Tag Archives: heart attack

Exercise, Part 1: Exercise Postpones Death

Earlier this month, many folks made New Years’ resolutions to start exercising in conjunction with their other resolution to lose excess weight. I’ve got bad news for them.

Exercise is overrated as a pathway to major weight loss.

Sure, a physically inactive young man with only five or 10 pounds (2 to 4 kg) to lose might be able to do it simply by starting an exercise program. That doesn’t work nearly as well for women. The problem is that exercise stimulates appetite, so any calories burned by exercise tend to be counteracted by increased food consumption.

"Should I go with aerobic or strength training....?"

On the other hand, exercise is particularly important for diabetics and prediabetics in two respects: 1) it helps in avoidance of overweight, especially after weight loss, and 2) it helps control blood sugar levels by improving insulin resistance, perhaps even bypassing it.

Even if it doesn’t help much with weight loss, regular physical activity has myriad general health benefits. First, let’s look at its effect on death rates.   

EXERCISE PREVENTS DEATH

As many as 250,000 deaths per year in the United States (approximately 12% of the total) are attributable to a lack of regular physical activity. We know now that regular physical activity can prevent a significant number of these deaths.

Exercise induces metabolic changes that lessen the impact of, or prevent altogether, several major illnesses, such as high blood pressure, coronary artery disease, diabetes, and obesity. There are also psychological benefits. Even if you’re just interested in looking better, awareness of exercise’s other advantages can be motivational.

Exercise is defined as planned, structured, and repetitive bodily movement done to improve or maintain physical fitness.

Physical fitness is a set of attributes that relate to your ability to perform physical activity. These attributes include resting heart rate, blood pressure at rest and during exercise, lung capacity, body composition (weight in relation to height, percentage of body fat and muscle, bone structure), and aerobic power.

Aerobic power takes some explanation. Muscles perform their work by contracting, which shortens the muscles, pulling on attached tendons or bones. The resultant movement is physical activity. Muscle contraction requires energy, which is obtained from chemical reactions that use oxygen. Oxygen from the air we breathe is delivered to muscle tissue by the lungs, heart, and blood vessels. The ability of the cardiopulmonary system to transport oxygen from the atmosphere to the working muscles is called maximal oxygen uptake, or aerobic power. It’s the primary factor limiting performance of muscular activity.

Aerobic power is commonly measured by having a person perform progressively more difficult exercise on a treadmill or bicycle to the point of exhaustion. The treadmill test starts at a walking pace and gets faster and steeper every few minutes. The longer the subject can last on the treadmill, the greater his aerobic power. A large aerobic power is one of the most reliable indicators of good physical fitness. It’s cultivated through consistent, repetitive physical activity.

Physical Fitness Effect on Death Rates

Regular physical activity postpones death.

Higher levels of physical fitness are linked to lower rates of death primarily from cancer and cardiovascular disease (e.g., heart attacks and stroke). What’s more, moving from a lower to a higher level of fitness also prolongs life, even for people over 60.

Part 2 of this series will cover all the other health benefits of exercise. Part 3 will outline specific exercise recommendations, such as the type and duration of activity.

Steve Parker, M.D.

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Heart Patients, Listen Up: Mediterranean Diet to the Rescue

The Mediterranean diet preserves heart muscle performance and reduces future heart disease events, according to Greek researchers reporting in the American Journal of Clinical Nutrition, May 19, 2010

Reuters and other news services have covered the story.

The Mediterranean diet is well-established as an eating pattern that reduces the risk of death or illness related to cardiovascular disease—mostly heart attacks and strokes.  Most of the studies in support of the heart-healthy diet looked at development of disease in general populations.  The study at hand examined whether the diet had any effect on patients with known heart disease, which has not been studied much.

How Was the Study Done? 

 The study population was 1,000 consecutive patients admitted with heart disease to a Greek hospital between 2006 and 2009.  In this context, heart disease refers to a first or recurrent heart attack (70-80% of participants) or unstable angina pectoris.  Acute heart attacks and unstable angina are “acute coronary syndromes.”  Average age was 64.  Sixty percent had a prior diagnosis of cardiovascular disease (coronary heart disease or stroke).  Thirty percent had diabetes.  At the time of hospitalization, half had diminished function of the main heart pumping chamber (the left ventricle), half had normal pump function.  Men totalled 788; women 212.

On the third hospital day, participants were given a 75-item food frequency questionnaire asking about consumption over the prior year.  If a potential enrollee died in the first two hospital days, he was not included in the study.  A Mediterranean diet score was calculated to determine adherence to the Mediterranean diet.  Mediterranean diet items were nonrefined cereals and products, fruits, nuts, vegetables, potatoes, dairy products, fish and seafood, poultry, red meats and meat products, olive oil, and alcohol. 

Left ventricle function was determined by echocardiogram (ultrasound) at the time of study entry, at the time of hospital discharge, and three months after discharge.  Systolic dysfunction was defined as an ejection fraction of under 40%.  [Normal is 65%: when the left ventricle is full of blood, and then squeezes on that blood to pump it into the aorta, 65% of the blood squirts out.]

Participants were then divided into two groups: preserved (normal) systolic left ventricular function, or diminished left ventricular function. 

They were followed over the next two years, with attention to cardiovascular disease events (not clearly defined in the article, but I assume including heart attacks, strokes, unstable angina, coronary revascularization, heart failure, arrhythmia, and death from heart disease or stroke.

Results

  • Four percent of participants died during the initial hospitalization.
  • At the three month follow-up visit, those with greater adherence to the Mediterranean diet (a high Mediterranean diet score) had higher left ventricular performance (P=0.02).
  • At the time of hospital admission, higher ejection fractions were associated with greater adherence to the Mediterranean diet (P<0.001).
  • Those who developed diminished left ventricular dysfunction had a lower Mediterranean diet score (P<0.001)
  • During the hospital stay, those in the highest third of Mediterranean diet score had lower in-hospital deaths (compared with the lower third scores) (P=0.009).
  • Among those who survived the initial hospitalization, there was no differences in fatal cardiovascular outcomes based on Mediterranean diet score.
  • Food-specific analysis tended to favor better cardiovascular health (at two-year follow-up) for those with higher “vegetable and salad”  and nut consumption.  No significant effect was found for other components of the Mediterranean diet score.
  • Of those in the highest third of Mediterranean adherence, 75% had avoided additional fatal and nonfatal cardiovasclar disease events as measured at two years.  Of those in the lowest third of Mediterranean diet score, only 53% avoided additional cardiovascular disease events.   

The Authors’ Conclusion

Greater adherence to the Mediterranean diet seems to preserve left ventricular systolic function and is associated with better long-term prognosis of patients who have had an acute coronary syndrome.

My Comments

I agree with the authors’ conclusion.

We’re assuming these patients didn’t change their way of eating after the initial hospitalization.  We don’t know that.  No information is given regarding dietary instruction of these patients while they were hospitalized.  In the U.S., such instruction is usually given, and it varies quite a bit.

In this study, lower risk of cardiovascular death was linked to the Mediterranean diet only during the initial hospital stay.  Most experts on the Mediterranean diet would have predicted lower cardiovascular death rates over the subsequent two years.  Mysteriously, the authors don’t bother to discuss this finding.

For those who don’t enjoy red wine or other alcoholic beverages, this study suggests that the Mediterranean diet may be just as heart-healthy without  alcohol.  A 2009 study by Trichopoulou et al suggests otherwise.

Steve Parker, M.D.

Reference: Chrysohoou, C., et al.  The Mediterranean diet contributes to the preservation of left ventricular systolic function and to the long-term favorable prognosis of patients who have had an acute coronary eventAmerican Journal of Clinical Nutrition, May 10, 2010.  doi:10.3945/ajcn.2009.28982

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Filed under coronary heart disease, Health Benefits, Mediterranean Diet

Heart and Stroke Patients: Avoid Weight-Loss Drug Sibutramine (Meridia)

The weight-loss drug sibutramine (Meridia) should be withdrawn from the U.S. market, suggests an editorialist in the September 2, 2010, New England Journal of Medicine.  Based on a clinical study in the same issue, it’s more accurate to conclude that sibutramine shouldn’t be prescribed for people who aren’t supposed to be taking it in the first place.

Sibutramine is sold in the U.S. as Meridia and has been available since 1997.  Judging from the patients I run across, it’s not a very popular drug.  Why not?  It’s expensive and most people don’t lose much weight.

The recent multi-continent SCOUT trial enrolled 9,800 male and female study subjects at least 55 years old (average age 63) who had either:

  1. 1) History of cardiovascular disease (here defined as coronary artery disease, stroke, or peripheral artery disease)
  2. 2) Type 2 diabetes plus one or more of the following: high blood pressure, adverse cholesterol levels, current smoking, or diabetic kidney disease.
  3. Or both of the above (which ended up being 60% of the study population)`.

Here’s a problem from the get-go (“git-go” if you’re from southern U.S.).  For years, Meridia’s manufacturer and the U.S. Food and Drug Administration have told doctors they shouldn’t use the drug in patients with history of cardiovascular disease.  It’s not the scary “black box warning,” but it’s clearly in the package insert of full prescribing information.

Half the subjects were randomized to sibutramine 10 mg/day and the other half to placebo.  All were instructed in diet and exercise aiming for a 600 calorie per day energy deficit.  They should lose about a pound a week if they followed the program.  Average follow-up was 3.4 years.

What Did the Researchers Find?

Forty percent of both drug and placebo users dropped out of the study, a very high rate.

As measured at one year, the sibutramine-users averaged a weight loss of 9.5 pounds (4.3 kg), the majority of which was in the first 6 weeks.  After the first year, they tended to regain a little weight, but kept most of it off.

Death rates were the same for sibutramine and placebo.

Sibutramine users with a history of cardiovascular disease had a 16% increase in non-fatal heart attack and stroke compared to placebo.  To “cause” one heart attack or stroke in a person with known cardiovascular disease, you would have to treat 52 such patients.

Folks in the “diabetes plus risk factor(s)” group who took sibutramine had no increased risk of heart attack or stroke.

So What?

Average weight loss with sibutramine isn’t much.  Nothing new there.  [Your mileage may vary.]

People with cardiovascular disease shouldn’t take sibutramine.  Nothing new there either.

Steve Parker, M.D.

Reference:  James, W. Philip, et al.  Effect of sibutramine on cardiovascular outcomes in overweight and obese subjects.  New England Journal of Medicine, 363 (2010): 905-917.

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Filed under coronary heart disease, Drugs for Diabetes, Overweight and Obesity, Stroke, Weight Loss

Diabetes and Shortened Lifespan: “How Bad Is It, Doc?”

Diabetes mellitus for years has been linked with cardiovascular disease such as heart failure and coronary heart disease (blocked arteries in the heart, and the leading cause of death in the Western world).  How scared should diabetics be?

An article  in the Archives of Internal Medicine gives us one answer.

Researchers from the Netherlands and Harvard examined medical records of 5,209 people (mostly white, 64% men) enrolled in the Framingham (Massachusetts, USA) Heart Study.  This cohort has been examined every other year for more than 46 years. 

Study subjects who had diabetes at age 50 were identified; health outcomes going forward were then analyzed, with particular attention to lifespan and cardiovascular disease.  “Cardiovascular disease” in this context means coronary heart disease, stroke, congestive heart failure, intermittent claudication (leg pain during exertion caused by blocked arteries), and transient ischemic attack (stroke-like symptoms that resolve within 24 hours).

Results

Compared to those in the cohort free of diabetes, having diabetes at age 50 more than doubled the risk of developing cardiovascular disease for both women and men. 

Compared to those without diabetes, having both cardiovascular disease and diabetes approximately doubled the risk of dying, regardless of sex.

Compared to those without diabetes, women and men with diabetes at age 50 died 7 or 8 years earlier, on average.

[Specific causes of death were not reported.]

Take-Home Points

We’d likely see longer lifespans and less cardiovascular disease if we could prevent diabetes in the first place.  How do we do that?  Strategies include regular physical activity, avoidance or reversal of overweight and obesity, and low-glycemic-index diets.

The Mediterranean diet it linked to reduced heart attacks and strokes, and longer lifespan.  That’s why I’ve been working for the last year and a half to adapt it for diabetics.

ResearchBlogging.orgWe have better treatments for cardiovascular disease and diabetes and these days, so the death rates and illness numbers shouldn’t  be quite so alarming.  Up-to-date management of diabetes and cardiovascular disease will prevent some acute disease events—such as heart attacks and strokes—and prolong life.   

Steve Parker, M.D.

References: 

Franco, O., Steyerberg, E., Hu, F., Mackenbach, J., & Nusselder, W. (2007). Associations of Diabetes Mellitus With Total Life Expectancy and Life Expectancy With and Without Cardiovascular Disease Archives of Internal Medicine, 167 (11), 1145-1151 DOI: 10.1001/archinte.167.11.1145

Knowler, W.C., et al.  Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin.  New England Journal of Medicine, 346 (2002): 393-403.

Tuomilehto, J., et al.  Prevention of type 2 diabetes mellitus by changes in lifestyle among subjects with impaired glucose tolerance.  New England Journal of Medicine, 344 (2001): 1,343-1,350.

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Filed under coronary heart disease, Diabetes Complications, Stroke

Rosiglitazone Severely Restricted by FDA

MedPageToday reported yesterday on the U.S. Food & Drug Administration’s ruling that the diabetes drug rosiglitazone should be used in new patients only if blood sugars are not controlled with other diabetes drugs, such as pioglitazone.

It sounds as if new users and their doctors may have to jump through some paperwork hoops to get the drug, which is more reason not to prescribe it.

The problem is that scientific studies suggest that rosiglitazone increases the risk of heart attack, heart failure, and death.

Steve Parker, M.D.

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Filed under Diabetes Complications, Drugs for Diabetes

Do Calcium Supplements Cause Heart Attacks?

They might, if you’re a woman over 50 taking over 500 mg elemental calcium daily without a vitamin D supplement.

Details are at my recent Self/NutritionData Heart Health Blog post.

Steve Parker, M.D.

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Filed under coronary heart disease

Whole Grains Lower Blood Pressure: So What?

The American Journal of Clinical Nutrition earlier this month published a research report on whole grain consumption and various cardiovascular disease risk factors.  U.K. investigators compared the effects of refined grains versus whole grains in healthy middle-aged adults.  The strongest finding was that three servings a day of whole grains—wheat and oats in this instance—reduced systolic blood pressure by 5 mmHg. 

The investigators suggest this BP lowering may be responsible for the reduced risk of heart attack and stroke associated with whole grain consumption in observational studies.

Additional details are at my Self/NutritionData Heart Health Blog post of August 17, 2010.  The researchers noted a three or four percent reduction in LDL cholesterol (“bad cholesterol”) in study participants eating refined grains, yet , mysteriously, had nothing to say about that.

Steve Parker, M.D.

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