Background and aims: We aimed to assess bone mineral density (BMD) in geriatric patients with hyperthyroidism caused by TNG.
Materials and methods: Bone mineral density was measured at the lumbar spine and proximal femur, using dual-X-ray absorptiometry (DXA) in 90 patients with TNG (mean age; 69.2 ± 4.4 years) and compared with those in 42 age-matched healthy subjects (mean age; 68.40 ± 4.3 years). Serum levels of TSH, fT3, fT4, 25-OH vitamin D and PTH were measured.
Results: BMD was significantly lower at total spine (0.904 ± 0.1 vs. 1.114 ± 0.1 g/cm(2)) and total hip (0.850 ± 0.1 vs. 1.079 ± 0.1 g/cm(2)) in male patients with TNG in comparison to the healthy men (p = 0.001, p < 0.001). Postmenopausal women with TNG had lower BMD measurements at total lumbar spine (0.754 ± 0.1 vs. 0.870 ± 0.2 g/cm(2), p < 0.001) and total hip (0.765 ± 0.1 vs. 0.831 ± 0.2 g/cm(2), p < 0.001) in comparison to the healthy women. T scores of total lumbar spine and hip were lower in patients with subclinical hyperthyroidism compared to the control group, respectively (-1.9 ± 1.7 vs -0.8 ± 1.8, p = 0.007; -1.09 ± 1.2 vs. -0.02 ± 1.6, p = 0.001). While serum levels of fT3 and fT4 revealed a negative correlation with T score of BMD measurements at the total spine and hip, TSH levels were positively correlated. We did not find a difference in serum calcium, phosphorus, 25-OH vitamin D and PTH levels between the two groups (p > 0.005).
Conclusion: Geriatric patients with hyperthyroidism secondary to TNG had reduced BMD at the total spine and hip. Thus, we suggest to investigate bone mineral density in geriatric patients with TNG.