Relationship Between Appetite-Related Peptides and Frailty in Older Adults

Frailty, is a geriatric syndrome that reduces the resistance to stress situations caused by activities of daily living and increases morbidity and mortality. We hypothesized that a decrease in orexigenic peptides or an increase in anorexigenic peptides might be associated with frailty. We aimed to investigate the relationship between frailty and six appetite-related peptides: ghrelin, neuropeptide Y (NPY), agouti-related peptide (AgRP), cocaine-amphetamine-associated peptide (CART), peptide YY, and alpha MSH (α-MSH).

This cross-sectional study was conducted on 85 older adults who visited the outpatient clinic. All patients underwent comprehensive geriatric assessment. Frailty status was assessed using the Fried frailty index. Plasma levels of six appetite-related peptides were studied.

The mean age was 73.7 ± 5.4 years, 27 (31.8%) of the patients were male, and 32 of the patients (37.6%) were frail. While plasma levels of ghrelin, NPY and AgRP were significantly lower in frail patients, CART and α-MSH levels were higher compared to non-frail patients (p < .05 for all). Peptide YY was found to be higher in the frail group, however, the difference did not reach statistical significance (p = .052). In multivariate logistic regression analysis, the ghrelin, AgRP, CART, and α-MSH levels were independent predictors of frailty. Moreover, a weak correlation was found between all peptides(except NPY) and handgrip strength and Lawton-Brody score.

Ghrelin, AgRP, CART, and α-MSH levels were found to be independent predictors of frailty. Our results suggest that appetite-related peptides might be playing roles in the pathogenesis of frailty. Further larger prospective studies are needed to test this hypothesis.