Fine particulate matter, vitamin D, physical activity, and major depressive disorder in elderly adults: Results from UK Biobank.

OBJECTIVE

The present study aims to investigate the association between PM exposure and major depressive disorder, and to examine whether vitamin D and physical activity could attenuate the impact of PM on major depressive disorder.

METHODS

39168 elderly adults (age≥60 years) who had valid estimates on exposure of PM in 2010 and data on major depressive disorder were extracted from the UK Biobank. Major depressive disorder was assessed by lifetime experience of mild, moderate, and severe major depression with validated instruments. Logistic regression models were used to estimate the association between PM exposure and major depressive disorder.

RESULTS

A total of 9079 participants had major depressive disorder, with a prevalence of 23.2%. The odds ratio (OR) of major depressive disorder was 1.096 (1.023, 1.175) for participants in the highest quartile compared with the lowest quartile of PM. The correlation of PM with major depressive disorder generally increased with the decreasing levels of vitamin D. For instance, in participants with the highest quartile of PM, the corresponding ORs were 1.141 (0.951, 1.369), 1.232 (1.027, 1.478), 1.286 (1.072, 1.543), and 1.390 (1.159, 1.667) for those who had adequate, desirable, insufficient, and deficient levels of vitamin D, respectively. Additionally, significant modification effects of physical activity on the relationship between PM and major depressive disorder were also observed.

CONCLUSIONS

Our study suggests that high levels of vitamin D and physical activity may attenuate the relationship between PM and major depressive disorder among elderly adults.