Abstract. Bone turnover is reported to increase in favour of resorption in overt hyperthyroidism and the rate of resorption is associated with the levels of thyroid hormones. Hypothyroidism, on the other hand, was shown to cause no disturbance of calcium kinetics and found to associate lower trabecular resorption surfaces and increased bone cortical thickness. Similar studies are very rare in subclinical thyroid disorders and consequently we aimed to examine calcium and bone metabolism in subclinical thyroid disorders. Thirteen patients with subclinical hyperthyroidism secondary to untreated Graves' disease, 20 patients with subclinical hypothyroidism and 10 healthy subjects participated in this survey. Briefly calcium, phosphorus, and creatinine (Cre), urinary deoxypyridinoline (U-DPD) and serum osteocalcin (OC) were measured as biochemical markers for calcium metabolism. Concerning serum Ca and phosphorus levels, there were no differences between three of the groups, but urinary Ca excretion was higher in subclinical hyperthyroid patients compared to control and hypothyroid subjects. Hypothyroid patients had similar U-DPD levels with control subjects (p = 0.218). Serum OC and U-DPD were higher in subclinical hyperthyroid compared to control subjects ( p<0.001 and p<0.001 respectively). We demonstrated a higher bone turnover and greater calcium excretion in subclinical hyperthyroid patients. Additionally, we found that subclinical hypothyroidism is not associated with disturbed calcium metabolism. As persistent increase in bone turnover is responsible for accelerated bone loss, patients with Graves' disease may have increased risk for osteoporosis. THE combination of an undetectable serum thyrotropin concentration, as measured by an assay with a threshold of detection 0.1 mU per liter or less, and normal serum triiodothyronine and thyroxine concentrations (usually at the upper end of the normal range) is known as subclinical hyperthyroidism. It is not a rare finding; rates between 0.2% and 11.8% have been reported in different groups, according to age, sex, etc [1]. The etiology is usually the same as that of overt hyperthyroidism [1]. The health implications include general symptoms, effects on the cardiovascular system, and decreased bone density. Subclinical hypothyroidism is defined as a state where the patient is eumetabolic but has a modest increase in the serum TSH level (5 to 15 mU/L), a normal serum T 3 concentration, and low-normal or slightly decreased serum fT 4 levels. The overall prevalence has been reported to range from 4-10% in large general population screening surveys [2].There are a few studies performed to examine calcium and bone metabolism in subclinical thyroid disorders with conflicting results. Bone turnover is increased in favour of resorption and the rate of resorption is associated with the serum levels of thyroid hormones in hyperthyroidism [3]. Thyroid hormone exerts its effect on osteoblasts via nuclear receptors to stimulate osteoclastic bone resorption [4,5]; hyperthyroidism is...

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Objectives. Our aim was to determine the effect of chronic regular exercise on ischemia-modified albumin (IMA) levels and oxidative stress in type 2 diabetes mellitus (DM). Design and methods. Sixty patients with type 2 DM were randomly divided into two groups as exercise (17 M, 13 F) and non-exercise (12 M, 18 F) groups, each consisting of 30 patients. The exercise group underwent a 3-month aerobic regular exercise consisting of moderate-intensity power walking. The non-exercise subjects remained sedentary throughout the study period. Serum total antioxidant status (TAS), total oxidant status (TOS), and IMA levels of the groups were determined at baseline and 3 months later. Results. There was no significant change in TOS and IMA levels of exercise group but TAS levels were significantly increased (p < 0.05). Also, postexercise systolic (p < 0.001) and diastolic (p < 0.05) blood pressures of the exercise group were significantly lower than the baseline values. In addition, there was no significant change in TAS and TOS levels of the non-exercise group; however, IMA levels were significantly increased (p < 0.01). Conclusion. We have shown, for the first time, that exercise prevents increase in IMA levels in type 2 DM which might have resulted from increased levels of TAS and reduces the risk of ischemia in these patients. These findings show that chronic exercise is beneficial in the prevention of oxidative stress in patients with type 2 DM as documented by decreased IMA levels.