Boris Schouten

Erectile dysfunction prospectively associated with cardiovascular disease in the Dutch general population: results from the Krimpen Study

The possible relationship between erectile dysfunction and the later occurrence of cardiovascular disease while biologically plausible has been evaluated in only a few studies. Our objective is to determine the relation between ED as defined by a single question on erectile rigidity and the later occurrence of myocardial infarction, stroke and sudden death in a population-based cohort study. In Krimpen aan den IJssel, a municipality near Rotterdam, all men aged 50–75 years, without cancer of the prostate or the bladder, without a history of radical prostectomy, neurogenic bladder disease, were invited to participate for a response rate of 50%. The answer to a single question on erectile rigidity included in the International Continence Society male sex questionnaire was used to define the severity of erectile dysfunction at baseline. Data on cardiovascular risk factors at baseline (age smoking, blood pressure, total- and high-density lipoprotein cholesterol, diabetes) were used to calculate Framingham risk scores. During an average of 6.3 years of follow-up, cardiovascular end points including acute myocardial infarction, stroke and sudden death were determined. Of the 1248 men free of CVD at baseline, 258 (22.8%) had reduced erectile rigidity and 108 (8.7%) had severely reduced erectile rigidity. In 7945 person-years of follow-up, 58 cardiovascular events occurred. In multiple variable Cox proportional hazards model adjusting for age and CVD risk score, hazard ratio was 1.6 (95% confidence interval (CI): 1.2–2.3) for reduced erectile rigidity and 2.6 (95% CI: 1.3–5.2) for severely reduced erectile rigidity. The population attributable risk fraction for reduced and severely reduced erectile rigidity was 11.7%. In this population-based study, a single question on erectile rigidity proved to be a predictor for the combined outcome of acute myocardial infarction, stroke and sudden death, independent of the risk factors used in the Framingham risk profile.

Incidence rates of erectile dysfunction in the Dutch general population. Effects of definition, clinical relevance and duration of follow-up in the Krimpen Study.

This study aims to describe the incidence rate of erectile dysfunction (ED) in older men in the Netherlands according to three definitions. The influence of the duration of follow-up on the incidence rate is also explored. In a large community-based follow-up study, 1661 men aged 50–75 y completed the International Continence Society sex questionnaire and a question on sexual activity, at baseline and at a mean of 2.1 and 4.2 y of follow-up. We defined ‘ED’ as a report of erections with ‘reduced rigidity’ or worse; ‘Significant_ED’ as ‘severely reduced rigidity’ or ‘no erections’; and ‘Clinically_Relevant_ED’ as either ‘ED’ reported as ‘quite a problem’ or ‘a serious problem’, or ‘Significant_ED’ reported as at least ‘a bit of a problem’. Incidence rates of ED status were calculated in those men who completed at least one period of follow-up and were not diagnosed with prostate cancer (n=1604). For ‘ED’ the incidence rate (cases per 1000 person-years) is 99 and ranges over the 10-y age groups from 77 (50–59 y) to 205 (70–78 y); for ‘Significant_ED’ these rates were 33, 21, and 97, respectively and for ‘Clinically_Relevant_ED’ 28, 25, and 39, respectively. In general, incidence rates should not vary with the duration of follow-up. However, for ‘ED’ the 4.2 y incidence rate is about 69% of the 2.1 y incidence rate. This study presents incidence rates, for the general population, as well as based on a definition of ED that takes concern/bother into account. ‘Clinically_Relevant_ED’ has a lower increase in incidence with increasing age than other definitions that do not take concern/bother into account. The phenomenon of lower incidence rates with longer duration of follow-up may account for the differences in reported incidence rates between different studies. The effects of differences related to the duration of follow-up should be taken into consideration in future incidence reports.

Loss to Follow-Up in a Longitudinal Study on Urogenital Tract Symptoms in Dutch Older Men

Objective: To describe loss to follow-up (LTFU) in a longitudinal community-based study on urogenital tract dysfunction in older men. Patients and Methods: A cohort study of men recruited from a Dutch municipality was performed. A baseline study and two follow-up rounds – all with questionnaires and additional measurements – were performed with, on average, 2.1-year intervals. Baseline characteristics were compared between participants and non-participants in the first and in the second follow-up study. Results: The response rates in the first and in the second follow-up were 78.0 and 80.0%, respectively. Various characteristics were found to be related to LTFU (i.e., more than 5% difference in response rate). Lower urinary tract symptoms were related to LTFU in the first and second follow-up. Sexual dysfunction was related to LTFU only in the second follow-up. Adjustment for confounders yielded odds ratios for the primary outcome variables (lower urinary tract symptoms, sexual dysfunction, and health status) that approximated the value of 1. LTFU according to these variables was different in men with and without other chronic illnesses. Conclusions: LTFU seems not to be related to the primary outcome variables in this study. Describing response patterns in longitudinal studies is important, especially in studies involving older participants, as often is the case in urological research.