PLASMA AND TISSUE ANTIOXIDANT MICRONUTRIENT LEVELS IN PSYCHIATRIC PATIENTS ATTENDING THE OBAFEMI AWOLOWO UNIVERSITY TEACHING HOSPITALS COMPLEX, ILE - IFE

Abstract

BACKGROUND: Antioxidant micronutrients including trace elements and vitamins are routinely
involved in metabolic processes and oxidation-reduction reactions in the central nervous system.
The relationship between antioxidant micronutrients and psychiatric disorders had not been
extensively investigated in the local population.
METHODS: Simple random sampling of age-matched subjects was used to recruit Seventy (70)
newly diagnosed patients with schizophrenia, Sixty (60) newly diagnosed patients with manic
depressive (bipolar-affective) disorder. Sixty (60) age-matched healthy individuals were recruited
as control group. Plasma levels of zinc, copper, manganese and selenium were measured using
atomic absorption spectrophotometer (AAS), toe nail levels of zinc, copper, manganese and
selenium were measured using inductively-coupled plasma optical emission spectroscopy (ICP
OES) while plasma levels of vitamins A, C and E were determined using high performance liquid
chromatography (HPLC).
RESULTS: Mean concentrations of plasma zinc (11.8 ± 3.4µmol/L), copper (19.3 ± 2.9µmol/L)
and manganese (7.1 ± 1.9nmol/L) among newly diagnosed patients with schizophrenia were
significantly lower compared to controls (16.7 ± 1.1µmol/L), (22.2 ± 2.5µmol/L) and (12.3 ±
2.1µmol/L) with p-values < 0.001 respectively. Mean concentrations of toe nail zinc (1.61 ±
0.2mmol/L), copper (566.5 ± 64.5µmol/L) and manganese (38.2 ± 3.6nmol/L) among newly
diagnosed patients with schizophrenia were significantly lower compared to controls (1.83 ±
0.2mmol/L), (637.3 ± 89.7µmol/ L) and (43.7 ± 5.5nmol/L) with p-values < 0.001 respectively.
Mean concentration of plasma selenium (1.3 ± 0.3µmol/L) in schizophrenic subjects was
significantly higher compared to control (0.8 ± 0.3µmol/L) ( p < 0.001). Mean concentration of
toe nail selenium (5.1 ± 0.6µmol/L) remains unchanged in subjects with newly diagnosed
schizophrenia when compared to control (5.1 ± 1.5µmol/L) (p > 0.05). In subjects with newly
diagnosed manic-depressive (bipolar-affective) disorder, the mean concentrations of plasma zinc
(11.3 ± 3.1µmol/L), copper (19.3 ± 3.7µmol/L) and manganese (7.2 ± 1.7nmol/L) were
significantly lower compared to controls (16.7 ± 1.1µmol/L), (22.2 ± 2.5µmol/L) and (12.3 ±
2.1nmol/L) respectively ( p < 0.001 in all groups). Mean concentration of toe nail zinc (1.55 ±
0.2mmol//L), copper (552 ± 75.5µmol//L) and manganese (38.2 ± 3.6nmol//L) among newly
diagnosed patients with manic-depression were significantly lower compared to controls (1.83 ±
0.2mmol//L), (637.3 ± 89.7µmol/L ) and (43.7 ± 5.5nmol//L) with p-values < 0.001 respectively.
The mean concentration of plasma selenium (1.3 ± 0.3µmol/L ) was significantly higher compared
to control (0.8± 0.3µmol//L) in subjects with manic-depression (p < 0.001). The mean
concentration of toe nail selenium (5.1 ± 0.8µmol/L) remains unchanged when compared to control
(5.1 ± 1.5µmol//L) (p > 0.05). The mean concentrations of plasma vitamins A (2.0 ± 0.3µmol/L),
C (49.4 ± 11.8µmol//L) and E (17.6 ± 5.2µmol//L) in patients with newly diagnosed schizophrenia
and in patients with manic-depressive ( bipolar-affective) disorder (2.1 ± 0.4µmol/L), (43.9 ±
10.6µmol/L) and (15.7 ± 4.0µmol/L) were significantly lower when compared to controls (2.5 ±
0.2µmol/L), 69.0 ± 10.0µmol/L) and 31.9 ± 7.5µmol/L) respectively ( p < 0.001 in all groups).
Pearson’s correlation analysis showed that only vitamins A, C and E concentrations of patients
with schizophrenia had a significant inverse relationship with the severity of illness using PANSS
score ( r = - 0.329, r = - 0.323, r = - 0.339) respectively. There was no significant relationship
between plasma and toe nail concentrations of zinc, copper, manganese and selenium and the
severity of illness in schizophrenia, mania and depression using PANSS, YMRS and PHQ-9 scales
respectively ( p > 0.05 in all groups). There was also no significant relationship between plasma
and toe nail concentrations of zinc, manganese and selenium among the three groups (p > 0.05 in
all groups). However, there was a significant positive correlation between plasma copper and toe
nail copper in control group
CONCLUSION: This study provides insight into an apparent disturbances and alterations in
metabolism and homeostasis of antioxidant micronutrient levels (trace elements and vitamins) in
psychiatric individuals. It is clear from this study that during the progression of psychiatric
disorders, there is significantly reduced scavenging activities of antioxidant vitamins which may
suggest a concomitant induction in cellular oxidative stress in psychiatric disorders. Further studies
are suggested to confirm these findings.