Pulse wave velocity is decreased in an overweight Chinese elderly population

Objective The protective aspect of increased body weight, as inherent in the “obesity paradox”, may be related to the observation that subjects in the upper ranges of body weight and blood pressure often have levels of arterial elasticity that show normal or even lower pulse wave velocity compared to subjects of normal body weight. This study aimed to investigate this characteristic in an elderly Chinese population. Methods Elderly participants (N=414, age 77 ± 11 years, 211 males) were recruited from a Chinese community-dwelling elderly cohort. Subjects were divided into 3 groups according to Body Mass Index (BMI ≤25, normal; 25-28, overweight and ≥ 28, obese). Arterial stiffness was assessed by brachial ankle pulse wave velocity (baPWV) and the atherosclerosis status was evaluated with the ankle brachial index (ABI). Results Brachial systolic blood pressure (BSBP) was significantly higher as BMI increased (135±18.4, 138±18.3, 147±17.6mmHg; p = 0.003) adjusted for age, sex and heart rate. However, baPWV, was significantly lower as BMI increased (baPWV 1830±18, 1793±25, 1704±36cm/s; p = 0.008) in the three groups even with additional adjustment for BSBP. BMI showed a significant negative correlation with baPWV (r = -0.170, p = 0.001) after adjusting for confounding factors, including ABI. Using multiple linear regression, BMI was negatively and independently associated with baPWV (β = -0.190, P<0.001) especially for age less than 80 years. Conclusion Arterial stiffness, as measured by baPWV, is lower in overweight subjects in a Chinese elderly population compared to those with normal body weight. These findings suggest that reduced arterial stiffness in the overweight population, independent of confounding factors, may contribute to the explanation of the “obesity paradox”.