Biomedical subjects

Omer Demir

Publications and source records attributed to Omer Demir.

3 recordsLinked to original sources

PubMed2006

Hyperhomocysteinemia: a novel risk factor for erectile dysfunction.

Nitric oxide (NO), the key mediator synthesized by different NO synthase isoenzymes, plays an important role in endothelial function. It was recently shown that hyperhomocysteinemia is an important regulator of NO synthase. We investigated the role of homocysteine (Hcys) in erectile dysfunction (ED), which is associated with the defect in NO generation. Thirty-one nondiabetic patients and 33 control cases were evaluated. Patients with diabetes, coronary artery disease, vitamin B(12), or folate deficiency were excluded in the study. The International Index of Erectile Function questionnaire was used to gauge identified erectile quality. Fasting plasma glucose, total cholesterol, triglyceride, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, vitamin B(12), folic acid, and Hcys levels of patients were measured. Penile color Dupplex ultrasound was used to detect vascular abnormalities in nondiabetic patients with ED. Patients with ED were older than the control subjects (55.6 +/- 8.4 vs 44.5 +/- 4.7 years, respectively; P < .001). Patients with ED had higher fasting plasma glucose, total cholesterol, low-density lipoprotein cholesterol, and Hcys levels. There was a significant negative correlation between mean Hcys level and mean International Index of Erectile Function domain score (P < .001). The penile color Doppler ultrasound findings showed that there was a negative significant correlation between mean Hcys level and the 1st, 5th, and 10th minute's peak-systolic velocity. Logistic regression analysis revealed that age and Hcys levels were the main determinants in ED. Hyperhomocysteinemia, known to be an important risk factor in endothelial dysfunction, seems to be an important determinant in ED. These data suggest that slightly elevated Hcys levels are significantly related with arterial and probably endothelial dysfunction in patients with ED.

Adult↗

PubMed2006

Effect of doxazosin with and without rho-kinase inhibitor on human corpus cavernosum smooth muscle in the presence of bladder outlet obstruction.

PURPOSE: We investigated the relationship of adrenergic responses in corpus cavernosum tissues in the presence of BOO using the alpha1-adrenergic receptor antagonist doxazosin (Pfizer, New York, New York) and the rho-kinase inhibitor Y-27632 (Calbiochem, San Diego, California). MATERIALS AND METHODS: CCSM tissue was obtained from patients who underwent penile prosthesis implantation. Patients were divided into 2 groups according to the presence of BOO. The submaximal (EC80) concentration of phenylephrine (Sigma Chemical Co., St. Louis, Missouri) was calculated by evaluating adrenergic activity responses with cumulatively applied phenylephrine. After achieving a stable contraction plateau test compounds were put in an organ bath. The relaxant potencies of doxazosin and Y-27632 were expressed as the percent of inhibition of the contraction plateau induced EC80 concentration of phenylephrine. Relaxation responses in the 2 groups were compared. RESULTS: At the highest dose of increasing concentrations phenylephrine generated 70% more contraction response in the BOO positive group than in the BOO negative group. Doxazosin and Y-27632 caused concentration dependent relaxation in CCSM precontracted by phenylephrine. With doxazosin significantly higher relaxation responses were attained in the BOO positive group in terms of log IC50 and the maximal relaxation response (p = 0.0353 and 0.0003, respectively). Maximum relaxation responses following Y-27632 administration were significantly higher in the BOO positive group. CONCLUSIONS: The contractility of human corpus cavernosum is increased in the presence of BOO. Doxazosin and Y-27632 generate effective CCSM relaxation in the presence of BOO. Doxazosin and Y-27632 may be the alternatives for the treatment of erectile dysfunction associated with BPH.

Adrenergic alpha-Antagonists↗

PubMed2006

Prevalence of erectile dysfunction in patients with metabolic syndrome.

AIM: We wished to investigate the relationship between metabolic syndrome and erectile dysfunction (ED). MATERIALS AND METHODS: A total of 268 patients were included in this study. All of the patients were asked to fill in an International Index for Erectile Function (IIEF) questionnaire. The presence of metabolic syndrome was determined when any three or more of the five risk factors were present according to the National Cholesterol Education Program (NCEP) Adult Treatment Panel (ATP)-III. The relationship between risk factor for metabolic syndrome and ED status was determined according to logistic regression analysis. RESULTS: Eighty-nine patients (33%) constituted the metabolic syndrome group. IIEF-EF domain scores of patients with and without metabolic syndrome were 17.7 +/- 7.9 and 21.7 +/- 7.5, respectively (P < 0.001). Seventy-four percent of patients with metabolic syndrome and 50% of patients without metabolic syndrome had ED (P < 0.001; odds ratio 2.9; 95% CI 1.7-5.0). Erectile function domain scores significantly decreased as the number of metabolic risk factors increased (P < 0.001). Patients with the risk factor of fasting blood glucose (FBG), waist circumference (WC), or hypertension (HT) had lower erectile function domain scores than the patients with other metabolic risk factors. Logistic regression analysis revealed that FBG and WC were the most important criteria for ED. CONCLUSIONS: Metabolic syndrome seems to be a potential risk factor for ED. We recommend patients with metabolic syndrome should be questioned about ED, and WC measurement might take part in the evaluation of ED.

Erectile Dysfunction↗