The Relationship between Depressive Symptoms and Modifiable Lifestyle Risk Factors in Office Workers

Background: This study investigated the relationship between depressive symptoms and physical fitness, obesity indices, and vitamin D status in office workers. Methods: The subjects were 514 adults with more 30 years of experience as office workers in the city of Seoul. Lifestyle risk factors, obesity indices, physical fitness, and serum vitamin D levels were assessed with a standardized protocol. The Beck Depression Inventory (BDI) was used to assess depression status. Vitamin D status was assessed by measuring serum 25-hydroxyvitamin D concentrations. Based on the BDI scores, participants were classified into no depression (ND, $BDI{\leq}9$), mild depression (MiD, $10{\leq}BDI{\leq}15$), and moderate depression (MoD, $16{\leq}BDI{\leq}23$) groups. Results: Compared with the high cardiorespriatory fitness group, the low cardiorespiratory fitness (men OR=2.618, women OR=1.596) an middle cardiorespiratory fitness group (men OR=1.256, women OR=1.110) had significantly higher odds ratio for having depressive symptoms, even after adjustment for age, hypertension, diabetes, hyperlipidemia, cardiovascular disease, alcohol intake, smoking, body mass index (BMI), percent body fat (%BF), and waist circumference (WC). Compared with the insufficient or deficient vitamin D group , the sufficient vitamin D group had significantly lower odds ratios for having depressive symptoms (men OR=0.121, women OR=0.114), even after adjustment for age, hypertension, diabetes, hyperlipidemia, cardiovascular disease, alcohol intake, smoking, BMI, %BF, and WC. Conclusion: Vitamin D supplementation and outdoor activities should be key components of a lifestyle intervention against office workers' depression.