ORIGINAL RESEARCHTestosterone Deficiency in Patients with Erectile Dysfunction: When Should a Higher Cardiovascular Risk Be Considered?
Introduction
Erectile dysfunction (ED) is a common disorder in aging men affecting over 50% of men aged 40–70 years [1]. ED is frequently associated with modifiable risk factors such as diabetes, hypertension, hyperlipidemia, obesity, smoking, and a sedentary lifestyle 1, 2, 3, 4. ED has shown to increase the risk for cardiovascular (CV) events and all‐cause mortality, showing also a trend to increase the risk for CV mortality [5]. ED nearly doubles the risk for CV events in men with diabetes [6]. Men with ED are therefore advised to undergo a detailed medical assessment for early intervention on cardiovascular health 7, 8.
ED is one of the most common symptoms of testosterone deficiency syndrome (TDS), a condition associated with advancing age that is characterized by low levels of serum testosterone (low T) and the presence of compatible symptoms that are not specific of the condition 9, 10. The relationship between ED and low T has been recently reviewed [11].
Low T is thought to be associated with diabetes, metabolic syndrome (MetS), and CV disease [12]. A meta‐analysis of epidemiological data has shown that MetS is associated with lower levels of total T (TT) [13]. Longitudinal evidence has also shown that low T is associated with a higher risk for developing MetS, although it is unclear which is the cause and which is the consequence [14]. Some authors also support that low T might be a fundamental component of MetS [15].
Association between MetS and low T levels has shown to be more evident in men with ED [13], which may result in increased CV risk in these men. Comorbidities such as diabetes, hypertension, and obesity have been found to be associated with increased CV diseases in men with low T, independently of age [14]. Looking for low T among men with CV comorbidities and, conversely, identifying CV comorbidities when hypogonadism is found, is therefore of great importance [14].
Among symptoms associated with low T, ED is an important reason to seek medical advice. Most guidelines recommend the determination of serum T in men with ED signs 9, 10; however, a biochemical threshold for the definition of low T is still lacking, with differences among professional societies. Determining T thresholds may be of value as a reference to start testosterone replacement therapy (TRT) but also to adopt more intensive measures, beyond lifestyle modifications, to reduce CV risk. European Guidelines recommend TRT in men with ED and low T (defined as TT ≤8 nmol/L; 230 ng/dL) and also in those with “borderline” T levels (8–12 nmol/L) and a clinical picture of low T, where a short trial is advisable [9]. However, the T level associated with an increased CV risk in men with ED is unknown.
Section snippets
Aim
We analyzed the prevalence of common CV risk factors in a large cohort of men with ED with the aims of (i) analyzing which TT threshold, using the two thresholds proposed by European guidelines (8 and 12 nmol/L) as a reference, is associated with a higher prevalence of CV risk factors; and (ii) identifying which of these CV risk factors is associated with a higher likelihood for low T. The relative weight of each risk factor across the lifespan was also assessed.
Method
This was a multicenter, cross‐sectional, observational study conducted in Spain with the objective of assessing the relationship of ED and cardiovascular risk factors, including the prevalence of low T levels, among men seeking specialized medical attention due to sexual dysfunction. Patients aged ≥18 years were consecutively recruited by 394 urologists and andrologists from January to September 2009. Inclusion criteria included a diagnosis of ED according to the Erectile Function domain of the
Subjects' Characteristics
Participants were mainly white (98.4%), heterosexual (97.1%), with a stable partner (89.9%), with primary education, high school, or college degree (93.8%), and actively employed (64.5%). ED was diagnosed at the screening visit in 74.3% of subjects; a similar number of men (69%) had one or more comorbidities (hyperlipidemia, diabetes, or hypertension), with 46% of them having two or more comorbidities. Besides hypolipidemic therapy (16.7%), 36.9% of men were on antihypertensive therapy.
Testosterone Levels and Erectile Dysfunction
Discussion
Low T is known to be common among men consulting for ED [21]. Our study has revealed a prevalence of low T levels among men with ED ranging from 13.7% to 33.3% when thresholds are set at 8 or 12 nmol/L, respectively. Obesity and severe ED would be the strongest predictors of low T. In addition, we found that several CV risk factors that are commonly observed in men with ED 1, 2, 3, 4 are more prevalent not only in formal hypogonadic men according to European Guidelines [9], but also in those
Conclusion
T levels associated with increased CV risk could go as high as 12 nmol/L in men with ED, with distribution of risk factors showing differences according to age. Obesity and severe ED are the best predictors of low T‐related CV risk.
Conflict of Interest
José M. Martínez‐Jabaloyas is a scientific study/trial investigator for Bayer, Pfizer Inc, Lilly and GlaxoSmithKline.
Category 1
- (a)
Conception and Design
José M. Martínez‐Jabaloyas
- (b)
Acquisition of Data
José M. Martínez‐Jabaloyas
- (c)
Analysis and Interpretation of Data
José M. Martínez‐Jabaloyas
Category 2
- (a)
Drafting the Article
José M. Martínez‐Jabaloyas
- (b)
Revising It for Intellectual Content
José M. Martínez‐Jabaloyas
Category 3
- (a)
Final Approval of the Completed Article
José M. Martínez‐Jabaloyas
Acknowledgments
The author wishes to thank all members of the DE‐SDT study for their contribution. This research was supported by an unrestricted grant from Bayer Hispania SL. The authors wish to thank Beatriz Viejo, PhD, for her help in the writing of the manuscript and for her editorial support.
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