Muscle strength as a predictor of bone fragility in patients with type 2 diabetes mellitus

Introduction: Most studies have shown a decrease in muscle function and strength in patients with type 2 diabetes mellitus (DM2). However, the relationship between muscle function and bone health in patients with DM2 is not well defined. Objective: The objective of this study was to analyze the relationship between muscle strength and bone fragility in patients with DM2. Material and methods: This observational cross-sectional study included 60 patients with DM2 (60% men and 40% postmenopausal women) ranging in age from 49 to 85 years. Demographic, anthropometric, clinical and biochemical variables were studied. Bone mineral density (BMD) in the lumbar spine (LS), femoral neck and total hip was determined using DXA (Hologic QDR 4500), and TBS values (TBS iNsight Software, version 3.0.2.0, Medimaps, Merignac, France). Hand grip (kg/cm(2)) was measured with a Jamar (R) manual hydraulic dynamometer (5030j1; Jackson, MI). To assess the level of mobility and the risk of falls, the Time Up and Go test was carried out. Statistical analysis was performed using the SPSS program (SPSS, inc, v 25.0). Results: The mean age of the patients was 66.3 +/- 8.3 years. The mean HbA1c was 7.7 +/- 1.1%, with inadequate glycemic control (HbA1c >7.5%) observed in 73.3% of the patients. 91.7% of the women and 77.8% of the men had low muscle strength. 41.7% of women and 25% of men presented a high risk of falls. Subjects with low hand grip strength and those with high risk of falls had significantly lower TBS values than those with greater hand grip strength (0.99 +/- 0.17 vs 1.12 +/- 0.15; p=0.03) and low risk of falls (0.94 +/- 0.13 vs 1.04 +/- 0.19; p=0.02). Patients with normal and partially degraded TBS had greater hand grip strength than subjects with degraded TBS (p=0.031). Hand grip strength was positively associated with TBS (p<0.05) regardless of age, waist circumference, 25OH vitamin D levels, and BMD in LS. There were no significant differences in hand grip strength as a function of BMD values. Conclusion: Our study shows that the reduction in muscle strength may be related to bone microarchitecture deterioration determined by TBS in patients with DM2.