Age-dependent Changes in Skeletal Muscle Mass and Visceral Fat Area in a Chinese Population

Objective:The present study was conducted to demonstrate the age-dependent changes in skeletal muscle mass and visceral fat area in a population of Chinese adults aged 30-92 years old.Methods:A total of 6669 healthy Chinese men and 4494 healthy Chinese women aged 30-92 years old were assessed for their skeletal muscle mass and visceral fat area.Results:The results showed age-dependent decreases in the total skeletal muscle mass indexes in both men and women aged 40-92 years old as well as age-dependent increases in the visceral fat area in men aged 30-92 years old and in women aged 30-80 years old.Multivariate regression models showed that the total skeletal muscle mass index was positively associated with the body mass index and negatively associated with the age and visceral fat area in both sexes.Conclusion:The loss of skeletal muscle mass becomes obvious at approximately 50 years of age,and the visceral fat area commences to increase at approximately 40 years of age in this Chinese population.

PNPLA3 rs738409 C>G Variant Influences the Association Between Visceral Fat and Significant Fibrosis in Biopsyproven Nonalcoholic Fatty Liver Disease

Background and Aims:Intra-abdominal visceral fat accumulation and patatin-like phospholipase domain containing 3(PNPLA3)rs738409 G/C gene polymorphism confer a greater susceptibility to nonalcoholic fatty liver disease(NAFLD).We examined whether the relationship between visceral fat accumulation and liver disease severity may be influenced by PNPLA3 rs738409 polymorphism.Methods:The variant of PNPLA3 rs738409 was genotyped within 523 Han individuals with biopsy-confirmed NAFLD.Visceral fat area(VFA)was measured by bioelectrical impedance.Significant liver fibrosis(SF),defined as stage F≥2 on histology,was the outcome measure of interest.Results:The distribution of PNPLA3 genotypes was CC:27.5%,CG:48.2%,and GG:24.3%.Higher VFA was associated with greater risk of having SF(adjusted-odds ratio[OR]:1.03;95%confidence interval[CI]:1.02–1.04,p<0.05),independent of potential confounders.Among subjects with the same VFA level,the risk of SF was greater among carriers of the rs738409 G genotype than among those who did not.Stratified analysis showed that PNPLA3 rs738409 significantly influenced the association between VFA and SF.VFA remained significantly associated with SF only among the rs738409 G-allele carriers(adjusted-OR:1.05;95%CI:1.03–1.08 for the GG group;and adjusted-OR:1.03;95%CI:1.01–1.04 for the GC group).There was a significant interaction between VFA and PNPLA3 rs738409 genotype(Pinteraction=0.004).Conclusions:PNPLA3 rs738409 G allele has a moderate effect on the association between VFA and risk of SF in adult individuals with biopsy-proven NAFLD.Existence of the PNPLA3 rs738409 G allele and VFA interact to increase risk of SF。