Climate change and cardiovascular disease mortality: exploring the association in Puducherry, India

Abstract

Background and Aim: Climate change has far reaching consequences on all aspects of life, including health. Cardiovascular diseases (CVDs), the global leading cause of death, have also been found to be climate sensitive, mainly to temperature. However, the associations between CVDs and temperature are region-specific with relatively few studies on the topic from low-and-middle-income countries (LMICs). This study explores these associations in Puducherry, a coastal district in Eastern India. Methods: We analyzed the association between apparent temperature (Tapp) and CVD mortalities to estimate the burden of in-hospital CVD mortalities attributable to non-optimal temperatures between 2010-2020. We used a binomial regression model to analyze the temperature-mortality association along with a distributed lag non-linear model to capture the delayed and non-linear trends. Results: We found that the optimal temperature range for Puducherry is between 33⁰C and 35⁰C with respect to CVDs. Temperatures both above and below the optimal temperature range were associated with an increased risk of overall in-hospital CVD mortalities, resulting in a U-shaped association curve. Up to 20% of the CVD deaths could be attributable to non-optimal temperatures, with a slightly higher burden attributable to cold (11.2%) than heat (9.12%). We also found that males below 50 years of age were more vulnerable to colder temperatures while females above 50 years were more vulnerable to the heat. Mortality with cerebrovascular accidents was associated more with heat compared to cold, while ischemic heart diseases did not seem to be affected by temperature. Conclusions: This study analyses the temperature-CVD mortality association for the first time in the Puducherry district. It also identified the age and gender differences in temperature attributable CVD mortalities, which can be socio-cultural. Further studies from India could identify the regional associations and enhance the development of regional and contextual climate-health action plans. Keywords: climate-change, cardiovascular diseases,temperature, health, LMIC