Abnormal blood biomarkers and trajectories of depressive symptoms among Chinese middle-aged and older adults

Abstract

Objective

Although previous studies have demonstrated allostatic load (AL) predicts depressive symptoms, few studies have considered the association between AL and trajectories of depressive symptoms. This study aims to systematically examine the associations of abnormal blood biomarkers in the three biological systems with trajectories of depressive symptoms.

Methods

A total of 6251 participants aged 45+ from the China Health and Retirement Longitudinal Study (CHARLS). Depressive symptoms were assessed using the 10-item Center for Epidemiological Studies Depression Scale (CESD-10) in five visits (waves 2011, 2013, 2015, 2018, and 2020). Biomarkers in three biological systems were evaluated based on standard criteria, including C-reactive protein in the inflammation system; systolic and diastolic blood pressures in the cardiovascular system; and high-density lipoprotein cholesterol (HDLC), total cholesterol/HDL-C ratio, and glycosylated hemoglobin (HbA1c) in the metabolic system. The trajectories of depressive symptoms were measured using group-based trajectory modelling (GBTM). Multinomial logistic regression models were conducted to examine the association between the number of abnormal biological systems and trajectories of depressive symptoms.

Results

Four different trajectories of depressive symptoms were identified: mild (44.22 %), moderate (42.09 %), increasing (9.39 %), and severe (4.30 %). Compared to participants with normal values of biomarkers in all three systems, those with abnormal values of biomarkers in three systems had a 2.26-fold risk of developing the severe depressive symptoms trajectory.

Conclusions

Our findings highlight the importance of monitoring multiple biological systems to prevent long-term accelerated severe depressive symptoms trajectory.