Impact of fast-food outlet density on incidence of myocardial infarction in the Hunter region

Background There is an established association between fast-food consumption and metabolic diseases. Some studies also suggest that calorie-dense food promotes a proinflammatory response, which is itself linked with myocardial infarction (MI). Whether increased fast-food availability is a risk factor for MI remains unknown. Aim To investigate the role of fast-food outlet density (FFD) as a novel environmental risk factor for MI in the Hunter region, New South Wales (NSW). Methods We conducted a retrospective cohort study using a database of all MI events between 1996 and 2013, extracted from the Hunter Cardiac and Stroke Outcomes unit. FFD was calculated for each local government area (LGA) of the Hunter region, allowing for a comparative analysis. Stratification by fast-food outlet data and LGA resulted in a total of 3070 cases. Weighted linear regression was used to investigate the role of FFD on incidence of MI in regional and rural Australia. Results FFD was positively correlated with rates of MI, remaining consistent in both single and multivariate predictor models adjusting for age, obesity, hyperlipidaemia, hypertension, smoking status, diabetes and socioeconomic status (P < 0.001). An increase of one fast-food outlet corresponded with four additional cases of MI per 100 000 people per year (4.07, 95% confidence interval, 3.86-4.28). Conclusions FFD was positively associated with incidence of MI in both rural and metropolitan areas of NSW. This relationship remained consistent after multivariate adjustment for standard cardiovascular risk factors, highlighting the importance of an individual's food environment as a potential contributor towards their health.

Automated summary

The study found a positive association between fast-food outlet density and incidence of myocardial infarction, with an increase of one fast-food outlet corresponding to four additional cases of MI per 100,000 people per year. This relationship remained consistent in both rural and metropolitan areas.