Hugh Jones, MD: Thank you. Historically, back in the 1940s, there were several publications throughout the world, many from America and the United Kingdom, where patients with angina, males, were given testosterone and it did show an improvement in their symptoms of angina. However, those studies were not properly controlled scientifically. What then happened was not a lot until 1977, when there was a proper study done that did show benefit but, again, a long gap before things were taken further. Over the last six to eight years, there have been several publications looking at the benefits of testosterone in heart disease.

For many, many years, testosterone has been contraindicated in heart disease and a lot of the licenses for drugs in their details show it should not be given or given with caution to men with coronary artery disease and also not to be given to men with heart failure. Now, the actual basis for that, there does not seem to be any clear basis. Men are known to be more prone to dying from heart disease than women. This is a relationship which occurs throughout the world. What does happen is that if you remove the differences between smoking and obesity between the sexes, males are still more than two-to-one more likely to develop heart disease.

Why is that? Is it something to do with the male sex hormone? We undertook studies to look at what the incidence or prevalence of low testosterone levels were in men with heart disease. Several studies have been done in the past, but they used different assays and not used a control group and what we showed was that men who have got proven coronary disease on angiography, narrowing of their coronary arteries, up to 70% of their arteries, have lower testosterone when compared to a group of men who have normal coronary arteries, they just attended because they have had chest pain or valve heart disease for further investigation. It was clear that men do have lower testosterone if they have heart disease. But which is the chicken, which is the egg?

Hugh Jones, MD: Is it that you have a low testosterone and that makes you more likely to develop heart disease or is the fact that you have heart disease lowering the testosterone? We need long-term studies of giving testosterone to men to see whether it improves their outlook in the long term. But what we have done is shorter-term studies. We have looked at men with angina and treated them with testosterone because there is evidence now that testosterone actually makes blood vessels larger, it vasodilates the blood vessels and enhances the blood flow to not only the heart, but to other tissues, as well. We have been looking mainly at the heart and we did a study of three-month therapy to men with chronic stable angina and monitored the improvement by treadmill testing and looking at the heart’s electrophysiology and we showed that men were actually walking after three months about 52 seconds further before they got the same degree of lack of blood supply to the heart. But what we did show was that those men who had lower testosterone had more of an improvement and we have done a follow-up study where we just picked men with very low testosterone levels and heart disease and in that group, after a month, they were walking 73 seconds further. So the lower your testosterone, the better the improvement.

Now the question is, where is testosterone acting? There are several anti-anginal drugs and we have managed to identify that testosterone, one of its actions is to block calcium entry into cells, it is a calcium channel blocker. Now we have evidence that it is working at the same site or the same pore of the calcium channel as Nifedipine and other similar drugs which are used commonly as anti-anginals.

So I think we now have evidence to take this further forward and do longer-term studies because at the moment we have only done studies in angina for three months, but we want to see whether this effect is long-term. I have had individual patients who have continued now for two or three years and from anecdotal, if you like, data from following these patients, the benefit is long-term.

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