Serum Sestrin-1 Concentration Is Higher in Frail than Non-Frail Older People Living in Nursing Homes

Abstract

Given the increasing prevalence of frailty and its implications for public health, the identification of biomarkers to detect frailty is essential. Sestrin-1 is a protein with a protective role in muscle function. This study aimed to determine whether the serum sestrin-1 concentration differed between frail and non-frail populations and to investigate its association with frailty-related variables in 225 older women and men living in nursing homes (Gipuzkoa, Spain). Serum sestrin-1 concentration was measured by ELISA. Frailty, dependence, anthropometry, physical function, and physical activity were determined by validated tests and tools. The associations between sestrin-1 concentration and the other variables were determined using generalized linear models. The differences between frail and non-frail individuals were analyzed by the Mann-Whitney U-test, and receiver operating characteristic (ROC) curves were constructed to calculate the capability of sestrin-1 to detect frailty. Unexpectedly, frail individuals-according to the Fried Frailty Phenotype or the Clinical Frailty Scale-had higher serum sestrin-1 concentrations than non-frail individuals. Furthermore, the higher serum sestrin-1 concentration was associated with the increased frailty scores and dependence as well as the poorer physical function and the less physical activity. Given the contradictory results regarding serum sestrin-1 and frailty, further investigation is required to propose it as a molecular biomarker of frailty.

Keywords: aging; biomarker; dependence; frailty; physical activity; physical function; sestrin-1.

Figure 1

Medians and interquartile ranges of the serum sestrin-1 concentration (s-[Sestrin-1] (ng/mL)) in frail and non-frail participants following the Fried Frailty Phenotype (A), the Clinical Frailty Scale (B), and the Tilburg Frailty Indicator (C) criteria.

Figure 2

Receiver operating characteristic (ROC) curves for the serum sestrin-1 concentration as a test variable and frailty following the Fried Frailty Phenotype (A), the Clinical Frailty Scale (B), and the Tilburg Frailty Indicator (C) criteria as state variables. SEN, sensitivity; SPE, specificity; AUC ± SE, area under the curve ± standard error; CI, confidence interval.