Trends in low-density lipoprotein cholesterol level among Chinese young adults hospitalized with first acute myocardial infarction

Background: Representative data has shown a linear increase in mean low-density lipoprotein cholesterol (LDL-C) levels among Chinese adults, contributing to the burden of atherosclerotic cardiovascular disease (ASCVD). This study aimed to assess the trends in LDL-C levels and their association with coronary artery stenosis during the first acute myocardial infarction (AMI) in young Chinese adults. Methods: A retrospective study including 2,781 adults, aged 18-44 years, hospitalized for their first AMI in Beijing Anzhen hospital between 2007 and 2017 was performed. Results: Mean LDL-C level was 2.82 +/- 0.97 mmol/L with the prevalence of elevated LDL-C being 21.6% (601/2,781). Of the study, only 4.2% were aware of their elevated LDL-C status. Neither mean LDL-C concentration nor prevalence of elevated LDL-C showed a downward trend between 2007 and 2017 (P>0.05). Patients aged <35 years had the highest LDL-C level and frequency of elevated LDL-C among the three age groups (aged <35, 35-39, and 40-44 years; P<0.01). Patients with LDL-C >= 3.4 mmol/L evinced a more than 50% increased risk of coronary artery stenosis compared with those with LDL-C <1.4 mmol/L [adjusted odds ratio (OR) 3.19; 95% confidence interval (CI): 1.62 to 6.29]. Of the study, 62.0% had at least two conventional risk factors (RFs), and smoking, accompanied by hypertension, obesity, or elevated LDL-C were the most common combinations. Conclusions: The current study provides an overview of trends in LDL-C level and elevated LDL-C among young adults at the time of first AMI. Patients had a high prevalence of elevated LDL-C but low awareness of this status. Coronary artery stenosis was positively correlated with LDL-C level. Preventive strategies, including public education regarding cholesterol levels and benefits of maintaining LDL-C below 3.4 mmol/L should be considered for young adults as a primary preventive strategy.