International variations in air pollution and cardiometabolic risk among Ghanaian migrants: The RODAM study

Background and aim: Long-term exposure to ambient air pollution has many links to cardiovascular diseases. However, its role on migrant populations, especially those who originated in low-and-middle-income countries is less well known. The aim of this project was to examine the relationship between ambient air pollution and cardiovascular risk factors in the Research on Obesity and Diabetes Among African Migrants (RODAM) study. Methods: We examined cardiovascular risk factors (hypertension and/or diabetes) for 5,889 Ghanaian migrants living either in Berlin (578), Amsterdam (1,663), London (1,120) or urban (1,449) or rural Ghana (1,109). Ambient PM2.5 and NO2 was predicted using global satellite models and paired to the residential co-ordinates for RODAM participants living in Europe and to pooled area co-ordinates for those in Ghana. Logistic regression models evaluated the relationship between ambient air pollutants and cardiovascular risk factors. Results: Overall, inverse or null relationships were observed for PM2.5 and NO2 when examining hypertension and diabetes separately. However, for those with one (or both) of these conditions, a positive association with NO2 was observed where a 5 µg/m3 increase in NO2 was associated with an OR of 1.16 (95% CI: 1.00, 1.34). This association varied across the various RODAM sites including an inverse relationship in rural Ghana (OR: 0.87, 95% CI: 0.24, 1.02) a null relationship in Berlin (OR: 0.99, 95% CI: 0.72, 1.27) and a positive relationship in London (OR: 1.05, 95% CI: 1.02, 1.63). Conclusions A positive association between having one or more cardiovascular risk factor and NO2 was observed. However, no such association was observed when examining risk facts individually. A more detailed analysis, including more precise pollution predictions (including more information on domestic fuel use) and a wider array of cardiovascular risk factors (e.g. BMI) is required to better understand this relationship. Keywords Migrant health; Air pollution; Cardiovascular health