Trace elements in bipolar disorder.
BACKGROUND
Trace elements may play an important role in bipolar disorders. The objective of this study is to determine serum copper and zinc, blood lead and cadmium and urine lead, cadmium and thallium concentrations in patients diagnosed with bipolar disorders and to compare these levels with those of a healthy control group.


METHODS
A total of 25 patients diagnosed with bipolar disorder and 29 healthy subjects participated in this study. Serum copper and zinc concentrations were measured using flame atomic absorption spectrometry; the blood lead and cadmium concentrations were measured by electrothermal atomization atomic absorption spectrometry with Zeeman background correction; urine lead, cadmium and thallium concentrations were measured by inductively coupled plasma mass spectrometry.


RESULTS
Median blood and urine lead and cadmium levels were significantly higher among the bipolar patients than among the control group: Blood lead (μg/dL): patient median: 3.00 (IQR: 1.40-4.20); control median (μg/dL): 2.20 (IQR: 0.90-3.00) p=0.040. Blood cadmium (μg/L): patient median: 0.39 (IQR: 0.10-1.15); control median: 0.10 (IQR: 0.10-0.17) p<0.001. The median of cadmium (μg/L) in patients who smoked (1.20 IQR: 0.44-2.30) was higher than that in non-smokers (0.12 IQR: 0.10-0.34) p<0.001. There was a statistically significant increase (p=0.001) in zinc levels among patients in the manic phase (mean 111.28, SD: 33.36 μg/dL) with respect to the control group (mean 86.07, SD: 12.39 μg/dL).


CONCLUSIONS
The results suggest that there could be higher levels of some toxic trace elements in the group of patients with bipolar disorder than in the healthy control group.
Trace Element Unit and Laboratory Medicine Department, Hospital Clínico San Carlos, Madrid, Spain. montse@cmpx.net
Montserrat
M
González-Estecha
Elena M
EM
Trasobares
Kazuhiro
K
Tajima
Sara
S
Cano
Cristina
C
Fernández
José Luis
JL
López
Belén
B
Unzeta
Manuel
M
Arroyo
Filiberto
F
Fuentenebro
D001714:Bipolar Disorder / Q000097:blood* / Q000150:complications / Q000652:urine*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012907:Smoking / Q000097:blood / Q000652:urine; D019966:Substance-Related Disorders / Q000097:blood / Q000150:complications / Q000652:urine; D014131:Trace Elements / Q000097:blood* / Q000652:urine*
D014131:Trace Elements