Background: Depression is reported to be the most common psychological problem in patients with chronic kidney disease (CKD). Several studies have reported that lower levels of serum vitamin D are significantly associated with depression. Both vitamin D deficiency and depression are prevalent in patients with CKD, yet the relationship between these two factors remains poorly understood. This study aimed to investigate the association between vitamin D levels and depression among CKD patients.
Methods: Totally, 21,257 individuals who participated in the Korean National Health and Nutrition Examination Survey (KNHANES V, VI) from 2010-2014 were screened for the study; 533 CKD patients were included. Vitamin D deficiency was defined as serum 25-hydroxyvitamin D3 [25(OH)D3] ≤10 ng/mL. Patients were divided into vitamin D deficient or sufficient groups. Depression was screened for using the Korean version of the WHO Composite International Diagnostic Interview-Short Form. The association between vitamin D deficiency and depression was evaluated by multivariate logistic regression analysis.
Results: The mean participant age was 70.1±9.4 years; 262 patients (49.2%) were male. The median 25(OH)D3 level was 19.1±6.9 ng/mL. The prevalence of depression was higher in CKD patients than in the general population (14.3 vs. 11.1%, P = 0.03). Additionally, the prevalence of depression was significantly higher in CKD patients with (vs. without) vitamin D deficiency (32.5% vs. 50.0%, P<0.001). Multivariate logistic regression analysis showed that vitamin D deficiency was a significant independent predictor of depression after adjusting for confounding factors (adjusted odds ratio, 6.15; 95% confidence interval, 2.02-8.75; P = 0.001).
Conclusion: Depression was highly prevalent in CKD patients, in whom vitamin D deficiency was a significant independent predictor of depression. Therefore, management of vitamin D deficiency might help prevent depression in CKD patients.