Prevalence and association of single nucleotide polymorphisms with sarcopenia in older women depends on definition

Praval Khanal,Martine Thomis,Lingxiao He,Gladys L Onambele-Pearson,Hans Degens,Alun Williams,Christopher I Morse,Georgina Stebbings

doi:10.1038/s41598-020-59722-9

Abstract

The prevalence of sarcopenia depends on the definition used. There are, however, consistent sarcopenic characteristics, including a low muscle mass and muscle strength. Few studies have investigated the relationship between sarcopenia and genotype. A cross-sectional study was conducted with 307 community-dwelling ≥60-year-old women in South Cheshire, UK. Handgrip strength was assessed with a handgrip dynamometer and skeletal muscle mass was estimated using bioelectrical impedance. DNA was extracted from saliva (∼38%) or blood (∼62%) and 24 single-nucleotide polymorphisms (SNPs) were genotyped. Three established sarcopenia definitions - %Skeletal Muscle Mass (%SMM), Skeletal Muscle Mass Index (SMI) and European Working Group on Sarcopenia in Older People (EWGSOP) - were used to assess sarcopenia prevalence. Binary logistic regression with age as covariate was used to identify SNPs associated with sarcopenia. The prevalence of sarcopenia was: %SMM 14.7%, SMI 60.6% and EWGSOP 1.3%. Four SNPs were associated with the %SMM and SMI definitions of sarcopenia; FTO rs9939609, ESR1 rs4870044, NOS3 rs1799983 and TRHR rs7832552. The first three were associated with the %SMM definition, and TRHR rs7832552 with the SMI definition, but none were common to both sarcopenia definitions. The gene variants associated with sarcopenia may help proper counselling and interventions to prevent individuals from developing sarcopenia.

Highlights

The prevalence of sarcopenia depends on the definition used
The three chosen definitions were: skeletal muscle mass (SMM)/body mass (%Skeletal Muscle Mass (SMM))[27], SMM/height[2] (SMI)[28] and Skeletal Muscle Mass Index (SMI) and Handgrip strength (HGS) cut-offs as suggested by European Working Group on Sarcopenia in Older People (EWGSOP)[1]
Individuals identified as sarcopenic with EWGSOP were sarcopenic by the SMI definition, while there was a discrepancy in individuals identified as sarcopenic between the SMI and %SMM definitions: 34 elderly women were sarcopenic using both the %SMM and SMI definitions, but 11 were sarcopenic using only the %SMM definition and 152 were sarcopenic using only the SMI definition

Summary

Introduction

The prevalence of sarcopenia depends on the definition used. There are, consistent sarcopenic characteristics, including a low muscle mass and muscle strength. Three established sarcopenia definitions - %Skeletal Muscle Mass (%SMM), Skeletal Muscle Mass Index (SMI) and European Working Group on Sarcopenia in Older People (EWGSOP) - were used to assess sarcopenia prevalence. Several studies have reported an association of single nucleotide polymorphisms (SNPs) with lean mass, muscle volume and muscle strength[16,17,18]. The three chosen definitions were: skeletal muscle mass (SMM)/body mass (%SMM) (sarcopenia defined to individuals with %SMM < 22.1%)[27], SMM/height[2] (SMI) (sarcopenia defined to individuals with SMI ≤ 6.76 kg/m2)[28] and SMI and Handgrip strength (HGS) cut-offs as suggested by European Working Group on Sarcopenia in Older People (EWGSOP) (sarcopenia defined to individuals with SMI < 6.76 kg/m2 and HGS < 20 kg)[1]

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Conclusion