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

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.

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.

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.

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.