Archives for: August 2004
STUDY: Leptin, the "Obesity Hormone" thought to be involved in appetite regulation
JOURNAL: Circulation 2002;10.1161
AUTHORS: Dr. Virend K. Somers
ABSTRACT: Members of an African tribe who eat fish every day have relatively low blood levels of leptin, the "obesity hormone" thought to be involved in appetite regulation, according to new research.
COMMENTARY: Fat cells and other tissues in the body produce leptin, which is believed to notify the brain to reduce appetite when fat cells are "full." Exactly how the hormone works to control appetite is uncertain, however.
Leptin has generated great scientific interest in recent years due to its apparent role in fat metabolism and weight gain. For example, previous research has linked high levels of leptin to an increased risk of cardiovascular disease, while eating fish has been shown to reduce that risk.
A diet rich in fish is associated with lower plasma leptin, independent of body fat. These findings may have implications for understanding the reduced cardiovascular risk in subjects on a high-fish diet.
Somers and his team measured the effect of fish consumption on leptin levels in the blood by comparing two neighboring tribes in Tanzania, one whose 279 members consumed fish daily, while the 329 members of the other tribe ate fish only rarely.
Both tribes consumed around the same number of calories each day, and both maintained similar lifestyles. However, the group that lived close to a lake consumed about one quarter of their total calories from fish, while the other, whose members lived further inland, consumed most of their calories from fruits and vegetables.
Reporting in Journal of the American Heart Association Somers and his colleagues found that male fish-eaters had 2.5 nanograms of leptin per milliliter of blood (ng/mL), less than one quarter of the leptin level of the male vegetarians. Female fish-eaters also had markedly lower leptin levels than their vegetarian peers, with 5 ng/mL versus 12 ng/mL for female vegetarians.
Members of both tribes had virtually identical body mass indices, an indication of obesity that measures weight in relation to height, which suggests that these findings are not influenced by obesity.
In addition, the investigators found the relationship between leptin and diet persisted even when they accounted for age, body fat, alcohol consumption or insulin. "We speculate that a fish diet may change the relationship between leptin and body fat and somehow help make the body more sensitive to the leptin message," Somers said in a statement.
He added that it was not clear whether these results would apply to other people living in different environments. "We don't know if the findings will apply to a semi-overweight, urban-dwelling North American population."
Regardless I think that the take home message here is to try and eat as much fish as possible.
STUDY: Many people do not routinely protect themselves against bites from disease-carrying ticks.
JOURNAL: American Journal of Preventive Medicine 2002;29
AUTHORS: Dr. Timothy F. Jones
ABSTRACT: Many people do not routinely protect themselves against bites from disease-carrying ticks, according to the results of a new US study.
COMMENTARY: What is most surprising, or disheartening, is that people don't adhere very well to pretty basic preventive recommendations," said study lead author Dr. Timothy F. Jones from the Tennessee Department of Health in Nashville.
Jones and his colleagues focused on the use of insect repellent by 1,820 Tennessee residents included in a nine-state telephone survey conducted by the Centers for Disease Control and Prevention (CDC) in Atlanta between February 2000 and February 2001. Although people of all ages were included, more than two thirds of the respondents were between 16 and 60. Almost 40% were male, and nearly 80% were white.
In the July issue of the American Journal of Preventive Medicine, the authors report that only one quarter of those surveyed said they used insect repellent before entering a tick-infested area and also checked their bodies for ticks after leaving. Over 60% said they ever used repellent in such situations, while 29% said they always did. Women and whites generally used repellent more often than men and blacks, respectively.
One in six respondents said a tick had bitten them in the past year. Multiple bites, however, did not seem to drive preventive messages home, the researchers found. Although 12% of those surveyed said they had been bitten at least twice in the past year, less than half of this group said they usually put on repellent in appropriate situations.
Among the more than 40% of those surveyed who owned dogs, about one-quarter said they had picked ticks off their pets using their bare hands--despite public health advisories to avoid such contact. Dog owners were much more likely to report at least one tick bite in the past year than non-owners.
Vulnerability to tick bites appeared to be related to location, the investigators found--with more than one third of rural residents reporting tick bites, compared with about 10% of urban residents and about 18% of suburban residents. Rural residents were, however, less likely than non-rural residents to use insect repellent.
Jones and his team note that in the absence of vaccines for any tick-borne illness other than Lyme disease (which is now being withdrawn from the market), education efforts must be ratcheted up to better promote effective and easy-to-follow bite prevention measures.
If there are easy steps you can take to protect yourself from some pretty severe diseases--even if they're relatively rare--then it's certainly worth doing. "It's kind of like putting on your seatbelt. After you've done it for a while you don't even think about it."
In 1999, there were over 16,000 cases of Lyme disease, 579 cases of Rocky Mountain spotted fever, and 302 cases of ehrlichiosis diagnosed in the US. Tennessee is one of three states that account for nearly half of US Rocky Mountain spotted fever cases.
Remember that an ounce of prevention can go a long way to avoid serious consequences.
STUDY: Frequency f previously unrecognized adverse drug reactions.
JOURNAL: Journal of the American Medical Association
AUTHORS: Dr Karen Lasser
ABSTRACT: The May 1 2002 issue of the Journal of the American Medical Association reported the results of a study that sought to determine the frequency of previously unrecognized adverse drug reactions occurring in recently approved drugs.
COMMENTARY: By analyzing volumes of the Physician's Desk Reference published over a twenty-five year period as well as other information, researchers at Harvard University discovered that half of the newly established adverse effects, which include liver, bone marrow and heart damage as well as pregnancy risks, are found within seven years of their approval, and half of the drugs withdrawn were taken off the market within two years following their release.
Study author and primary care physician and researcher at Cambridge Hospital and Harvard Medical School, Dr Karen Lasser, stated, "This study will change the way I talk to patients about the use of new drugs. If there is a safer, effective drug that has been in use for a number of years, I would strongly recommend it over a newer drug whose safety profile is unknown. I would prescribe a new drug only when absolutely necessary, and then watch for adverse effects very, very closely."
The authors attribute the widespread use of new drugs to extensive promotion by pharmaceutical companies. They note that drug companies may fail to conduct the postmarketing studies the Food and Drug Administration requires when a safety issue is discovered during the drug's preapproval phase.
Coauthor Dr. Paul Allen , an internal medicine specialist at Cambridge Hospital and Harvard Medical School, commented, "Twenty million patients, almost 10 percent of the U.S. population, were exposed to the five drugs withdrawn from the market between September 1997 and September 1998. Yet the drug companies push the public and doctors to use new drugs that are more profitable but also more dangerous."
What this tells us is that using safer natural alternatives where possible is the most prudent path to take.
STUDY: Men who unwind after work with a mug of beer or a glass of wine may be less likely to develop type 2 diabetes
JOURNAL: Diabetes 2001;50:2390-2395
AUTHORS: Dr. Katherine M. Conigrave
ABSTRACT: Men who unwind after work with a mug of beer or a glass of wine may be less likely to develop type 2 diabetes than their teetotaling peers, results of a new study suggest.
COMMENTARY: Researchers found that men who consumed 15 to 29 grams (g) of alcohol daily had a 36% lower risk of diabetes over 12 years, compared with men who did not drink and with men who were lighter drinkers. Findings were similar when it came to beer, white wine or liquor.
Heavy drinkers, or those who consumed more than 50 g of alcohol daily, were 39% less likely to develop diabetes, although there were few men in the study who consumed this much alcohol, the researchers note. For this reason, the findings may not apply to all heavy drinkers, according to investigators led by Dr. Katherine M. Conigrave from the Harvard School of Public Health in Boston, Massachusetts.
Fifty grams of alcohol is roughly equivalent to three or four 12-ounce cans of beer, three or four 5-ounce glasses of wine, or three or four shots of hard liquor.
The report in the October issue of Diabetes also indicates that drinking on at least 5 days of the week provided the best insurance against developing diabetes, even when the amount of alcohol consumed was minimal. Men who drank no more than twice during the week did not have a lower risk of diabetes, the investigators found.
Their findings are based on information from nearly 47,000 middle-aged and elderly male health professionals who answered questions about their drinking habits. Body mass index (a measure of weight in relation to height) and age did not alter the results.
"Decisions about alcohol consumption should consider the full range of benefits and risks to an individual. The data suggest that a reduction in type 2 diabetes may be among the benefits of regular moderate consumption.
The results support those of earlier studies showing an association between moderate alcohol consumption and a lower risk for some chronic disorders, including heart disease and type 2 diabetes, the authors note.
The findings suggested that frequent alcohol consumption conveys the greatest protection against type 2 diabetes, even if the level of consumption per drinking day is low.
STUDY: Kids who are overly hygienic appear to be at increased risk of developing wheezing
JOURNAL: Archives of Disease in Childhood 2002;87:26-29.
AUTHORS: Dr. Andrea Sherriff
ABSTRACT: Kids who are overly hygienic appear to be at increased risk of developing wheezing--a symptom of asthma--and the allergy-related skin condition eczema, according to new study findings.
COMMENTARY: Dr. Andrea Sherriff of the University of Bristol, UK, and her colleagues based their results on surveys of more than 9,000 parents, who indicated how often their 15-month-old children bathed and washed their faces and hands.
The investigators found that children with the highest degree of personal hygiene--those who washed their faces and hands more than five times per day, cleaned before meals, and bathed more than two times each day--were the most likely to develop eczema and wheezing between the ages of 30 and 42 months.
The relationship between hygiene and allergies spanned different hygiene levels. As the level of hygiene increased, so did the risk of developing eczema or wheezing.
Increasing levels of hygiene appeared to be especially linked to a risk of developing severe eczema, the authors note in the current issue of the Archives of Disease in Childhood. In infants and young children, eczema manifests as intensely itchy, red patches that can ooze and crust over. The condition is treated with ointments and antihistamines, and avoidance of substances that trigger the condition.
Sherriff's team found that taking into account additional factors that might influence the results, such as family history of allergies or contact with furry pets, did not affect the relationship between hygiene and the allergy symptoms.
The link between hygiene and allergies is in step with the so-called "hygiene hypothesis"--the theory that a lower exposure to germs affects the immune system's development in such a way that it is more prone to allergic reactions.
For example, previous studies have found that adults who had grown up on a farm were less likely to develop allergies, while young children exposed to older siblings at home and those who attend day care also have a lower risk of allergies and asthma.
This study should not be interpreted as a call to parents to abandon all hygiene practices. We do not want to go back to the days of infectious diseases--which we have eradicated partly because of improved hygiene. Just don't over do it.
STUDY: People who are more spiritual are better able to deal with the discomforts and limitations of chronic disease
JOURNAL: American Geriatrics Society
AUTHORS: S. Chung
ABSTRACT: People who are more spiritual are better able to deal with the discomforts and limitations of chronic disease than their less-spiritual counterparts. That's the conclusion of a Johns Hopkins study presented at the American Geriatrics Society's annual meeting.
COMMENTARY: Recent studies have suggested that acutely ill people with strong religious faith or an optimistic personality may get better quicker or live longer than people who lack those traits. The aim of the Hopkins study was to assess the relation between spirituality, disease severity and perceptions of well-being in patients with chronic disease.
To do so, the researchers examined data on 77 patients aged 30 or older who had suffered from rheumatoid arthritis for a minimum of 2 years. Spirituality was defined as "the capacity of an individual to stand outside of his/her immediate sense of time and place and to view life from a larger, more detached perspective."
While being spiritual did not lessen the effects of the arthritis, reduce pain or improve mobility, people who were more spiritual tended to be happier and feel better about their general health, the study found.
Putting this into practice could be as simple as teaching relaxation skills, meditation and yoga, said Hopkins investigator S. Chung. The way we define spirituality, it's not necessarily a particular faith orientation, but certain things like feeling like a part of the community by volunteering. And for elderly people, there's so many things that could be done to make them feel part of the mainstream of things.
Having a belief system can really help to lower stress and during times of sickness and health.
STUDY: DHEA supplementation decreased the number of flare-ups and reduced disease severity
JOURNAL: Arthritis and Rheumatism (2002;46:2924–7)
ABSTRACT: Supplementing with dehydroepiandrosterone (DHEA) is beneficial for women with systemic lupus erythematosus (lupus), according to a report in Arthritis and Rheumatism (2002;46:2924–7)
COMMENTARY: The results indicate that DHEA supplementation decreased the number of flare-ups and reduced disease severity in women with active lupus.
DHEA is a steroid hormone manufactured in the adrenal glands, ovaries, and testes. Blood levels of DHEA are low in many people with lupus, and some scientists believe that DHEA deficiency may be a contributing factor to the development of the disease. DHEA modulates the activity of the immune system, which tends to be overly aggressive in individuals with lupus.
JOURNAL: Journal of Wound, Ostomy, and Continence Nursing (2002;29:295–300)
ABSTRACT: Topical application of honey is beneficial in the treatment of wounds and burns.
COMMENTARY: A number of properties inherent to honey might contribute to its ability to fight infection and promote healing.
Its high sugar content allows it to draw infection and fluid from wounds by a process called “osmosis.” Honey prevents bacterial growth through its acidic pH and through the work of an enzyme that produces small amounts of hydrogen peroxide.
Its ability to keep the area around a wound moist and protected promotes fast healing and prevents scarring.
Honeys also contain components from the specific plants used by the bees in their production, and it is speculated that some of these components might further add to the antibacterial and wound-healing effects of certain honeys. The process of pasteurization, used to sterilize commercial honeys, destroys the enzyme involved in the production of hydrogen peroxide, rendering these honeys less antibacterial.
Raw honeys maintain their enzymes, and honeys produced for therapeutic use are sterilized through an irradiation process that does not damage their constituents. There are currently two therapeutic honeys available: Medihoney of Australia and Active Manuka Honey of New Zealand. Both are derived from bees using the flowers of tea trees (Leptospermum spp.) as their
STUDY: Women Worry
JOURNAL: Journal of the National Cancer Institute
ABSTRACT: Conflicting information on what factors determine radiologists' accuracy in reading mammograms may have some women wondering what they can do to ensure a correct diagnosis.
COMMENTARY: The busiest radiologists--those who had evaluated the most mammograms--did not necessarily do the best job at identifying signs of breast cancer.
There are a number of steps women can take to boost the accuracy of the breast cancer screening test.
First and foremost women should attempt to go to the same breast cancer screening clinic year after year.
If that is not possible, women should obtain the X-rays from their previous mammograms for comparison sake.
For younger women they should avoid getting a mammogram while they are menstruating because the breast tissue undergoes changes during this time that can affect mammogram accuracy.
Younger women are better off scheduling mammograms during the follicular phase of their cycle--the first and second week after the first day of their period.
STUDY: No age requirement for exercise
JOURNAL: Arthritis Care & Research 2003;19:129-135
AUTHORS: Dr. Jennifer M. Hootman
ABSTRACT: While people with arthritis may know that joint-friendly activities such as walking and gardening can help reduce their pain and disability, study findings show that many of them still remain completely inactive.
COMMENTARY: One possible reason is that such exercise may initially increase arthritis-related pain, and, in some cases, arthritis patients had been inappropriately advised against participating in regular physical activity, according to the authors of the study. But the new findings show that people with arthritis can not only exercise regularly but can also meet national recommendations for the general population.
People with arthritis should strive to become more physically active by engaging in moderate intensity physical activity, such as walking, bicycling or swimming, for 30 minutes a day at least three times per week.
And there's no age requirement for exercise. A recent study found that even people aged 80 and older who exercise just a couple of times a week can improve their health.
STUDY: Take Your Vitamins
JOURNAL: Memorial University of Newfoundland
ABSTRACT: Recent clinical studies showed that dietary supplements can treat nutritional deficiencies in the elderly, boost their immune systems, combat short-term memory loss, reduce risks of Alzheimer's, and improve seniors' overall health.
COMMENTARY: The first, conducted at Memorial University of Newfoundland, concluded that supplementation with moderate amounts of 18 vitamins, minerals, and trace elements improved short-term memory and overall cognitive abilities and strengthened immune system function in 86 elderly people treated over the course of one year.
A separate study published in the May 2001 issue of Neurology found that seniors with low levels of folate and vitamin B12 have an increased risk of developing Alzheimer's disease.
A third study, published in the August 2001 issue of Nutrition, showed that nutritional deficiencies greatly increase with age, and that supplement use helps eliminate these deficiencies in the elderly. However, a recent survey conducted by Harris Interactive found that the age group over 65 is least likely to discuss dietary supplements with doctors
JOURNAL: Diabetes Care. 2003;26:446-451
AUTHORS: Ronald A. Sherman, MD, MSC
ABSTRACT: Maggot therapy is more successful in debriding nonhealing ulcers than is continued conventional care.
COMMENTARY: "Over the past few years, there has been a resurgence in the use of maggot therapy, even though its optimal role has not been clearly defined," write Ronald A. Sherman, MD, MSC, and colleagues from the Veterans Affairs Medical Center in Long Beach and the University of California, Irvine.
In the study, of 20 nonhealing ulcers in 18 patients, six wounds were treated with conventional therapy, six with maggot therapy, and eight with conventional therapy followed by maggot therapy.
Although conventional therapy failed to achieve any significant debridement during the first 14 days, maggot therapy allowed necrotic tissue to decrease by an average of 4.1 cm2 during the same time frame (P = .02). After five weeks of therapy, necrotic tissue still covered more than 33% of the surface of conventionally treated wounds, but maggot-treated wounds were completely debrided after four weeks of therapy (P = .001).
Growth of granulation tissue was faster and wound healing rates were also better with maggot therapy.
"Maggot therapy was more effective and efficient in debriding nonhealing foot and leg ulcers in male diabetic veterans than was continued conventional care," the authors write.
STUDY: CVD risk is at least doubled among people with undiagnosed diabetes
JOURNAL: Ann Intern Med 2003;138:212-229.
AUTHORS: Dr. Alfred Berg
ABSTRACT: Patients with high blood pressure or high cholesterol levels should be screened for diabetes mellitus type 2.
COMMENTARY: While screening can detect diabetes in the preclinical, asymptomatic stage, the most beneficial interventions are those that reduce cardiovascular risk.
CVD risk is at least doubled among people with undiagnosed diabetes, and aggressive treatment of hypertension or dyslipidemia reduces morbidity and mortality within 5 years of diagnosis.
Glycemic levels are often only slightly elevated during the preclinical phase, the authors note. The benefit of glycemic control during the ensuing 15 years following diagnosis, or in the presence of impaired fasting glucose and impaired glucose tolerance, "is unknown but probably small" because the risk for severe visual impairment, end stage renal disease or amputation is low during this time.
The task force recommends screening for diabetes in patients with hypertension or lipid abnormalities.
JOURNAL: N Engl J Med 2003;348:489-490,518-526.
AUTHORS: Dr. Munoz
ABSTRACT: Results of a pooled analysis of 11 case-control studies provide robust estimates of the level of risk of cervical cancer associated with 30 different human papillomavirus (HPV) types.
COMMENTARY: The data indicate that, in addition to HPV types 16 and 18, the following types should be considered carcinogenic or high-risk: types 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 68, 73, and 82.
Three HPV types--26, 53, and 66--should be classified "probably carcinogenic" or "probable high-risk types," according to the data, as they were detected in only one to three cervical cancer patients and in none of the controls.
Low-risk HPV types are types 6, 11, 40, 42, 43, 44, 54, 61, 70, 72, 81, and CP6108. Three HPV types--34, 57, and 83--were not detected in any of the samples and so were classified as of "undetermined risk."
Based on the classification, Dr. Munoz said, the "composition of 'cocktails' used to diagnose high-risk HPV types could be expanded. For example, the commercially available Hybrid Capture II test (Digene), includes only 13 out of the 18 HPV types that we classified as high-risk or probably high-risk, which would result in missing 1% of women with cervical cancer."
Importantly, Dr. Munoz added, "if a woman is found positive for 1 of the 12 HPV types that we classified as low-risk, she can be told not to worry."
The investigators believe this classification system will be useful in "planning prevention by HPV vaccines and for screening programs based on HPV testing."
STUDY: Balanced Exercise Best
JOURNAL: Euro J Clin Nutrition 2003;57;531-542
AUTHORS: Dr. S. Rao
ABSTRACT: Strenuous physical activity by mothers during pregnancy results in small birth size of their offspring, according to a study from India by a multinational team of researchers.
COMMENTARY: Women from rural areas of India and other developing countries continue to engage in physical activities during pregnancy, both at home and in their farms.
To examine the hypothesis that physical activity during pregnancy may be a "potentially modifiable risk factor" for improving the birth weights, the researchers followed 797 women through their pregnancy.
Trained health workers performed a detailed clinical assessment during their monthly visits and assessed the nutritional intake at 18 weeks and 28 weeks of pregnancy. Physical activity was graded as low, medium and high and scored using a questionnaire, which was administered at around 18 and 28 weeks gestation.
The researchers observed that over two-thirds of the women had performed medium and high levels of activity during pregnancy, including working in their farms, collecting firewood and carrying water.
Moderate and high physical activities at 18 weeks and 28 weeks gestation were associated with lower birth weights, head circumference and mid arm circumference, Dr. S. Rao and colleagues report.
Physical activity at 18 weeks was also associated with lower placental weights, they add. The association was more significant among mothers with pre-pregnant weight less than 45 kilograms, indicating the role of maternal weight in birth size, they explain.
Among the physical activities, "fetching water" was considered the most demanding and had the strongest association with small birth size.
Weight gain during pregnancy was also lowest among mothers with medium and high activity scores at 28 weeks gestation, the investigators note. However, they found that premature deliveries, neonatal length and body fat were not affected by maternal physical activity.
Strenuous physical activity may decrease the placental blood flow resulting in poor fetal growth, Dr. Rao's team postulates. Postures like bending that are adopted while carrying water, may exacerbate the problem, they add.
"Limiting maternal strenuous activities could be a potential intervention for improving birth size," the authors conclude in their paper.
Take home message is to keep your exercise levels moderate and not overdo it.
STUDY: Body fat levels during middle childhood are causally implicated in earlier timing of puberty among white girls
JOURNAL: Pediatrics 2003;111:815-821.
AUTHORS: Dr. Davison
ABSTRACT: Girls who have more body fat at age 5 tend to be closer to puberty at age 9 than other 9-year-old girls with less body fat. Girls who have large increases in body fat between the ages of 5 and 9 also tend to reach puberty at an earlier age.
COMMENTARY: The study findings suggest that weight control efforts may need to start as early as preschool.
Some experts believe that the rising rate of obesity among U.S. children has spurred early maturation. On average, girls are starting to show the first signs of breast development at ages 8 and 9, a year earlier than 20 years ago, according to the report in the journal Pediatrics.
Dr. Davison's team evaluated 181 girls at the age of 5, 7 and 9 years. All the girls underwent weight and body fat measurements, and at age 9 had pubertal development assessed. All the girls were white and from families with a median annual income that ranged from $35,000 to $50,000.
"Girls with higher percent body fat at 5 years, and girls with higher percent body fat, higher BMI percentile, or larger waist circumferences at 7 years, were more likely to be classified with earlier pubertal development at 9 years," the authors write.
Girls who gained the highest percentage of body fat between the ages of 5 and 9, and those who saw the largest increase in their waist size between the ages of 7 and 9 were also more likely to show signs of puberty onset at age 9, the study indicates. Overall, 30% of the girls were overweight and 56% showed the first signs of breast development by age 9.
"This study indicates that body fat levels during middle childhood are causally implicated in earlier timing of puberty among white girls," the authors conclude. "
The practical implications of these findings emphasize the need for implementation of early prevention and treatment programs for childhood overweight, beginning as early as the preschool period," they add.
STUDY: Pelvic inflammation may promote ovarian cancer
JOURNAL: J Infect Dis 2003;187:1147-1152.
AUTHORS: Dr. Roberta Ness
ABSTRACT: Past or ongoing Chlamydia trachomatis infection may be a risk factor for ovarian cancer.
COMMENTARY: Dr. Roberta Ness from University of Pittsburgh, Pennsylvania and colleagues measured IgG antibodies to C. trachomatis elementary bodies (E and to chlamydia outer-membrane 60-kDa or 10-kDa heat-shock protein (CHSP60 and CHSP10, respectively) in 117 women with ovarian cancer and 171 age- and ethnicity-matched women without ovarian cancer.
Women with ovarian cancer were more likely than women without ovarian cancer to have high levels of chlamydia-EB antibodies, the authors report, and the probability of ovarian cancer was 90% higher among women with the highest levels of antibodies against chlamydia-EB compared with the lowest levels.
CHSP60 significantly correlated with chlamydia-EB IgG, but higher levels of CHSP10 and CHSP60 were not associated with a higher risk of ovarian cancer.
"This study adds more data in support of our hypothesis that pelvic inflammation may promote ovarian cancer."