Can atherogenic indices and the triglyceride-glucose index be used to predict erectile dysfunction?

Background: Atherosclerosis and insulin resistance play an important role in the development of erectile dysfunction (ED), and few studies have comprehensively evaluated more specific indicators like atherogenic indices and the triglyceride-glucose (TyG) index in the assessment of ED. Aim: This study aimed to reveal the role of atherogenic indices (atherogenic index of plasma [AIP], Castelli risk index-1/2 [CRI-1/2], and atherogenic coefficient [AC]) based on plasma lipid ratios, which have been used as more sensitive indicators of atherosclerosis in recent years, and the TyG index, a practical indicator of insulin resistance, in predicting vasculogenic ED. Methods: The study included a total of 199 patients who met the inclusion criteria and a total of 51 control subjects without ED complaints according to the International Index of Erectile Function (IIEF-5) scores (>21) between May 2021 and October 2022. For all participants, the demographic and biochemical parameters were evaluated, and atherogenic indices, namely CRI-1 (total cholesterol/high-density lipoprotein [HDL]), CRI-2 (LDL/HDL) AIP [log10(triglycerides/HDL)], and AC (non-HDL/HDL), as well as the TyG index [Ln {fasting triglycerides (mg/dL) x fasting glucose (mg/dL)/2}] were calculated. Outcomes: The TyG index, which is an indicator of insulin resistance, and atherogenic indices such as CRI-1, AIP, and AC were significantly associated with ED, and especially AIP and the TyG index seem to be more important in the evaluation of ED. Results: According to the univariate analysis, the patient group had significantly higher CRI-1 (5.3 +/- 1.4 vs 4.7 +/- 1.3; P = .005), AIP (0.31 +/- 0.26 vs 0.13 +/- 0.2; P < .001), AC (4.1 +/- 1.4 vs 3.70 +/- 1.2; P = .026), and TyG (9.16 +/- 0.71 vs 8.77 +/- 0.52; P < .001) values compared with the control group. In the correlation analysis, a significant negative correlation was found between the AIP and TyG index and the IIEF-5 scores (r(2) = 0.120, P < .001 between AIP and IIEF-5; r2 = 0.091, P < .001 between TyG index and IIEF-5). The multivariate analysis revealed AIP and the TyG index as independent predictive factors for ED. Clinical Implications: The use of atherogenic indices and TyG index in daily urology practice can help physicians in the diagnosis and follow-up of ED. Strengths and Limitations: The lack of sex hormone-binding globulin and free testosterone levels represents a limitation of our study. Another limitation is that the severity of ED was determined using the IIEF-5 scores, rather than a more objective method, such as penile artery ultrasound. Conclusion: Atherogenic indices and the TyG index can be used as inexpensive and practical markers to predict the severity of arteriogenic ED.