DISSIMILARITIES IN TRAJECTORIES OF PHYSICAL FUNCTION DECLINE IN OLDER ADULTS BY SEX

Purpose: Aging is associated with decline of physical function with heterogeneous rates of decline across individuals. We aimed at identifying risk factors for accelerated decline of lower extremity performance over 9-year follow up in participants of the InCHIANTI study aged 65–75 years, with a Short Physical Performance Battery (SPPB) score >9 and non-disabled at baseline evaluation. Methods: Time trajectories of SPPB were characterized by Latent Class Growth Curve, separately in men and women and categorized as fast and slow linear decline. Predictors of SPPB decline were identified by logistic regression among demographic, physiological and biomarker variables. Fit of the model prediction was explored by ROC curve. Results: 507 participants (246M, 261F both 70 ± 3.0ys of age) were included. Average baseline SPPB was 11.7 ± 0.6 for men and 11.2 ± 1.0 for women. Significant predictors of SPPB decline for males were none and low physical activity (OR=9.4 and OR=4.1), number of diseases (OR=1.4), hip flexion strength (OR=0.9) and total cholesterol (OR=0.98). Main predictors for women were different and included: age (OR=1.5), vitamin D 5µg/mL (OR=2.9) and hip flexion strength (OR=0.8). AUC values derived from ROC analyses were 81.9% for males and 85.6% for females. Conclusion: Risk factors for differential rates of decline of physical function with age include both functional variables and blood biomarkers but are different between men and women. Of particular interest, C-reactive protein is a risk factor only in women confirming previous reports.