The correlation of serum concentration of copper and prevalence of depressive mood in psychiatric night shift nurses

Abstract

Objective The aim of this study was to investigate the correlation of serum copper levels and mental health in psychiatric shift nurses. Methods The participants were divided into day shift nurses (control group,n=60) and night shift nurses (n=60) . The concentrations of trace mineral, serum biochemical levels, inflammatory and oxidative markers in blood samples of 120 shift nurses were measured. The depressive mood was measured with second edition of Chinese version of the Beck Depression Inventory,(BDI-Ⅱ) . Results The night shift nurses showed moderate-to-severe depression levels, which were significantly higher than those of the day shift nurses, 23.3% (14/60) and 11.7% (7/60) vs. 6.7% (4/60) and 1.7% (1/60) ,χ2=6.536, 4.82,P < 0.05. Night-shift nurses also had higher levels of serum copper, hs-CRP, IL-6, T-SOD and Cu-Zn SOD than the control group, (19.57±4.14) μmol/L vs. (18.03±3.20) μmol/L, 1.32 (0.78-1.89) mg/L vs.0.89(0.45-1.44) mg/L, 68.54 (51.43-96.78) ng/L vs. 56.39 (35.56-78.71) ng/L, (66.78± 14.72) kU/L vs. (47.32±17.84) kU/L, (54.22±14.91) kU/L vs. (48.17±17.23) kU/L,t=-3.133~-2.057,P < 0.01 or 0.05. BDI-Ⅱscores correlated positively with serum copper, hs-CRP, IL-6, T-SOD and Cu-Zn SOD,r=0.248-0.457, all P <0.01. In night shift group, multivariate regression analysis showed that serum copper, hs-CRP, IL-6 and T-SOD (β=0.097-5.340,P<0.01 or 0.05) were independently related factors influencing BDI-Ⅱ scores (R2 = 0.609,P = 0.000) . Conclusions Serum copper may serve as an evaluation index for depressive mood in psychiatric shift nurses, and serum copper concentrations in night shift nurses should be monitored regularly. Clinical Trial Registry Chinese Clinical Trial Registry, ChiCTR-OOC-14005540. Key words: Psychiatric; Night shift; Nurse; Depressive mood; Copper