Long-term exposure to airborne particulate matter and NO and prevalent and incident metabolic syndrome - Results from the Heinz Nixdorf Recall Study.

INTRODUCTION

Recently, epidemiological studies have found a link between air pollution (AP) and individual components of the metabolic syndrome (MetS), a condition predisposing to cardiometabolic diseases. However, very few studies have explored a possible association between air pollution and MetS.

OBJECTIVE

We analyzed the effects of long-term exposure to airborne particulate matter and NO on prevalence and incidence of MetS.

METHODS

We used data of the population-based prospective Heinz Nixdorf Recall study (baseline 2000-2003) to investigate the association(s) between AP exposure and MetS prevalence at baseline (n = 4457) and MetS incidence at first follow-up visit (n = 3074; average follow-up: 5.1 years). Mean annual exposure to size-fractioned particulate matter (PM, PM, PM, and PMabs) and nitrogen dioxide (NO) was assessed using a land use regression model. MetS was defined as central obesity plus two out of four additional risk factors (i.e., elevated triglycerides, reduced high-density lipoprotein cholesterol, elevated blood pressure or elevated plasma glucose). We estimated odds ratios (ORs) of MetS prevalence and incidence per interquartile range (IQR) of exposure, adjusting for demographic and lifestyle variables.

RESULTS

We observed a MetS prevalence of 20.7% (n = 922) and an incidence of 9.7% (n = 299). NO was positively associated with MetS prevalence, with an OR increase per IQR of 1.12 (95%-CI 1.02-1.24, IQR = 6.1 μg/m). PM and PM were both borderline positively associated with MetS incidence, with ORs of 1.14 (95%-CI 0.99-1.32, IQR = 2.1 μg/m) and 1.19 (95%-CI 0.98-1.44, IQR = 1.5 μg/m) per IQR, respectively.

CONCLUSION

In summary, we found a weak positive association between air pollution and MetS. The strongest and most consistent effects were observed between NO and prevalent MetS.