Lack of association between circulating apelin level and frailty-related functional parameters in older adults: a cross-sectional study. BMC Geriatr. 2020 [제1저자]

Il-Young Jang 1, Seungjoo Lee 2, Jeoung Hee Kim 2, Eunju Lee 1, Jin Young Lee 3, So Jeong Park 3, Da Ae Kim 3, Mark W Hamrick 4, Jin Hoon Park 5, Beom-Jun Kim 6

DOI: 10.1186/s12877-020-01837-9

Abstract

Background: Apelin, an active endogenous peptide, has been recently receiving great attention as a promising target for antiaging intervention, primarily based on results from genetically altered mice. To validate previous experimental data and investigate the possible role of apelin in humans, in this study, we examined serum apelin level in relation to frailty and its associated parameters in a cohort of ambulatory, community-dwelling older adults.

Methods: Blood samples were collected from 80 participants who underwent a comprehensive geriatric assessment, and apelin level was measured using an enzyme immunoassay kit. Phenotypic frailty and deficit-accumulation frailty index (FI) were assessed using widely validated approaches, proposed by Fried and Rockwood groups, respectively.

Results: After adjustment for sex, age, and body mass index, serum apelin level was found to be not significantly different according to phenotypic frailty status (P = 0.550) and not associated with FI, grip strength, gait speed, time to complete 5 chair stands, and muscle mass (P = 0.433 to 0.982). To determine whether the association between serum apelin level and frailty has a threshold effect, we divided the participants into quartiles according to serum apelin level. However, there were no differences in terms of frailty-related parameters and the risk for frailty among the quartile groups (P = 0.248 to 0.741).

Conclusions: The serum apelin level was not associated with both phenotypic frailty and functional parameters in older adults, despite its beneficial effects against age-related physiologic decline in animal models. Further large-scale longitudinal studies are necessary to understand the definite role of circulating apelin in frailty risk assessment.

Keywords: Aging; Apelin; Biomarker; Frailty; Sarcopenia.

Fig. 2

Differences in frailty-related parameters according to serum apelin quartiles (a) before and (b) after adjustment for sex, age, and BMI. The estimated means with 95% confidence intervals were generated and compared using analysis of covariance. Serum apelin quartiles: Q1 = 0.087–0.199 ng/mL, Q2 = 0.200–0.269 ng/mL, Q3 = 0.270–0.378 ng/mL, and Q4 = 0.379–2.440 ng/mL. BMI, body mass index; SPPB, short physical performance battery; ASMI, appendicular skeletal muscle mass index; PHQ-2, patient health questionnaire-2