Age-dependent association of metabolic dyslipidemia with clinical expression of hypertrophic cardiomyopathy

Background: Previous studies have shown that the clinical expression of hypertrophic cardiomyopathy (HCM) can be determined by obesity and metabolic syndrome. The present study aimed to investigate the association between triglyceride and high-density lipoprotein cholesterol (HDL C) level, the two dyslipidemia-related components of metabolic syndrome, and the incidence of HCM. We also explored an age-dependent association between them. Methods: Individuals without previous HCM diagnosis who underwent a designated national health examination in 2009 were recruited. Individuals who used lipid-lowering medications within 1-year of the baseline were excluded. The outcome of interest was a newly diagnosed HCM. Results: Our cohort consisted of 8,652,709 individuals (mean 46 years, 55.6% men). During the median 9.3 years of follow-up, 5932 (0.07%) individuals were newly diagnosed with HCM. There was a gradual increase in the incidence of HCM towards higher triglyceride and lower HDL-C levels (log-rank p < 0.001). When stratified by age, the incidence of HCM was highest in individuals aged >= 65 years, followed by those aged 40-64 and 20-39 years (0.22% vs. 0.07% vs. 0.03%, log-rank p < 0.001). In individuals aged 20-39 years, a higher triglyceride level was associated with a higher incidence of HCM (i.e., >= 200 vs. <100 mg/dL: adjusted hazard ratio 2.28, 95% confidence interval 1.89-2.75), whereas there was no significant association in older groups (p-for-interaction<0.001). Similarly, a lower HDL-C level was associated with a higher incidence of HCM, particularly in individuals aged 20-39 years (p-for-interaction = 0.001). Conclusions: High triglyceride and low HDL-C levels are associated with a higher incidence of HCM, particularly in young individuals.