Biomedical subjects

Ahmet Taha Alper

Publications and source records attributed to Ahmet Taha Alper.

4 recordsLinked to original sources

PubMed2006

Erectile dysfunction as a generalized vascular dysfunction.

OBJECTIVE: We hypothesize that generalized vascular dysfunction may be the underlying cause in patients with erectile dysfunction (ED) without atherosclerosis and its major risk factors. METHODS: In all, 30 outpatients with ED and 25 healthy volunteers as a control group were enrolled for this study. Aortic stiffness was calculated from data obtained by echocardiographic examination, which was performed using commercially available equipment with a 2.5- to 3.5-MHz transducer. Endothelium-dependent flow-mediated dilation (FMD) of the brachial artery was assessed using a high-resolution ultrasound system with a 10-MHz linear-array vascular transducer. Shear stress and nitroglycerin was used as a stimulus for assessing endothelium-dependent FMD and nonendothelium-dependent dilation of the brachial artery. RESULTS: FMD was significantly decreased in the ED group compared with control group (4.1 +/- 3.1% vs 9.7 +/- 3.5%, P < .001). Nonendothelium-dependent dilation was statistically insignificant in patients with ED compared with control subjects (13 +/- 3.9% vs 15.4 +/- 3.8%, P = .55). The relationship between ED and FMD was significant (r = -0.66, P < .001), whereas no relationship was found between ED and nonendothelium-dependent dilation (r = -0.23, P > .05). Aortic strain (3.7 +/- 2.7% vs 9.5 +/- 3.2%, P < .001) and distensibility (1.5 +/- 1.0 vs 4.7 +/- 2.9 cm2.dyne(-1).10(-3), P < .001) were found significantly lower in the ED group than in the control group. The relationship between ED and aortic stiffness was also significant (for aortic strain; r = -0.62, P < .001 and for aortic distensibility; r = -0.60, P < .001). CONCLUSION: Aortic and brachial artery functions are impaired in men with ED without cardiovascular disease or its major risk factors, indicating a more generalized vascular disease.

Aorta↗

PubMed2006

Metabolic syndrome as a predictor of non-dipping hypertension.

Metabolic syndrome (MS) and non-dipping hypertension both increase cardiovascular mortality. Although both clinical modalities share common pathophysiologic factors in their etiologies, previous studies did not find any association between them. We aimed to investigate the association between MS and non-dipping blood pressure by comparing different definitions of MS. One-hundred-thirty-two consecutive patients (58 men) who underwent 24-hour ambulatory blood pressure monitoring were analyzed. MS was evaluated according to the currently used Adult Treatment Panel (ATP) III definition criteria, named MS-ATP III. In order to reveal the weights of risk contributing to MS, a new diagnostic scoring method (MS-Score) was used in comparison with MS-ATP III. Nocturnal non-dipping refers to a reduction in average systolic and/or diastolic blood pressure at night (< or = 10%) compared with daytime average values. Non-dipping pattern was found in 61.4% of patients. The frequency of MS according to MS-Score, but not MS ATP III, was significantly higher in patients with non-dipping pattern than those without it (p = 0.009). Although more prominent in the nighttime, MS-Score showed positive correlation with all systolic blood pressure results (r = 0.27, p = 0.002). Adjusted for baseline characteristics, high (> or = 27.5) MS-Score remained as an independent predictor of non-dipping pattern (OR 2.64, p = 0.038). Finally, high MS-Score, but not MS-ATP III, is a predictor of non-dipping pattern. Nighttime systolic blood pressure is higher in patients with high MS-Score. Therefore, patients with high MS-Score may be more prone to cardiovascular events than those with low MS-Score.

Adult↗

PubMed2005

Influence of angiotensin converting enzyme insertion/deletion polymorphism on long-term total graft occlusion after coronary artery bypass surgery.

BACKGROUND: The renin-angiotensin system has a very important role in coronary thrombosis and restenosis. Plasma angiotensin converting enzyme (ACE) activity is associated with an insertion/deletion polymorphism in the gene coding for ACE. It is known that there is a strong correlation between ACE DD and atherosclerosis. However, little has been documented about its role in venous graft failure. The objective of this study was to investigate the relationships among the ACE gen polymorphism and long-term vein graft occlusion. METHODS: The study population consisted of 87 consecutive white patients with symptomatic coronary artery disease in the previous month, who had had aorto-coronary bypass surgery (ACBS) more than 5 years back and who underwent coronary angiography for diagnostic purposes. On the same day of angiography, 10 mL whole blood was taken for ACE gene insertion/deletion (I/D) polymorphism. RESULTS: Mean age of the patients was 64.4 +/- 8.6 years, and 71 (82%) of the patients were men. The average ACBS time was 7.9 +/- 1.9 years. The ACE genotype was II in 15 patients (17.2%), ID in 47 patients (54.0%), and DD in 25 patients (28.7%). Thus, D allele frequency was .82. There was no significant difference between the cases with regard to age, body mass index, blood pressure status, plasma glucose level, plasma lipid profile, smoking status, average of ACBS time or family history of coronary heart disease. In ACE II group 5 patients had total venous graft occlusion, in ACE ID group 27 patients had total occlusion and in ACE DD group 20 patients had at least one graft total occlusion. The frequency of the venous graft occlusion about total venous grafts is 36% in the ACE II group, 49% in the ACE ID group, and 80% in the ACE DD group (P = .01). CONCLUSION: The ACE I/D gene polymorphism is associated with long-term survival of venous conduit. The ACE DD genotype or D allele influences the angiographic outcome of patients post-ACBS. These data suggest that routine determination of the ACE genotype may help identify patients who are at higher risk of venous graft failure after ACBS.

Aged↗

PubMed2005

Is there a link between nickel allergy and coronary stent restenosis?

Although many patients with coronary artery disease are being treated by coronary stents, in-stent restenosis is the major limitation of percutaneous coronary stenting procedures. Most stents are made of stainless steel, and that, allergic reactions to nickel ions released from coronary stainless-steel stents may be one of the triggering mechanisms for in-stent restenosis. We aimed to evaluate the relationship between in-stent restenosis and nickel allergy in a prospective study. For this purpose, we applied epicutaneous patch test for nickel in 43 patients who had undergone elective intracoronary stent placement for stable angina pectoris in the day following stent placement and evaluated the presence of nickel allergy. Control angiography was performed at 6 months to determine in-stent restenosis. Three (6.9%) patients had allergic reaction to nickel and 16 (37%) patients had developed in-stent restenosis. One of the 3 patients with nickel allergy had diffuse in-stent restenosis and the others not. The present study therefore does not support the proposed relationship between nickel allergy and development of in-stent restenosis in patients having stainless steel stents. Large scale studies are needed to reach a final conclusion.

Aged↗