The effect of cigarette smoking on vitamin D level and depression in male patients with acute ischemic stroke

Abstract

Objective: The association between low vitamin D levels and depression has been well documented in nonstroke subjects. Accumulating evidence shows that low vitamin D levels may be also associated with depression post stroke. Cigarette smoking was associated with lower vitamin D levels. The purposes of this study were to compare vitamin D levels in smokers to nonsmokers and examine the association between vitamin D levels and depression symptoms in patients with acute ischemic stroke.

Materials and methods: Serum levels of 25-hydroxyvitamin D [25(OH)D] were measured in 194 males within 24h after admission: 116 smokers and 78 nonsmokers. Depression symptoms were assessed with the 17-item Hamilton Depression Scale (HAMD-17). Patients with the HAMD-17 score >7 were identified to have depression symptoms.

Results: The chi-square test showed that the frequency of depression in the smoker group was 23.3% (27/116), which was significantly higher than that in the nonsmoker group (11.5%=9/78), with an odds ratios (OR) of 2.33 (95% CI: 1.03-5.27; χ(2)=4.25, df=1, p=0.039, φ=0.15). Vitamin D levels were significantly lower in smokers than in nonsmokers (52.4±20.8 vs 61.7±19.2; F=9.88, p=0.002), with an effect size of 0.05 (ηp(2)). Patients with depression symptoms showed lower vitamin D levels than those with no depression symptoms (49.2±19.6 vs 57.7±20.6; F=5.03, p=0.03), with an effect size of 0.03 (ηp(2)).

Conclusion: Higher rates of depression in smokers with acute ischemic stroke may be associated with lower vitamin D levels induced by smoking.