Temporal trends of the burden of ischemic stroke attributable to high low-density lipoprotein cholesterol in China from 1999 to 2019.

Background: High levels of low-density lipoprotein cholesterol (LDL-C) can lead to the occurrence and development of atherosclerosis, which is one of the important risk factors for ischemic stroke (IS). However, details regarding the evolution of the IS burden attributable to high LDL-C in China has not been available. The objective of this study was to examine the changes over time, from 1990 to 2019, in the burden of IS attributed to high levels of LDL-C in China and to estimate the individual impacts of age, period, and cohort on the burden of IS associated with high LDL-C.

Methods: Detailed data on IS burden attributable to high LDL-C from 1990 to 2019 in China were extracted from the Global Burden of Disease (GBD) Study 2019. The numbers and age-standardized rates of IS-related mortality and disability-adjusted life years (DALYs) attributable to high LDL-C were assessed by age and sex. The annual percentage change (APC) and average annual percentage change (AAPC) in the burden of IS due to high LDL-C were analyzed using Joinpoint regression model. The age-period-cohort analysis was carried out to assess the individual impacts of age, period, and cohort on the trends over time of mortality and DALY rate.

Results: The number of IS-related deaths and DALYs due to high LDL-C in China were 182.7 thousand and 4.43 million in 2019, respectively, both more than double the corresponding numbers reported in 1990. However, despite these increased, the age-standardized mortality rate (ASMR) and age-standardized DALY rate (ASDR) remained unchanged. In 2019, men under 84 years of age had higher death and under 79 years of age had higher DALYs than women. However, above these ages, the gender disparities were reversed. Furthermore, age-specific rates of death, as well as DALY of IS attributable to high LDL-C in 2019 increased with age for both women and men, except for death in adults over 95 years old; and were greater in men than in women. From 1990 to 2019, males consistently had a higher ASMR and ASDR than females in China. During 1990-2019, the ASMR in women slightly decreased before 1997, sharply increased from 1997 to 2004, and then continuously decreased from 2004 to 2019, with an overall AAPC value of -0.4% (95% CI -0.8%, -0.0%). However, for the ASMR of men in China, the overall trend is upward and the AAPC is 0.5%(95% CI 0.1%, 0.8%). The ASDR in women and men had the similar trend as the ASMR over the time, with an AAPC of -0.4% (95% CI -0.7%, -0.1%) and 0.3% (95% CI 0.1%, 0.5%), respectively. The age-period-cohort analysis indicated a rise in period effects and a decline in cohort effects on mortality and DALY rate associated with IS caused by high LDL-C in both genders. Age effect on mortality rates from IS due to high LDL-C showed an exponential increased with age in all women and men except for the 60-69 age group and over 95 age group. The age relative risk of IS DALY rate due to high LDL-C increased with age in both genders except for 65-74 age group and over 95 age group.

Conclusions: From 1990 to 2019, the burden of IS caused by high LDL-C in China significantly increased among both sexes combined and among men, while significantly decreased among women. Elderly have a substantial burden of IS attributable to high LDL-C. Therefore, effective and tailored strategies based on gender and age for IS primary prevention and management of IS and high LDL-C are urgently needed in China.