Temperature and Cardiovascular Mortality Associations in Four Southern Chinese Cities: A Time-Series Study Using a Distributed Lag Non-Linear Model

Abstract

Abstract:Few studies on population-specific health effects of extreme temperature on cardiovascular diseases (CVDs) deaths have been conducted in the subtropical and tropical climates of China. We examined the association between extreme temperature and CVD across four cities in China. We performed a two-stage analysis; we generated city-specific estimates using a distributed lag non-linear model (DLNM) and estimated the overall effects by conducting a meta-analysis. Heat thresholds of 29 • C, 29 • C, 29 • C, and 30 • C and cold thresholds of 6 • C, 10 • C, 14 • C, and 15 • C were observed in Hefei, Changsha, Nanning, and Haikou, respectively. The lag periods for heat-related CVD mortality were observed only for 0-2 days, while those of cold-related CVD mortality were observed for 10-15 days. The meta-analysis showed that a 1 • C increase above the city-specific heat threshold was associated with average overall CVD mortality increases of 4.6% (3.0%-6.2%), 6.4% (3.4%-9.4%), and 0.2% (−4.8%-5.2%) for all ages, ≥65 years, and <65 years over a lag period of 0-2 days, respectively. Similarly, a 1 • C decrease below the city-specific cold threshold was associated with average overall CVD mortality increases of 4.2% (3.0%-5.4%), 4.9% (3.5%-6.3%), and 3.1% (1.7%-4.5%), for all ages, ≥65 years, and <65 years over a lag period of 0-15 days, respectively. This work will help to take appropriate measures to reduce temperature-mortality risk in different populations in the subtropical and tropical climates of China.

Mapping the increased minimum mortality temperatures in the context of global climate change

“…A total of 210 papers investigated the relationships between daily temperature and human mortality counts for non-external causes using the DLNM method. Excluding the literature from the repeated study areas, 16 papers 1,[11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] of which are chosen. These studies involved 420 locations from 30 countries, covering six continents (Antarctica was excluded).…”

dLagM: An R package for distributed lag models and ARDL bounds testing

“…Bello et al [17] employ DLMs for modelling the longitudinal effects of chemicals to figure out the time-delayed effect of an exposure on an outcome. Huang et al [18] investigate the association between cardiovascular mortality and temperature using nonlinear DLMs. Zhu et al [19] analyze the relationship between air pollution and years of life lost using nonlinear DLMs.…”

“…The dlnm package takes into account nonlinear and delayed relationships between dependent and independent series, simultaneously. Huang et al [18] and Zhu et al [19] employ the dlnm package for fitting nonlinear DLMs in their studies. Although this approach provides a powerful solution for fitting nonlinear DLMs, it requires a good understanding of the idea of cross-basis functions and their construction with dlnm for linear DLMs.…”

Modelos de predição de óbitos por doenças cardiovasculares utilizando variáveis ambientais e estudo exploratório com cenários de mudanças climáticas

“…Da literatura, inúmeros estudos mostram que tanto eventos extremos de frio quanto de calor são prejudiciais à saúde humana. Tipicamente, os trabalhos apresentam uma associação não-linear entre risco relativo de óbito por doença cardiovascular e temperatura de exposição, observando-se aumento do risco a partir de determinados limiares de temperatura, como exemplificado na Figura 2.1, na qual se observa uma elevação do risco relativo para temperaturas médias abaixo de 15 °C ou acima de 25 °C (LIU et al, 2015;HUANG et al, 2017;SILVEIRA et al, 2021).…”

“…No entanto, os trabalhos também mostram que os limiares de temperatura variam de acordo com o local ou a região na qual o estudo foi realizado (SILVEIRA et al, 2019;SILVEIRA et al, 2021). Dessa forma, evidencia-se que diferentes populações podem estar mais ou menos adaptadas às variações de temperatura ambiente, e que outros fatores ambientais, tais como níveis de poluição ou acesso a moradias com isolamento térmico, são relevantes para o entendimento do impacto de eventos climáticos extremos na saúde de uma determinada população (HUANG et al, 2017;MOGHADAMNIA et al, 2017;SONG et al, 2017).…”