| Abstrakt: |
Body composition of 30 patients with primary hypothyroidism (28 women, 2 men; age range, 24–77 years) was studied with dual-energy x-ray absorptiometry (DXA). Nineteen patients were overweight, of which 11 were obese. Their lean body mass (LBM), fat mass (FM), and total body bone mineral content (TBBMC) were compared with the same components found in control subjects matched for age, sex, and body mass index (BMI). Each component also was expressed for every patient as sd (z) score above or below the mean found among normal subjects. Hypothyroid patients’ body composition did not differ from that found among euthyroid control subjects. Overweight patients had significantly higher LBM (P<0.05) and FM (P<0.01) z-scores than lean patients. A significant positive correlation (P<0.05) was found between BMI and FM, FM z-score, and LBM z-score, whereas TBBMC z-score was positively correlated with FM. Thyroid-stimulating hormone levels did not correlate with any of the components. Eighteen patients were studied again 2 months after reaching euthyroidism. In average, body weight decreased 2.8 kg and LBM decreased 3.9 kg (P<0.01). LBM significantly decreased in the trunk, abdomen, and limbs. TBBMC and FM were unchanged, although %FM rose from 45.2 ± 9.2 to 48.9 ± 8.6 (P<0.02). Body composition of untreated hypothyroid patients is similar to that found among euthyroid control subjects. FM and LBM are significantly correlated with BMI. Correction of hypothyroidism produces a modest but significant weight loss at the expense of LBM, which decreases in both lean and obese patients, and in all anatomic regions. FM does not change significantly after treatment, but %FM increases, calling attention to the need of complementary intervention (ie, diet and exercise), especially in obese hypothyroid patients. |
