The purpose of this study was to investigate the risks of
stroke in subjects with metabolically abnormal normal weight (MANW) in China. We recruited 102,037 participants from the Zhejiang
Metabolic Syndrome Cohort and the Kailuan cohort. The mean years of follow-up were 9.9 years. General
obesity was defined by body mass index (BMI) ≥ 28,
overweight by BMI < 28 and ≥ 24, and normal weight by BMI < 24 and ≥ 18.5. Metabolic abnormality was defined as two or more abnormal components (elevated
triglycerides, low
high-density lipoprotein cholesterol, elevated systolic blood pressure or diastolic blood pressure, or use of
antihypertensive drug therapy, elevated fasting plasma
glucose, or
antidiabetic treatment). A multiple Cox regression model was used to calculate hazard ratio (HR) and its 95% confidence interval (CI), adjusted by potential confounding factors. Overall HR of the risks in two cohorts was calculated by a meta-analysis. Compared with the subjects who were metabolically normal with normal weight (MNNW), the pooled HR for
stroke in MANW subjects was 1.82 (95% CI, 1.59-2.07). The risks of
stroke in MANW subjects were significantly lower than that in subjects with metabolically abnormal
obesity (
MAO), but higher than that in those with metabolically normal
obesity (MNO) (P < 0.05). These associations remained in the subtypes of
cerebral infarction and
cerebral hemorrhage. In normal-weight subjects, the HR for
stroke was significantly positively correlated with the number of abnormal metabolic components (Ptrend < 0.001). In brief, metabolic abnormality increased the risk of
stroke irrespective of
obesity status. MANW individuals showed a greater risk of
stroke, and this risk was positively correlated with the number of abnormal metabolic components.