Clinical and hormonal characteristics of central hypothyroidism at diagnosis and during follow-up in adult patients

Abstract

Objective: We studied the clinical and hormonal profiles of patients with central hypothyroidism (CH), the adequacy of levothyroxine (L-T4) treatment and the influence of other pituitary hormone replacement therapies. Methods: We reviewed medical records of 108 adult patients with child-onset (CO; n ¼ 26) or adultonset (AO; n ¼ 82) CH. Results: At diagnosis, the most frequently reported symptoms were fatigue and headaches in AO patients, and growth retardation in CO patients. Serum TSH was normal in a majority of CH patients, low in 8% and elevated in 8%. Serum free thyroxine (fT 4 ) was usually reduced, but remained within the low normal range in 28% of the study population (mostly CO patients). Similarly, serum total T 4 (tT 4 ), total triiodothyronine (tT 3 ) and free T 3 (fT 3 ) were found to be within the normal range in significant subsets of patients. Interestingly, the clinical and biochemical characteristics of CH patients with normal f/t T 4 levels were not different from those of the patients with low fT 4 values. The thyroid hormonal profile was not influenced by gender, etiology or by the number of hormone deficiencies. At last evaluation, the mean dose of L-T 4 was 1.6^0.5 mg/kg/day and was negatively correlated to current age (P , 0.001) but positively correlated to the number of hormone deficiencies (P , 0.05). Treatment suppressed TSH in 75% of the patients, induced normal fT 4 in 94%, but normal fT 3 in only 49% of them. Male GH-treated patients and estrogen-treated females needed a higher L-T 4 dose compared with non-treated patients. Conclusions: fT 4 is clearly the best indicator of CH, but remains in the low normal range in a significant subset of patients, especially in those with CO disease. Adequacy of therapy is mostly reflected by the combination of upper normal fT 4 and low normal fT 3 levels. Pituitary hormone replacement therapy may require an adjustment of T 4 treatment, as female patients under estrogen treatment and male patients under GH treatment will need a higher T 4 dose in order to remain in the euthyroid range.European Journal of Endocrinology 150 1-8

Testosterone and Erectile Function: From Basic Research to a New Clinical Paradigm for Managing Men with Androgen Insufficiency and Erectile Dysfunction

“…In examining the clinical and hormonal profiles of patients, screening is performed by obtaining a thyroid-stimulating hormone (TSH) blood value for primary hypothyroidism. In suspected cases of central hypothyroidism, serum-free thyroxine (T4) is considered the best indicator [128]. In men presenting for initial evaluation and therapy of ED, 4.0% had increased TSH [129].…”

Median-lower normal levels of serum thyroxine are associated with low triiodothyronine levels and body temperature in patients with central hypothyroidism

“…Generally, serum thyroid-stimulating hormone (TSH) level is used as a marker for dose adjustment of L-T 4 replacement therapy (4,5,6). However, in patients with CeH, TSH secretion does not often accurately reflect the changes in serum free thyroxine (FT 4 ) levels.…”

Options of Replacement Therapy in Hypothyroidism

“…Although the T3 level in spite of L-T4 substitution is often reduced. Thus, according to Alexopoulou et al, the level of free T3 is reduced in more than half of patients, despite normal levels of freeT4 [Alexopoulou, 2004].…”

“…First of all, as secondary hypothyroidism in adults is often associated with deficit of other pituitary hormones, the symptoms of thyroid hormone deficiency are "disguised" by deficiency of other hormones. In addition the level of TSH in SH is often normal at the time of diagnosis [Ferretti E.,1999, Alexopoulou, 2004, and decreases after the beginning of replacement therapy (in 2/3 of patients) [Carrozza V, 1999]. Corticosteroids taking for secondary hypocorticism also lead to reducing the TSH level.…”