An increased atherogenic index is associated with a higher risk of erectile dysfunction

New research highlights the crucial role of lipid profile in men’s health, revealing that higher levels of atherogenic index may not only signal heart problems but also significantly increase the risk of erectile dysfunction.

Study: Association between plasma atherogenic index and erectile dysfunction in US men: a population-based cross-sectional study. Image source: Rocos / Shutterstock

In a recent study published in International Journal of Impotence ResearchA group of researchers specifically examined the relationship between the atherosclerotic index (AIP) (the ratio of triglycerides to HDL cholesterol, a marker of the severity of coronary artery disease) and erectile dysfunction (ED) (the inability to maintain an erection) using data from the National Health and Nutrition Examination Survey (NHANES).

Background

Erectile dysfunction (ED), or the inability to achieve or maintain an erection sufficient for satisfactory sexual intercourse, affects a significant percentage of men worldwide.

While not life-threatening, ED can significantly impact a man’s physical and mental health, as well as their relationships. It shares risk factors with cardiovascular disease (CVD), such as atherosclerosis (narrowing of the arteries due to the buildup of plaque), endothelial dysfunction (impaired function of the lining of blood vessels, affecting circulation), and inflammation, making ED a potential biomarker of CVD.

AIP, a measure of cardiovascular risk based on lipid profiles, is gaining popularity. However, the exact mechanisms linking AIP and ED require further investigation, particularly through large-scale population studies in diverse cohorts.

Understanding this relationship is clinically important as it may lead to better risk assessment and early intervention strategies for both erectile dysfunction and cardiovascular disease.

About the study

The study population was selected from the NHANES database, and all participants provided informed consent. NHANES uses complex sampling designs, interviews, laboratory tests, and physical examinations to assess the health status of the U.S. population.

Data from two cycles of NHANES (2001–2002 and 2003–2004) were selected for analysis because these cycles included information on ED and AIP. Exclusion criteria included participants over 70 years of age (due to higher prevalence of confounding health conditions), missing data on AIP or ED, participants over 70 years of age, and individuals with incomplete information on important variables such as poverty income index (PIR), body mass index (BMI), and hypertension.

Participants reported their ability to achieve and maintain an erection, and responses were classified as “never,” “usually,” “sometimes,” or “almost always.” Those who responded “sometimes” or “never” were classified as having ED. AIP was calculated as log10 (triglycerides (TG)/high-density lipoprotein cholesterol (HDL-C)). Covariates included age, BMI, glycemia, PIR, ethnicity, cholesterol level, marital status, diabetes, hypertension, education, CVD, alcohol consumption, hyperlipidemia (high blood fat), and smoking status. These covariates were grouped into categories such as demographic factors, health status, and lifestyle factors to provide a more comprehensive analysis.

Statistical analysis was performed using R software, applying sampling weights to reflect the complex study design of NHANES. Linear regression was used for continuous variables, chi-square tests for categorical variables, and multivariable logistic regression to assess the association between AIP and ED.

A comprehensive set of sensitivity analyses was conducted to confirm the robustness of the findings, particularly using a stricter definition of ED (patients who “never” achieved a satisfactory erection). This approach ensured that the observed associations between AIP and ED were not due to methodological inconsistencies. Statistical significance was set at P < .05.

Research results

In the study, AIP was significantly higher in participants with ED (0.21 ± 0.02) compared to those without ED (0.08 ± 0.01), showing a strong statistical difference (P < 0.0001). In addition, those with ED tended to have higher age, BMI, fasting blood glucose (FBG), TG, alcohol consumption, diabetes, CVD, smoking, and hypertension, while their HDL-C levels, education, and PIR were lower. A higher proportion of ED patients were also married or lived with a partner.

The study found statistically significantly higher AIP in participants with ED, indicating its potential as a biomarker for predicting the risk of ED. The association between AIP and ED was rigorously analyzed, and the results indicated that AIP, treated as a continuous variable, was positively associated with ED.

This association remained statistically significant after adjustment for various factors, including age, race, education, and marital status, and after further adjustment for additional covariates. When AIP was divided into tertiles, a progressive increase in the odds of developing ED was observed across tertile groups, further supporting the association between higher levels of AIP and increased risk of ED.

Sensitivity analyses further strengthened these findings by showing that the association between AIP and ED was not only statistically significant but also consistent, even when using more stringent criteria for defining ED. A generalized additive model and smooth curve fitting further demonstrated a positive, linear association between AIP and ED.

Subgroup analyses showed that the risk of ED was particularly high in individuals over 50 years of age, non-Hispanic whites, individuals with cardiovascular disease, and individuals with a low or moderate BMI.

These results underscore the importance of considering specific population characteristics when assessing the risk of ED associated with AIP. No significant interactions were detected in the subgroups analyzed.

In sensitivity analyses using a stricter definition of ED (patients who “never” achieved a satisfactory erection), the association between AIP and ED remained strong, confirming the robustness of the initial findings. The linear positive association between AIP and severe ED persisted in these analyses.

Sensitivity subgroup analyses also showed stronger associations in older adults, those with moderate BMI, and patients with hypertension or diabetes, further underlining the association between AIP and ED, especially in specific populations. When AIP was divided into tertiles, a progressive increase in the odds of developing ED was observed across tertile groups, further supporting the association between higher AIP levels and increased risk of ED.

Conclusions

In summary, this study not only identified a significant association between higher AIP levels and increased risk of ED among U.S. men, but also demonstrated the robustness of these findings through rigorous sensitivity analyses and detailed subgroup assessments. Even after adjustment for potential confounders, the association between elevated AIP and ED remained strong.

These results are consistent with similar studies conducted at the same time, further supporting the reproducibility of the results. Sensitivity analyses strengthened the association, and the study also found a higher incidence of CVD among ED patients. This suggests that atherogenic dyslipidemia, indicated by elevated AIP levels, may play a role in the development of ED.

The implications for clinical practice are significant. Early assessment of AIP may be crucial to identify individuals at increased risk of developing ED, particularly in specific subpopulations such as those with CVD or metabolic disorders.

Further research should focus on elucidating the causal mechanisms underlying this association and exploring the potential for targeted interventions to reduce the risk of ED in individuals with high AIP.