[Changes of bone mineral density and bone metabolic marker in patients with subclinical hypothyroidism]

To investigate the change of bone mineral density and bone metabolism biochemical markers in subclinical hypothyroidism.

This study included total 122 patients with subclinical hypothyroidism and 153 healthy age and gender matched people as control. All the patients and controls were subjected to the measurements of bone density by dual energy X-ray absorptiometry (DEXA), and serum free triiodothyronine (FT3), free thyroxine (FT4), thyroid stimulating hormone (TSH), Ca2+, PO4(3+), alkaline phosphatase (ALP) levels. All the data was analyzed statistically with the stratification of gender and menopause status.

Compared to the control, the patients with subclinical hypothyroidism had significantly higher incidence of bone mass loss (P < 0.005) and lower level of Serum Ca2+ (P < 0.05) and higher levels of serum PO4(3+), T-value and Z-value (P < 0.05). Furthermore, premenopausal women had higher Z-value (P < 0.01) , but no significantly differences of T-value, serum PO4(3+) was found either in pre-menopause or post-menopause women when compared to the control. Multiple linear regression analysis showed gender (B = 0.543, P < 0.0001) was positive correlation with T value, female had lower T values. Moreover, T value was negative correlated to menopausal status (B = -0.274, P = 0.001), age (B = -0.161, P < 0.0001) and TSH (B = -0.108, P < 0.0001).

Subclinical hypothyroism appears decreased serum calcium and low bone density.