Erectile dysfunction (ED) was established to be linked to the risk factors of coronary artery disease such as metabolic syndrome, hypertension, diabetes, smoking, obesity and dyslipidemia.To study the influence of smoking and obesity on penile hemodynamics in patients with erectile dysfunction.This prospective study was carried out on 130 patients above 40 years and suffering from ED for more than 6 months. Selected patients were divided into four groups: group 1 (nonsmokers/non-obese) N = 36, group 2 (nonsmokers/obese) N = 30, group 3 (smokers/non-obese) N = 34, group 4 (smokers and obese) N = 30. Other risk factors for ED were excluded except dyslipidemia. All patients were subjected to personal history, sexual history, history of medical disorders or operations, evaluation of erectile function using an abridged IIEF-5. Measuring of BMI, fasting lipid profile, blood sugar, TT, prolactin, and PSA was performed. Penile hemodynamics was evaluated using intracavernosal injection of 1 cc Bimix (papaverin + phentolamine) and penile duplex ultrasound measuring the peak systolic velocity (PSV), end diastolic velocity (EDV), resistive index (RI), and cavernosal artery diameter before and after injection.The mean ages of group 1, group 2, group 3 and group 4 were 50.92 ± 6.52, 55.20 ± 7.18, 50.88 ± 7.66 and 52.30 ± 7.61, respectively, with no statistically significant (p = 0.341). A statistically significant difference observed between mean value of PSV between group 1 and all other groups on both sides and between group 3 and 4. Also, our results recorded a statistically significant difference between mean value of EDV and RI between group 1 and all other groups on both sides. Concerning the change in the cavernosal artery diameter after ICI, there was a significant difference was seen between the following groups 1 and 4, 3 and 4 on both sides and between groups 1 and 2 at right side only. There was a statistically significant difference between the study groups concerning patient's response to ICI (p value 0.000). A significant negative correlation between BMI and total testosterone was recorded (p = 0.001). Regarding the mean value of testosterone, a significant difference was observed between the different four groups (p = 0.002). And a statistically significant difference was reported between group 1 and group 2 (p = 0.004) and group 2 and group 3 (p = 0.007).Both smoking and BMI are strong risk factors for ED and affect response to ICI and penile duplex parameters (PSV, EDV, RI). Smoking and BMI together cause more deterioration of penile duplex parameters and response to ICI. The effect of smoking on EDV and RI was more than BMI. The effect of BMI on PSV, response to ICI and testosterone levels was more than smoking.
