Adverse effect of obesity and dysglycemia on bone microarchitecture and strength in youth: sex-related differences.

Abstract

The relationship between obesity, type 2 diabetes (T2D), and bone health in youth is not clear. Objective; To examine the relationship of adiposity and glucose metabolism with bone mineral content (BMC) and quality (microarchitecture and strength) in youth across the glycemia spectrum, and evaluate sex-related differences. Cross-sectional study. Research Center. 92 adolescents (56 females); 32% normal weight (NW), 29% overweight-normal glucose tolerance (OW-NGT), 39% OW-impaired glucose regulation (OW-IGR), including prediabetes (n=9) or T2D (n=27). Bone quality (HRpQCT), body composition and BMC (DXA), anthropometrics, OGTT with glucose and insulin indices, vitamin D and calcium metabolism. BMC and distal tibia bone microarchitecture and strength (modulus) measures were worse in OW-IGR and OW-NGT compared with NW in males but not in females. In multivariable models, accounting for age, Tanner stage and sex, age and lean mass (β=3.9, p<0.001) positively, while height (β=-4.5, p<0.001) and HOMA-IR (β=-4.6, p=0.005) negatively contributed to the variance in tibial volumetric BMD (vBMD) (R2=0.45, p<0.001). Similar relationships were found with radial vBMD and with whole bone modulus at the tibia and radius independent of sex. Fasting glucose was inversely related to trabecular thickness at the tibia and radius. There is a negative relationship between adiposity and insulin resistance with bone microarchitecture and strength in youth after accounting for age, sex, height and lean mass. There appears to be sexual dimorphism in these relationships, with more negative effect of adiposity and dysglycemia on bone quality in males.