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

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.