Aim: The changes in body composition and biomarker levels that occur during the aging process are complex and remain poorly understood. The present study aimed to evaluate changes in serum C-peptide levels and fat mass-to-lean mass ratio (FM/LM ratio) with increasing age, and to explore the associations between serum C-peptide levels and FM/LM ratio.
Methods: This was a population-based cross-sectional study that included 3912 participants aged 30-85 years. Body composition was measured using dual-energy X-ray absorptiometry. Analysis of covariance was used to evaluate how the serum C-peptide level and FM/LM ratio change with increasing age, as well as how the FM/LM ratio changes in line with increasing serum C-peptide level. A multiple linear regression analysis was carried out to determine the association between serum C-peptide level and FM/LM ratio.
Results: Analysis of covariance showed that serum C-peptide levels, and most regional FM/LM ratios tended to increase in line with increasing age. Total fat mass, total lean mass, percentage total fat mass and total FM/LM ratio were significantly elevated, and percentage total lean mass decreased significantly with increasing serum C-peptide levels in both men and women. Multiple linear regression analysis showed that serum C-peptide level was strongly associated with the total FM/LM ratio.
Conclusions: The findings showed that both serum C-peptide level and FM/LM ratio increased with increasing age, and the serum C-peptide level was closely associated with changes in the total FM/LM ratio.
Keywords: aging; dual-energy X-ray absorptiometry; fat mass to lean mass ratio; public health; serum C-peptide.
© 2014 Japan Geriatrics Society.