Appetite Loss, Inflammation, and Incident Functional Loss Among Community-Dwelling Older Adults.

Abstract

Background: Aging is associated with both reduced appetite and increased inflammation. Whether and how these factors contribute to or exacerbate functional decline in older adults is unclear.

Methods: Data from 3073 men and women aged 70-79 years participating in the Health, Aging, and Body Composition (Health ABC) with reported appetite (good or poor) and inflammatory markers (Interleukin (IL)-6, tumor necrosis factor (TNF)-α and C-reactive protein (CRP)) at baseline were followed for up to 6 years to determine if they developed Persistent Lower Extremity Limitation (PLL), defined as two consecutive reports of difficulty walking a quarter mile and/or climbing 10 steps without resting 6 months apart, using Fine-Gray Proportional hazards models adjusted for demographics, chronic diseases, anxiety, depression, medications, and sensory factors.

Results: A total of 388 (12.6%) participants reported impaired appetite. These individuals were mainly female (59%), Black (54%), with a mean age of 73.9 (±3) years. Those with impaired appetite vs. good appetite were more likely to develop PLL (64% vs. 47%; p < 0.001) and had higher IL-6, TNF-α, and CRP levels (p < 0.001 for each). Cumulative incidence curves showed that 40% and 20% of those with impaired and good appetite, respectively, developed PLL by 18 months. Subjects with impaired appetite experienced a higher risk of developing PLL (hazard ratio, adjusted = 1.44; 95% CI = 1.2, 1.7), as did those with elevated inflammatory markers. Cumulative incidence curves indicated that individuals with impaired appetite and elevated CRP, IL-6, and TNF-α experienced the fastest onset of functional loss, reaching 50% at around 12 months, and nearly all had mobility limitations by 32 months.

Conclusion: Impaired appetite and increased inflammatory biomarkers are independently linked to mobility loss. Appetite impairment might signal early nutritional and supportive care needs, but inflammation-targeted interventions require further study.