The Association Between Adiposity and Perceived Physical Fatigability in Mid-to-Late Life

OBJECTIVE: Compare and contrast the associations between measures of adiposity and fat distribution and perceived fatigability among well-functioning individuals in mid-to-late life. METHODS: In 1,054 adults (70.4 years ±12.4, 52% female), adiposity was measured as: Body Mass Index (BMI), percent fat (DEXA), waist and hip circumferences, and waist-to-height ratio. In a subset of 383 visceral fat (CT) was measured. Perceived fatigability was evaluated after a 5-min, treadmill walk (1.5 mph) using the Borg rating of perceived exertion (RPE, ranging 6–20). Associations between adiposity measures and perceived fatigability were assessed using regression models adjusting for age, sex, race, smoking, and comorbidities. RESULTS: All adiposity measures, except subcutaneous fat, were positively associated with perceived fatigability after adjustment (p<0.05 for all). Standardized coefficients indicate that BMI, hip circumference, and visceral fat have the strongest associations with fatigability. Associations between BMI and fatigability were present only among those above the threshold for overweight, and strongest in those aged ≥65. Moreover, BMI was only associated with fatigability among participants with higher waist circumference. CONCLUSIONS: Measures of adiposity – particularly central adiposity- are strongly associated with fatigability, suggesting that weight management may be an effective target for curbing fatigability and maintaining quality of life with aging.