Quadrant Analysis of Quantitative Computed Tomography Scans of the Femoral Neck Reveals Superior Region-Specific Weakness in Young and Middle-Aged Men With Type 1 Diabetes Mellitus

Abstract

We have previously shown that the intertrochanter of young and middle-aged patients with type 1 diabetes mellitus (T1DM) showed higher buckling ratio (an index of cortical instability) and lower volumetric bone mineral density (vBMD). However, we have not yet reported the detailed findings regarding the mechanical and density properties of the femoral neck. Therefore, we present a subanalysis of our previous study with the aim of further evaluating the middle third of the femoral neck via quadrant quantitative computed tomography in young and middle-aged patients with T1DM. Bone parameters in 4 anatomical quadrants (superoanterior [SA], inferoanterior [IA], inferoposterior [IP], and superoposterior [SP]) were cross-sectionally evaluated in 17 male T1DM patients and 18 sex-matched healthy controls aged between 18 and 49 yr using quadrant quantitative computed tomography analysis. Patients with T1DM had a thinner cortical thickness in the SP quadrant and a significantly lower cortical vBMD in the SA quadrant than the controls. The serum insulin-like growth factor-1 values in patients with T1DM were positively correlated with the average cortical thickness in the SA quadrant and the average trabecular vBMD in the SP quadrant of the femoral neck. The cortical thickness in controls was negatively correlated with age in the SP and IP quadrants. The cortical thickness in patients with T1DM showed no correlation with age in all quadrants. The fragility of the femoral neck was remarkable in the superior region of patients with T1DM. Insulin-like growth factor-1 may play an important role in superior cortical thinning and in lowering cortical vBMD. Furthermore, in young and middle-aged men with T1DM, the structure of the femoral neck exhibits similar changes as those observed with aging.