Category: Prior Clinic Blog
STUDY: Losing just over two pounds is associated with a 1% reduction in cholesterol and a 2% reduction in triglycerides.
JOURNAL: Journal of the American Medical Association 2003;289:323-330
AUTHORS: Dr. Anne McTiernan
ABSTRACT: Regular, moderate exercise can lower the risk of heart disease among older women by boosting fitness and trimming tummy fat, new research shows.
COMMENTARY: The study found that postmenopausal women who began an exercise program of brisk walking or cycling five days a week lowered their levels of abdominal fat by about 6% and lost weight, regardless of body weight or age.
Not surprisingly, the most active women lost the most body fat and the most weight.
Women who did no cardiovascular exercise but performed stretching exercises one day a week actually saw intra-abdominal fat and weight increase slightly after a year.
The results suggest a strategy for lowering the risk of heart disease, a leading cause of death among women. Intra-abdominal fat is considered a major risk factor for heart disease and is also associated with type 2 diabetes, high blood pressure and high cholesterol.
Fit individuals, or those able to maintain an elevated heart rate over time, are also less likely to die of heart disease regardless of body weight, Dr. Anne McTiernan from the Fred Hutchinson Cancer Research Center in Seattle, Washington, and colleagues explain.
Therefore, the study has implications for the soaring rates of obesity in the US. Nearly two-thirds of the adult population is now considered overweight or obese, as measured by body mass index (BMI). An adult with a BMI above 25 is considered overweight and one with a BMI exceeding 29 is considered obese.
Dieting, previous studies have shown, may be just part of the solution. To investigate the effect of regular exercise on body fat and weight, researchers divided 168 inactive women aged 50 to 75 years into two groups. All women had BMIs over 25.
The exercisers were instructed to walk on a treadmill or cycle on a stationary bicycle for at least 45 minutes, five days a week, for one year. Weight training was recommended but not required. Women in the control group performed a series of stretching exercises one day a week for the year.
The most active women, or those who exercised more than 3 hours and 15 minutes a week, lost about 7% of their intra-abdominal fat, compared with a loss of 6% among intermediate exercisers, as measured by a CT scan. Those who exercised less than 2 hours and 15 minutes a week lost 3.4% of their intra-abdominal fat, while women in the control group gained 0.1% intra-abdominal fat, the study found.
Body weight decreased by an average of 1.3 kilograms (kg) or nearly three pounds in the group of exercises, while body weight rose very slightly (.2 pounds) in the group of stretchers.
"Women should be relieved that when they increase their exercise levels, they are doing good things for their bodies and health, even if they don't see much change on the scale," McTiernan said in an interview.
According to a study cited in her article, losing just over two pounds is associated with a 1% reduction in cholesterol and a 2% reduction in triglycerides, a type of body fat associated with heart disease. Losing this amount of weight can also reduce fasting blood sugar, an indicator of diabetes risk.
STUDY: FDA hopes to cut down on unnecessary prescriptions
JOURNAL: Food and Drug Administration
AUTHORS: Mark McClellan
ABSTRACT: Antibiotics will soon need to carry warnings advising doctors to avoid unnecessary prescriptions, which have become a major contributor to the problem of drug-resistant infections.
COMMENTARY: The new requirement, announced by the Food and Drug Administration on Wednesday, aims to reduce inappropriate prescribing of antibiotics for common ailments such as ear infections and chronic coughs, which often are caused by viruses that do not respond to antibiotics.
Antibiotics only kill bacteria, but patients often request them for treating a variety of infections.
Starting next year, antibiotic labels will be required to include instructions for doctors to prescribe them only when an infection is proven or strongly suspected to be caused by bacteria.
The labels also will encourage physicians to counsel patients about what types of infections require antibiotic treatment, as well as remind them to take all of their medication, even if they feel better in a few days.
Not completing a full course of treatment can give microbes the chance to mutate to resist antibiotics, causing infections that are harder to treat.
According to the Center for Disease Control and Prevention, half of the 100 million prescriptions a year written by office-based physicians in the United States are unnecessary because they are prescribed for the common cold and other viral infections.
“Antibiotic resistance is a serious and growing public health problem, not only in this country but worldwide,” FDA Commissioner Mark McClellan said, noting that the growth of resistant germs is outpacing development of new antibiotics.
“We may end up in a situation where we don’t have effective antibiotic drugs for common infections that were once easily treated.”
The agency plans to try and publicize the warnings through medical journals and professional medical societies.
STUDY: Progesterone could help stem growing problem
JOURNAL: Society for Maternal-Fetal Medicine
AUTHORS: Dr. Paul Meis
ABSTRACT: Obstetricians say they may have discovered a powerful new solution to the dramatic rise in premature births in the last two decades.
The hormone progesterone prevented premature births in a surprisingly high number of high-risk pregnancies, according to a groundbreaking study.
COMMENTARY: “The evidence of this treatment’s effectiveness was so dramatic, the research was stopped early,” said the study’s lead researcher, Dr. Paul Meis of Wake Forest University Baptist Medical Center.
Progesterone is naturally produced by the ovaries. It softens the uterus lining into a spongy bed that holds a fertilized egg.
Weekly injections of the hormone reduced the chance of premature births by 34 percent in the 306 high-risk women who received the therapy, the study reported. Another 153 women were injected with a placebo. All the women had previously given birth prematurely, the single biggest indication of risk.
“The results are so good that it’s surprising,” said Dr. Fredric Frigoletto, chief of obstetrics at Massachusetts General Hospital in Boston. “No intervention that we have ever applied has had any measurable effect. This is very good news.”
Doctors have prescribed progesterone for years to help infertile and menopausal women.
STUDY: Cutting 100 calories a day could prevent annual weight gain
AUTHORS: Dr. James Hill
ABSTRACT: The average adult slips on about 2 extra pounds a year, a weight creep that some researchers argue could be prevented merely by eating one less cookie a day.
That treat or even three fewer bites of a fast-food hamburger — the equivalent of 100 calories daily — can keep the pounds off in the first place so people do not face the harder battle of losing weight.
COMMENTARY: Scientists are searching for different approaches to what is fast becoming a national epidemic. Sixty percent of U.S. adults are overweight, and the government blames 300,000 deaths a year on weight-related diseases.
“The biggest problem we face in America is not terrorism. The biggest health problem we’re facing is obesity,” Dr. Julie Gerberding, head of the Centers for Disease Control and Prevention.
It is just a theory, and Hill acknowledges he has not proved yet that such a simple step works. But scientists are searching for different approaches to what is fast becoming a national epidemic.
Sixty percent of U.S. adults are overweight, and the government blames 300,000 deaths a year on weight-related diseases.
“The biggest problem we face in America is not terrorism. The biggest health problem we’re facing is obesity,” Dr. Julie Gerberding, head of the Centers for Disease Control and Prevention, said last week.
Fixing the problem will require changing societal norms starting with children, she added, such as doing more and eating less in a society that encourages more driving than walking and provides unfettered access to calorie-laden foods.
To focus attention on the problem, the journal Science, turned to some well-known obesity researchers for opinions on what it will take to lower the scales.
Hill’s response was to examine government figures showing about 40 million adults are obese and how steadily Americans have put on weight in recent years.
“The future is not hopeful unless we act now,” he concluded. Hill estimated that if current trends continue, 39 percent of adults will be obese by 2008, compared with 31 percent in 2000.
Losing weight and keeping it off can be hard. The possibly easier short-term goal would be to get no fatter. So Hill and colleagues calculated what he calls the energy gap — how many calories are eaten but not burned off.
Using that same government data, he estimates that on average people gain 2 pounds a year, which equals 50 extra calories stored each day. Because the body can store half of calories consumed, he said preventing that 2-pound weight gain might simply require eating 100 fewer calories a day.
There are problems with that simple approach, says Dr. Jeffrey Friedman of Rockefeller University, who discovered the obesity hormone leptin in 1995. Some people gain 10 pounds in a year while others gain none. Few people actually know how many calories they consume, a key difficulty in cutting them.
Scientists have discovered a number of hormones and genes that generate a basic biological drive to eat that can be difficult to fight, he explains.
Genetics aside, scientists also know that the more volume and variety of food people are offered — think super-sized restaurant portions and buffets — the more they’ll overeat, adds CDC nutrition chief Dr. Willian Dietz.
“Portion size is an issue. How one goes about controlling it is not so simple,” he cautions.
For people reluctant to eat less, Colorado’s Hill points to a current experiment in which Colorado is encouraging people to buy $20 battery-operated step-counters and take an extra 2,000 steps a day, enough to walk a mile and burn 100 calories.
Hill is studying 500 participants to see if that extra little bit helps their weight; results are not due for another year or two. He plans to add his theory on eating 100 fewer calories to the study, too.
STUDY: Testosterone Replacement: Good or Bad
JOURNAL: National Institutes of Health
AUTHORS: Marc Blackman
ABSTRACT: Federal advisers began the first of several meetings that will result in recommendations later this year on how to best determine if testosterone replacement therapy is good or bad for aging men.
COMMENTARY: An unknown, but significant number of older men have begun using patches, gels or other forms of testosterone in the hopes of reversing the aging process and a flagging sex drive, but there is no scientific evidence that hormone supplements can help.
And, there may even be some dangerous side effects, including an increased risk of prostate cancer.
"The chasms of our ignorance here are vast," Marc Blackman, an endocrinologist with the National Institutes of Health, told a 17-member Institute of Medicine (IOM) advisory committee.
The panel has been asked to make recommendations on how to answer questions on the pros and cons of testosterone replacement, and its mechanism of action.
They are also weighing how to properly inform potential study participants when the benefits and the risks of therapy are very unclear.
Over the last few decades, studies on relatively young men with testosterone deficiencies have shown that replacement can counter increased body fat and cholesterol levels, decreased skeletal strength and decline in immune function associated with lower testosterone levels, said Blackman.
Four to five million relatively young American men have below-normal testosterone levels, and 5% are receiving replacement therapy, he said.
The few studies in older men with naturally declining testosterone levels has shown that replacement therapy decreases fat and increases lean muscle mass. But only one, a small 15-person study in very frail elderly men, has shown any improvement in muscle strength or function. So it is unclear if increased muscle mass leads to better physical functioning, Blackman said.
It's also not known if testosterone replacement reduces the risk of disability, falls, or fractures, or otherwise improves health outcomes. And it's unclear if supplementation would have similar effects in healthy older men and physically impaired older men.
A big concern is whether testosterone supplementation will increase the risk of prostate cancer. Increased levels of male hormones can enlarge the gland, and most researchers believe that increased prostate volume eventually leads to cancer.
Scientists at Baylor College of Medicine have drawn up plans to carry out a large, long-term study of testosterone replacement therapy in older men. The trial has been put on hold while the IOM panel considers its merits.
Lead investigator Glenn Cunningham said the study aims to enroll 6,000 men over age 65. They would be in the study for four years, and then followed for five years more. The main goal is to see if testosterone replacement reduces fractures, since men, just like women, are at risk for osteoporosis as they age, primarily due to declining hormone levels.
Researchers will also measure testosterone replacement's ability to reduce heart attacks and strokes, and to improve mood, energy levels, cognition and sexual function.
Finally, they will assess whether replacement therapy increases the incidence of prostate cancer or leads to more procedures to reduce prostate size.