Sex-specific muscle and metabolic biomarkers associated with gait speed and cognitive transitions in older adults: a 9-year follow-up.

Physical frailty and cognitive frailty share biological mechanisms, but sex-specific biomarkers associated with transitions in gait speed and cognition during ageing are poorly understood.Gait speed, cognition (3MSE), body composition (DXA) and serological biomarkers were assessed annually over 9 years in 216 males (72.7 + 8.07 years) and 384 females (71.1 + 8.44 years). In females, maintaining normal gait speed was associated with lower percent body fat (IRR 0.793, p = 0.001, 95%CI 0.691-0.910) and lower lactate dehydrogenase (LDH) (IRR 0.623, p = 0.00, 95%CI 0.514-0.752), and in males, the association was with higher cholesterol (IRR 1.394, p = 0.001, 95%CI 1.154-1.684). Abnormal to normal gait speed transitions were associated with higher insulin in females (IRR 1.325, p = 0.022, 95%CI 1.041-1.685) and lower creatinine in males (IRR 0.520, p = 0.01, 95%CI 0.310-0.870). Normal to slow gait speed transitions in males were associated with IGF-1 (IRR 1.74, p = 0.022, 95%CI 1.08-2.79) and leptin in females (IRR 1.39, p = 0.043, 95%CI 1.01-1.91.) Maintaining normal cognition was associated with lower LDH in females (IRR 0.276, p = 0.013, 95%CI 0.099-0.765) and higher appendicular skeletal muscle mass in males (IRR 1.52, p = 0.02, 95%CI 1.076-2.135). Improved cognition was associated with higher leptin (IRR 7.5, p = 0.03, 95%CI 1.282-44.34) and lower triglyceride (IRR 0.299, p = 0.017, 95%CI 0.110-0.809) in males. Education was protective against cognitive decline in females (IRR 0.84, p = 0.037, 0.732-0.982). Sex-specific biomarkers of muscle (LDH, Creatinine, IGF-1, APSM) and metabolism (%fat, insulin,cholesterol, leptin, tryglycerides) were associated with gait speed and cognitive transitions. These data suggest that modifiable biomarkers of muscle and metabolism could be targeted for interventions.

Relationship of Incident Falls with Balance Deficits and Body Composition in Male and Female Community-Dwelling Elders.

OBJECTIVE: Sarcopenia and obesity are reported risk factors for falls, although the data are not consistent and most studies do not make sex comparisons. We investigated whether falls were associated with balance, gait, and body composition, and whether these relationships are sex-specific. DESIGN: Secondary analysis of 4-year follow-up data from of the New Mexico Aging Process Study. SETTING: Albuquerque, New Mexico. PARTICIPANTS: 307 participants (M, n=122, 75.8 yr. SD5.5; F, n=183, 74.6yr SD6.1). MEASUREMENTS: Gait and balance were assessed annually using the Tinetti test. Lean body mass (LBM), appendicular skeletal muscle mass (ASM), fat free mass (FFM), total fat mass (FM) were assessed annually by DXA. Falls were assessed using bimonthly falls calendars. Hazard ratios (HR) for 2-point worsening in gait and balance score and falls were calculated by Cox proportional hazard for men and women. RESULTS: Baseline balance deficits, and not body composition, represented the strongest predictor of falls. For the total balance score, the variables with significant sex interactions were ASM (Male-HR 1.02 95%CI 0.60-1.73; Female-HR 1.92 95%CI 1.05-3.52, p=0.03) and FFM (Male-HR 1.04 95%CI 0.64-1.70; Female-HR 1.91 95%CI 1.12-3.24, p=0.04), after adjustment for age, sarcopenia and physical activity. The body composition relationship with balance deficits was U-shaped with the strongest predictors being low LBM in males and high FM in females. CONCLUSIONS: Specific body composition components and balance deficits are risk factors for falls following sex-specific patterns. Sex differences need to be explored and considered in interventions for worsening balance and falls prevention.