Time trends in cardiovascular disease mortality attributable to non-optimal temperatures in China: An age-period-cohort analysis using the Global Burden of Disease Study 2019

Abstract

Background: Associations between non-optimal temperatures and cardiovascular disease (CVD) mortality risk have been previously reported, yet the trends of CVD mortality attributable to non-optimal temperatures remain unclear in China. We analyzed trends in CVD mortality attributable to non-optimal temperatures and associations with age, period, and birth cohort.

Methods: Data were obtained from the Global Burden of Disease Study (GBD) 2019. Joinpoint regression analysis was used to calculate annual percent change (APC) and average annual percent change (AAPC) from 1990 to 2019. We used the age-period-cohort model to analyze age, period, and cohort effects in CVD mortality attributable to non-optimal temperatures between 1990 and 2019.

Results: The age-standardized mortality rate (ASMR) of CVD attributable to non-optimal temperature generally declined in China from 1990 to 2019, whereas ischemic heart disease (IHD) increased slightly. Low temperatures have a greater death burden than high temperatures, but the death burden from high temperatures showed steady increases. Joinpoint regression analysis showed that CVD mortality decreased in all age groups except for IHD, and the decreases were greater in females than in males. The mortality of CVD attributable to non-optimal temperatures of males was higher than females. The mortality rate showed an upwards trend with age across all CVD categories. Period risks were generally found in unfavorable trends. The cohort effects showed a progressive downward trend during the entire period.

Conclusion: Although there have been reductions in CVD mortality attributable to non-optimum temperatures, the mortality of IHD has increased and the burden from non-optimal temperatures remains high in China. In the context of global climate change, our results call for more attention and strategies to address climate change that protect human health from non-optimal temperatures.

Keywords: age-period-cohort model; cardiovascular diseases; mortality; myocardial ischemia; non-optimal temperatures; stroke.

Figure 1

The trends of age-standardized mortality rate (ASMR) for CVD (A), stroke (B), and IHD (C) mortality attributable to non-optimal temperatures during 1990–2019 and the corresponding 95% CI.

Figure 2

Age-specific mortality of CVD attributable to non-optimal temperatures from 1990 to 2019 and cohort-specific mortality of CVD attributable to non-optimal temperatures from 1990 to 2019. (A–C) Survey years were arranged into consecutive 6-year periods from 1990 to 1994 (median, 1992), 1995 to 1999 (median, 1997), 2000 to 2004 (median, 2002), 2005 to 2009 (median, 2007), and 2010 to 2014 (median, 2012), and the CVD, stroke, and IHD mortality attributable to non-optimal temperatures increased with age group. (D–F), the data of CVD, stroke, and IHD mortality attributable to non-optimal temperatures were arranged into 17 consecutive birth cohorts, including those born from 1910 to 1914 (median, 1912) to 1990 to 1994 (median, 1992), and successive 5-year age intervals from 25 to 29 years (median, 27 years) to 80 to 84 (median, 82 years) years of age.

Figure 3

Joinpoint regression analysis in sex-specific age-standardized mortality rate (ASMR) of CVD, stroke, and IHD attributable to non-optimal temperatures from 1990 to 2019. (A) CVD in males; (B) CVD in females; (C) stroke in males; (D) stroke in females; (E) IHD in males; (F) IHD in females. Notes: an asterisk indicates that the annual percent change is statistically significantly different from zero at the α = 0.05 level.

Figure 4

Parameter estimates of age, period, and cohort effects on CVD, stroke, and IHD mortality attributable to non-optimal temperatures from 1990 to 2019. (A, D, G) Age relative risk of CVD, stroke, and IHD mortality attributable to non-optimal temperatures and the corresponding 95% CI. (B, E, H) Period relative risks of CVD, stroke, and IHD mortality attributable to non-optimal temperatures and the corresponding 95% CI. The period relative risk was adjusted for age and nonlinear cohort effects. (C, F, I) Cohort relative risks of CVD, stroke, and IHD mortality attributable to non-optimal temperatures and the corresponding 95% CI. The cohort relative risk was adjusted for age and nonlinear period effects.