Risk Factors for Early-Onset Versus Late-Onset Coronary Heart Disease (CHD): Systematic Review and Meta-Analysis

Aim: We aimed to systematically compare literature on prevalence of modifiable and non-modifiable risk factors for early compared to late-onset coronary heart disease (CHD). Methods: PubMed, CINAHL, Embase, and Web of Science databases were searched (review protocol registered in PROSPERO CRD42020173216). Study quality was assessed using the National Heart, Lung and Blood Institute tool for observational and case-control studies. Review Manager 5.3 was used for meta-analysis. Effect sizes were expressed as odds ratio (OR) and mean differences (MD)/standardised MD (SMD) with 95% confidence intervals (CI) for categorical and continuous variables. Results: Individuals presenting with early-onset CHD (age <65 years) compared to late-onset CHD had higher mean body mass index (MD 1.07 kg/m²; 95% CI 0.31−1.83), total cholesterol (SMD 0.43; 95% CI 0.23−0.62), low-density lipoprotein (SMD 0.26; 95% CI 0.15−0.36) and triglycerides (SMD 0.50; 95% CI 0.22−0.68) with lower high-density lipoprotein-cholesterol (SMD 0.26; 95% CI -0.42−-0.11). They were more likely to be smokers (OR 1.76, 95% CI 1.39−2.22) and have a positive family history of CHD (OR 2.08, 95% CI 1.74−2.48). They had lower mean systolic blood pressure (MD 4.07 mmHg; 95% CI -7.36−-0.78) and were less likely to have hypertension (OR 0.47, 95% CI 0.39−0.57), diabetes mellitus (OR 0.56, 95% CI 0.51−0.61) or stroke (OR 0.31, 95% CI 0.24−0.42). Conclusion: A focus on weight management and smoking cessation and aggressive management of dyslipidaemia in young adults may reduce the risk of early-onset CHD.