Relationship between body mass index and arterial stiffness in a health assessment Chinese population.

Pulse wave velocity (PWV) is a reliable measurement of arterial stiffness. Our study assesses the association between body mass index (BMI) and brachial-ankle PWV (baPWV) in a healthy cohort and seeks to explain possible mechanisms associated with the obesity paradox. A cross-sectional study was conducted in 578 normal individuals. The mean age was 48.3 +/- 14.6 years, and 468 (81.0%) were men. 288 subjects (49.8%) were overweight and obese. baPWV and ankle-brachial index (ABI) were performed to evaluate arterial stiffness and atherosclerosis respectively. Normal weight was defined as 18.5 < BMI <25 kg/m(2), overweight as 25 <= BMI < 28 kg/m(2) and obesity as BMI >= 28 kg/m(2). The overweight/obese subjects had significantly higher baPWV than the normal-weight group (1490.0 +/- 308.0/1445.2 +/- 245.2 cm/s vs 1371.2 +/- 306.4 cm/s, P < .001). For the whole cohort, baPWV showed a significant positive correlation with BMI (r = 0.205, P < .001). However, baPWV was significantly lower as BMI increased: 1490.0 +/- 308.0 cm/s (overweight); 1445.2 +/- 245.2 cm/s (obese); P < .001) when adjusted for age, gender, heart rate, mean blood pressure, and cardiovascular risk factors (glucose, cholesterol, triglyceride, and low-density lipoprotein). For the whole cohort BMI was negatively associated with baPWV (beta = -0.06, P = .042). ABI showed no relationship with BMI. In a middle-age healthy Chinese population, arterial stiffness measured as baPWV increased with BMI. Evidence of reduced arterial stiffness with increasing BMI when accounting for all other cardiovascular risk factors may contribute to underlying factors involved in the obesity paradox that becomes more prominent with increasing age.