Sex differences in outcomes after stroke among patients with low total cholesterol levels: a large hospital-based prospective study

Background: Previous studies have shown that total cholesterol (TC) levels are associated with stroke outcomes, but sex differences in the association between TC levels, especially a low TC level, and ischemic stroke outcomes are unknown. We aimed to assess the sex differences in stroke outcomes among patients with atherothrombotic infarctions and low TC levels in China. Methods: This study recruited patients with atherothrombotic infarctions from Tianjin, China, between May 2005 and September 2014. Patients with low TC levels (defined as TC <4.22 mmol/L) were analyzed in this study. Sex differences in stroke subtypes, severity, risk factors, and outcomes at 3 and 12 months after stroke were compared. Results: Overall, 1587 patients with low TC levels were recruited to this study from among 6407 patients with atherothrombotic infarctions listed in a stroke registry. Women were more likely than men to have posterior circulation infarcts, severe stroke, hypertension, and obesity but less likely to be current smokers or to consume alcohol. There were no sex differences in stroke outcomes. Older age and severe stroke were common risk factors for poor outcomes after stroke in this study. The presence of diabetes mellitus was an independent predictor of low mortality at 12 months after stroke, possibly because a drug commonly used to treat diabetes, metformin, enhances angiogenesis. Obesity was the determinant of the recurrence and dependency rates at 12 months after stroke. Conclusions: These findings suggest that patients (both men and women) with atherothrombotic infarction who have low TC levels would not benefit from receiving statin treatment. Therefore, it is crucial to explore the impact of statin treatment on outcomes in Asian patients, especially Chinese patients with atherothrombotic and low TC levels, in order to improve outcomes after stroke and reduce the disease burden.