Osteoporosis in patients with subclinical hypothyroidism treated with thyroid hormone

Objective: to estimate the prevalence of osteoporosis in patients being treated with thyroid hormone. Method: cross-sectional retrospective study of primary care patients. Experimental Group: patients diagnosed with subclinical hypothyroidism receiving thyroid hormone replacement therapy. Control Group: patients not receiving replacement therapy. Once the sample was selected its members were summoned to complete a clinical questionnaire and undergo a bone density scan with a validated measuring device. The description of qualitative data was done in absolute frequencies and percentages and that of the quantitative data as mean standard deviation, median. In the comparison of qualitative data between groups we used the Chi-square test and contingency tables by rearranging the percentages of several variables. Results: 182 patients were studied (112 experimental and 70 control), diagnosed with subclinical hypothyroidism. The average age at diagnosis was 42.5 and 41.2 years, respectively. 32.7% and 33.2% were smokers. In the experimental group the coexistence of two or more cardiovascular risk factors was detected in 5.7% of the patients. Mean TSH was 6.67 mU/L, mean freeT(4) 1,04 ng/dl. 67% of the patients studied had some level of bone loss: 87% osteopenia and 14% osteoporosis. 56% of those suffering from bone less were women. With regard to the size of the thyroid hormone treatment, only 12% received 150 mu g/day or more. 61% had received treatment for between 5 and 10 years and 19.5% for more than 10 years. Conclusions: there is a high prevalence of bone loss in patients with subclinical hypothyroidism treated with exogenous thyroxin.