Independent associations of educational attainment and its joint associations with LE8 score for risk of cardiovascular disease incidence and mortality among Chinese people

Abstract Background/Introduction Educational attainment is a social determinant of health. Quantifying its associations with risk of cardiovascular disease (CVD) incidence and mortality has public health importance. Recently, the American Heart Association introduced the Life’s Essential 8 (LE8) score to evaluate CVD risk. However, it remains unclear how educational attainment and the LE8 score interact in their joint associations with CVD and mortality. Purpose To examine the associations of educational level with the incidence of CVD, including coronary heart disease (CHD) and stroke, and total mortality. Also, we examined the joint associations of educational level and the LE8 score with CVD incidence and total mortality. Methods We prospectively followed 91,744 Chinese adults from the Kailuan Study (2006-2021), who were free of CVD at baseline. Information on educational level, diet, lifestyle, and health conditions was collected every 2 years. LE8 score was calculated based on eight components: diet quality, physical activity, smoking status, sleep health, body mass index, blood lipids, blood glucose, and blood pressure. We used time-dependent Cox models to assess the associations of educational level with the outcomes as well as the joint associations of educational level and LE8 score, with adjustments for demographics, dietary and lifestyle factors, and medical history. Results During a mean follow-up of 13.1 years, there were 12,916 incident CVD cases and 13,090 deaths. Compared with the participants who only received illiteracy or elementary education, those who received high school education and above had a lower risk of CVD incidence (HR = 0.82, 95% CI = 0.76, 0.88), stroke incidence (0.72, (0.66, 0.79)), and total mortality (0.73, (0.68, 0.77)). Educational level was not associated with risk of CHD. Furthermore, significant additive interactions between educational attainment and LE8 score on the risk of CVD and mortality were observed (all p values for additive interactions <0.01). Compared with the participants who only received illiteracy or elementary education and had a low LE8 score, those who only received illiteracy or elementary education but had a high LE8 score still had a 27%-47% lower risk of CVD and total mortality, while those who received high school education and above and had a high LE8 score had a 51%-74% lower risk of CVD and total mortality. Conclusions Higher educational level was associated with a lower risk of CVD and mortality. These inverse associations were most apparent among participants with both a high educational level and a high LE8 score, while the participants with a low educational level but with a high LE8 score still had a significantly lower risk. These findings highlight the importance of improvement in educational attainment in preventing CVD events and deaths, and suggest that CVD events and deaths attributable to lower levels of education may be reduced by improving LE8 score.