Relationship between skeletal muscle mass indexes and muscular function, metabolic profile and bone mineral density in women with recommendation for bariatric surgery

Abstract

Background and aim: We evaluated low skeletal muscle mass (LMM) in women prior to bariatric surgery (BS) through different skeletal muscle mass indexes (MMIs) regarding body fat percentage (BFP), handgrip strength (HS), six-minute walk test (6MWT), metabolic profile and bone mineral density (BMD). Methods: Women (n=62) were allocated into two groups according to LMM: obesity with low muscle mass (OLMM) or obesity with normal muscle mass (ONMM). LMM was defined by the appendicular skeletal muscle mass (ASM) adjusted for weight (ASM/wt × 100) and ASM adjusted for body mass index (ASM/BMI), considering the lowest quintile of the indexes studied. Results: OLMM was found in 30.5% by ASM/wt × 100 and 20.3% by ASM/BMI. Using the ASM/wt × 100, OLMM group had a high BFP, low HS and BMD in L1-L4, femoral neck (FN) and total femur (TF) when compared with ONMM (p < 0.05). Using ASM/BMI, OLMM group had increased BFP, reduced HS and 6MWT in comparison to ONMM (p < 0.05). Metabolic profile was similar between OLMM and ONMM groups by the two MMIs. MMIs were negatively correlated with BFP (p < 0.05) and positively correlated with HS (p < 0.05), and none of them with 6MWT (p > 0.05). ASM/wt × 100 was positively correlated with all BMD sites assessed (p < 0.05). There was positive correlation between ASM/wt × 100 and ASM/BMI. Conclusion: OLMM identified by the ASM/wt × 100 and ASM/BMI had higher adiposity and lower HS. Using ASM/BMI, we found that OLMN had a poor physical performance, while the ASM/wt × 100 identified a lower BMD at all sites.