Association of body flexibility and carotid atherosclerosis in Japanese middle-aged men: a cross-sectional study

OBJECTIVE This study examined the associations of body flexibility with carotid arterial remodelling, including intima-media thickness (IMT) and plaque formation in middle-aged men. METHODS The subjects of this cross-sectional study included 1354 Japanese men aged 35-59 years without histories of stroke or cardiac diseases. The arm extensibility test, which can estimate flexibility of the upper extremity (composed of shoulder external rotation and forearm supination), and the sit-and-reach test were performed. Common carotid IMT and plaque formation (≥1.1 mm) were estimated by ultrasound. RESULTS The proportion of subjects who fully completed the arm extensibility test was 55.0%, and who had plaques in the common carotid artery was 37.8%. IMT was associated with poor arm extensibility (β=-0.073, 95% CI -0.02224 to -0.00041, P=0.004), while plaque formation was associated with poor sit-and-reach (OR 0.98579, 95% CI 0.97257 to 0.99919, P=0.038) after adjustment by all covariates. CONCLUSIONS This study demonstrated that poor upper extremity and trunk flexibility were associated with characteristics of early onset of atherosclerosis. Furthermore, these associations were independent of covariates such as age, blood pressure, blood lipids glucose levels and abdominal fat accumulation, handgrip strength and lifestyle, including sleeping, drinking, exercise and smoking habits. Poor flexibility may reflect subclinical atherosclerosis in middle-aged men.