Increased Serum Cystatin C Levels Were Associated with Depressive Symptoms in Patients with Type 2 Diabetes

Background: Existing studies have reported that patients with diabetes mellitus (DM) have an increased risk of depressive symptoms. We aimed to evaluate the association between serum cystatin C levels and depressive symptoms in DM patients. Methods: Serum levels of cystatin C were measured in 254 patients with DM at baseline. Cox proportional hazard analysis was used to evaluate the value of serum cystatin C in predicting depressive symptoms in patients with DM. Results: Multivariate linear regression analysis showed that serum cystatin C levels were independently associated with Centre for Epidemiological Studies Depression (CES-D) scores after adjusting for age, sex, body mass index (BMI), current smoking status, current drinking, admission systolic and diastolic blood pressure (BP), cardiovascular disease (CVD) history and laboratory measurements in patients with DM at baseline (S beta= -0.127; 95% CI, - 0.185- - 0.083; P=0.002). The multivariate Cox proportional hazard analysis revealed that serum cystatin C (HR=2.360, 95% CI 1.500-3.891, P-trend <0.001) was an independent prognostic factor for cognitive decline in these patients with DM during the follow-up period. Conclusion: Our results showed that increased serum cystatin C levels were significantly and independently associated with depressive symptoms and had independent predictive value for depressive symptoms in patients with DM. Serum cystatin C might enable early recognition of depressive symptoms among DM patients.