Study Finds U-Shaped Relationship Between NHHR and Mortality Risk in Obese Adults

Obesity, commonly linked to dyslipidemia and a heightened risk of cardiovascular complications, remains a major contributor to overall mortality. The non-high-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio has emerged as a crucial marker for evaluating lipid imbalances. Recognizing its significance, Zi Lin, Department of Cardiology, Fujian Medical University Union Hospital, Fuzhou, China, and colleagues investigate the association between NHHR and mortality risk in obese individuals, providing deeper insights into its potential role in risk assessment and management.

For this purpose, the researchers analyzed data from the National Health and Nutrition Examination Survey (1999–2018) to explore the relationship between NHHR and mortality from all causes and cardiovascular disease. Multivariable Cox regression and restricted cubic splines (RCS) were utilized to assess this association. Segmented multivariable Cox regression and subgroup analyses were performed when segmented effects were observed. Multiple sensitivity analyses were conducted to ensure the reliability and robustness of the findings.

The study findings were as follows:

• The analysis included 7,504 participants, with a median follow-up of 119 months.
• During the follow-up, 866 participants died from all causes, including 318 deaths due to cardiovascular disease.
• Restricted cubic spline (RCS) analysis revealed a U-shaped association between NHHR and mortality, with the lowest risk points at 3.409 for cardiovascular mortality and 3.369 for all-cause mortality.
• Below the cut-off value, each 1 mmol/L increase in NHHR was associated with a lower risk of cardiovascular mortality (HR = 0.68) and all-cause mortality (HR = 0.82).
• Above the cut-off point, NHHR was positively linked to an increased risk of cardiovascular mortality (HR = 1.18) and all-cause mortality (HR = 1.13).
• Sensitivity analyses confirmed the robustness of these findings, with no significant interactions in NHHR levels observed across different subgroups.

The researchers found that NHHR demonstrated a U-shaped association with cardiovascular and all-cause mortality in obese adults. Their findings highlight the importance of monitoring and managing NHHR levels to mitigate mortality risk in this population.

"However, the study emphasized the need for validation across diverse countries and ethnic backgrounds to assess the generalizability of their findings. Further studies are required to confirm the minimum risk threshold and determine its applicability to specific populations in different settings," the researchers concluded.

Reference:

Lin, Z., Yi, T., Hu, F., Chen, J., & Chen, L. (2025). U-shaped association between the non-high-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio and mortality risk in obese adults: Evidence from NHANES 1999–2018. Frontiers in Cardiovascular Medicine, 11, 1524465. https://doi.org/10.3389/fcvm.2024.1524465