Quick Study: Heart Disease,
Osteoporosis and More
By Haleh V. Samiei
Washington Post, July 18, 2000
HEART DISEASE
Diet and lifestyle have a powerful impact on heart disease risk.
·
THE STUDY AND RESULTS Researchers in Boston investigated the
relationship between diet and lifestyle and development of heart disease
in more than 84,000 women who were participating in a Nurse's Health Study
program. The women, who were between the ages of 30 to 55, filled out
questionnaires on diet, exercise frequency, body mass index (a measure of
weight versus height), smoking status and alcohol consumption at regular
intervals for 14 years. Dietary factors studied included consumption of
cereal fiber, fish fatty acids, folate, trans fats and foods that
excessively increase blood sugar levels, as well as the ratio of
polyunsaturated to saturated fats. There were 1,128 incidents of fatal and
nonfatal heart attacks during the study period. Women who did not smoke
cigarettes, were not overweight, had a healthy diet, exercised moderately
or vigorously for half an hour a day and drank moderate amounts of alcohol
reduced their chances of developing heart disease by more than 80 percent.
* WHAT'S NEW this is one of few studies to investigate the effects of a
combination of lifestyle practices on the risk of heart disease. Most
studies focus on a single behavior.
* CAVEATS Much of the study relies on self-reports of diet and
lifestyle. In addition, other variables, such as dietary consumption of
nuts or the use of aspirin or postmenopausal hormones, could affect the
risk of heart disease.
* BOTTOM LINE Women may be able to reduce their chances of developing
heart disease significantly through diet and lifestyle modifications.
* FIND THIS STUDY July 6 issue of The New England Journal of Medicine;
abstract online at http://www.nejm.org.
BLOOD PRESSURE
Exercise and weight loss can reduce blood pressure.
* THE STUDY AND RESULTS Researchers randomly divided 133 men and women
with mildly high blood pressure (130 to 180 over 85 to 110) into three
treatment groups for 26 weeks. One group participated in 55-minute
exercise sessions three to four times a week; a second group participated
in the same exercise sessions as well as a weekly group weight-loss
program; and the third group, which served as comparison, was asked to
maintain usual dietary and exercise habits for six months. The researchers
measured the blood pressure of the participants under many different
circumstances, such as while resting during a regular clinic visit, while
working, while under mental stress and while exercising. Both active
groups lowered their blood pressures, but those participating in the
weight management program lowered their blood pressure even more than
those participating in the exercise program alone.
* WHAT'S NEW This is the largest, most comprehensive study to look at
the effects of exercise and weight loss on the unmedicated blood pressure
of both men and women.
* CAVEATS It is difficult to compare this study with others that ran
for a different length of time with participants of different weights,
different methods of blood pressure measurement or with a different
history of medication. In addition, socioeconomic factors may influence
how well people adhere to the exercise and weight-loss programs.
* BOTTOM LINE Sedentary, overweight people with mild hypertension may
be able to reduce their blood pressure through exercise and weight loss.
* FIND THIS STUDY July 10 issue of the Archives of Internal Medicine or
http://archinte.ama-assn.org/.
OSTEOPOROSIS
Exercise during adolescence can improve bone density in adulthood.
* THE STUDY AND RESULTS Women typically gain 40 to 50 percent of their
bone mass during adolescence. Researchers compared the effects of exercise
vs. calcium intake on the bone minerals of 81 white 18-year-old females
participating in the ongoing Penn State Young Women's Health Study. The
women provided food and exercise records at regular intervals between the
ages of 12 and 18. The researchers collected data on calcium
supplementation and total body and hip bone mineral measurements. The
young women who exercised more often during teenage years had higher hip
bone mineral density at age 18 than those who did not. However, variations
in calcium intake--the women in this study consumed between 500 and 1,500
milligrams a day--did not seem to affect hip bone mineral density or total
body bone mineral gain.
* WHAT'S NEW This is one of few studies to examine the effect of random
exercise programs on adolescent bone gain and bone density. Previous
studies looked at athletes and women involved in specific activities.
* CAVEATS The average daily calcium intake of these young women was 919
milligrams a day, which is slightly higher than the national average of
833 milligrams for this age and ethnic group. There is no information
available for the effect of calcium intakes below 500 milligrams in this
study. The results need to be verified for other ethnic groups.
* BOTTOM LINE Young women can have healthier bones in adulthood by
leading an active lifestyle.
* FIND THIS STUDY July issue of Pediatrics; abstract online at http://www.pediatrics.org/current.shtml.
EMPHYSEMA
Reducing both lungs is better in short term than reducing just one.
* THE STUDY AND RESULTS In people with emphysema, the walls of the tiny
air sacs in the lung are damaged, often from smoking. This makes the lung
lose its elasticity, causing problems with inhaling and exhaling.
Researchers believe that lung volume reduction surgery--in which portions
of the damaged lung are cut away--may pull the airways open again allowing
easier breathing. This study reviews 6 to 24 months of follow-up data on
nearly 700 patients who had lung reduction surgery on one or both sides in
five different medical centers. While both types of surgery resulted in
improvement of emphysema symptoms, patients who had surgery on both lungs
had better recoveries as measured by shortness of breath and quality of
life.
* WHAT'S NEW This study aims to sort out controversial findings on
whether lung reduction surgery on both lungs is superior to just one lung.
* CAVEATS Risks associated with double lung volume reduction surgery
are higher than surgery on just one. It is possible that surgery on one
lung followed in two to three years by surgery on the other may provide
longer relief from symptoms. The patients in the two study groups did not
match in terms of age and progression of the disease, perhaps skewing
results. Finally, large numbers of patients did not participate in the
follow-up tests.
* BOTTOM LINE People with emphysema may have a better short-term
recovery from their symptoms by having lung reduction surgery done on both
lungs, provided they don't have risk factors such as age that might lead
to complications.
* FIND THIS STUDY June issue of the Annals of Thoracic Surgery or
http://ats.ctsnetjournals.org/current.shtml.
HEART DISEASE
Triglycerides are no more indicative of heart disease than cholesterol
alone.
* THE STUDY AND RESULTS Researchers in San Francisco investigated the
value of measuring the levels of a blood chemical called triglyceride
along with cholesterol levels in predicting the development of heart
disease. They analyzed data from three previous studies involving close to
80,000 people to see who developed heart problems. The triglyceride levels
did not provide any additional information on the risk of heart disease in
men compared with the warning signs of high cholesterol levels alone. In
one study that involved women, however, those with high cholesterol and
triglyceride levels were more likely to develop heart disease than those
with only high cholesterol, but the researchers noted that the numbers
were small.
* WHAT'S NEW The question of whether high triglyceride levels increase
the risk of heart disease has long been disputed and is still
inconclusive. This study goes beyond that to ask whether screening for
high triglyceride levels is a useful test in conjunction with cholesterol
screening for prediction and prevention of heart disease. The researchers
conclude that it is not.
* CAVEATS It is still possible that treatment of high triglyceride
levels, which was not investigated here, may reduce the risk of heart
disease. The results obtained for triglyceride levels in women need to be
verified in a larger group. In addition, the study combined studies using
different variables, which can affect results.
* BOTTOM LINE The use of triglyceride screening does not appear to
improve the diagnosis or treatment of heart disease for men.
* FIND THIS STUDY July 10 issue of the Archives of Internal Medicine or
http://archinte.ama-assn.org/.
