfavorable long-term functional outcome. 1. Introduction Hyperglycemia (HG) in relation to acute IS is common both in patients with and in patients without a diagnosis of DM, and it has been suggested to worsen survival. However, recent results from several clinical studies indicate that particularly patients with stroke and stress HG, but not diabetes, have increased mortality [1–3]. On the contrary, older data by Woo et al. [4] found that patients with acute IS and similar glucose concentrations had similar outcome regardless of whether they had diabetes or not. According to a review published by Capes et al. [5], acute HG predicted increased risk of in-hospital mortality after ischemic stroke (IS) in nondiabetic patients and increased risk of poor functional recovery in nondiabetic stroke survivors. The recent results of Nardi et al. [2] are also in line with this conclusion. In a study published in 2012, Hu et al. [1] evaluated the effects of HG and prestroke glycemic control, as measured by HbA1c, on all-cause and cardiovascular mortality among 1277 IS patients and found a significant association between initial glucose level and mortality in nondiabetic patients. Surprisingly, they also found that DM patients with HbA1c <7.0% had a higher incidence rate of all-cause and cardiovascular death than those with HbA1c ≥7%. Contradictory data have been published by Kamouchi et al. in 2011,