Dear Editor

I recently have read with great interest an article by Ali Hamidi Madani and colleagues, entitled “Associated Factors for Erectile Dysfunction Occurrence in Patients with Coronary Artery Disease: A Cross-sectional Study”, which was published in your esteemed journal (IJMS Vol 50, No. 1, January 2025). ¹ The authors provided valuable insights into the relationship between erectile dysfunction (ED) and coronary artery disease (CAD) severity. However, I would like to highlight several methodological concerns that might limit the conclusions of the study.

First, the study considered “being married” as an inclusion criterion, which prompted a selection bias by excluding unmarried men with CAD who might also be at risk. According to 2017 data, approximately 11% of Iranian men over 30 were unmarried, and this figure has likely increased in recent years. ² Excluding this population might overlook key demographic variations, potentially skewing the results.

Second, several confounding factors were not adequately addressed. While the study excluded numerous comorbidities, it failed to account for hypertension, a well-documented contributor to ED. ³ Additionally, neurologic disorders (e.g., Parkinson’s disease, lumbar disc herniation), which have reported ED prevalence rates of 68% and 77%, respectively, ^{4 , 5} were not explicitly considered in patient selection. Furthermore, although the study excluded patients taking beta-blockers and diuretics, it failed to mention other commonly used anti-hypertensive drugs, such as calcium channel blockers, angiotensin receptor blockers (ARBS), and angiotensin-converting enzyme (ACE) inhibitors, which might influence ED. ³ Adjusting for or excluding these confounders could strengthen the validity of the findings.

Lastly, the study relied solely on self-reported data (International Index of Erectile Function [IIEF-15] questionnaire), which is susceptible to recall bias and fails to differentiate between vasculogenic and psycho-neurogenic causes of ED. The authors suggested that ED should prompt cardiovascular risk assessment. However, this assumed the reported ED prevalence was primarily due to vascular dysfunction rather than neuropsychological factors. Penile duplex Doppler ultrasonography (PDDU) offers a minimally invasive approach to evaluate both arterial insufficiency and veno-occlusive dysfunction, while dual-energy CT arteriography provides a non-invasive alternative for assessing the penile arterial system and shows high sensitivity and specificity in the diagnosis of arterial ED diagnosis. ⁶ Incorporation of these robust diagnostic approaches could significantly enhance diagnostic certainty and provide a more definitive pathophysiological characterization of ED in CAD patients.

In conclusion, while the study contributed meaningfully to the CAD-ED literature, the aforementioned limitations warrant caution in interpreting the results. Future research should incorporate broader confounding factors and objective tools for ED assessments. I appreciate the authors’ work and hope this letter aids both researchers and readers in refining future studies.

Conflict of Interest:

None declared.

References

1. Hamidi Madani A, Mirbolouk F, Naghshbandi M, Hasandokht T, Gholipour M, Zabihi MS, et al. Associated Factors for Erectile Dysfunction Occurrence in Patients with Coronary Artery Disease: A Cross-sectional Study. Iran J Med Sci. 2025; 50:37-43. Publisher Full Text | DOI | PubMed [ PMC Free Article ]
2. UNdata [Internet].. Population by marital status, age, sex and urban/rural residence. [cited 17 September 2024). Available from: https://data.un.org/Data.aspx?d=POP&f=tableCode%3A23
3. Lou IX, Chen J, Ali K, Chen Q. Relationship Between Hypertension, Antihypertensive Drugs and Sexual Dysfunction in Men and Women: A Literature Review. Vasc Health Risk Manag. 2023; 19:691-705.
4. Kinateder T, Marinho D, Gruber D, Hatzler L, Ebersbach G, Gandor F. Sexual Dysfunctions in Parkinson’s Disease and Their Influence on Partnership-Data of the PRISM Study. Brain Sci. 2022; 12 doi
5. Panneerselvam K, Kanna RM, Shetty AP, Rajasekaran S. Impact of Acute Lumbar Disk Herniation on Sexual Function in Male Patients. Asian Spine J. 2022; 16:510-8. Publisher Full Text | DOI | PubMed [ PMC Free Article ]
6. Pang K, Pan D, Xu H, Ma Y, Wang J, Xu P, et al. Advances in physical diagnosis and treatment of male erectile dysfunction. Front Physiol. 2022; 13:1096741. Publisher Full Text | DOI | PubMed [ PMC Free Article ]