A Phase 4 interventional study of Thyroxin, Triiodothyronine in Secondary Hypothyroidism, Hypopituitarism and Hyperlipidemias, sponsored by University Hospital Freiburg. Completed at 1 site in Germany. Open to participants aged 18 Years to 75 Years. Per ClinicalTrials.gov, last updated 2008-06-09.
Sponsored by University Hospital Freiburg · Phase 4, Interventional, and Treatment
The purpose of this study is to determine whether a body weight adjusted dose of thyroxin is superior to treatment guided by laboratory results of thyroxin hormones in patients with central hypothyroidism. Moreover beneficial effects of triiodthyronine supplementation are investigated.
Backround: A normal thyroid function is critical for metabolism, well-being and cognitive function. It is now well accepted that primary subclinical hypothyroidism, characterized by normal circulating thyroid hormones (fT3 and fT4) and elevated TSH, should be treated to improve reduced quality of life and abnormalities of lipid metabolism. In central hypothyroidism (CH) the dose of replacement therapy aims to achieve normal thyroxin (T4) concentrations as defined by appropriate reference populations. Adequate thyroxin treatment is especially challenging, as T4 cannot be titrated according to endogenous TSH levels because of the impaired hypothalamic-pituitary unit. The majority of untreated CH patients show normal (40 %) or elevated TSH levels (35 %) while only a minority has reduced concentrations (25 %) {Faglia, 1979 #1}. These findings are explained by the lack of pulsatile secretion and nocturnal TSH surge, which has been attributed to impaired thyrotroph function in CH patients {Caron, 1986 #2}. Moreover, impaired biological activity of TSH itself due to reduced glycosylation has been described in secondary hypothyroidism.
In a cross sectional study performed in patients with central hypothyroidism, we found elevated cholesterol levels and increased ankle reflex time suggesting subtle hypothyroidism, though fT3 and fT4 serum concentrations were within the normal range. The average dose of thyroxin (T4) applied in these patients with central hypothyroidism was 1.1 µg/kg bw, which is below the average dose recommended in primary hypothyroidism (1.6 µg/kg bw). We hypothesized that these results might indicate suboptimal T4 replacement therapy, not detectable by current laboratory testing.
Hypothesis: To investigate the effects of a body weight adjusted T4 or T3T4 dose on metabolism, well-being and cognitive function.
Study design: Placebo controlled trial in patients with central hypothyroidism following a double blind cross-over design.
Intervention: Three different treatment regimes (5 weeks each) were compared: "CON-T4", empirically chosen, current dose of T4 (1 ± 0.05 μg/kg body weight (bw); "OPT-T4", optimized T4 treatment (1.6 μg/kg bw T4); "T3T4", combination of triiodothyronine (T3, 0.16) and T4 (1.44 μg/kg bw). Biochemical parameters, ankle reflex time and neurocognitive functions were assessed.
217 studies on the registry are indexed under Hypothyroidism; 50 are open to participants now.
This study's enrollment of 25 is below the median of 70 across 109 interventional studies indexed under Hypothyroidism.
Browse Hypothyroidism studies →University Hospital Freiburg is the lead sponsor of 94 studies on the registry; 18 are open to participants now.
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Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Drug pages: Thyroxine · Triiodothyronine
well-being
Time frame: 3 weeks of treatment
cognitive function
Time frame: 3 weeks of treatment
lipid metabolism
Time frame: 3 weeks of treatment
muscle function / ankle reflex time
Time frame: 3 weeks of treatment
The record gives a start of Feb 2004 and a completion of Apr 2007. It does not say whether these dates are actual or estimated.
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This study is completed, as verified in Jun 2008. You cannot join it, but the record below documents what was studied.
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Studies of the drugs tested here: Thyroxine · Triiodothyronine
University Hospital Freiburg