Thyroid echogenicity in manic-depressive patients receiving lithium therapy.
BACKGROUND
Lithium is known to induce subclinical or overt hypothyroidism and changes of thyroid volume in manic-depressive patients. Little is known about alterations of thyroid echogenicity due to drug-induced dysfunction.


METHODS
Twenty manic-depressive patients receiving lithium therapy for at least 6 months and 20 euthyroid volunteers without any antidepressive medication as control group, matched in age and gender, were investigated by laboratory measurements and thyroid ultrasonography including standardized grey scale analyses in representative regions of interest (ROI).


RESULTS
Thyroid function was normal in all patients (mean FT4 1.1+/-0.2 ng/dl, mean TSH 1.6+/-0.9 micro U/ml) and controls (mean FT4 1.5+/-0.4 ng/dl, TSH 1.1+/-0.3 micro U/ml). Except for two patients, no thyroid autoantibody levels could been detected. Thyroid volumetry revealed significant higher mean values for the lithium treated patients (16.9+/-11.9 ml) compared with the controls (11.4+/-4.5 ml, P<0.05) with a considerable number of goiters (six patients vs. one control). Thyroid echogenicities in both groups were similar (patients 23.9+/-3.7 grey scales, Grauwerteinheiten = GWE, controls 24.2+/-1.3 GWE) and did not depend on the size of the organs.


CONCLUSIONS
Lithium treatment contributes to increased thyroid volumes, probably due to inhibition of thyroid function and TSH upregulation, but not to changes of thyroid echo levels in patients with still euthyroid function. Further echogenicity studies on patients with lithium-induced overt hypothyroidism and autoimmune activity will be of special interest.
Medizinische Poliklinik, Klinikum Innenstadt der Ludwig-Maximilians-Universität München, Pettenkoferstr. 8a, 80336 München, Germany. uwe.schiemann@pk-i.med.uni-muenchen.de
Uwe
U
Schiemann
Karin
K
Hengst
D000328:Adult; D000368:Aged; D000928:Antidepressive Agents / Q000009:adverse effects / Q000627:therapeutic use*; D001714:Bipolar Disorder / Q000000981:diagnostic imaging / Q000188:drug therapy*; D005260:Female; D006801:Humans; D016651:Lithium Carbonate / Q000009:adverse effects / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D013960:Thyroid Function Tests; D013961:Thyroid Gland / Q000000981:diagnostic imaging / Q000187:drug effects*; D014463:Ultrasonography
D000928:Antidepressive Agents; D016651:Lithium Carbonate