Fatigue and fatigue-related symptoms in patients treated for different causes of hypothyroidism.

OBJECTIVE: Research on determinants of well-being in patients on thyroid hormone replacement therapy is warranted, as persistent fatigue-related complaints are common in this population. In this study, we evaluated the impact of different states of hypothyroidism on fatigue and fatigue-related symptoms. Furthermore, the relationship between fatigue and the TSH receptor (TSHR)-Asp727Glu polymorphism, a common genetic variant of the TSHR, was analyzed. DESIGN: A cross-sectional study was performed in 278 patients (140 patients treated for differentiated thyroid carcinoma (DTC) and 138 with autoimmune hypothyroidism (AIH)) genotyped for the TSHR-Asp727Glu polymorphism. METHODS: The multidimensional fatigue inventory (MFI-20) was used to assess fatigue, with higher MFI-20 scores indicating more fatigue-related complaints. MFI-20 scores were related to disease status and Asp727Glu polymorphism status. RESULTS: AIH patients scored significantly higher than DTC patients on all five MFI-20 subscales (P<0.001), independent of clinical and thyroid hormone parameters. The frequency of the TSHR-Glu727 allele was 7.2%. Heterozygous DTC patients had more favorable MFI-20 scores than wild-type DTC patients on four of five subscales. The modest effect of the TSHR-Asp727Glu polymorphism on fatigue was found in DTC patients only. CONCLUSIONS: AIH patients had significantly higher levels of fatigue compared with DTC patients, which could not be attributed to clinical or thyroid hormone parameters. The modest effect of the TSHR-Asp727Glu polymorphism on fatigue in DTC patients should be confirmed in other cohorts.

Simultaneous initiation (coinitiation) of pharmacotherapy with triiodothyronine and a selective serotonin reuptake inhibitor for major depressive disorder: a quantitative synthesis of double-blind studies.

To examine the efficacy and overall tolerability of the simultaneous initiation of treatment (coinitiation) with triiodothyronine (T3) and a selective serotonin reuptake inhibitor (SSRI) for major depressive disorder (MDD). Sources of date were Medline/Pubmed, EMBASE, the Cochrane database, and program syllabi from major psychiatric meetings held since 1995. The study selection comprised double-blind, randomized clinical trials comparing T3-SSRI coinitiation therapy versus SSRI monotherapy for MDD. Data were extracted with the use of a precoded form. Data from four clinical trials involving a total of 444 patients with MDD were identified and combined using a random effects model. There was no statistically significant difference in terms of remission rates or response rates at week 1, week 2, or at endpoint between the two treatment groups (SSRI+T3 coinitiation therapy vs. SSRI monotherapy). Pooled response and remission rates at endpoint for the SSRI+T3 versus SSRI monotherapy groups were 64.6 versus 58.5% and 46.8 versus 44.8%, respectively. In addition, there was no statistically significant difference in overall rates of premature discontinuation of treatment, or in the rate of premature discontinuation of treatment owing to inefficacy or intolerance between the two treatment groups. Notwithstanding important methodological differences between the studies included in the meta-analysis in terms of patient characteristics and treatment protocols, these results do not support the notion that simultaneous initiation of treatment of MDD with an SSRI and T3 is more effective than SSRI monotherapy. However, given the etiologically diverse and clinically heterogeneous nature of MDD, it is at least plausible that T3-SSRIs coinitiation therapy may be effective for a particular subgroup of patients including patients with atypical depression or patients with a functional polymorphism of the D-1 deiodinase gene. Clearly, further work is needed to help determine whether there are specific MDD populations that can, indeed, benefit from T3-SSRI coinitiation therapy.

Polymorphisms in the brain-specific thyroid hormone transporter OATP1C1 are associated with fatigue and depression in hypothyroid patients.

INTRODUCTION: Some hypothyroid patients continue to have significant impairments in psychological well-being, despite adequate treatment with levothyroxine (LT4). T4 transport across the blood-brain barrier is one of the crucial processes for thyroid hormone action in the brain. OATP1C1, a thyroid hormone transporter expressed at the blood-brain barrier, is considered to play a key role in delivering serum T4 to the brain. OBJECTIVE: To examine whether polymorphisms in OATP1C1 are determinants of well-being, neurocognitive functioning and preference for replacement therapy with a combination of LT4 and liothyronine (LT3). DESIGN AND PARTICIPANTS: We studied 141 patients with primary autoimmune hypothyroidism, adequately treated with LT4 monotherapy and participating in a randomized clinical trial comparing LT4 therapy with LT4-LT3 combination therapy. OUTCOME MEASUREMENTS: Different questionnaires on well-being and neurocognitive tests were performed at baseline. Serum thyroid parameters, OATP1C1-intron3C > T, OATP1C1-Pro143Thr and OATP1C1-C3035T polymorphisms were determined. RESULTS: Allele frequencies of the OATP1C1 polymorphisms in patients with primary hypothyroidism were similar to those of healthy controls. Both the OATP1C1-intron3C > T and the OATP1C1-C3035T polymorphism, but not the OATP1C1-Pro143Thr polymorphism, were associated with symptoms of fatigue and depression. OATP1C1 polymorphisms were not associated with measures of neurocognitive functioning or preference for combined LT4-LT3 therapy. CONCLUSIONS: OATP1C1 polymorphisms are associated with fatigue and depression, but do not explain differences in neurocognitive functioning or appreciation of LT4-LT3 combination therapy. Future studies are needed to confirm these findings.

Prediction of treatment response by HPA-axis and glucocorticoid receptor polymorphisms in major depression.

OBJECTIVE: We investigated whether treatment response is predicted by hypothalamus-pituitary-adrenal (HPA) axis parameters, or by genetic polymorphisms in the glucocorticoid receptor (GR), that regulates its feedback. METHODS: Ninety-eight outpatients completed 8 weeks of paroxetine treatment. Treatment response was defined as a 50% decrease in Hamilton Rating Scale for depression (HRSD) ratings. At baseline, 24h urinary cortisol excretion, and cortisol and ACTH concentrations in a DEX/CRH test were measured. The presence of polymorphisms in the GR DNA sequence (BclI, ER22/23EK, N363S) was determined. Prediction of treatment response was analysed by calculating response rates per tertile of an HPA-axis parameter and per GR genotype. RESULTS: The response rate in the high ACTH tertile was significantly lower as compared to the intermediate tertile, but not compared to the low tertile (response rates from high to low tertile: 33%, 67% and 42%). Carriers of the BclI polymorphism had higher ACTH values than non-carriers (baseline ACTH: 3 versus 5ng/l, p=0.02) and showed a trend towards lower decrease of HRSD rates than non-carriers (HRSD decrease: 8 versus 11, respectively, p=0.07). In a subgroup of BclI carriers, patients in the high ACTH tertile had a lower decrease in HRSD and lower response rates than patients in the low ACTH tertiles (HRSD decrease from high to low tertile: 5, 9 and 11, p<0.01). CONCLUSION: The results suggest that hyperactivity of the HPA-axis predict worse treatment outcome. The BclI polymorphism explains, in part, DEX/CRH test results and tends to be associated with worse treatment outcome.

Thyrotropin, but not a polymorphism in type II deiodinase, predicts response to paroxetine in major depression.

OBJECTIVE: The determinants of response to antidepressant treatment in major depression are unknown at present. The aim of the present study was to establish whether response is predicted by Hypothalamus-Pituitary-Thyroid (HPT) axis parameters or by a recently discovered polymorphism in the enzyme type II deiodinase (DII), which catalyzes the production of T3 in the brain. DESIGN: We analyzed prediction of response to paroxetine treatment by calculating response rates per tertile of HPT-axis parameters and per DII genotype. METHODS: Ninety-eight outpatients with major depression (DSM-IV) were included. Serum concentrations of TSH, FT4 and delta TSH in a DEX/CRH-TRH test were measured. In addition, the presence of a polymorphism in the DII sequence (Thr92Ala) was determined. RESULTS: The overall treatment response was 48 of 98 patients (49%). After exclusion of patients with subclinical hypothyroidism and/or TPO antibodies (n = 16), higher serum TSH significantly predicted response (response rate per tertile from low to high TSH: 36%, 42%, and 67%). Heterozygous patients for the DII polymorphism (44%) had slightly lower serum TSH (P = 0.03) as compared to patients with the wild-type DII (47%). The polymorphism was unrelated to treatment response. CONCLUSION: Higher serum TSH was associated with response to paroxetine in patients with major depression.

Glucocorticoids and relapse of major depression (dexamethasone/corticotropin-releasing hormone test in relation to relapse of major depression).

BACKGROUND: Knowledge of pathogenic mechanisms and predictors of relapse in major depressive disorder is still limited. Hypothalamic-pituitary-adrenocortical (HPA) axis dysregulation is thought to be related to the development and course of depression. METHODS: We investigated whether dexamethasone/corticotropin-releasing hormone (DEX/CRH) test parameters were related to the occurrence of relapse in 45 outpatients with clinically remitted major depression. The DEX/CRH test was administered before and after 8 weeks of antidepressant treatment. RESULTS: Posttreatment maximal adrenocorticotropic hormone (ACTH) and maximal cortisol levels, as well as delta ACTH and delta cortisol levels, were significantly higher (all p < .05) among patients who relapsed (n = 22) compared with patients in whom no relapse occurred (n = 23). Higher posttreatment maximal cortisol response on the DEX/CRH test was associated with shorter "relapse-free survival" (p = .05). CONCLUSIONS: In outpatients with clinically remitted major depression, higher posttreatment maximal cortisol levels on the DEX/CRH test were associated with relapse of major depression.

Cognitive functioning and well-being in euthyroid patients on thyroxine replacement therapy for primary hypothyroidism.

OBJECTIVE: Hypothyroidism is associated with neurocognitive impairment. Sparse data suggest that treatment of hypothyroidism, resulting in a return to euthyroidism, may be associated with only partial recovery of overall neurocognitive functioning. The aim of this study was to assess neurocognitive functioning and well-being in euthyroid patients with primary hypothyroidism on adequate thyroxine (T4) treatment. We also investigated whether serum TSH and thyroid antibodies are determinants of neurocognitive functioning and well-being. DESIGN: We assessed neurocognitive functioning and well-being in 141 patients with primary hypothyroidism. METHODS: Neurocognitive test results and scores on questionnaires measuring well-being of 141 patients were compared with the reference values for these tests as published and used in Dutch clinical neuropsychological practice. Assessment of neurocognitive functioning included tests for cognitive or psychomotor speed, attention, working memory as well as learning and memory. Well-being was measured with the Symptom Check List-90 total score and the Rand 36-item Health Survey subscales for 'mental health' and 'vitality'. RESULTS: Patients showed poor performance on various domains of neurocognitive functioning compared with mean standard reference values, especially on a complex attention task and on verbal memory tests. Levels of well-being were significantly lower for patients compared with those of the general population. Neither serum TSH nor thyroid antibodies were determinants of neurocognitive functioning and well-being. CONCLUSION: The results of this study suggest that neurocognitive functioning as well as psychological well-being may not be completely restored in patients with hypothyroidism, despite T4 treatment.

Polymorphisms in type 2 deiodinase are not associated with well-being, neurocognitive functioning, and preference for combined thyroxine/3,5,3'-triiodothyronine therapy.

INTRODUCTION: Some patients on levothyroxine replacement display significant impairment in psychological well-being, compared with sex- and age-matched controls. Levothyroxine-treated patients can be assumed to derive T3 exclusively from deiodination of T4, which, in the central nervous system, is regulated by type II deiodinase (DII). OBJECTIVE: We investigated whether two recently identified polymorphisms in the DII gene (DII-ORFa-Gly3Asp and DII-Thr92Ala) are determinants of well-being and neurocognitive functioning and associated with a preference for replacement with a combination of T3 and T4. METHODS: Genotypes for both polymorphisms were determined in 141 patients with primary autoimmune hypothyroidism, adequately treated with levothyroxine monotherapy and participating in a randomized clinical trial comparing T4 therapy with T4/T3 combination therapy. Questionnaires on well-being and neurocognitive tests were performed at baseline. RESULTS: Allele frequencies in patients with primary hypothyroidism were similar to those of healthy blood bank donors (32.0 vs. 33.9% for DII-ORFa-Gly3Asp and 40.4 vs. 38.8% for DII-Thr92Ala). DII polymorphisms were not associated with measures of well-being, neurocognitive functioning, or preference for combined T4/T3 therapy. CONCLUSION: The DII-ORFa-Gly3Asp and DII-Thr92Ala polymorphisms do not explain differences in well-being, neurocognitive functioning, or appreciation of T4/T3 combination therapy in patients treated for hypothyroidism.

Thyroid and adrenal axis in major depression: a controlled study in outpatients.

OBJECTIVE: Major depressive disorder has been associated with changes in the hypothalamus-pituitary-thyroid (HPT) axis and with hypercortisolism. However, the changes reported have been at variance, probably related to in- or outpatient status, the use of antidepressant medication and the heterogeneity of depression. We therefore conducted a controlled study in unipolar depressed outpatients who had been free of antidepressants for at least 3 months. DESIGN: We assessed endocrine parameters in 113 depressed outpatients and in 113 sex- and age-matched controls. METHODS: Patients were included if they had a major depression according to a Structural Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders (DSM), fourth edition (SCID-IV) and if they had a 17-item Hamilton rating scale for depression (HRSD) score of > or =16. Endocrine parameters contained serum concentrations of TSH, (free) thyroxine, tri-iodothyronine, cortisol, thyroid peroxidase (TPO) antibody titre and 24-h urinary excretion of cortisol. RESULTS: The serum concentration of TSH was slightly higher in depressed patients as compared with controls (P < 0.001), independent of the presence of subclinical hypothyroidism and/or TPO antibodies (n = 28). All other HPT axis parameters were similar in both groups. The 24-h urinary cortisol excretion was similar in patients and controls. In atypical depression, serum cortisol was lower than in non-atypical depression (P = 0.01). Patients with neither melancholic depression nor severe depression (HRSD > or =23) had altered endocrine parameters. Finally, serum TSH values could not be related to cortisol values. CONCLUSION: When compared with matched control subjects, outpatients with major depression had slightly higher serum TSH, while urinary cortisol levels were similar. Furthermore, we observed lower serum cortisol in atypical depression than in non-atypical depression.

Combined therapy with levothyroxine and liothyronine in two ratios, compared with levothyroxine monotherapy in primary hypothyroidism: a double-blind, randomized, controlled clinical trial.

Controversy remains about the value of combined treatment with levothyroxine (LT4) and liothyronine (LT3), compared with LT4 alone in primary hypothyroidism. We compared combined treatment with LT4 and LT3 in a ratio of 5:1 or 10:1 with LT4 monotherapy. We conducted a double-blind, randomized, controlled trial in 141 patients (18-70 yr old) with primary autoimmune hypothyroidism, recruited via general practitioners. Inclusion criteria included: LT4 treatment for 6 months or more, a stable dose for 6 wk or more, and serum TSH levels between 0.11 and 4.0 microU/ml (mU/liter). Randomization groups were: 1) continuation of LT4 (n = 48); 2) LT4/LT3, ratio 10:1 (n = 46); and 3) LT4/LT3, ratio 5:1 (n = 47). Subjective preference of study medication after 15 wk, compared with usual LT4, was the primary outcome measure. Secondary outcomes included scores on questionnaires on mood, fatigue, psychological symptoms, and a substantial set of neurocognitive tests. Study medication was preferred to usual treatment by 29.2, 41.3, and 52.2% in the LT4, 10:1 ratio, and 5:1 ratio groups, respectively (chi2 test for trend, P = 0.024). This linear trend was not substantiated by results on any of the secondary outcome measures: scores on questionnaires and neurocognitive tests consistently ameliorated, but the amelioration was not different among the treatment groups. Median end point serum TSH was 0.64 microU/ml (mU/liter), 0.35 microU/ml (mU/liter), and 0.07 microU/ml (mU/liter), respectively [ANOVA on ln(TSH) for linear trend, P < 0.01]. Mean body weight change was +0.1, -0.5, and -1.7 kg, respectively (ANOVA for trend, P = 0.01). Decrease in weight, but not decrease in serum TSH was correlated with increased satisfaction with study medication. Of the patients who preferred combined LT4/LT3 therapy, 44% had serum TSH less than 0.11 microU/ml (mU/liter). Patients preferred combined LT4/LT3 therapy to usual LT4 therapy, but changes in mood, fatigue, well-being, and neurocognitive functions could not satisfactorily explain why the primary outcome was in favor of LT4/LT3 combination therapy. Decrease in body weight was associated with satisfaction with study medication.

Triiodothyronine addition to paroxetine in the treatment of major depressive disorder.

There is evidence that thyroid hormone T3 increases serotonergic neurotransmission. Therefore, T3 addition to antidepressants may improve treatment response in major depression. In nonrefractory depression, T3 addition to tricyclic antidepressants indeed accelerates treatment response. Current therapeutic practice favors selective serotonin reuptake inhibitors. This is the first study to investigate the efficacy of T3 addition to paroxetine in major depression. One hundred thirteen patients with major depressive disorder were randomly assigned to 8 wk of double-blind outpatient treatment with low-dose T3 (25 microg), high-dose T3 (25 microg twice daily), or placebo in addition to paroxetine 30 mg daily. A total of 106 patients started treatment and were included in the outcome analysis. Response rate after 8 wk (reduction of Hamilton Rating Scale for Depression score > or = 50%) was 46% in all three treatment arms (P = 0.99). T3 addition did not accelerate clinical response to paroxetine, nor was an effect of T3 found when only women were analyzed. Patients on T3 addition reported more adverse events than patients on placebo comedication. In conclusion, these results do not support a role for T3 addition to selective serotonin reuptake inhibitors in the treatment of nonrefractory major depressive disorder. On the contrary, more adverse reactions occurred in T3-treated patients.