Beta Blockers Worsen Blood Sugar--May Cause Diabetes

Many people know that it is a bad idea for anyone who takes insulin or a sulfonylurea drug to take a beta blocker. This is because it has long been known that these drugs block the counter-regulatory response that prevents a dangerous hypo or--if it cannot prevent the hypo--at least gives the victim some warning that one is coming by causing shakes and pounding pulse.

Now evidence from a huge study of almost 20,000 people has learned that beta blockers are dangerous to anyone with any blood sugar abnormality. The study is Anglo-Scandinavian Cardiac Outcomes Trial-Blood Pressure Lowering Arm (ASCOT-BPLA,). It was published in Diabetes Care in May.

Determinants of new-onset diabetes among 19,257 hypertensive patients randomized in the Anglo-Scandinavian Cardiac Outcomes Trial--Blood Pressure Lowering Arm and the relative influence of antihypertensive medication.

It concluded: "Baseline FPG >5 mmol/l, BMI, and use of an atenolol +/- diuretic regimen were among the major determinants of NOD [Non-insulin dependent diabetes i.e. Type 2] in hypertensive patients."

An analysis of the study (which is still only available as an abstract to non-subscribers) published in Irish Medical News explains "Hypertensive patients allocated to amlodipine and perindopril were found 34% less likely to develop NOD [Type 2] compared with those allocated to the β-blocker/diuretic combination."

Diabetes in Control adds the following: "Says Dr Anoop Misra, director and head (diabetes and metabolic diseases) Fortis Hospitals: "In patients with hypertension, beta blocker drugs are no longer frontline therapy. These drugs may not only increase blood sugar levels in those who don't have diabetes, but may worsen sugar control in those with diabetes and also blunt warning symptoms when low sugar occurs."

My mail suggests that American doctors are not aware of the negative impact of beta blockers on the blood sugar of their patients as many people with Type 2 who contact me are taking these drugs. My own doctors have also prescribed beta blockers for me in the past.

Here is a list of commonly prescribed beta blockers:

Generic name/Brand Name
cebutolol- Sectral
Atenolol (G)- Tenormin
Betaxolol- Kerlone
Bisoprolol fumarate- Zebeta
Carteolol hydrochloride- Cartrol
Metoprolol tartrate (G)- Lopressor
Metoprolol succinate- Toprol-XL
Nadolol (G)- Corgard
Penbutolol sulfate- Levatol
Pindolol (G)- Visken
Propranolol hydrochloride (G)- Inderal, Inderal LA
Timolol maleate (G)- Blocadren

CAUTION! Do NOT Stop These Drugs Without Help from Your Doctor

One of the nastier problems with Beta Blockers is that if you are taking one and stop it suddenly you raise the risk of having a heart attack. So if you are taking a beta blocker, you MUST contact your doctor and ask for guidance as to the safe way of getting off of it and onto a drug that is safer for people with diabetes.

There are alternatives to Beta Blockers. ACE inhibitors like Lisinopril do not raise blood sugar and also appear to have some kidney-protective qualities. Those who cannot tolerate ACE inhibitors usually do well on ARB drugs which include Diovan (Valsartan) and Avapro (Irbesartan). ARB drugs besides lowering blood pressure, also lower insulin resistance slightly. Though this effect is not usually detectable in people who are severely insulin resistant, I see an immediate impact on my own blood sugar when I take a dose of Diovan after not having used it in a while.

HCTZ (Hydrocholorothiazide, often abbreviated HCT) is a diuretic which is prescribed alone or combined in pills containing other blood pressure drugs. It has been shown to raise blood sugar. This may be because as a diuretic it eliminates water from the blood stream and this concentrates the glucose that is left. Whatever the explanation, if you can control your blood pressure with medications that do not contain HCT do so. Your blood sugar will thank you. Many doctors immediately prescribe the combination pills that contain this diuretic as a first line treatment, rather than prescribing the other drug alone. But if you cannot get adequate control with just the one pill, HCT may help. Just make sure you drink a lot of water with it.

Blood pressure control is as important as blood sugar control in preventing heart disease and stroke and it is thought that the overall improvement in stroke and heart attack statistics over the past decade are due to patients having better blood pressure control. So don't let this news make you avoid doing something about high blood pressure. Just make sure that the drugs you take to control your blood pressure are ones that are safe for people with pre- and full fledged diabetes.

Other ways to lower blood pressure are:

1. Cut way down on carbohydrates. Many people, though not all, will see dramatic drops in their blood pressure when they cut down on their carbohydrate intake.

2. Exercise.

3. Lose weight.

4. Eliminate salt from your diet. Whether this works depends on your genetic make up. For people whose genes make them salt sensitive, cutting salt causes a dramatic improvement in blood pressure. For others it has no effect.