The Washington Post (and others) reported recently on a study in the recent Annals of Internal Medicine that showed diuretics were just as good as preventing heart attacks or strokes in patients with metabolic syndrome (pre-diabetes condition) than other agents, and was better in preventing heart failure in this group. The authors considered this important because new drugs like calcium channel blockers and ACE inhibitors are often used in these patients because diuretics can increase sugar and elevate cholesterol.
Bottom Line: Though the study did show an advantage to diuretics, it also showed they were more likely to increase sugar levels, possibly leading to diabetes. It is not clear which pressure medicine is best.
More if you are interested: This new study is part of a larger study called ALLHAT that examined patients with and without metabolic syndrome designed to look at the same question: do new more expensive drugs have any benefit than the older, cheaper diuretics? Answer: The diuretics acutally did better!
The current US hypertension guidlines (based on ALLHAT and other studies) recommend diuretics as first line therapy for most patients.
So everyone shoud be on a diuretic, right?????.
First, the US guidelines were published right before another big study, very similar to ALLHAT called ASCOT that found just the opposite, that calcium channel blockers and ACE inhibitors did better than diuretics. In fact, the European guidelines , which are more recent, recommend an ACE inhibitor for patients younger than 55 and a diuretic or calcium channel blocker to patients older than 55.
1. Why the discrepancy in studies and guidelines?
2. Which pressure medication should I take?
Guidelines are based on more than just how good a drug works.
Part of the US recommendations are based on cost. At the time of the studies, diuretics (like hydrochlorothiazide or HCTZ) had been generic for some time. ACE inhibitors (lisinopril) and calcium channel blockers (amlodipine), once blockbuster expensive drugs are now generic. Without looking at ASCOT, and looking at prices at the time, the NIH basically recommended diuretics for all.
Blood pressure control, not choice of drug is probably most important. ASCOT was a more Anglo poputlation, and ACE inhibitors tend to work better on whites. In ASCOT, ACE and calcium channel blockers lowered blood pressure better than diuretics, and had fewer heart attacks and strokes. In ALLHAT, the diuretics did a better job on blood pressure, and also on heart attacks and strokes. The key then is lowering blood pressure.
Diuretics may lead to diabetes. The recent report shows that diuretics did increase sugar more. The authors argue that despite this, there was no worsening of heart attacks and stroke. However, it takes years for people with pre-diabetes to develop substantially increased risk for a heart attacks and stroke. If the trial would have gone longer, you would probably see more diabetes in the diueretic group, and likely more heart atttacks and strokes. An interesting article last year in the Lancet analyzed all the large studies that looked for new onset diabetes. They found that ACE inhibitors were less likely to cause diabetes compared to other drugs, especially diuretics. In fact, diuretics were more likely to cause new diabetes compared to placebo!
Most patients need more than one drug. In both ASCOT and ALLHAT, almost all patients needed more than one drug to control their pressure, and many patients needed three or four. Thus, which is the best drug probably doesn't matter Fortunately, there are multiple combinations of old and new drugs that are now available as a generics: (lisinopril/HCTZ, amlodipine/benazapril, atenolol/chlorthalidone).
Chose the drug that's right for you. Look at side effects and benefits. Take what works to keep your blood pressure under control. Consider taking combination pills if needed.
Diuretics (hydrochorothiazide) - best studied, cheapest. May increase risk of diabetes, can cause frequent urination. Reduces risk of heart failure
ACE inhibitors (lisinopril)- fewest side effects (small chance of chronic cough which stops when drug is discontinued), won't increase risk of diabetes, protects the kidney. May not be as effective in black patients
Calcium channel blockers (amlodipine)- generally tolerated well, but can cause edema (swelling in the legs). May be more effective in black patients.
Beta-blockers- (atenolol, metoprolol) also best studied. Tend to cause more dizziness and tiredness. Excellent for patients with known coronary artery disease, and mandatory after a heart attack.