Association Between Inflammatory Markers And Depressive Symptoms Among Chinese Adults

ObjectiveThe prevalence of depression in the general population has risen sharply over the past few decades and has become a worldwide public health problem.Increasing evidence suggests that chronic inflammation plays an important role in the pathogenesis of depression.In order to better understand the role of inflammation in the pathogenesis of depression,we designed a cross-sectional study to investigate the relationships between several markers of inflammation(serum high-sensitivity CRP,WBC count,neutrophil count,lymphocyte count and neutrophil to lymphocyte ratio)and the prevalence of depressive symptoms in the adult population of Tianjin.MethodsTianjin Chronic Low-Grade Systemic Inflammation and Health(TCLSIHealth)Cohort Study data from 2013 to 2016 was used to perform a cross-sectional analysis in the present study.After the relevant inclusion exclusion criteria,6891 participants were eventually included in the study.Epidemiological data collected by professional investigators cover social demographic characteristics,lifestyle data,physical measurement data,and laboratory biochemical test data.Depressive symptoms were assessed using the Zung Self-Rating Depression Scale(SDS).The total score ranged from 20 to 80 points,and participants with a score of 45 or more were considered to have depressive symptoms.Analysis of variance and logistic regression analysis were used to describe differences in basic characteristics of populations based on the different levels of inflammatory markers.Levels of inflammatory markers and the prevalence of depressive symptoms were selected as independent variables,and dependent variables,respectively.Multivariate logistic regression analysis was used to assess the association between serum inflammatory markers and depressive symptoms in both male and female populations.ResultsIn the present study,the overall prevalence of depressive symptoms was 15.34% among all participants,and 13.85% and 17.42% for males and females,respectively.In men,participants with depressive symptoms status tended to have a lower level of physical activity(P<0.001),vegetable intake(P<0.01),education,employ as Managers,household income and visiting to friends(P<0.001),but they were more likely to be current smokers(P<0.001).In women,those with depressive symptoms status were more likely to be current smokers and living alone(P<0.01),and have a lower level of physical activity(P<0.001),total energy intake,education,employ as Managers,household income and visiting to friends(P<0.01).Among women,NLR levels(both as quartiles and as continuous variables)were positively associated with the presence of depressive symptoms in the final adjustment model.After final multiple adjustments,the ORs of depressive symptoms were 1.00(reference),1.19(95 % CI 0.90,1.57),1.27(95 % CI 1.02,1.66),1.42(95 % CI 1.09,1.85),respectively,for participants with NLR in the 1st,2nd,3rd and 4th quintiles(P for trend=0.017).The multivariate-adjusted OR for depressive symptoms per unit increase of NLR was 1.38(95% CI 1.05,1.82;P<0.01).This suggests a positive association between serum NLR levels and the presence of depressive symptoms,but no significant association was found in men.In addition,there was no significant correlation between high sensitivity C-reactive protein,white blood cell count,neutrophils,lymphocytes and the presence of depressive symptoms.ConclusionsThis study showed a positive association between depressive symptoms and NLR levels in women but not in men,which persisted even after adjusting for potential confounders.There was no significant association between serum high sensitivity C-reactive protein,white blood cell count,neutrophils,lymphocytes concentrations and the presence of depressive symptoms.These findings support the view that inflammation is related to depression,but this association may be gender-specific.Additional experimental and longitudinal studies are needed to better understand the biological mechanisms of sex differences and provide an effective theoretical basis for the prevention and treatment of depression.