Kaufman J S, Asuzu M C, Mufunda J, Forrester T, Wilks R, Luke A, Long A E, Cooper R S
Department of Preventive Medicine and Epidemiology, Loyola University Stritch School of Medicine, Maywood, Ill, USA.
Hypertension. 1997 Dec;30(6):1511-6. doi: 10.1161/01.hyp.30.6.1511.
Associations between body mass index (BMI) and blood pressure (BP) have been consistently observed, but remain poorly understood. One unresolved question is whether there is a linear relationship across the entire BMI range. We investigated this question among 11,235 adult men and women from seven low-BMI populations in Africa and the Caribbean. We used kernel smoothing and multivariate linear and spline regression modeling to examine gender differences in the relationship and to test for a threshold. Age-adjusted slopes of BP on BMI were uniformly higher in men than women, with pooled slope ratios of 2.00 and 2.20 for systolic and diastolic BPs, respectively. Men displayed no evidence of age modification or nonlinearity in the relationship, and the age-adjusted slope of systolic BP on BMI was 0.90 (95% confidence interval [CI], 0.76 to 1.04). Women demonstrated both age modification and nonlinearity. For both younger (<45 years) and older (45+ years) women, the optimal change point for a single threshold model was found to be 21 kg/m2. Slopes of systolic BP on BMI above this threshold were positive and significant: 0.68 (95% CI, 0.54 to 0.81) and 0.53 (95% CI, 0.29 to 0.76) for younger and older women, respectively. Slopes below the threshold were essentially zero for both groups of women, and the difference between the slopes above and below the threshold was significant for younger women (P=.019). In summary, we observed a threshold at 21 kg/m2 in the relationship between BMI and BP for women but not for men. This contributes to the effort to identify the mechanisms that underlie this relationship and how they differ by gender.
体重指数（BMI）与血压（BP）之间的关联一直存在，但人们对此仍知之甚少。一个尚未解决的问题是，在整个BMI范围内是否存在线性关系。我们在来自非洲和加勒比地区七个低BMI人群的11235名成年男性和女性中研究了这个问题。我们使用核平滑以及多元线性和样条回归模型来研究这种关系中的性别差异，并检验是否存在阈值。BMI对血压的年龄调整斜率在男性中普遍高于女性，收缩压和舒张压的合并斜率比分别为2.00和2.20。男性在这种关系中没有年龄修正或非线性的迹象，收缩压对BMI的年龄调整斜率为0.90（95%置信区间[CI]，0.76至1.04）。女性则表现出年龄修正和非线性。对于年轻（<45岁）和年长（45岁及以上）女性，单阈值模型的最佳变化点均为21kg/m²。高于此阈值时，BMI对收缩压的斜率为正且显著：年轻女性为0.68（95%CI，0.54至0.81），年长女性为0.53（95%CI，0.29至0.76）。两组女性低于阈值时的斜率基本为零，年轻女性高于和低于阈值的斜率差异显著（P = 0.019）。总之，我们观察到BMI与血压之间的关系在女性中有一个21kg/m²的阈值，而在男性中则没有。这有助于我们努力确定这种关系背后的机制以及它们在性别上的差异。
