Triglyceride levels and risk of cardiovascular disease and all-cause mortality in Chinese adults younger than 40 years old: a prospective cohort study.

Background: Data on the associations of triglyceride (TG) levels with cardiovascular disease (CVD) and all-cause mortality mainly focused on the middle-aged or elderly population, with limited information available for younger adults. This study aimed to identify such associations among Chinese young adults.

Methods: This study included Chinese adults younger than 40 years free of CVD, cancer, and lipid-lowering agents at baseline in the Kailuan study who were enrolled during 2006 through 2016. All participants were biennially followed up till December 2020. The enzymatic colorimetric method was used to measure baseline fasting TG. Participants were categorized into four groups by quartiles of TG, with the lowest quartile (Q1) as the reference group. The primary outcomes were CVD [composite of myocardial infarction (MI) and ischemic stroke] and all-cause mortality. CVD and mortality risks were estimated with Cox regression models.

Results: A total of 43,882 participants were included. Their mean age was 30.6±5.56 years, and 80.2% were males. During a median follow-up of 11.2 years, 298 CVD events and 345 deaths occurred. The incidences of CVD and all-cause mortality were 0.67 and 0.76 per 1,000 person-years, respectively. Compared with individuals in the lowest quartile (Q1), participants in the highest quartile (Q4) showed a 126% higher risk of developing CVD [adjusted hazard ratio (HR) 2.26; 95% confidence interval (CI): 1.56 to 3.29; P=0.001] and a 61% higher risk of all-cause mortality (adjusted HR 1.61; 95% CI: 1.14 to 2.28; P=0.007). In addition, analyses of CVD subtypes showed that adjusted HRs (Q4 vs. Q1) were 3.25 (95% CI: 1.33 to 7.97; P=0.01) for MI, and 1.88 (95% CI: 1.16 to 3.04; P=0.01) for ischemic stroke.

Conclusions: Among Chinese young adults, elevated fasting TG levels were associated with increased CVD and all-cause mortality risks.