Low total cholesterol level is the independent predictor of poor outcomes in patients with acute ischemic stroke: a hospital-based prospective study

Wenjuan Zhao, Zhongping An, Yan Hong, Guanen Zhou, Jingjing Guo, Yongli Zhang, Yuanju Yang, Xianjia Ning, Jinghua Wang

Total cholesterol is a well-documented risk factor for coronary disease. Previous studies have shown that high total cholesterol level is associated with better stroke outcomes, but the association of low total cholesterol levels and ischemic stroke outcomes is rare. Therefore, we aimed to assess the association of low total cholesterol levels and stroke outcomes among acute ischemic stroke patients in China. This study recruited 6407 atherothrombotic infarction patients from Tianjin, China, between May 2005 and September 2014. All patients were categorized into five groups according to TC level quintiles at admission. Differences in subtypes, severity, risk factors, and outcomes at 3, 12, and 36 months after stroke were compared between these groups. In total, 1256 (19.6 %) patients had low cholesterol levels, with a higher prevalence in men than in women (23.7 % vs. 11.2 %, P < 0.001). Compared with higher cholesterol levels, the lowest cholesterol level quintile (TC, <4.07 mmol/L) was associated with older age (64.7 years, P = 0.033), anterior circulation infarct (22.8 %), atrial fibrillation (4.9 %), current smoking (41.1 %), and alcohol consumption (21.1 %) and lower frequencies of hypertension (72.9 %), diabetes (30.7 %), and obesity (9.9 %). Dependency and recurrence rates were significantly higher at 36 months in patients in the lowest TC level quintile than in those with higher cholesterol levels (dependency rates, 51.2 % vs 45.2 %; P = 0.007 and recurrence rates, 46.3 % vs 37.3 %, P = 0.001). Moreover, these differences remained after adjustment for age, sex, stroke severity, and Oxfordshire Community Stroke Project classification (odds ratios [ORs] for dependency rate, 1.41; 95 % confidence interval [CI], 1.11, 1.79; P = 0.005 and recurrence rate, 1.50; 95 % CI, 1.19, 1.89; P = 0.001). However, mortality rates after stroke were not significantly different between the groups. These findings suggest that statin treatment for patients with atherothrombotic infarction and low cholesterol levels increase long-term dependency and recurrence rates, but do not increase mortality rates. It is crucial to highlight the different impact of statin treatment on patients with atherothrombotic infarction and lower cholesterol levels for secondary stroke prevention in China.