- Research article
- Open Access
- Open Peer Review
Erectile dysfunction, physical activity and metabolic syndrome: differences in markers of atherosclerosis
© Pohjantähti-Maaroos et al; licensee BioMed Central Ltd. 2011
- Received: 14 March 2011
- Accepted: 27 June 2011
- Published: 27 June 2011
Erectile dysfunction (ED), impaired arterial elasticity, elevated resting heart rate as well as increased levels of oxidized LDL and fibrinogen associate with future cardiovascular events. Physical activity is crucial in the prevention of cardiovascular diseases (CVD), while metabolic syndrome (MetS) comprises an increased risk for CVD events. The aim of this study was to assess whether markers of subclinical atherosclerosis are associated with the presence of ED and MetS, and whether physical activity is protective of ED.
57 MetS (51.3 ± 8.0 years) and 48 physically active (PhA) (51.1 ± 8.1 years) subjects participated in the study. ED was assessed by the International Index of Erectile Function (IIEF) questionnaire, arterial elasticity by a radial artery tonometer (HDI/PulseWave™ CR-2000) and circulating oxLDL by a capture ELISA immunoassay. Fibrinogen and lipids were assessed by validated methods. The calculation of mean daily energy expenditure of physical exercise was based on a structured questionnaire.
ED was more often present among MetS compared to PhA subjects, 63.2% and 27.1%, respectively (p < 0.001). Regular physical exercise at the level of > 400 kcal/day was protective of ED (OR 0.12, 95% CI 0.017-0.778, p = 0.027), whereas increased fibrinogen (OR 4.67, 95% CI 1.171-18.627, p = 0.029) and elevated resting heart rate (OR 1.07, 95% CI 1.003-1.138, p = 0.04) were independently associated with the presence of ED. In addition, large arterial elasticity (ml/mmHgx10) was lower among MetS compared to PhA subjects (16.6 ± 4.0 vs. 19.6 ± 4.2, p < 0.001), as well as among ED compared to non-ED subjects (16.7 ± 4.6 vs. 19.0 ± 3.9, p = 0.008). Fibrinogen and resting heart rate were highest and large arterial elasticity lowest among subjects with both MetS and ED.
Markers of subclinical atherosclerosis associated with the presence of ED and were most evident among subjects with both MetS and ED. Thus, especially MetS patients presenting with ED should be considered at high risk for CVD events. Physical activity, on its part, seems to be protective of ED.
- Erectile Dysfunction
- Erectile Function
- Rest Heart Rate
- Subclinical Atherosclerosis
- Arterial Elasticity
Atherosclerosis begins with oxidation of LDL particles in the arterial wall . Oxidatively modified LDL (oxLDL) damages the endothelium of the artery - a pathophysiology similar to that of vascular erectile dysfunction (ED) [1, 2]. As a result, the elasticity of the arteries deteriorates. Impaired arterial elasticity and increased levels of circulating oxLDL as well as elevated fibrinogen and resting heart rate associate with subclinical atherosclerosis and increased risk of cardiovascular disease (CVD) events [3–8].
Besides similar pathophysiology, ED and CVD share same risk factors . In addition, a high prevalence of both silent and clinical CVD has been reported among ED patients [9, 10]. ED has also been reported as an independent predictor of incident CVD [11, 12]. Since ED often precedes CVD symptoms from other vascular beds, it is thought to be an early clinical manifestation of systemic atherosclerosis [9, 13].
Physical activity is known to be crucial in the prevention of CVD. Sedentary lifestyle, on its part, predisposes to metabolic syndrome (MetS), a clustering of metabolic disorders; visceral obesity, hypertension, dyslipidaemia and insulin resistance or diabetes . MetS comprises a high risk for CVD events even in the absence of diabetes . Mechanisms that link MetS to increased CVD risk are, however, incompletely understood.
In the present study we assessed arterial elasticity, circulating oxLDL levels, fibrinogen and resting heart rate among MetS and physically active (PhA) subjects. The aim was to study whether these markers of subclinical atherosclerosis associate with ED and MetS, and whether physical activity is protective of ED.
120 men with MetS and 80 physically active (PhA) men participating in the Hämeenlinna Metabolic Syndrome research program (HMS) were recruited in the study. MetS was diagnosed according to National Cholesterol Education Program (NCEP) criteria . We interviewed the subjects on their medical history and lifestyle habits. Participation of a PhA subject was accepted if he exercised more than three times a week and 30 minutes per exercise on a regular basis without chest pain, dyspnea or fatigue, and did not fulfil the criteria of MetS. Exclusion criteria were non-specific beta-blocker medication and suspected non-vascular ED. Suspicion of non-vascular ED was based on patient records and patients' self-report during in the presence of possible psychogenic, urogenital, neurological or endocrinological cause for ED. Diagnoses of diabetes, hypertension and CVD were based on patients' report on previously diagnosed diseases, patient records and the use of antihyperglycemic, antihypertensive or antianginal medication. Positive family history of CVD was considered among subjects reporting previously diagnosed CVD in a first degree relative.
Subjects filled in a structured questionnaire on their average amount, type and intensity of leisure time physical exercise per week. The compendium of physical activities and subjects' self-rated intensity levels were used in estimating the metabolic equivalent (MET) values . The energy expenditure of mean daily physical exercise was calculated in kilocalories by multiplying the MET value and exercise times per week and mean duration of exercise in hours and person's weight in kilograms and finally dividing it by seven. Physical activity level was considered low if mean daily energy expenditure of physical exercise was < 200 kcal/day, moderate if 200-400 kcal/day and high if > 400 kcal/day. In addition, waist circumference, height, weight and blood pressure were measured.
Each study subject signed an informed consent. The ethics committee of the Kanta-Häme Hospital District in Finland approved the study which was carried out in compliance with the Helsinki Declaration.
International Index of Erectile Dysfunction (IIEF) questionnaire
Subjects filled in the IIEF questionnaire . The sum of the questions 1-5 and 15 was calculated to assess the presence of ED. Subjects with maximal score of 30 were considered to have normal erectile function and subjects with score of ≤25, were considered to have ED. To ensure that the study subjects truly had either completely normal or impaired erectile function, subjects with IIEF score 26 to 29 were excluded. The question number 15 (how do you rate your confidence that you can get and keep your erection?) was used to assess the presence of erectile function in men reporting lack of sexual activity in questions 1-5. A subject reporting very high confidence in the question number 15, was considered to have normal erectile function. Those reporting very low to medium confidence were considered to have ED, and those reporting high confidence were excluded.
Arterial elasticity and laboratory procedures
Arterial elasticity was assessed by a non-invasive radial artery tonometer (HDI/PulseWave™CR-2000) in a semi-sitting position. Arterial tonometer uses a modified Windkessel method to estimate systemic large (C1) and small (C2) arterial elasticity . C1 identifies the elasticity of the aorta and other large arteries, C2 the elasticity and endothelial function of the microvascular circulation. Indices determined by this validated method correlate tightly with those determined invasively [3, 19]. In addition, C1 seems to correlate significantly with MRI-determined aortic distensibility, whereas C2 correlate with endothelial function assessed by flow-mediated dilation [20, 21]. In addition, elasticity indices assessed by the HDI/Pulsewave™CR-2000 have been reported reliable and repeatable over a short and long period of observation [19, 22]. The reference values depend on age and gender. Among men aged 50-59 years, C1 above 11 ml/mmHgx10 and C2 above 7 ml/mmHgx100 are considered normal.
Arterial elasticity indices were assessed automatically by the tonometer as a mean of five most similar pulse waves appearing during 30 seconds of measurement. Mean of four consecutive measurements was assessed. Blood pressure and resting heart rate were automatically measured by the CR-2000 during the elasticity measurement. Intraindividual CV% was 9.0% for C1 and 8.8% for C2. Same experienced nurse performed all measurements.
Plasma levels of oxLDL were determined as duplicates by a capture ELISA immunoassay (Mercodia AB, Uppsala, Sweden). It uses the same monoclonal antibody as in the assays by Holvoet et al . CV% of oxLDL measurement was 7.7%. Fibrinogen and lipids were assessed by validated methods.
Statistics were analyzed with SPSS for Windows 17.0. Data are presented as mean ± SD if not mentioned otherwise. A probability value < 0.05 was considered statistically significant.
Student's T-test was used in assessing the differences between subjects with ED and normal erectile function as well as between MetS and PhA subjects in case of normality. Mann Whitney U-test was used in case of non-normality. ANOVA was used to analyze the adjusted p values for differences in two-dimensional variables as well as in four-dimensional variables in case of normality. Bonferroni post hoc analysis was used for multiple comparisons regarding fibrinogen, resting heart rate and arterial elasticity. The differences were adjusted for age, smoking, blood pressure, diabetes, CVD, and LDL cholesterol. Kruskall-Wallis test was used in case of non-normality. Differences in categorical values were calculated by χ2 test. Univariate and multivariate analyses of the associations between risk factors and markers of CVD and the presence of ED were conducted with binary logistic regression model. Traditional CVD risk factors and assessed markers of subclinical atherosclerosis without strong correlation with each other were included as covariates in the multivariate analysis. Multivariate analysis was conducted with the enter method by removing covariates without association to ED one by one. The result was verified with the forward conditional method and adjusted for the use of medications. OR, 95% CI and p values for covariates in the univariate analyses and for significant covariates in the adjusted multivariate analysis, as well as Nagelkerke R2 of the final model are presented.
Clinical characteristics of study subjects.
(n = 35)
(n = 13)
(n = 21)
(n = 36)
49.4 ± 7.5
56.9 ± 6.7
45.9 ± 4.6
54.1 ± 8.2
CVD in family, n (%)
Diagnosed CVDb, n (%)
Diabetics2,a, n (%)
Hypertension2,a, n (%)
ASAc, n (%)
β1-blocker2,a, n (%)
ACE-inhibitor, n (%)
ATR-blockera, n (%)
Ca-blocker, n (%)
Diureticb, n (%)
Statinb, n (%)
-current, n (%)
-former, n (%)
-never, n (%)
Physical activity2,a, kcal/day
506.9 ± 300
467.1 ± 256
209.4 ± 265
156.4 ± 172
Alcohol intakeb, g/day
7.8 ± 6.0
6.0 ± 4.3
15.0 ± 13.5
20.1 ± 22.8
23.8 ± 2.0
24.6 ± 3.0
32.7 ± 4.5
32.0 ± 4.8
Waist circumf.2,a, cm
88.6 ± 7.1
90.8 ± 8.9
113.5 ± 10.5
114.8 ± 13.3
127.2 ± 9.2
126.9 ± 11.2
136.5 ± 12.2
139.8 ± 16.5
73.9 ± 6.7
74.5 ± 5.6
82.1 ± 7.4
81.7 ± 8.8
Clinical chemistry of study subjects.
(n = 35)
(n = 13)
(n = 21)
(n = 36)
5.27 ± 0.7
5.33 ± 0.8
5.26 ± 1.1
5.30 ± 1.6
3.47 ± 0.7
3.32 ± 0.9
3.24 ± 0.9
3.21 ± 1.0
1.61 ± 0.3
1.81 ± 0.4
1.20 ± 0.2
1.16 ± 0.3
0.94 ± 0.5
0.86 ± 0.4
2.49 ± 1.4
3.19 ± 5.1
71.8 ± 21.4
75.5 ± 35.5
78.5 ± 40.1
80.8 ± 33.5
5.49 ± 0.4
5.59 ± 0.6
6.54 ± 1.0
6.99 ± 2.2
5.61 ± 0.2
5.60 ± 0.2
6.03 ± 0.6
6.47 ± 1.2
There was an evident difference in the amount of daily physical exercise between PhA and MetS subjects, 496.7 ± 286.9 kcal/day vs. 176.3 ± 210.8 kcal/day, respectively (p < 0.001). In addition, subjects with normal erectile function were physically more active compared to subjects with ED, 395.3 ± 319.5 kcal/day vs. 235.7 ± 237.3 kcal/day, respectively (p = 0.005). Physical activity of the study groups is presented in Table 1.
Univariate analyses of risk factors and markers of CVD as predictors of ED.
No of pack-years in smokers
Metabolic syndrome, yes/no
Family history of CVD, yes/no
Physical activity, >400 vs. <200 kcal/day
HDL cholesterol, mmol/L
LDL cholesterol, mmol/L
Heart rate, beats/min
Significant predictors of ED in the multivariate analysis.
Heart rate, beats/min
Physical activity, >400 vs. <200 kcal/day
In the multivariate analysis among MetS subjects only, age (OR 1.23, 95% CI 1.09-1.39, p = 0.001) and fibrinogen (OR 4.30 95% CI 1.21-15.2, p = 0.024) associated directly and physical activity > 400 kcal/day (OR 0.05, 95% CI 0.004-0.65, p = 0.022) inversely with the presence of ED. These covariates were significant predictors of ED even after adjustment for smoking, diabetes, hypertension, CVD, LDL and HDL cholesterol, triglycerides, BMI, family history of CVD, and selective beta-blockers. Among PhA subjects, age was the only significant predictor for the presence of ED (OR 1.16, 95% CI 1.04-1.30, p = 0.008).
In the present study, physical activity was an independent predictor of normal erectile function, whereas increased fibrinogen and resting heart rate associated independently with erectile dysfunction (ED). Impaired large arterial elasticity (C1) was related to the presence of ED as well as to the presence of MetS. Markers of subclinical atherosclerosis were most evident among subjects with both MetS and ED.
Previously physical activity has been found to decrease the risk of ED and to improve sexual function among those with established ED [23–25]. We found a physical exercise level of > 400 kcal/day (i.e. > 2800 kcal/week) to associate independently with normal erectile function in the analyses among all participants as well as in the analyses restricted to MetS subjects only. To our knowledge, this is the first study reporting the positive association between physical activity and the presence of normal erectile function among MetS.
PhA subjects presented often with normal erectile function, whereas ED was highly prevalent among men with MetS. Although we excluded subjects with submaximal IIEF score (score 26-29), still considered as normal erectile function by the IIEF, the presence of ED among PhA subjects was lower than expected . Since obesity, smoking and excess alcohol consumption have been reported to associate with ED, and physical activity is protective of ED, the overall healthy behaviour of the PhA subjects must have contributed to the high existence of normal erectile function among them [23–25, 27].
In a recent study, MetS did not improve prediction of CVD after adjustment for its individual components . In agreement, MetS per se was not an independent predictor of ED in the present study. However, we found a high prevalence of ED among MetS which has also been reported previously . The prevalence of ED in the presence of diabetes or CVD is known to be even higher [13, 30]. Accordingly, there were more diabetics and CVD patients among those with MetS and ED in the present study. Those with ED were also older and more often hypertensive. Although subjects with non-selective β-blocker medication were excluded, ED subjects were more often on selective beta-blockers. These factors may contribute to the higher number of ED among MetS, and thereby to the findings of the study. However, neither diabetes nor CVD were significant predictors of ED in the multivariate analyses of the present study. In addition, although the risk of sexual dysfunction caused by β-blockers was low in a previous systematic review of randomized trials, the results of the present study were adjusted for the use of selective beta-blockers . Furthermore, also medications reported to improve sexual function were more often used among subjects with MetS and ED [32, 33]. Thus, the high use of medications among MetS seems rather reflect the physical inactivity, obesity and concomitant diseases among them, whereas the high prevalence of ED among MetS may reflect the presence of underlying, atherosclerotic disease.
We found increased fibrinogen levels among MetS compared to PhA subjects which agrees with previous studies [34, 35]. Physical inactivity, obesity and smoking have been reported to associate with increased fibrinogen levels, and thus may partly explain the difference [35–37]. Fibrinogen levels were significantly higher also in the presence of ED compared to the levels in the presence of normal erectile function in the analyses among all participants but also among only MetS subjects. In addition, increased fibrinogen levels associated with the presence of ED independently of multiple other CVD risk factors. There are no previous studies on the association of increased fibrinogen and ED among MetS. However, our finding agrees with a previous study by Vlachopoulos et al  reporting an independent predictive value of fibrinogen for the presence of ED both among men with and without coronary artery disease. Differing from the analyses restricted to MetS subjects only, fibrinogen levels did not associate with the presence of ED among PhA subjects in the present study. The reason may be the small number of ED among them, again reflecting the protective effect of healthy, active lifestyle.
In line with previous publications we found a decrease in large arterial elasticity (C1) among MetS compared to PhA subjects [39, 40]. In addition, impaired C1 associated with the presence of ED. C1 was especially low among men with both MetS and ED. There are also previous reports on the connection between impaired large arterial elasticity and ED [41, 42]. However, in these studies arterial elasticity was assessed by ultrasound or pulse-wave velocity measurements, not by the pulse-wave analysis as in our previous and the present study .
Endothelial dysfunction is believed to be a key mechanism in the pathogenesis of ED as well as of other atherosclerotic cardiovascular diseases [1, 2]. In studies assessing endothelial function by a regional measurement of brachial flow-mediated dilation, endothelial dysfunction associated with ED [44, 45]. Small arterial elasticity (C2), assessed in the present study, reflects the systemic endothelial function of the microvascular circulation but is also affected by alterations in the elastic properties of the arterial wall . Since C2 is not a mere measurement of endothelial function, it may explain why the association between C2 and the presence of ED did not remain significant after adjustments.
Regular aerobic exercise may attenuate age-related reduction in large arterial elasticity  and decrease circulating oxLDL levels . However, a significant decrease in arterial elasticity and increase in oxidative stress have been reported after exercise at a vigorous level [48, 49]. In our study, large arterial elasticity was better among PhA compared to MetS subjects whereas oxLDL levels were comparable between the groups. The relatively small number of study subjects may explain why the trend of increasing oxLDL in the presence of MetS and ED remained non-significant. In addition, although the inclusion criterion of minimum physical exercise for the PhA subjects was relatively low, the reported high level and intensity of exercise among them might have influenced the results.
Previously MetS variables, such as hypertension, insulin resistance and obesity, have been reported to associate with adrenergic overdrive . Accompanying elevation in resting heart rate increases peak blood flow during diastole which in turn enhances pulsatile and shear stress on the endothelium . Resulting endothelial dysfunction and loss of arterial elasticity may explain the connection between elevated resting heart rate and ED [51, 52]. In agreement, resting heart rate was higher among MetS compared to PhA subjects in the present study, despite the higher use of beta-blockers among MetS. In addition, heart rate was higher among ED compared to non-ED subjects, being highest among men with both MetS and ED. Since MetS subjects with ED were physically most inactive, the elevated resting heart rate was at least partly a consequence of their physical unfitness. However, elevated resting heart rate predicted the presence of ED independently of physical activity, multiple other CVD risk factors, and beta-blocker medication.
Because of the cross-sectional design, we cannot make assumptions on the linkage between the markers of subclinical CVD and true CVD risk in the future. However, the present study provides possible pathophysiological links between erectile dysfunction and increased cardiovascular risk among MetS. Subjects with MetS are known to be at high risk for CVD . ED, on its part, is considered as an early clinical manifestation of systemic atherosclerosis [9, 13]. Markers of subclinical atherosclerosis, assessed in the present study, have previously been reported to associate with increased risk of CVD events and mortality [4, 5, 7, 8]. Since increased fibrinogen and elevated resting heart rate as well as impaired arterial elasticity were present among MetS compared to PhA subjects, as well as among ED compared to non-ED subjects, they may partly explain the increased CVD risk associated both with MetS and with ED. Since these markers of subclinical atherosclerosis were most evident among subjects with both MetS and ED, especially these patients should be considered at high cardiovascular risk.
One mechanism linking MetS to ED is believed to be hypogonadism associated with visceral obesity . In addition, physical activity may partly intermediate its benefits through an induced increase in testosterone levels . Another possible pathophysiologic linkage between MetS and ED is subclinical inflammation . We did not assess testosterone or CRP levels which was a limitation of the study.
IIEF questionnaire is a reliable method to assess the presence and severity of ED . In our study, number of subjects reported lack of sexual activity and thus were unable to answer the IIEF questions concerning erectile function during intercourse. Among them, we used a single-question assessment of ED. Although the single-question assessment has been found to properly identify men with ED , we wanted to be sure that subjects participating in the study truly had either completely normal erectile function or real ED. Therefore, we accepted only men with either full score or score ≤25 in the six-question IIEF or men with full score or score ≤3 in the single-question assessment to participate in the study. Because of the relatively small number of study subjects and the fact that a single-question assessment of ED was used among subjects without previous sexual activity, we could not study the effects of severity of ED.
Increased fibrinogen and resting heart rate as well as impaired arterial elasticity associated with the presence of ED and were most evident among subjects with both MetS and ED. Physical exercise, on its part, was a strong and independent predictor of normal erectile function among all as well as among only MetS subjects. Thus, especially MetS patients presenting with ED should be considered at high risk for CVD. In addition, our findings support the importance of physical exercise in the management of MetS and concomitant diseases.
Acknowledgements and Funding
We sincerely acknowledge Kalevi Oksanen, Päivi Kankkunen, Paula Lahtinen, Kirsti Inkilä, Annika Palomäki, Sanna Haavisto and Outi Vanha-Kämppä for their professional technical aid. The authors gratefully acknowledge the co-operation of the study subjects.
The study was supported by grants from the Ministry of Health and Social Welfare in Finland through the Medical Research Fund of Kanta-Häme Central Hospital, the Häme and Pohjois-Savo Regional Funds under the auspices of the Finnish Cultural Foundation, and Oy Eli Lilly Finland Ab. None of them had a role in data collection, analysis of the results, or preparation of the manuscript.
- Stocker R, Keaney JF: Role of oxidative modifications in atherosclerosis. Physiol Rev. 2004, 84: 1381-1478. 10.1152/physrev.00047.2003.View ArticlePubMedGoogle Scholar
- Kirby M, Jackson G, Simonsen U: Endothelial dysfunction links erectile dysfunction to heart Disease. Int J Clin Pract. 2005, 59: 225-229. 10.1111/j.1742-1241.2005.00453.x.View ArticlePubMedGoogle Scholar
- Cohn J, Finkelstein S, McVeigh G, Morgan D, LeMay L, Robinson J, Mock J: Non-invasive Pulse Wave Analysis for the Early Detection of Vascular Disease. Hypertension. 1995, 26: 503-508.View ArticlePubMedGoogle Scholar
- Boutouyrie P, Tropeano I, Asmar R, Gautier I, Benetos A, Lacolley P, Laurent S: Aortic stiffness is an independent predictor of primary coronary events in hypertensive patients. A longitudinal study. Hypertension. 2002, 39: 10-15. 10.1161/hy0102.099031.View ArticlePubMedGoogle Scholar
- Van Popele N, Grobbee D, Bots M, Asmar R, Topouchian J, Reneman R, Hoeks A, Van der Kuip D, Hofman A, Witteman J: Association between arterial stiffness and atherosclerosis. The Rotterdam study. Stroke. 2001, 32: 454-460. 10.1161/01.STR.32.2.454.View ArticlePubMedGoogle Scholar
- Holvoet P, Mertens A, Verhamme P, Bogaerts K, Beyens G, Verhaeghe R, Collen D, Muls E, Van de Werf F: Circulating oxidized LDL is a useful marker for identifying patients with coronary artery disease. Arterioscler Thromb Vasc Biol. 2001, 21: 844-848. 10.1161/01.ATV.21.5.844.View ArticlePubMedGoogle Scholar
- Fibrinogen Studies Collaboration: Plasma fibrinogen level and the risk of major cardiovascular diseases and nonvascular mortality: an individual participant meta-analysis. JAMA. 2005, 294: 1799-1809.Google Scholar
- Cooney M, Vartiainen E, Laatikainen T, Juolevi A, Dudina A, Graham I: Elevated resting heart rate is an independent risk factor for cardiovascular disease in healthy men and women. Am Heart J. 2010, 159: 612-619. 10.1016/j.ahj.2009.12.029.View ArticlePubMedGoogle Scholar
- Jackson G, Boon N, Eardley I, Kirby M, Dean J, Hackett G, Montorsi P, Montorsi F, Vlachopoulos C, Kloner R, Sharlip I, Miner M: Erectile dysfunction and coronary artery disease prediction: evidence-based guidance and consensus. Int J Clin Pract. 2010, 64: 848-857. 10.1111/j.1742-1241.2010.02410.x.View ArticlePubMedGoogle Scholar
- Thompson I, Tangen C, Goodman P, Probstfield J, Moinpour C, Coltman C: Erectile dysfunction and subsequent cardiovascular disease. JAMA. 2005, 294: 2996-3002. 10.1001/jama.294.23.2996.View ArticlePubMedGoogle Scholar
- Inman B, Sauver J, Jacobson D, McGree M, Nehra A, Lieber M, Roger V, Jacobsen S: A population-based, longitudinal study of erectile dysfunction and future coronary artery disease. Mayo Clin Proc. 2009, 84: 108-113. 10.4065/84.2.108.View ArticlePubMedPubMed CentralGoogle Scholar
- Araujo A, Hall S, Ganz P, Chiu G, Rosen R, Kupelian V, Travison T, McKinlay J: Does erectile dysfunction contribute to cardiovascular disease risk prediction beyond the Framingham risk score. J Am Coll Cardiol. 2010, 55: 350-356. 10.1016/j.jacc.2009.08.058.View ArticlePubMedPubMed CentralGoogle Scholar
- Montorsi P, Ravagnani PM, Galli S, Rotatori F, Briganti A, Salonia A, Rigatti P, Montorsi F: The artery size hypothesis: a macrovascular link between erectile dysfunction and coronary artery disease. Am J Cardiol. 2005, 96 (Suppl): 19M-23M.View ArticlePubMedGoogle Scholar
- Sisson SB, Camhi SM, Church TS, Martin CK, Tudor-Locke C, Bouchard C, Earnest CP, Smith SR, Newton RL, Rankinen T, Katzmarzyk PT: Leisure time sedentary behaviour, occupational/domestic physical activity and metabolic syndrome in U.S. men and women. Metab Syndr Relat Disord. 2009, 7: 529-536. 10.1089/met.2009.0023.View ArticlePubMedGoogle Scholar
- Hu G, Qiao Q, Tuomilehto J, Balkau B, Borch-Johnsen K, Pyorala K, for the DECODE study group: Prevalence of the metabolic syndrome and its relation to all-cause and cardiovascular mortality in nondiabetic European men and women. Arch Intern Med. 2004, 164: 1066-1067. 10.1001/archinte.164.10.1066.View ArticlePubMedGoogle Scholar
- Third report of the National Cholesterol Education Program (NCEP) expert panel on: detection, evaluation and treatment of high blood cholesterol in adults (Adult Treatment Panel III) Final report. Circulation. 2002, 106: 3143-3421.Google Scholar
- Ainsworth B, Haskell W, Whitt M, Irwin M, Swartz A, Strath S, O'Brien W, Basset D, Schmitz K, Emplaincourt P, Jacobs D, Leon A: Compendium of physical activities: an update of activity codes and MET intensities. Med Sci Sports Exerc. 2000, 32: 498-516. 10.1097/00005768-200009001-00009.View ArticleGoogle Scholar
- Rosen R, Riley A, Wagner G, Osterloh I, Kirkpatrick J, Mishra A: The international index of erectile function (IIEF): a multidimensional scale for assessment of erectile dysfunction. Urology. 1997, 6: 822-830.View ArticleGoogle Scholar
- Prisant LM, Pasi M, Jupin D, Prisant ME: Assessment of repeatability and correlates of arterial compliance. Blood Press Monit. 2000, 7: 231-235.View ArticleGoogle Scholar
- Resnick LM, Militianu D, Cunnings AJ, Pipe JG, Evelhoch JL, Soulen RL, Lester MA: Pulse waveform analysis of arterial compliance: relation to other techniques, age, and metabolic variables. Am J Hypertens. 2000, 13: 1243-1249. 10.1016/S0895-7061(00)01219-X.View ArticlePubMedGoogle Scholar
- Wilson AM, O'Neal D, Nelson CL, Prior DL, Best JD, Jenkins AJ: Comparison of arterial assessments in low and high vascular disease groups. Am J Hypertens. 2004, 17: 285-291. 10.1016/j.amjhyper.2003.10.009.View ArticlePubMedGoogle Scholar
- Zimlichman R, Shargorodsky M, Boaz M, Duprez D, Rahn KH, Rizzoni D, Payeras AC, Hamm C, McVeigh G: Determination of arterial compliance using blood pressure waveform analysis with the CR-2000 system: reliability, repeatability, and establishment of normal values for healthy European population - the seven European sites study (SESS). Am J Hypertens. 2005, 18: 65-71.View ArticlePubMedGoogle Scholar
- Bacon CG, Mittleman MA, Kawachi I, Giovannucci E, Glasser DB, Rimm EB: A prospective study of risk factors for erectile dysfunction. J Urol. 2006, 176: 217-221. 10.1016/S0022-5347(06)00589-1.View ArticlePubMedGoogle Scholar
- Kratzik CW, Lackner JE, Märk I, Rücklinger E, Schmidbauer J, Lunglmayr G, Schatzl G: How much physical activity is needed to maintain erectile function? Results of The Androx Vienna Municipality study. Eur Urol. 2009, 55: 509-517. 10.1016/j.eururo.2008.02.020.View ArticlePubMedGoogle Scholar
- Esposito K, Giugliano F, Di Palo C, Giugliano G, Marfella R, D'Andrea F, D'Armiento M, Giugliano D: Effect of lifestyle changes on erectile dysfunction in obese men. A randomized controlled trial. JAMA. 2004, 291: 2978-2984. 10.1001/jama.291.24.2978.View ArticlePubMedGoogle Scholar
- Teles AG, Carreira M, Alarcão V, Sociol D, Aragüés JM, Lopes L, Mascarenhas M, Costa JG: Prevalence, severity, and risk factors for erectile dysfunction in a representative sample of 3,548 Portuguese men aged 40 to 69 years attending primary healthcare centers: results of the Portuguese erectile dysfunction study. J Sex Med. 2008, 5: 1317-1324. 10.1111/j.1743-6109.2007.00745.x.View ArticlePubMedGoogle Scholar
- Christensen BS, Grønbaek M, Pedersen BV, Graugaard C, Frisch M, Horansanli K, Boylu U, Kendirci M, Miroglu C: Associations of unhealthy lifestyle factors with sexual inactivity and sexual dysfunctions in Denmark. J Sex Med. 2011Google Scholar
- Hadaegh F, Zabetian A, Khalili D, Safarkhani M, James WP, Azizi F: A new approach to compare the predictive power of metabolic syndrome defined by a joint interim statement versus its components for incident cardiovascular disease in Middle East Caucasian residents in Tehran. J Epidemiol Community Health. 2010Google Scholar
- Bal K, Öder M, Şahin A, Karataş C, Demir Ö, Can E, Gümüş B, Özer K, Şahin O, Esen A: Prevalence of metabolic syndrome and its association with erectile dysfunction among urologic patients: metabolic backgrounds of erectile dysfunction. Urology. 2007, 69: 356-360. 10.1016/j.urology.2006.09.057.View ArticlePubMedGoogle Scholar
- Selvin E, Burnett AL, Platz EA: Prevalence and risk factors for erectile dysfunction in the US. Am J Med. 2007, 120: 151-157. 10.1016/j.amjmed.2006.06.010.View ArticlePubMedGoogle Scholar
- Ko DT, Hebert PR, Coffey CS, Sedrakyan A, Curtis JP, Krumholz HM: Beta-blocker therapy and symptoms of depression, fatigue, and sexual dysfunction. JAMA. 2002, 288: 351-357. 10.1001/jama.288.3.351.View ArticlePubMedGoogle Scholar
- Düsing R: Effect of the angiotensin II antagonist valsartan on sexual function in hypertensive men. Blood Press Suppl. 2003, 2: 29-34.View ArticlePubMedGoogle Scholar
- Doğru MT, Başar MM, Simşek A, Yuvanç E, Güneri M, Ebinç H, Batislam E: Effects of statin treatment on serum sex steroids levels and autonomic and erectile function. Urology. 2008, 71: 703-707. 10.1016/j.urology.2007.11.059.View ArticlePubMedGoogle Scholar
- Ford ES: The metabolic syndrome and C-reactive protein, fibrinogen, and leukocyte count: findings from the Third National Health and Nutrition Examination Survey. Atherosclerosis. 2003, 168: 351-358. 10.1016/S0021-9150(03)00134-5.View ArticlePubMedGoogle Scholar
- Church TS, Finley CE, Earnest CP, Kampert JB, Gibbons LW, Blair SN: Relative associations of fitness and fatness to fibrinogen, white blood cell count, uric acid and metabolic syndrome. Int J Obes. 2002, 26: 805-813.View ArticleGoogle Scholar
- Myint PK, Luben RN, Wareham NJ, Welch AA, Bingham SA, Khaw KT: Physical activity and fibrinogen concentrations in 23,201 men and women in the EPIC-Norfolk population-based study. Atherosclerosis. 2008, 198: 419-425. 10.1016/j.atherosclerosis.2007.09.021.View ArticlePubMedGoogle Scholar
- Sinha S, Luben RN, Welch A, Bingham S, Wareham NJ, Day NE, Khaw KT: Fibrinogen and cigarette smoking in men and women in the European Prospective Investigation into Cancer in Norfolk (EPIC-Norfolk) population. Eur J Cardiovasc Prev Rehabil. 2005, 12: 144-150.View ArticlePubMedGoogle Scholar
- Vlachopoulos C, Aznaouridis K, Ioakeimidis N, Rokkas K, Vasiliadou C, Alexopoulos N, Stefanadi E, Askitis A, Stefanadis C: Unfavourable endothelial and inflammatory state in erectile dysfunction patients with or without coronary artery disease. Eur Heart J. 2006, 27: 2640-2648. 10.1093/eurheartj/ehl341.View ArticlePubMedGoogle Scholar
- Pohjantähti-Maaroos H, Palomäki A, Kankkunen P, Laitinen R, Husgafvel S, Oksanen K: Circulating oxidized low-density lipoproteins and arterial elasticity: comparison between men with metabolic syndrome and physically active counterparts. Cardiovasc Diabetol. 2010, 9: 41-10.1186/1475-2840-9-41.View ArticlePubMedPubMed CentralGoogle Scholar
- Ge JY, Li XL, Zhang HF, Xu Q, Tong M, Wang JG: Elasticity indices of large and small arteries in relation to the metabolic syndrome in Chinese. Am J Hypertens. 2008, 21: 143-147. 10.1038/ajh.2007.26.View ArticlePubMedGoogle Scholar
- Kaya C, Ergelen M, Ilktac A, Karaman I: Impaired elasticity of aorta in patients with erectile dysfunction. Urology. 2007, 70: 558-562. 10.1016/j.urology.2007.04.018.View ArticlePubMedGoogle Scholar
- Vlachopoulos C, Aznaouridis K, Ioakeimidis N, Rokkas K, Tsekoura D, Vasiliadou C, Stefanadi E, Askitis A, Stefanadis C: Arterial function and intima-media thickness in hypertensive patients with erectile dysfunction. J Hypertens. 2008, 26: 1829-1836. 10.1097/HJH.0b013e3283050886.View ArticlePubMedGoogle Scholar
- Pohjantähti-Maaroos H, Palomäki A: Comparison of metabolic syndrome subjects with and without erectile dysfunction - levels of circulating oxidised LDL and arterial elasticity. Int J Clin Pract. 2011, 65: 274-280. 10.1111/j.1742-1241.2010.02595.x.View ArticlePubMedGoogle Scholar
- Kaiser D, Billups K, Mason C, Wetterling R, Lundberg J, Bank A: Impaired brachial artery endothelium-dependent and -independent vasodilation in men with erectile dysfunction and no other clinical cardiovascular disease. J Am Coll Cardiol. 2004, 43: 179-184. 10.1016/j.jacc.2003.07.042.View ArticlePubMedGoogle Scholar
- Yavuzgil O, Altay B, Zoghi M, Gürgün C, Kayıkçıoğlu M, Kültürsay H: Endothelial function in patients with vasculogenic erectile dysfunction. Int J Cardiol. 2005, 103: 19-26. 10.1016/j.ijcard.2004.07.004.View ArticlePubMedGoogle Scholar
- Sugawara J, Inoue H, Haysashi K, Yokoi T, Kono I: Effect of low-intensity aerobic exercise training on arterial compliance in postmenopausal women. Hypertens Res. 2004, 27: 897-901. 10.1291/hypres.27.897.View ArticlePubMedGoogle Scholar
- Elosua R, Molina L, Fito M, Arquer A, Sanchez-Quesada JL, Covas MI, Ordonez-Llanos J, Marrugat J: Response of oxidative stress biomarkers to a 16-week aerobic physical activity program, and to acute physical activity, in healthy young men and women. Atherosclerosis. 2003, 167: 327-334. 10.1016/S0021-9150(03)00018-2.View ArticlePubMedGoogle Scholar
- Miyachi M, Kawano H, Sugawara J, Takahashi K, Hayashi K, Yamazaki K, Tabata I, Tanaka H: Unfavorable effects of resistance training on central arterial compliance. A randomized intervention study. Circulation. 2004, 110: 2858-2863. 10.1161/01.CIR.0000146380.08401.99.View ArticlePubMedGoogle Scholar
- Muñoz MD, Olcina G, Timón R, Robles MC, Caballero MJ, Maynar M: Effect of different exercise intensities on oxidative stress markers and antioxidant response in trained cyclists. J Sports Med Phys Fitness. 2010, 50: 93-98.Google Scholar
- Mancia G, Bousquet P, Elghozi JL, Esler M, Grassi G, Julius S, Reid J, Van Zwieten PA: The sympathetic nervous system and the metabolic syndrome. J Hypertens. 2007, 25: 909-920. 10.1097/HJH.0b013e328048d004.View ArticlePubMedGoogle Scholar
- Arnold JM, Fitchett DH, Howlett JG, Lonn EM, Tardif JC: Resting heart rate: a modifiable prognostic indicator of cardiovascular risk and outcomes?. Can J Cardiol. 2008, 24 (SupplA): 3A-8A.View ArticlePubMedPubMed CentralGoogle Scholar
- Tomiyama H, Hashimoto H, Tanaka H, Matsumoto C, Odaira M, Yamada J, Yoshida M, Shiina K, Nagata M, Yamashina A, baPWV/cfPWV Collaboration Group: Synergistic relationship between changes in the pulse wave velocity and changes in the heart rate in middle-aged Japanese adults: a prospective study. J Hypertens. 2010, 28: 687-694. 10.1097/HJH.0b013e3283369fe8.View ArticlePubMedGoogle Scholar
- Corona G, Mannucci E, Forti G, Maggi M: Hypogonadism, ED, metabolic syndrome and obesity: a pathological link supporting cardiovascular diseases. Int J Androl. 2009, 32: 587-598. 10.1111/j.1365-2605.2008.00951.x.View ArticlePubMedGoogle Scholar
- Revnic CR, Nica AS, Revnic F: The impact of physical training on endocrine modulation, muscle physiology and sexual functions in elderly men. Arch Gerontol Geriatr. 2007, 44 (Suppl 1): 339-342.View ArticlePubMedGoogle Scholar
- Vlachopoulos C, Rokkas K, Ioakeimidis N, Stefanadis C: Inflammation, metabolic syndrome, erectile dysfunction and coronary artery disease: common links. Eur Urol. 2007, 52: 1590-1600. 10.1016/j.eururo.2007.08.004.View ArticlePubMedGoogle Scholar
- Cappelleri J, Rosen R, Smith M, Mishra A, Osterloh I: Diagnostic evaluation of the erectile function domain of the international index of erectile function. Urology. 1999, 54: 346-351. 10.1016/S0090-4295(99)00099-0.View ArticlePubMedGoogle Scholar
- O'Donnell AB, Araujo AB, Goldstein I, McKinlay JB: The validity of a single-question self-report of erectile dysfunction. Results from the Massachusetts Male Aging Study. J Gen Intern Med. 2005, 20: 515-519. 10.1111/j.1525-1497.2005.0076.x.View ArticlePubMedPubMed CentralGoogle Scholar
- The pre-publication history for this paper can be accessed here:http://www.biomedcentral.com/1471-2261/11/36/prepub
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.