The association between type 2 diabetes mellitus/prediabetes status and femoral neck bone mineral density in old adults.

Background: The prevalence of both type 2 diabetes mellitus (T2DM) and osteoporosis has been increasing among older individuals, with these two health conditions often coexisting. Our aim in this study was to evaluate the association between T2DM status and bone mineral density (BMD) of the femoral neck among older adults in the United States.

Methods: This was a retrospective analysis of the data from 5695 adults, 60-80 years of age. The data were obtained from the National Health and Nutrition Examination Survey, for the following years: 2005-2006, 2007-2008, 2009-2010, 2013-2014, and 2017-2018. Weighted multivariable regression analyses, with subgroup analyses as appropriate, were performed to identify an association between T2DM/prediabetes status and femoral BMD and mediating factors.

Results: There was a significant positive association between T2DM/prediabetes status and femoral neck BMD among older women, but not men, after adjusting for body mass index (BMI). On subgroup analysis, stratified by BMI, the significant positive association was retained for T2DM women with a BMI of 25-29.9 kg/m² (β, 0.030; 95% CI, 0.007-0.052) or ≥30 kg/m² (β, 0.029; 95% CI, 0.007-0.05), and for prediabetes women with a BMI of 25-29.9 kg/m² (β, 0.016; 95% CI, 0.001-0.030).

Conclusions: The association between a positive T2DM/prediabetes status and femoral neck BMD differed by sex among older individuals, with the association being further modulated by BMI. For women with a BMI of 25-29.9 kg/m² or ≥30 kg/m², T2DM was associated with a significantly higher femoral neck BMD, compared to the non-diabetes group.