Some men with high blood pressure, although being treated with blood pressure lowering drugs (antihypertensives), still have heart attacks at an unexpectedly high rate. It now seems that at least some of these men have what is known as the metabolic syndrome, or "syndrome X", which is also called the insulin-resistant syndrome. They are usually moderately obese around the middle, have raised blood sugar levels, and show resistance to the normal effects of insulin (i.e. insulin doesn't lower the blood sugar as readily as in normal persons). Their blood lipid levels show that the "good" cholesterol - the high-density lipoprotein cholesterol (HDL-C) - is low, while their triglyceride level is increased. As well as these changes, they have high blood pressure, degenerative changes in the arteries (atheroma) and an increased risk of heart attack (myocardial infarction, or MI). Just treating the high blood pressure with antihypertensives in syndrome X men doesn't seem to reduce the risk of heart attack.

A lot of the research into this condition has been done in Scandinavia, where it seems to be more common. For instance, it's been shown that 14% of middle-aged Swedish men have a change in one of their genes concerned with the brain steroid receptors, which corresponds with a partial lack grow hormone. These men have the signs of syndrome X listed above, and treating them with growth hormone restores these changes towards normal, as well as reducing their abdominal fat stores.

A study on men in Copenhagen, Denmark (referenced above) shows that over an 8-year period those with high triglyceride and low "good" cholesterol levels were more likely to have a heart attack, even if their blood pressure was being treated by medication. In such types, there was no connection between their blood pressure readings and their risk of heart attack. In other men from the same city who had normal lipid levels, increased blood pressure was clearly associated with an increased risk of heart attack, and antihypertensive drugs were effective in reducing this risk.
What does this mean? First, physicians (and their patients) should realize that there is more to checking lipid levels than just measuring the total or the "bad" cholesterol. A full lipid profile is necessary to show any changes in the triglyceride and "good" cholesterol levels.

Second, if high blood pressure, high blood sugar, and abdominal fatness coexist in someone, suspicions should be raised and further tests done to see if they have syndrome X.

Third, treatment should be aimed at correcting the lipid levels. Use of medications called collectively 'statins' can help, as well as other specific drugs. Exercise, stopping smoking, and other steps towards a healthy lifestyle are also important. For such people, it's not enough just to take medication against high blood pressure.
Even if syndrome X isn't as common in other parts of the world as it is in Scandinavia (and we don't know that yet), we must be alert to recognizing and treating it. There may be new ways to attack the problem further down the road. Once the cause of a condition is known, new treatment methods often become feasible. In the case of syndrome X, it may indeed be possible to give growth hormone supplements if a deficiency can be demonstrated, although the use of this hormone is not without its risks. Before this becomes a recognized method of treatment, extensive clinical trials will have to be completed. In the meantime, we should be grateful to the Scandinavians for doing useful research into a complicated but important condition,