Abstract
Background: Modifiable risk factors contribute to the pathogenesis of cardiovascular disease (CVD) and erectile dysfunction (ED). We aimed to compare the knowledge about the contribution of modifiable risk factors to the pathogenesis of CVD and ED. The impact of patients’ having modifiable risk factors on the awareness of their negative influence on the development of CVD and ED was examined.
Methods: To this multicenter cohort study, we included 417 patients with CHD who had been hospitalized in the cardiology or cardiac surgery department during the previous six weeks and underwent cardiac rehabilitation in one of the five centers. Knowledge about modifiable risk factors was collected. ED was assessed by an abridged IIEF-5 questionnaire. Comparisons between groups were conducted using the Student’s t-test, Mann–Whitney U test, and Kruskal–Wallis test. Relationships were analyzed with Spearman's rank correlation coefficient.
Results: The mean number of correctly identified risk factors for CVD was significantly higher than those for ED (3.71 ± 1.87 vs. 2.00 ± 1.94; p < .0001). Smoking was the most recognized risk factor both for CVD and ED. Dyslipidemia was least frequently identified as a risk factor for CVD. Sedentary lifestyle was the only risk factor whose incidence did not affect the level of patient knowledge.
Conclusions: Cardiac patients with ED know more about risk factors for CVD than ED. It is necessary to include information about the negative impact of modifiable risk factors on sexual health into education programs promoting healthy lifestyles in men with cardiovascular diseases.
Introduction
Modifiable risk factors play an important role in the pathogenesis of cardiovascular disease (CVD) and erectile dysfunction (ED). In patients with coronary heart disease (CHD), the percentage of patients with ED exceeds 80%. According to European guidelines, increased awareness about the contribution of modifiable risk factors to the pathogenesis of CVD fosters significant behavioral changes in those patients and their implementation of a health-promoting lifestyle [Citation1]. Benjamin and Smith claimed that the fight against risk factors is a basic element of any level of prevention for CVD [Citation2], but it has particular importance in patients experiencing risk factors or CVD associated with them. Contribution of modifiable risk factors to the pathogenesis of CVD is connected to their harmful impact on the functioning of the endothelium that lines the interior surface of all blood vessels supplying blood to the corpora cavernosa. Therefore, modifiable risk factors underlie vasculogenic ED, which makes up about 40% of all cases of ED. Limiting the effect of risk factors by lifestyle modification is an effective method of treating CVD and ED; however, it requires men know about the negative influence of those risk factors on their general health and sexual function. The aim of our study was to conduct a comparative analysis between the level of knowledge of the contribution of risk factors to the pathogenesis of CVD and the level of knowledge of the same risk factors to the pathogenesis of ED. Additionally, the study aimed to discover whether the incidence of those risk factors in patients having those risk factors affects their awareness about their negative impact on the development of CVD and ED.
Methods
Four hundred and seventeen patients with CHD confirmed by angiography were recruited for the study. All had been hospitalized in the cardiology or cardiac surgery department during the six weeks prior to the study and underwent cardiac rehabilitation in one of the five centers. All the patients gave written informed consent to participate in the study. Patients completed the survey by themselves, but they could explain doubts to an interviewer; however they were assured of full confidentiality and were not influenced by any third party. The clinical patient characteristics are presented in .
Table 1. Characteristics of the study group.
First, patients answered questions about demographics and the presence of modifiable risk factors for ED and CVD (i.e. smoking, arterial hypertension, dyslipidemia, diabetes, incorrect body mass, and physical activity). Clinical data were retrieved from medical records. Intensity of physical activity was assessed with a form modeled on the Framingham questionnaire on the basis of the instructions of the original questionnaire [Citation3]. A 1000 kcal was set as the standard for the minimal intensity of leisure-time physical activity per week, as conducted with the goal of preventing primary diseases of the cardiovascular system [Citation4].
The presence of ED was determined using an abridged International Index of Erectile Function 5 (IIEF-5) Questionnaire [Citation5]. None of the patients reported previous surgery for prostatic hyperplasia or prostate cancer, repair of the abdominal aorta or iliac arteries, treatment for any vascular event in the central nervous system or injuries to the spine or pelvis. None stayed under psychiatric supervision, took antidepressants, or hormone therapy. None used dialysis.
The study was approved by the local Bioethics Committee. It was conducted as part of the PREVANDRO project and served as an introduction to targeted cardiosexology education. This education program has been conducted since 2011 and has covered 12,375 patients to date.
For comparisons between groups of variables with a normal distribution, Student’s t-test for independent variables was used, while of variables with a distribution other than normal, the Mann–Whitney U test was used. Relationships were analyzed with Spearman's rank correlation coefficient. In simple comparisons of dichotomous variables, the X2 test (with the Yates correction for 2 × 2 tables) was used. For comparisons of more than two groups, the Kruskal–Wallis test with multiple comparisons was performed.
Results
Smoking was the most recognized risk factor both for CVD and ED. Dyslipidemia was least frequently identified as a risk factor for CVD. The smallest number of patients was aware that low leisure-time physical activity contributed to the development of ED. All risk factors were more frequently identified as being connected with the development of CVD than ED. shows the number and percentage of patients knowing risk factors for CVD and ED.
Table 2. Number and percentage of patients knowing risk factors that contribute to pathogenesis of CVD and ED.
The biggest percentage of men identified all of the six risk factors for CVD correctly, yet it was also the largest percentage of men who were not able to correctly identify any of the risk factors for ED. shows the number and percentage of men knowing the risk factors for CVD and ED, separately.
Figure 1. Number and percentage of respondents knowing the number of risk factors, from zero to six.
The mean number of correctly identified risk factors for CVD was significantly higher than those for ED (3.71 ± 1.87 vs. 2.00 ± 1.94; p < .0001). Better education, higher economic status, and the presence of three of the risk factors (arterial hypertension, diabetes, dyslipidemia) significantly increased the number of correctly identified risk factors for both CVD and ED. Younger age, fewer pack-years, sedentary lifestyle, higher BMI, and higher IIEF-5 score determined a significantly greater number of correctly identified risk factors for CVD, while higher weekly expenditure on physical activity, larger left ventricular end-diastolic diameter (LVEDD), and better effort tolerance determined a significantly greater number of correctly identified risk factors for ED. Knowledge of risk factors for CVD and ED was not associated significantly with marital status, smoking, current smoking, overweight, obesity, waist circumference, invasive treatment in general, type of invasive treatment, LVEDD, ejection fraction, and pharmacotherapy. shows risk factors that have been identified by patients as important for CVD and ED.
Table 3. Impact of demographic and clinical factors on the knowledge of the number of risk factors for CVD and ED.
In the group reporting hypertension, a majority of patients were aware of this risk factor contributing to the pathogenesis of CVD, but nearly 70% of them were not aware of the negative impact of hypertension on ED. Similarly, in patients with dyslipidemia, many more patients identified lipid disorders as a risk factor for CVD than ED; however, the overall level of knowledge about this risk factor was low. In smokers, significantly more respondents knew about the contribution of smoking to the development of CVD than ED. Additionally, among smokers, the percentage of respondents who had knowledge of smoking as a risk factor for ED was insignificantly smaller than the percentage of respondents who lacked this knowledge. A similar level of knowledge was found in obese and overweight patients. More respondents with reduced physical activity were aware that a sedentary lifestyle contributed to the development of CVD than those who did not know it. Inverse relations were observed for the knowledge about ED. The differences were not significant. shows the distribution of patients reporting analyzed risk factors in relation to their knowledge about the contribution of those risk factors to the pathogenesis of CVD and ED.
Table 4. The number and percentage of patients reporting analyzed risk factors who had and did not have knowledge about the contribution of those risk factors to the pathogenesis of CVD and ED.
Discussion
We found significant differences in the level of knowledge about the contribution of selected risk factors to the pathogenesis of CVD and ED. The overall percentage of patients who were aware of the contribution of a particular risk factor to the pathogenesis of CVD was significantly higher than those related to ED. Patients who smoked or had arterial hypertension, diabetes, dyslipidemia, a sedentary lifestyle, and/or increased body weight significantly more often identified these risk factors as contributing to the development of CVD than ED.
Modifiable risk factors have a proven participation in the pathogenesis of CVD, thus lifestyle modifications to limit their intensity contribute to a reduction in morbidity and mortality associated with diseases of cardiovascular system. The presence of risk factors helps to stratify the risk of serious cardiovascular events and select those patients who should undergo targeted prevention programs [Citation6,Citation7]. Apart from benefits related strictly to the cardiovascular system, preventive activities reduce the effect of other closely connected disorders with the same pathogenesis such as ED, which in the majority of cases is associated with arterial system dysfunction [Citation8]. The frequent co-occurrence of cardiovascular system diseases and ED negatively affects quality of life [Citation9,Citation10]. 81.52% of patients with CVD claim good sexual function to be very important or important to them [Citation11] and are interested in receiving treatment for ED, but still sexual counseling interventions in cardiac rehabilitation centers are rare [Citation11–14]. Thus, if shaping the knowledge about the negative impact of risk factors on the cardiovascular system promotes healthier behaviors among patients who have those risk factors, improving their knowledge may have a positive prophylactic effect against ED [Citation15].
Even preliminary quantitative analysis of knowledge about risk factors indicates the presence of a significant imbalance in the level of understanding of the contribution of risk factors to the pathogenesis of CVD and ED. In the study group, 21.82% of patients knew six risk factors for CVD and only 8.39% for ED, while 5.52% of patients knew none of the risk factors for CVD and 31.89% for ED. Education and economic status significantly influenced the level of patient knowledge is in line with other observations [Citation9]. The presence of diabetes, arterial hypertension, and hyperlipidemia significantly improved patient knowledge; it was associated with regular pharmacotherapy and thus, frequent contact with health care providers who educated them. Other parameters influenced patient knowledge separately, while some of them did not at all. Among these, the relationship between effort tolerance and knowledge of risk factors for ED is worth drawing attention to. In the study by Kałka et al. on 1007 post-MI patients, effort tolerance also significantly affected the level of knowledge about returning to sexual activity following a heart attack [Citation16].
Patient knowledge about risk factors for CVD in this study was relatively high when compared to data from the literature. In the Karthik et al. study conducted with 235 patients who had undergone their first coronary artery bypass grafting (CABG), awareness of the contribution of hyperlipidemia (55%) and arterial hypertension (75%) to the development of CVD was higher than in the present study, while awareness of the contributions of smoking (53.6%) or being obese and overweight (13.6%) was lower [Citation17]. These differences may be due to the fact that the Karthik et al. study was carried out over a decade ago, and since that time, there have been a number of initiatives aimed at improving knowledge about the negative impact on health of both smoking and excessive body weight. In Lechowicz et al. study, only 12% of obese and overweight patients and 33.1% of smokers were aware of the contribution of these risk factors to the development of CVD [Citation18]. Lower knowledge presented by these patients in comparison with the results from the present study may be rooted in the fact that the Lechowicz study was conducted among patients treated in the cardiology clinic in outpatient settings. Only 38% of these patients were diagnosed with atherosclerosis [Citation18]. On the contrary, the knowledge of patients from the present study in relation to the development of CVD is low and comparable to Kałka’s team observations [Citation9]; however, it was higher than the level presented by patients from Baumgartner et al.’s report, in which, of 126 men included in the study, only 18.51% and 16.04% of them were aware of the negative impact of diabetes and smoking on sexual health [Citation19].
Education conducted as a secondary prevention is directed mostly towards patients who have a particular risk factor. Thus, knowledge of this risk factor should be significantly better in the population with it than in risk-free patients. Diabetes is one of the major risk factors for CVD [Citation20]. In the current study, the presence of diabetes was associated with the highest percentage of patients being aware of its negative impact on both the cardiovascular system and the process of erection in comparison with other risk factors. Better knowledge about risk factors in diabetic patients may be rooted in activities of diabetic associations which educate patients about secondary prevention of diabetes and its complications. The presence of diabetes significantly improved knowledge about its contribution to the development of both CVD and ED. This finding corresponds to results obtained by Kałka et al., who reported awareness of the negative impact of diabetes on erection in 55.83% of diabetic patients with CVD [Citation9].
Arterial hypertension affects about 30% of the overall population, but this percentage increases to over 60% in patients with CVD [Citation21,Citation22]. The presence of hypertension increases patients knowledge. The percentage of hypertensive patients identifying hypertension as a cardiovascular risk factor was high (80.07%) and similar to that reported by Karthik et al. (75%) [Citation17]. Worse patient knowledge concerns the impact of hypertension on the development of ED. The percentage of hypertensive patients who were aware of its negative impact on sexual health was almost 10% lower than what Kałka et al. found in a group of 502 patients with CVD who were treated due to concomitant arterial hypertension – of whom 42.3% correctly identified hypertension as a risk factor for ED [Citation9].
Lipid disorders were another analyzed factor with a recognized negative effect on the development of CVD and ED. Coexistence of dyslipidemia improved knowledge of it harmful effects on cardiovascular system. Our results stand in opposition to Lechowicz’s observation, in which patients with hypercholesterolemia less frequently identified lipid disorders as a risk factor for CVD than patients with normal cholesterol concentration (24.1% vs. 41.1%) [Citation18]. In our study, the presence of dyslipidemia significantly correlated with a lower level of knowledge about contribution of this risk factor to the pathogenesis of ED. In the Kałka et al. study, 26.54% of patients with lipid disorders were aware of the negative influence of this risk factor on the development of ED. Additionally, the presence of dyslipidemia improved knowledge in this matter [Citation9].
Increased body weight and obesity are another important risk factor which incidence is growing rapidly in developed countries. In our study, the presence of this risk factor significantly affected knowledge about its contribution to the pathogenesis of CVD, but insignificantly about ED. Similarly, Kałka et al. reported that the presence of hyperlipidemia did not affect knowledge of this factor in relation to ED [Citation9]. It is worth noting that increased body weight may be a sign of hormonal disorders that may also contribute to the development of ED. A series of studies performed by Yassin et al. indicate that waist circumference is a better predictor of reduced IIEF-5 score than weight and BMI [Citation23].
Cigarette smoking and exposure to cigarette smoke are major causes of CVD [Citation24]. In our observation, smoking was the best known risk factor both for CVD and ED. It determined better knowledge about its contribution to the pathogenesis of CVD, but not of ED. In Kałka et al.’s analysis, smoking patients had significantly worse knowledge about the influence of this risk factor on ED than nonsmoking patients [Citation9].
Physical activity modifies cardiovascular risk as well [Citation4,Citation25]. It reduces cardiovascular risk due to its positive effect on lipid metabolism, blood pressure, and glucose tolerance [Citation6]. It is the only risk factor for which the presence did not significantly change patient awareness of its contribution to the pathogenesis of both CVD and ED. Similar relationships were found by Kałka’s team. In their analysis, physical activity had an insignificant effect on patient knowledge about risk factors for ED. Additionally, the percentage of men leading a sedentary lifestyle who could correctly link the lack of physical activity with the incidence of ED was low, only 18.42% [Citation9].
The human body is a complex homeostatic system. Appearance of comorbidities may mask or modify the course of many diseases. The level of testosterone is a factor strongly associated with inflammatory factors, urinary truck functioning, and sexual performance, therefore, its level should be checked in patients with ED. Low testosterone is a factor that presents with loss of libido and ED, and increases the risk of the development of CVD and metabolic disorders [Citation26–30]. In patients with hypogonadism, the presence of ED may indicate a higher risk of development both lipid and glucose metabolism disorders as well as increased level of highly sensitive C-reactive protein [Citation31,Citation32]. Replacement therapy in patients with low testosterone can help to manage metabolic parameters, body weight, and reduce cardiovascular risk [Citation33–37].
The current literature indicates that many family physicians, cardiologists, and nurses are not aware of the need to address the sexual health problems of cardiac patients [Citation38–42]. Moreover, our findings show that health care providers cannot assume that general knowledge about the negative impact of modifiable risk factors on the cardiovascular system and their role in CVD prevention translates into knowledge about the negative impact of the same risk factors on the development of ED. Thus, in light of the significant impact of ED on quality of life and the proven efficacy of reducing the impact of modifiable risk factors on improving sexual health, we propose introducing information about the harmful effect of modifiable risk factors on sexual health into campaigns promoting healthy lifestyles.
Conclusions
Knowledge of the contribution of modifiable risk factors to the development of CVD was significantly better than knowledge of these same factors in the development of ED. A sedentary lifestyle was the only risk factor which presence did not affect the level of patient knowledge. Taking into consideration our findings, we suggest the need to include information about the negative impact of modifiable risk factors on sexual health into education programs promoting healthy lifestyles among men with CVD.
Disclosure statement
No potential conflict of interest was reported by the authors.
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