The role of fat indices as factors leading to sarcopenia in older adults residing in underpopulated areas

Abstract

Simplifying the diagnostic criteria for sarcopenia is key to establishing effective interventions. Herein, we aimed to clarify novel diagnostic factors. We calculated novel fat indices [total fat index (TFI) and limb fat index (LFI)] and clarified factors leading to pre-sarcopenia and sarcopenia in 594 enrolled older adults. Physical measurements [height, weight, body mass index (BMI), gait speed, grip strength, and skeletal muscle mass] were performed. Sarcopenia was determined using established diagnostic criteria (pre-sarcopenia, n = 102; sarcopenia, n = 42). Age was associated with sarcopenia status. BMI, TFI, and LFI were lower in patients with pre-sarcopenia and sarcopenia. Logistic regression analysis showed the following odds ratios (ORs) for pre-sarcopenia: BMI [OR: 0.787, 95% confidence interval (CI): 0.7–0.885], LFI (OR: 0.589, 95% CI: 0.402–0.863), and age (OR: 1.06, 95% CI: 1.02–1.1). ORs for sarcopenia (vs pre-sarcopenia) were as follows: LFI (OR: 50.6, 95% CI: 10.2–250.0), age (OR: 1.1, 95% CI: 1.0–1.2), and BMI (OR: 0.418, 95% CI: 0.28–0.608). Our findings contribute to informing medical guidelines.

Can bone mass measured via bioelectrical impedance analysis be used to diagnose sarcopenia?

“…(14) Our study reveals that the progression from a healthy condition to pre-sarcopenia in older adults results in a lower limb fat index (LFI), which is a novel fat index. (15) Conversely, LFI became higher in the process of progression from pre-sarcopenia to sarcopenia, revealing that sarcopenia progression is associated with fat. (15) This suggests that fat infiltration into muscles may capture the mechanism that causes muscle inflammation.…”

“…(15) Conversely, LFI became higher in the process of progression from pre-sarcopenia to sarcopenia, revealing that sarcopenia progression is associated with fat. (15) This suggests that fat infiltration into muscles may capture the mechanism that causes muscle inflammation. (15) Additionally, this study discovered that the use of body composition analyzers employing the BIA method showed a significant difference in bone mass between the healthy (Normal), Pre-sarcopenia, and Sarcopenia groups in the overall examination and that each group can be separated.…”

“…(15) This suggests that fat infiltration into muscles may capture the mechanism that causes muscle inflammation. (15) Additionally, this study discovered that the use of body composition analyzers employing the BIA method showed a significant difference in bone mass between the healthy (Normal), Pre-sarcopenia, and Sarcopenia groups in the overall examination and that each group can be separated. In the multivariate analysis, bone mass was shown to be a good indicator as a factor of aggravation for identifying sarcopenia in both men and women.…”