Hyperthyroid Rage: When Bipolar Disorder Hides the Real Disorder

Lithium can cause hyperthyroidism as well as hypothyroidism: A systematic review of an under-recognised association

OBJECTIVE

Hypothyroidism is a well-documented consequence of lithium treatment. Less well known is a possible association between lithium therapy and hyperthyroidism. This may have clinical implications as rapid changes in thyroid hormones may worsen a person's affective state, while symptoms of hyperthyroidism can mimic those of mania. We therefore systematically reviewed the published literature for evidence of lithium-induced hyperthyroidism.

METHODS

We searched PubMed, Embase and CINAHL for articles where individuals developed biochemically confirmed hyperthyroidism (with or without clinical symptoms), while on lithium therapy for an affective illness. We included case reports, case series, cross-sectional, case control and cohort studies.

RESULTS

We included 52 studies, 39 of which were individual case reports and 3 were case series. There were 10 cross-sectional or case control or cohort studies. All the research designs suggested an association between the prescription of lithium and hyperthyroidism. However, these findings were limited by the quality of the included studies, small number of participants and the general lack of either a clear temporal relationship or dose response.

CONCLUSION

Hyperthyroidism is an uncommon side-effect of lithium compared to hypothyroidism but may have clinical implications. However, large prospective studies are required to clarify this association and to further inform the management of patients treated with lithium where hyperthyroidism occurs.

Thyroid stimulating hormone testing in ED evaluation of patients with atrial fibrillation and various psychiatric diagnoses

BACKGROUND

Previous studies of thyroid stimulating hormone (TSH) levels in Emergency Department (ED) patients largely have centered on patients with atrial fibrillation (AF). In our ED patients with AF as well as patients with Psychiatric diagnoses (psych) are screened. The purpose of the present study was to compare TSH levels in the 2 groups. Our hypotheses were that an abnormal TSH and/or AF predicted the need for hospital admission and that TSH is more likely decreased in AF and increased in psych patients.

METHODS

Our goal in the study was to compare the use of TSH testing in two ED populations, AF vs. psych patients. The study was a cross sectional cohort of AF vs. psych patients who had TSH levels drawn in the ED over a two year period. Our laboratory ranges were used to determine high vs. low TSH. Two chart examiners collected data after a training process. Charts were reviewed extracting demographic data, TSH levels, outcome (admit vs. discharge), history of AF, thyroid disease, psych diagnoses, presence of CHF, diabetes, hypertension. We compared AF vs. Psych groups using chi square and t-tests for parametric data. Odds ratios were calculated for comparisons between the 2 groups. For non-parametric data Mann Whitney U was used. A logistic regression was performed with the outcome of admission vs. discharge to find predictors of hospital admission. Kappa was calculated for inter-rater agreement. An a priori power analysis showed 80% power with 2 groups of 100 with an absolute difference of 20% between the 2 groups.

RESULTS

252 patients were included, 101 with AF and 152 Psych. Demographics differed in age only with AF patients being older. Mean TSH for AF vs. 2.4 for AF, 2.9 for psych (NS) with no differences in percentages with high or low TSH in the 2 groups. Fifty-three patients had abnormal TSH levels (21%), 27% of AF and 17% of Psych patients (NS). There were significant differences in incidence of CHF, DM, HTN, and tachycardia with more in the AF group (P < 0.001). Significantly more of the psych patients had a history of hypothyroidism (OR 2.28). Our logistic regression showed that taking into account demographics including age, the only predictors of admission were the presence of CHF (aOR 18.6) and having a diagnosis of AF (aOR 4.0).

CONCLUSION

There were no differences in TSH levels between the 2 groups. Twenty-one percent had an abnormal level. CHF and AF predicted hospital admission on regression analysis. Many with these AF or Psych diagnoses had abnormal ED TSH levels that could be useful in diagnosis, maintenance, or continuous treatment for their conditions diagnoses.