High-Density Lipoprotein Cholesterol and Objective Measures of Lower Extremity Performance in Older Nondisabled Persons: The InChianti Study: HDL-C, MUSCLE STRENGTH, AND PHYSICAL IMPAIRMENT

OBJECTIVES: To evaluate the independent association between high-density lipoprotein cholesterol (HDL-C) levels and objective measures of lower extremity performance. DESIGN: Cross-sectional cohort study. SETTING: Community-based. PARTICIPANTS: Eight hundred thirty-six nondisabled women and men aged 65 and older enrolled in the Invecchiare in Chianti study. MESASUREMENTS: Lower extremity performance was assessed using 4-m walking speed at fast pace, 400-m walking speed, and knee extension torque. Fasting HDL-C levels were determined using commercial enzymatic tests. RESULTS: The mean age of participants was 73.7 (65-92), and 55.6% were women. After adjusting for potential confounders (sociodemographic factors, smoking, physical activity, body composition, and clinical conditions including cardiovascular and cerebrovascular disease, inflammatory markers, and serum testosterone) HDL-C levels were significantly associated with knee extension torque in men and women and with 4-m and 400-m walking speed in men. Men in the highest tertile of the HDL-C distribution (> 55 mg/dL) had, on average, a three times greater probability of belonging to the best tertile of all indexes of lower extremity performance, including 4-m fast walking speed (odds ratio (OR)=2.57, 95%=confidence interval (CI)=1.07-6.17), 400-m walking speed (OR=3.74, 95% CI=1.20-11.7), and knee extension torque (OR=3.63, 95%=CI 1.41-9.33). Path analysis suggested a direct relationship between HDL-C and knee extension torque. In older nondisabled persons, HDL-C levels are highly correlated with knee extension torque and walking speed. Further research should focus on the biological mechanism of this association.