Low-normal or high-normal thyrotropin target levels during treatment of XXXX : a prospective, comparative study.

@entity1 @entity1375 @entity1674 @entity1955 @entity165
BACKGROUND: Recent literature advocates the decrease of the upper limit of the normal thyrotropin (TSH) reference range. The objective of this study was to determine whether treated @entity1375 @entity1 maintained within a low-normal TSH range (0.4-2.0 mIU/L) have better clinical outcomes than those maintained within a high-normal TSH range (2.0-4.0 mIU/L). METHODS: The study was performed in a thyroid outpatient clinic of a tertiary hospital. This was a prospective, interventional study. Forty-two @entity1 with newly diagnosed overt @entity1375 were paired in two groups: group 1 (n=20), low-normal target TSH; group 2 (n = 22), high-normal target TSH. @entity1955 was initiated, and dose was adjusted to achieve and sustain the target TSH value during the study period. After the target TSH was reached, @entity1 were evaluated every 3 months for thyroid function, serum lipid profile, resting energy expenditure (REE), body composition, and bone mineral density, for 12 months. RESULTS: Nineteen @entity1 in group 1 and 16 in group 2 completed the study. In the whole-group analysis, total @entity165 (p = 0.01), low-density lipoprotein @entity165 (p = 0.004), and @entity1674 (p < 0.001) decreased after treatment, whereas REE per kilogram of lean body mass (p = 0.001) and total fat body mass (p =0.02) increased. Group 1 @entity1 had a significantly higher relative increase in REE (+7.1%    11.3% vs. +3.6%    15.1%, p = 0.02). There was no difference between the groups in the other variables. CONCLUSIONS: Despite recent trends toward lowering the upper limit of normal TSH range, the results of this 12-month study provided no substantial clinical evidence to corroborate that treatment of @entity1375 should aim at maintaining TSH levels in a low-normal range
