title: Bone mineral density during maintenance treatment with supraphysiological doses of levothyroxine in affective disorders: a longitudinal study.
abstract: BACKGROUND
  This prospective study was designed to determine whether patients with prophylaxis-resistant affective disorders, receiving adjunctive maintenance therapy with supraphysiological doses of levothyroxine (L-T4), show evidence of accelerated bone loss compared to the reference population database.
  
  
  METHODS
  In 21 patients, bone mineral density (BMD) of the spine (lumbar vertebrae L1-L4) and femur (femoral neck, trochanter, and Ward's triangle) was measured by dual energy X-ray absorptiometry (DXA). BMD measurement was performed first after patients had been on thyroid-stimulating hormone (TSH)-suppressive therapy with L-T4 (mean dose=411 mcg/d) for an average of 16.4 months and again after 33.6 months of L-T4 (mean dose=416 mcg/d) therapy.
  
  
  RESULTS
  There was no statistically significant difference between the actual percentage decline in bone mineral density and the expected percentage decline in any of the measured bone regions. In a stepwise linear regression analysis, age was identified as a predictor of percentage change in BMD. After controlling for age, the only other variable that showed a consistent trend was the dose of L-T4, with higher doses being positively correlated with the percentage decline of BMD.
  
  
  CONCLUSIONS
  Relatively small sample size, no bone density assessment prior to treatment with L-T4, no patient control group with mood disorders who did not receive L-T4 treatment, and bone density follow-up intervals were variable.
  
  
  CONCLUSIONS
  This study did not demonstrate evidence that long-term treatment of affectively ill patients with supraphysiological doses of L-T4 significantly accelerates loss of bone mineral density compared to the age-matched reference population. However, the decline of BMD in one individual patient underscores that caution is indicated and that regular assessment of BMD during longer-term supraphysiological thyroid hormone treatment is needed.
authors.affiliation: Department of Psychiatry and Psychotherapy, Charité-University Medicine Berlin, Campus Charité Mitte, Berlin, Germany. michael.bauer@charite.de
authors.forename: Michael
authors.initials: M
authors.lastname: Bauer
authors.forename: Lynn
authors.initials: L
authors.lastname: Fairbanks
authors.forename: Anne
authors.initials: A
authors.lastname: Berghöfer
authors.forename: Johannes
authors.initials: J
authors.lastname: Hierholzer
authors.forename: Tom
authors.initials: T
authors.lastname: Bschor
authors.forename: Christopher
authors.initials: C
authors.lastname: Baethge
authors.forename: Natalie
authors.initials: N
authors.lastname: Rasgon
authors.forename: Johanna
authors.initials: J
authors.lastname: Sasse
authors.forename: Peter C
authors.initials: PC
authors.lastname: Whybrow
mesh_terms: D015502:Absorptiometry, Photon; D000328:Adult; D001714:Bipolar Disorder / Q000175:diagnosis / Q000188:drug therapy* / Q000523:psychology; D015519:Bone Density / Q000187:drug effects*; D003865:Major Depressive Disorder / Q000175:diagnosis / Q000188:drug therapy* / Q000523:psychology; D004305:Dose-Response Relationship, Drug; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011618:Psychotic Disorders / Q000175:diagnosis / Q000188:drug therapy* / Q000523:psychology; D013974:Thyroxine / Q000008:administration & dosage / Q000009:adverse effects*
chemical_list: D013974:Thyroxine