The role of vascular health on male sexual function
“I’m injecting 150 mg of testosterone cypionate every week. I look muscular. I have lots of energy – so much I actually need to take sleeping pills to wind down at night. So why can’t I get a good erection? What is wrong with me?”
I counsel countless men* with stories like this.
Typically, these fellows come to see me after visiting a “Low T” clinic and trying various hormones and hormone precursors. From testosterone creams to shots, to HCG (human chorionic gonadotropin), to breast cancer drugs and beyond, hormone treatments do indeed help some men with erectile dysfunction – but fewer men than you might think.
Erectile dysfunction (ED, impotence) is a fairly common medical condition, characterized by the inability to achieve and maintain a penile erection firm enough for satisfying sexual intercourse.1
I often explain to my clients with ED that testosterone is just one piece of the puzzle. ED can also be caused by dysfunctions in the nervous system (including mental health), in the adrenal glands, in metabolic function, in B vitamin status, and in endothelial health (the inner lining of the blood vessels). The latter is also known as “endothelial ED,” a commonly overlooked aspect of sexual health – and the focus of this article.
40% of men above the age of 40 are now estimated to have some degree of ED.
Although ED is more common among older men,16 it’s becoming more common among younger men as well: 40% of men above the age of 40 are now estimated to have some degree of ED.13 While an estimated 152 million men worldwide had ED in 1995, that number is expected to swell (no pun intended) to over 320 million people by 2025.17,18 It’s no coincidence that heart disease is also on the rise: ED is often a warning sign of impending cardiovascular disease.
The mechanics of erection
Tumescence (penile erection) relies on proper blood flow. During the male sexual response, blood flow into the penis through the arteries increases, as blood flow out of the penile veins decreases.2,3 This process effectively traps blood in the penis, resulting in an erection.
The issue with ED tends to be with the first part of this process – the delivery of blood into the penis. The integrity of the circulatory system – the system of “highways” by which blood circulates throughout the body – is essential for male sexual performance and satisfaction.4
A key component of a healthy circulatory system lies in an important little gas called nitric oxide.
Nitric oxide gets the blood flowing
Nitric oxide (NO) is a tiny gas molecule found throughout the circulatory system, causing relaxation of the cavernous smooth muscle of the penis as well as vasodilation (widening) of the penile blood vessels. These combined effects allow more blood to pass into the penis, causing a firmer erection.5,6
One of the biggest culprits for compromising NO levels, however, is inflammation – specifically inflammation of the endothelium (lining of the blood vessels).7 Vascular inflammation and the NO deficiency it causes are also to blame for other cardiovascular problems, like angina (chest pain), heart attacks, and strokes.
Erectile dysfunction can be a warning sign of other impending diseases
Even in “well-endowed” fellows, the vessels of the penis are relatively small compared to the arteries in other parts of the body. This makes the penile blood vessels fragile and sensitive to injury. The penis is therefore often the first place in the body to manifest the signs and symptoms of vascular disease.
If left untreated, the vascular inflammation and NO dysfunction associated with endothelial ED may begin to spread to blood vessels in other parts of the body, causing a variety of serious heart problems like angina (chest pain), heart attack, and stroke.8 Men can develop ED before they develop even so much as an elevated blood pressure reading!9 That’s why ED is sometimes referred to as “painless penile angina.”10
ED is a warning sign of poor vascular function and impending cardiovascular disease.
A shocking 70% of men with coronary artery disease (CAD) in one study reported that they had ED long before they developed any symptoms of CAD.11 ED is a warning sign of poor vascular function and impending cardiovascular disease.6,11-13
ED and CAD share many of the same risk factors, including obesity, sedentary lifestyle, smoking, high homocysteine levels, diabetes, high blood pressure, dyslipidemia (high cholesterol), and metabolic syndrome. All of these risk factors are also associated with poor NO activity.6,13-15
Won’t more testosterone help?
Testosterone plays an important role in sexual function via several mechanisms, including the stimulation of NO release,23 but it’s unlikely to control endothelial ED on its own for very long.
For some people with endothelial ED, testosterone replacement therapy (TRT) may help, but not sufficiently unless the dosage is ramped up high – too high. Guys on too much testosterone often experience irritability, anxiety attacks, insomnia, or other symptoms of testosterone overdose. Because of the hormone’s influence on red blood cell (RBC) production, furthermore, guys on TRT are at high risk of life-threatening events like blood clots, chest pain, heart attacks, and strokes. They’re also prone to acne, “backne” (pimples on the back), a reddish complexion, and/or a puffy appearance – effects that make a guy look a bit like the Kool-Aid Man.
For many fellows with endothelial ED, even high doses of testosterone won’t cause strong erections.
For many fellows with endothelial ED, however, even high doses of testosterone won’t cause strong erections, which does not mean that the man’s penis is “broken!”
If you have endothelial ED, it’s important to understand how and why your blood vessels are dysfunctional. Yes, there are of course nutritional supplements you can take to enhance nitric oxide production, but they’re unlikely to give you the best outcomes unless you’re also taking care to stop the cause(s) of your vascular inflammation. This is where diet and lifestyle become non-negotiable.
In the next post, we take a look at some healthy strategies for improving endothelial health, increasing nitric oxide levels, and achieving strong erections.
Click here to see References
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- Maiorino MI, et al. Lifestyle modifications and erectile dysfunction: what can be expected? Asian J Androl. 2015;17(1):5-10.
- Panchatsharam PK, et al. Physiology, erection. Treasure Island (FL): StatPearls Publishing; 2021 [cited 2021 Mar 30]. Available from: http://www.ncbi.nlm.nih.gov/pubmed/30020650
- Carlström M, et al. Mechanisms underlying blood pressure reduction by dietary inorganic nitrate. Acta Physiol. 2018;224(1):e13080.
- Gerbild H, et al. Physical activity to improve erectile function: a systematic review of intervention studies. Sex Med. 2018;6(2):75-89.
- Kirby M. The circle of lifestyle and erectile dysfunction. Sex Med Rev. 2015;3(3):169-82.
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- Thompson IM, et al. Erectile dysfunction and subsequent cardiovascular disease. J Am Med Assoc. 2005;294(23):2996-3002.
- Meldrum DR, et al. The link between erectile and cardiovascular health: the canary in the coal mine. Am J Cardiol. 2011;108(4):599-606.
- Montorsi F, et al. Erectile dysfunction prevalence, time of onset and association with risk factors in 300 consecutive patients with acute chest pain and angiographically documented coronary artery disease. Eur Urol. 2003;44(3):360-5.
- Montorsi P, et al. Association between erectile dysfunction and coronary artery disease. Role of coronary clinical presentation and extent of coronary vessels involvement: the COBRA trial. Eur Hear J. 2006;27(22):2632-9.
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- Raheem OA, et al. The association of erectile dysfunction and cardiovascular disease: a systematic critical review. Am J Mens Health. 2017;11(3):552-63.
- Sverdlov AL. Aging of the nitric oxide system: are we as old as our NO? J Am Heart Assoc. 2014;3(4).
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- Aytaç IA, et al. The likely worldwide increase in erectile dysfunction between 1995 and 2025 and some possible policy consequences. BJU Int. 1999;84(1):50-6.
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- Jeremy JY, et al. Effects of sildenafil, a type-5 cGMP phosphodiesterase inhibitor, and papaverine on cyclic GMP and cyclic AMP levels in the rabbit corpus cavernosum in vitro. Br J Urol. 1997;79(6):958-63.
- Cision PR Newswire. Testosterone replacement therapy market to touch US$1.3 billion by 2024 – TMR. New York (NY): PR Newswire; 2019 [cited 2021 Mar 30]. Available from: https://www.prnewswire.com/news-releases/testosterone-replacement-therapy-market-to-touch-us1-3-billion-by-2024—tmr-300899932.html
- Von Drehle D. Manopause?! Aging, insecurity and the $2 billion testosterone industry. New York (NY): Time Magazine; 2014 [cited 2021 Mar 30].
Available from: https://time.com/3062889/manopause-aging-insecurity-and-the-2-billion-testosterone-industry/
- Podlasek CA, et al. Translational perspective on the role of testosterone in sexual function and dysfunction. J Sex Med. 2016;13(8):1183-98.
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* Note: The words “man,” “guy,” “fellow,” and “male” as used within this article refer specifically to individuals who were born with XY chromosomes and a penis. I acknowledge and honor that not all men are born with this anatomy, and that not all people born male identify with that gender.