Serum progranulin as a potential biomarker for frailty in Chinese older adults

Frailty can increase adverse health outcomes in older adults. Progranulin is a secreted glycoprotein involved in regulating various biological processes. Different perspectives exist on the relationship between progranulin and frailty.

We aimed to evaluate the association of progranulin with frailty in older Chinese adults.

We included 265 older in-patients who were divided into the robust (n = 31), pre-frail (n = 116) and frail (n = 118) groups according to the FRAIL scale. Serum IL-6, CXCL-10, progranulin, and CRP levels were assayed. Spearman's correlation and logistic regression models were used to analyze the association of serum biomarkers with frailty, and ROC was used to evaluate the diagnostic progranulin value for frailty.

The frail group was older and had lower BMI, higher prevalence of coronary heart disease, worse grip strength and walking speed, and higher IL-6, CXCL-10, progranulin, and CRP serum levels than the robust and pre-frail groups. Progranulin levels were negatively correlated with grip strength (r = - 0.152, p = 0.016) and positively correlated with IL-6 (r = 0.207, p = 0.001) and CXCL-10 (r = 0.160, p = 0.009) after adjusting for age and sex. Furthermore, progranulin remained associated with frailty after adjusting for age, sex, BMI, smoking, chronic diseases, and pro-inflammatory cytokines (OR = 1.003, 95% CI 1.001-1.006, p = 0.022). The AUC of serum progranulin levels for diagnostic frailty was 0.927 (95% CI 0.896-0.958, p < 0.001).

High serum progranulin levels were observed in frail older adults and were associated with worse physical function and increased chronic inflammation. Progranulin may be a potential biomarker for frailty.