Category: Prior Clinic Blog
AUTHORS: Dr Robert Chen
ABSTRACT: The US Institute of Medicine’s immunisation safety review committee has been investigating whether the influenza vaccine might carry a risk of the demyelinating disorder Guillain-Barré syndrome.
COMMENTARY: A sharp increase in cases of the disorder occurred in 1993-4 after immunisation . There were 74 cases in 1994, compared with only 37 cases in 1993 and 23 in 1991. Although the number of reports of vaccine associated cases of the syndrome has remained low in recent years—between 20 and 40—the sudden increase in 1994 raised concerns about vaccine safety.
In a fact finding session earlier this month, the committee heard reviews of studies since 1976, when the numbers of vaccine associated cases of the syndrome stopped the US immunisation campaign against "swine flu." By then, 45 million people had been vaccinated. Ultimately, 581 cases of Guillain-Barré syndrome were reported that year, said the Centers for Disease Control and Prevention (CDC) in Atlanta, Georgia.
Initial studies suggested a causal relation between Guillain-Barré syndrome and the vaccine. Subsequently this was challenged on several grounds, including that the cases had been gathered by public health officers who had not been trained to diagnose the syndrome; reports were not based on medical records; some cases accepted by the CDC failed to meet the criteria for the syndrome; and the publicity over the possible link had biased the reporting of cases.
A later study, in 1991, reviewed all the cases of the syndrome in adults (whether vaccinated or unvaccinated) from two states. Using a standard definition of Guillain-Barré syndrome, it rejected 29% of them, said Dr Robert Chen of the CDC’s immunisation safety branch.
A 1998 study, summarised for the committee, showed that if there was a risk of flu vaccine causing the syndrome, it was extremely small. Dr Tamar Lasky from the University of Maryland School of Medicine put it at between 1 and 2 cases per million vaccinated persons a year.
One possible cause is that flu vaccine contains Campylobacter, said Dr Chen. He said that the vaccine is made in chicken eggs and that 40-50% of chickens are infected with Campylobacter, which is difficult to eradicate.
STUDY: Perspiration also reduces stress, alters menstrual cycle
JOURNAL: Biology of Reproduction
ABSTRACT: Biologists at the University of Pennsylvania said they found male perspiration had a surprisingly beneficial effect on women’s moods. It helps reduce stress, induces relaxation and even affects the menstrual cycle.
COMMENTARY: In a study to be published in the journal Biology of Reproduction, researchers collected samples from the underarms of men who refrained from using deodorant for four weeks. The extracts were then blended and applied to the upper lips of 18 women, aged 25 to 45.
The women rated their moods on a fixed scale for a period of six hours. The findings suggested something in the perspiration brightened their moods and helped them feel less tense.
Blood analyses also showed a rise in levels of the reproductive luteinizing hormone that typically surge before ovulation.
Wysocki, a study co-author, said the research could point to a “chemical communication” subtext between the sexes that enables men and women to coordinate their reproductive efforts subliminally.
There was no sign women were sexually aroused by male perspiration. In fact, the women never suspected they had men’s sweat under their noses and believed they were helping to test alcohol, perfume or lemon floor wax.
“The study was done in quite a sterile environment. It’s not strange that they were not thinking sexual thoughts,” said Wysocki. “In a more sensual setting, exposure to these odors might facilitate the emergence of sexual mood or feelings.”
Funded by the National Institutes of Health, researchers said the study could lead to new fertility therapies and treatments for premenstrual syndrome if the active agent in male perspiration could be isolated.
STUDY: Study finds more reasons for women not to take hormones
JOURNAL: Baylor College of Medicine
AUTHORS: Jennifer Hays
ABSTRACT: Long-term use of hormone replacement therapy, already shown to be bad for older women’s physical health, is found to be no panacea for their memory or mental outlook either.
In a challenge to popular belief, a large study finds that estrogen and progestin pills fail to make older women feel better by improving their memory, sleep or sex lives.
COMMENTARY: The results suggest this is nothing more than a placebo effect. The researchers conclude the pills are still an effective treatment for short-term relief from hot flashes and night sweats, but nothing else.
“The average woman will not experience an improvement in her quality of life by taking this pill,” said Jennifer Hays of Baylor College of Medicine, a psychologist who directed the analysis.
While hormone replacement decreases hip fractures and colon cancer, it slightly increases the chance of heart attacks, strokes and breast cancer.
Despite those findings, many women vowed to stick with hormone replacement because they felt it helps their memory and mood and generally made them think and feel better. The new report rejects that contention, too.
“There is a myth that hormone therapy improves quality of life, even in women without menopausal symptoms. This study dispels the myth,” said Dr. JoAnn Manson of Harvard’s Brigham and Women’s Hospital in Boston.
Experts now say the hormones’ only acceptable use is for the short-term relief of severe menopausal symptoms.
JOURNAL: American Journal of Epidemiology 2003;157:345-354
AUTHORS: Dr. James Cerhan
ABSTRACT: Zinc and an antioxidant found in citrus fruit may lower the risk for rheumatoid arthritis.
COMMENTARY: The researchers looked at nearly 30,000 women from the Iowa Women's Health Study. All had answered a food questionnaire in 1986 that assessed how much and how often they ate certain foods as well as their vitamin and supplement intake.
Years later, there were 158 cases of rheumatoid arthritis among the women. The diets of those women were compared with those of study participants who remained free of the illness.
The doctors found that women getting less than 40 micrograms of beta-cryptoxanthin, which is found in citrus fruits like oranges and grapefruit, were at a slightly higher risk of developing rheumatoid arthritis than women who consumed more than that amount.
When they looked at the amount of zinc in each woman's diet, they found that those who took zinc supplements had a lower risk of rheumatoid arthritis. But getting an equivalent amount of zinc from food was not associated with decreased risk.
The message to the general consumer, is here's another reason to eat your fruits and vegetables.
Not only can they protect you from chronic diseases such as cancer and heart disease, but now they may also prevent rheumatoid arthritis.
JOURNAL: American College of Preventive Medicine
AUTHORS: Dr. John Gaziano
ABSTRACT: After age 50, tall men have a moderately higher risk of developing prostate cancer than their shorter peers.
COMMENTARY: Using data from an ongoing health study of more than 22,000 US physicians, researchers at Boston's Brigham and Women's Hospital measured the relationship between body size and age to the risk of prostate cancer in 1,634 men who developed the cancer.
Prostate cancer is the second-biggest cancer killer of men in the United States. The American Cancer Society estimates that 220,000 new cases of prostate cancer will be diagnosed in 2003 and nearly 30,000 men will die from it.
But the disease's mortality rate is relatively low because it is a slow-growing cancer, easily cured if caught early.
The average age at which a man is diagnosed with prostate cancer is 70, but African Americans and men with a family history of the disease are at higher risk.
The study population of US physicians included about 7% to 8% minorities, a number too small to draw conclusions.
The Harvard researchers looked at three categories of height: under 5 ft. 10 inches, between 5 ft. 10 and 5 ft. 11 and taller than 5 ft. 11. Age was stratified to younger than 50 years, 50 years to 59 years, and over 60 years.
The results, announced at a meeting in San Diego of American College of Preventive Medicine, show that tallness appeared to raise the risk of prostate cancer by 23% to 43%, but only over age 50.
The relative risk is fairly modest compared to other high risk groups--men with a family history of prostate cancer have an increased risk of 200% to 300%, Gaziano noted.
The study detected no relationship between either body mass index or weight and the risk of prostate cancer.