There is emerging evidence that ambient air pollution exposure is linked with a variety of health outcomes, including respiratory, cardiovascular, metabolic and neurological disorders. Among air pollutants, particulate matter (PM) and nitrogen oxides have been identified by WHO and the European Environmental Agency as those of key human health concerns.1 2 Most non-communicable diseases have been associated, besides air pollution, with a number of behavioural risk factors, such as smoking, physical inactivity, alcohol consumption or unhealthy diet.3 4 An important question is whether the effects of air pollution on cardiometabolic health are modified by lifestyle factors5 or vice versa. The paper by Cai et al investigated the effects of long-term PM exposure on the hypertension and diabetes separately and as a combination of these outcomes, and the authors examined interaction effects between PM exposures and comprehensive set of lifestyle-related...]]>