Will smog affect my heart doctor?

18/03/24

Introduction

Cardiovascular disease (CVD), a leading cause of morbidity and mortality worldwide, has been thoroughly studied, and as such, has well known risk factors, including age, diet, family history, obesity and comorbidities like diabetes, hypertension and race (1). Genetics and environment play a role in the disease process, and epigenetic studies show that several processes like altered DNA methylation might predispose individuals to atherogenesis (2). Indeed, South Asians (Pakistanis, Indians and Bangladeshis) remain particularly affected as regards to cardiovascular health, with epidemiological evidence affirming the increased likelihood of atherosclerotic processes in the population (6.8% vs 4.4%; p<0.0001) (3).

A significant population of the South Asian diaspora reside in the United Kingdom, around 4% of the population, a number that has steadily risen in the past few years (4). As it happens, revisiting ‘home’ for holidays is a frequent practice, predisposing the population to risk factors abroad, with air pollution being perhaps the most prominent one.

According to 2021 European Society of Cardiology guidelines for cardiovascular disease prevention, individuals with a high risk of CVD should avoid regions with poor air quality and regular screening is recommended for the population living in such areas (5).

In recent years, Lahore, along with other parts of Punjab in Pakistan, has seen dense smog with air quality index (AQI) levels far exceeding the safe limit (6) which causes respiratory problems like asthma exacerbation, coughing and chronic bronchitis, but also has been particularly detrimental to cardiovascular health (7). However, despite the almost yearly occurrence, little to no data has emerged from Pakistan detailing the effects on cardiovascular system (CVS) associated mortality and morbidity (8), particularly from Punjab.