Low serum levels of bone turnover markers are associated with perirenal fat thickness in patients with type 2 diabetes mellitus

Background: Obesity is known as a common risk factor for osteoporosis and type 2 diabetes mellitus (T2DM). Perirenal fat, surrounding the kidneys, has been reported to be unique in anatomy and biological functions. This study aimed to explore the relationship between perirenal fat and bone metabolism in patients with T2DM. Methods: A total of 234 patients with T2DM were recruited from September 2019 to December 2019 in the cross-sectional study. The biochemical parameters and bone turnover markers (BTMs) were determined in all participants. Perirenal fat thickness (PrFT) was performed by ultrasounds via a duplex Doppler apparatus. Associations between PrFT and bone metabolism index were determined via correlation analysis and regression models. Results: The PrFT was significantly correlated with beta-C-terminal telopeptides of type I collagen (beta-CTX) (r = -0.14, P < 0.036), parathyroid hormone (iPTH) (r = -0.18, P <= 0.006), and 25 hydroxyvitamin D (25-OH-D)(r = -0.14, P = 0.001). Multivariate analysis confirmed that the association of PrFT and beta-CTX (beta = -0.136, P = 0.042) was independent of other variables. Conclusion: This study showed a negative and independent association between PrFT and beta-CTX in subjects with T2DM, suggesting a possible role of PrFT in bone metabolism. Follow-up studies and further research are necessary to validate the associations and to elucidate the underlying mechanisms.