Sex differences in the association between sarcopenia index and sarcopenia: a cross-sectional study from a Chinese community-based population

Abstract

Purpose: The sarcopenia index (SI) is a convenient method to screen for sarcopenia, but few studies have analysed whether there are sex differences. The aim of this study was to analyse sex differences in the relationship between SI and sarcopenia in a Chinese community-based population.

Methods: This cross-sectional study included participants from 2011 China Health and Retirement Longitudinal Study. The SI was defined as 100 × creatinine / cystatin C. Diagnosis of sarcopenia based on the Asian Working Group for Sarcopenia 2019 consensus. Logistic regression model, linear regression model, and natural spline model were used to analyze the association between SI and sarcopenia.

Results: A total of 7,118 participants with a mean age of 60.6 ± 10.1 were included, 53.4% females. In males, the prevalence of sarcopenia decreased by 25% for every 10 increase in SI, and skeletal muscle mass index (SMI) increased by 0.04, odds ratio (OR), β, and 95% confidence interval (CI) were 0.75 (0.65-0.87), 0.04 (0.02-0.05), both P < 0.001. In females, the SI was not significantly associated with sarcopenia, OR and 95% CI were 0.99 (0.9 ~ 1.08), P = 0.775; for every 10 increase in SI, the SMI in females decreased by 0.03, β and 95% CI were -0.03 (-0.04 ~ -0.01), P = 0.001.

Conclusion: In the Chinese community, the SI is negatively associated with sarcopenia in males and has moderate diagnostic test performance. It was not associated with sarcopenia in females, and using the SI to screen for sarcopenia in females may not be a reliable method.

Keywords: CHARLS; Creatinine; Cystatin C; Sarcopenia; Sarcopenia index.

Fig. 1

Flow chart of the screening of participants

Fig. 2

Multivariate analyses forest plot of the association of SI with sarcopenia (a), SMI (b), gait speed (c), 5-time chair stand test (d), and handgrip strength (e), with the SI as a continuous variable (per 10) and a categorical variable. The blue and pink colours represent males and females respectively, the squares represent OR or β, the lines represent 95% CI. Adjusted for: age, education, marital, residence, smoking, alcohol consumption, hypertension, dyslipidemia, diabetes, cancer, chronic lung diseases, liver disease, heart disease, stroke, kidney disease, digestive disease, emotional problems, memory related disease, arthritis, asthma, BUN, TG, HDL-c, LDL-c, CRP, UA, HB, eGFR. OR odds ratio; CI confidence interval; SI Sarcopenia Index; SMI skeletal muscle mass index; BUN blood urea nitrogen; TG total triglycerides; HDL-c high-density lipoprotein cholesterol; LDL-c low density lipoprotein cholesterol; CRP high sensitivity C-reactive protein; UA uric acid; HB hemoglobin; eGFR estimated glomerular filtration rate.

Fig. 3

Natural spline model of the association of SI with sarcopenia (a), SMI (b), gait speed (c), 5-time chair stand test (d), and handgrip strength (e). The blue and pink colours represent males and females, respectively; the lines represent trends; and the coloured areas around them represent the 95% CI. Only 98% participants were included, with a knot of 4. Adjusted for: age, education, marital, residence, smoking, alcohol consumption, hypertension, dyslipidemia, diabetes, cancer, chronic lung diseases, liver disease, heart disease, stroke, kidney disease, digestive disease, emotional problems, memory related disease, arthritis, asthma, BUN, TG, HDL-c, LDL-c, CRP, UA, HB, eGFR. SI Sarcopenia Index; SMI skeletal muscle mass index; CI confidence interval; BUN blood urea nitrogen; TG total triglycerides; HDL-c high-density lipoprotein cholesterol; LDL-c low density lipoprotein cholesterol; CRP high sensitivity C-reactive protein; UA uric acid; HB hemoglobin; eGFR estimated glomerular filtration rate

Fig. 4

Subgroup forest plots of multifactorial logistic regression models for the association between SI and sarcopenia. The blue and pink colours represent males and females respectively, the squares represent OR and the lines represent 95% CI. Multivariate: adjusted for: age, education, marital, residence, smoking, alcohol consumption, hypertension, dyslipidemia, diabetes, cancer, chronic lung diseases, liver disease, heart disease, stroke, kidney disease, digestive disease, emotional problems, memory related disease, arthritis, asthma, BUN, TG, HDL-c, LDL-c, CRP, UA, HB, eGFR. OR odds ratio; CI confidence interval; SI Sarcopenia Index; BUN blood urea nitrogen; TG total triglycerides; HDL-c high-density lipoprotein cholesterol; LDL-c low density lipoprotein cholesterol; CRP high sensitivity C-reactive protein; UA uric acid; HB, hemoglobin; eGFR estimated glomerular filtration rate.

Fig. 5

ROC curves for the sarcopenia index in males a an females, b SI sarcopenia index