A novel lipid index reflecting the balance between atherogenic and anti-atherogenic lipoproteins may help refine long-term sudden cardiac death (SCD) risk assessment. In a prospective cohort study published in Nutrition, Metabolism and Cardiovascular Diseases, a higher non-high-density lipoprotein cholesterol-to-high-density lipoprotein cholesterol ratio (NHHR) was associated with increased SCD risk in middle-aged and older men and improved risk discrimination beyond established cardiovascular risk factors.

The analysis included 2,575 men aged 42 to 61 years from the Finnish Kuopio Ischemic Heart Disease cohort who underwent baseline serum lipoprotein measurement. During a median follow-up of 27.8 years, 294 SCD events occurred. Cox regression models were used to estimate hazard ratios (HRs) with adjustment for multiple cardiovascular risk factors.

NHHR and non-high-density lipoprotein cholesterol (non-HDL-C) showed positive linear dose-response associations with SCD risk, whereas high-density lipoprotein cholesterol (HDL-C) showed an inverse association. The adjusted HR per 1 standard deviation increase was 1.68 (95% CI, 1.30-2.17) for NHHR and 2.40 (95% CI, 1.54-3.73) for non-HDL-C. Comparing extreme quartiles, the HR was 2.23 (95% CI, 1.55-3.21) for NHHR and 2.04 (95% CI, 1.44-2.89) for non-HDL-C.

For HDL-C, the adjusted HR per 1 standard deviation decrease was 2.33 (95% CI, 1.33-4.07), while the bottom versus top quartile comparison yielded an HR of 1.63 (95% CI, 1.13-2.34). Adding NHHR to a model with established risk factors significantly improved discrimination (ΔC-index 0.0079; P=0.037), whereas non-HDL-C and HDL-C did not. These findings suggest NHHR may offer incremental value for long-term SCD risk assessment in men.