Classification of hypothyroidism in evaluating patients after radioiodine therapy by serum cholesterol, T3-uptake. Total T4, FT4-index, total T3, basal TSH and TRH-test

Adjunctive thyroid hormone treatment in rapid cycling bipolar disorder: A double-blind placebo-controlled trial of levothyroxine (L-T4 ) and triiodothyronine (T3 )

OBJECTIVES

This report describes the first comparative double-blind, placebo-controlled trial of levothyroxine (L-T₄ ) and triiodothyronine (T₃ ) as adjunctive treatments in rapid cycling bipolar disorder.

METHODS

Thirty-two treatment-resistant, rapid cycling patients who had failed a trial of lithium were randomized into three treatment arms: L-T₄ , T₃ , or placebo. They were followed for ≥4 months with weekly clinical and endocrine assessments.

RESULTS

There were no statistically significant differences between the groups in age, gender, duration of illness, or thyroid status. Markov chain analyses were employed to assess treatment effects on cycling patterns among mood states (euthymia, depression, mania, and mixed). Within groups, post-treatment the L-T₄ group spent significantly less time depressed or in a mixed state and greater time euthymic. The T₃ and placebo groups did not differ significantly pre- and post-treatment in any mood state, although the pattern of effects was the same for the T₃ group as for the L-T₄ group. Between groups, the L-T₄ group had a significantly greater increase in time euthymic and decrease in time in the mixed state than the placebo group. Other group differences were not significant, although they were in the expected direction.

CONCLUSIONS

The findings in this first double-blind study directly comparing the effects of L-T₄ and T₃ therapy against placebo provide evidence for the benefit of adjunctive L-T₄ in alleviating resistant depression, reducing time in mixed states and increasing time euthymic. Adjunctive T₃ did not show statistically significant evidence of benefit over placebo in reducing the time spent in disturbed mood states.

Subclinical hypothyroidism, mood, and cognition in older adults: a review

OBJECTIVES

To perform a critical review of the literature on the mood and cognitive changes associated with subclinical hypothyroidism (SCH), with an emphasis on older adults. To evaluate these data against the Consensus Statement on the management of SCH from the American Association of Clinical Endocrinologists, the American Thyroid Association, and The Endocrine Society.

METHOD

A comprehensive literature review.

RESULTS

Subclinical hypothyroidism may be associated with an increased risk of mood and cognitive dysfunction, although the strength of this association and the efficacy of replacement hormone therapy require further investigation.

CONCLUSION

It remains unclear whether SCH leads to significant mood and cognitive impairments in most older patients. More research is required to determine the nature and extent of this association and whether thyroid hormone replacement therapy is appropriate and effective in treating SCH-associated neurobehavioral impairments.

Cognitive and neuropsychiatric aspects of subclinical hypothyroidism: significance in the elderly

The effects of overt hypothyroidism (HO) on cognition and mood are well established, and HO is considered a common cause of reversible dementia. There is now increasing evidence to suggest that subclinical hypothyroidism (ie, elevated thyroid stimulating hormone in the presence of normal thyroxine concentrations) may be a predisposing factor for depression, cognitive impairment, and dementia. Subclinical hypothyroidism is more common than HO and is most prevalent in the elderly, particularly in women. Older adults may be more vulnerable to the effects of subclinical hypothyroidism, given age-related changes to the hypothalamic-pituitary-thyroid axis, and there is an association between thyroid status and cognitive decline and dementia in the elderly. The purpose of this review is to summarize existing data on the cognitive and neuropsychiatric consequences of subclinical hypothyroidism, benefits of treatment, and recommendations for screening and monitoring in older adults.

Crohn’s disease and risk of fracture: does thyroid disease play a role?

AIM: To assess the role of thyroid disease as a risk for fractures in Crohn’s patients.

METHODS: A cross-sectional study was conducted from 1998 to 2000. The study group consisted of 210 patients with Crohn’s disease. A group of 206 patients without inflammatory bowel disease served as controls. Primary outcome was thyroid disorder. Secondary outcomes included use of steroids, immunosuppressive medications, surgery and incidence of fracture.

RESULTS: The prevalence of hyperthyroidism was similar in both groups. However, the prevalence of hypothyroidism was lower in Crohn’s patients (3.8% vs 8.2%, P = 0.05). Within the Crohn’s group, the use of immunosuppressive agents (0% vs 11%), steroid usage (12.5% vs 37%), small bowel surgery (12.5% vs 28%) and large bowel surgery (12.5% vs 27%) were lower in the hypothyroid subset as compared to the euthyroid subset. Seven (3.4%) Crohn’s patients suffered fracture, all of whom were euthyroid.

CONCLUSION: Thyroid disorder was not found to be associated with Crohn’s disease and was not found to increase the risk for fractures. Therefore, screening for thyroid disease is not a necessary component in the management of Crohn’s disease.

Novel uses of thyroid hormones in patients with affective disorders

Hormones of the thyroid axis have been used to treat patients with any of several mental illnesses. However, in recent decades interest has focused almost exclusively on depression, though thyroid hormones, mainly thyroxine (T4), are used with lithium in rapid cycling bipolar disorder, a condition in which depression and mania rapidly alternate. In depression L-triiodothyronine (T3) has been used in preference to T4 because of its rapid onset and offset of action. In women starting treatment, T3 hastens the onset of therapeutic action of standard antidepressant drugs. It fails to do so in depressed men, who anyway respond faster than women to standard antidepressants. Standard drugs fail to produce satisfactory improvement in one-quarter to one-third of depressed patients. Then, in both men and women, T3 converts about two-thirds of drug failures to successes in rapid fashion. Lithium, which has antithyroid properties, produces a similar conversion rate. The majority of depressed patients are grossly euthyroid, but many show one or another subtle change in thyroid axis activity. However, the thyroid state of patients has not been matched systematically with their response to thyroid hormone augmentation. It seems likely that a tendency toward hypothyroidism can predispose to depression, but when depression occurs in a euthyroid patient, the thyroid axis is often invoked in the process of restitution.

Borderline hypothyroidism and depression

This review defines subclinical hypothyroidism and examines its influence on the occurrence and course of major depression. Recommendations are presented for the identification and treatment of patients with coexisting mood disorders and borderline thyroid failure.

Subclinical hypothyroidism: neurobehavioral features and beneficial effect of L-thyroxine treatment

Frank hypothyroidism is known to induce neurological and mental dysfunction. The aim of this study was to assess selected neuropsychological and behavioral features by means of standardized tests in a group of 14 patients with subclinical hypothyroidism who were free from neuropsychological complaints and to evaluate the possible effects of L-thyroxine treatment on their performance. Patients were submitted to the Crown and Crisp Experiential Index and to the Wechsler Memory Scale; their ratings on the neurobehavioral tests and their thyroid hormone profile were compared to those of a control group of 50 age- and sex-matched subjects. Comparison was also carried out between pretreatment ratings and those obtained following a 6-month L-thyroxine course (0.1-0.15 mg/day). The Wechsler Memory Scale ratings showed a significant impairment in patients' memory-related abilities [memory quotient (MQ) = 89.1 +/- 2.9; P = 0.002 (patients versus controls)]; the Crown and Crisp Experiential Index ratings demonstrated moderate differences between untreated patients and controls with respect to hysteria (P = 0.03), anxiety (P = 0.05), somatic complaints (P = 0.0005), and depressive features (P = 0.002) scales; the total score was also significantly higher (42.0 +/- 3.8; P = 0.005). After L-thyroxine treatment the patients' performances showed an improvement in memory skills, as evaluated by the Wechsler Memory Scale [MQ = 99.9 +/- 4.0; P = 0.002 (treated versus untreated)]; somatic complaints (P = 0.02) and obsessionality (P = 0.04) ratings and the Crown and Crisp Experiential Index total score (P = 0.04) significantly decreased with respect to untreated patients.(ABSTRACT TRUNCATED AT 250 WORDS)