Zhou Maigeng, Offer Alison, Yang Gonghuan, Smith Margaret, Hui Gei, Whitlock Gary, Collins Rory, Huang Zhengjing, Peto Richard, Chen Zhengming
Disease Surveillance Points Central Office, Chinese Center for Disease Control, Beijing, People's Republic of China.
Stroke. 2008 Mar;39(3):753-9. doi: 10.1161/STROKEAHA.107.495374. Epub 2008 Jan 31.
Despite previous investigations, substantial uncertainty remains about the relation between body mass index (BMI) and stroke, especially in populations with a relatively low BMI but a high stroke rate.
A nationally representative prospective study of mortality included 212,000 Chinese men 40 to 79 years old without known cardiovascular disease in 1990 to 1991 who were followed up for 10 years. Standardized hazard ratios were calculated for stroke mortality by baseline systolic blood pressure (SBP) and BMI.
Mean SBP and BMI were 124 mm Hg and 21.7 kg/m(2), respectively. During 10 years of follow-up, 5766 stroke deaths were recorded. There were strong, positive relations between BMI and SBP and between SBP and stroke mortality, with a 3-mm Hg higher baseline SBP associated with a 5.6% (95% CI, 5.3% to 6.0%; P<0.00001) higher stroke mortality. The association between BMI and stroke mortality was, however, not linear, with the hazard increasing substantially only for BMI >25 kg/m(2) (P<0.001 for nonlinearity). Approximately 90% of men had a baseline BMI <25 kg/m(2), and among them, BMI was not associated with stroke mortality despite its strong association with BP (which continued to a BMI <18 kg/m(2)). The relation with BMI was similar for ischemic and hemorrhagic stroke but appeared to be steeper among lifelong nonsmokers than among current smokers (P=0.01 for difference between slopes) despite similarly positive relations between BMI and SBP and between SBP and stroke risk in both smoking categories.
High BMI was strongly associated with increased stroke mortality only among men who were overweight or obese.
尽管此前已有相关研究，但体重指数（BMI）与中风之间的关系仍存在很大不确定性，尤其是在BMI相对较低但中风发生率较高的人群中。
一项具有全国代表性的死亡率前瞻性研究纳入了1990年至1991年期间212,000名年龄在40至79岁之间、无已知心血管疾病的中国男性，并对其进行了10年的随访。通过基线收缩压（SBP）和BMI计算中风死亡率的标准化风险比。
平均SBP和BMI分别为124 mmHg和21.7 kg/m²。在10年的随访期间，记录了5766例中风死亡病例。BMI与SBP之间以及SBP与中风死亡率之间存在强烈的正相关关系，基线SBP每升高3 mmHg，中风死亡率就会升高5.6%（95% CI，5.3%至6.0%；P<0.00001）。然而，BMI与中风死亡率之间的关联并非线性，仅在BMI>25 kg/m²时风险大幅增加（非线性P<0.001）。约90%的男性基线BMI<25 kg/m²，在这些男性中，BMI与中风死亡率无关，尽管它与血压有很强的关联（这种关联在BMI<18 kg/m²时依然存在）。缺血性和出血性中风与BMI的关系相似，但在终生不吸烟者中，这种关系似乎比当前吸烟者中更明显（斜率差异P=0.01），尽管在这两类吸烟者中，BMI与SBP之间以及SBP与中风风险之间的关系同样呈正相关。
仅在超重或肥胖男性中，高BMI与中风死亡率增加密切相关。
