Friday, September 19, 2008


This scare never seems to die. Weak epidemiological associations below based on small samples of sufferers -- with causal inferences speculative, as usual. Interesting that one of the study participants did not think much of the results. Note that the vast majority of the sample were NOT ill and yet had bisphenol in them also. Also note that an unspecified number of both "heart" and "diabetic" patients were UNDIAGNOSED heart-disease and diabetes sufferers!

Exposure to a ubiquitous chemical used in plastic baby bottles, food cans and a host of other products may increase the risk of developing heart disease and diabetes, a study suggests. In the first significant study of the effects of bisphenol A (BPA), one of the world's most mass-produced substances, researchers found that even small traces in the body were potentially linked to health problems.

BPA, used in hardened plastics including food containers and compact discs, can be found in detectable levels in nine out of ten people. It enters the body primarily through food and drink but also through drinking water, dental sealants, through the skin or inhalation of household dusts.

The researchers, from the Peninsula Medical School, Exeter, found that relatively high levels of the chemical present in urine were associated with a threefold risk of cardiovascular disease and double the risk for type 2 diabetes. With possible public health implications, the results "deserve scientific follow-up", the study's authors said.

Previous studies of adverse effects in animals have created concern over long-term, low-level exposure to BPA in humans. But the findings, from a "snapshot" study of the American population, do not prove that the chemical causes health problems, the researchers said.

Heart disease is reckoned Britain's biggest killer, with about 270,000 heart attacks occurring each year, while 100,000 cases of type 2 diabetes, which is associated with obesity, are diagnosed each year.

The study, published in the Journal of the American Medical Association, looked at BPA levels in the urine of 1,455 American adults, and whether they had ever been diagnosed with one of eight main diseases, including arthritis and thyroid disease. In total 79 had had heart attacks, chest pain or other types of cardiovascular disease and 136 had diabetes. The average level of BPA exposure was 20 micrograms per day.

But 25 per cent of participants with highest BPA concentrations (between 35 to 50 micrograms per day) were nearly three times likelier to be diagnosed with cardiovascular disease than those in the lowest 25 per cent (10 micrograms per day). Similarly, those with highest BPA concentrations were 2.4 times likelier to have had diabetes diagnosed compared with those at lowest levels. Current guidelines suggest that an adult can safely consume up to 3,250 micrograms a day, a much higher amount than the study suggests.

BPA leaches from drinks bottles made from some polycarbonate plastics and from the epoxy linings of canned foods, especially if heated. "BPA-free" baby bottles have been sold in recent years, but there is little information for consumers on BPA.

David Melzer, who led the study at the University of Exeter, said: "At the moment we can't be sure BPA is the direct cause of the extra cases of heart disease and diabetes. If it is, some cases of these conditions could be prevented by reducing BPA exposure."

Iain Lang, a co-author of the study, added, "Measuring who has disease and high BPA levels at a single point in time cannot tell you which comes first. I'm not changing my behaviour on the basis of this single study."


Association of Urinary Bisphenol A Concentration With Medical Disorders and Laboratory Abnormalities in Adults

By Iain A. Lang et al.

Context: Bisphenol A (BPA) is widely used in epoxy resins lining food and beverage containers. Evidence of effects in animals has generated concern over low-level chronic exposures in humans.

Objective: To examine associations between urinary BPA concentrations and adult health status.

Design, Setting, and Participants: Cross-sectional analysis of BPA concentrations and health status in the general adult population of the United States, using data from the National Health and Nutrition Examination Survey 2003-2004.

Participants were 1455 adults aged 18 through 74 years with measured urinary BPA and urine creatinine concentrations. Regression models were adjusted for age, sex, race/ethnicity, education, income, smoking, body mass index, waist circumference, and urinary creatinine concentration. The sample provided 80% power to detect unadjusted odds ratios (ORs) of 1.4 for diagnoses of 5% prevalence per 1-SD change in BPA concentration, or standardized regression coefficients of 0.075 for liver enzyme concentrations, at a significance level of P <.05.

Main Outcome Measures: Chronic disease diagnoses plus blood markers of liver function, glucose homeostasis, inflammation, and lipid changes.

Results: Higher urinary BPA concentrations were associated with cardiovascular diagnoses in age-, sex-, and fully adjusted models (OR per 1-SD increase in BPA concentration, 1.39; 95% confidence interval [CI], 1.18-1.63; P = .001 with full adjustment). Higher BPA concentrations were also associated with diabetes (OR per 1-SD increase in BPA concentration, 1.39; 95% confidence interval [CI], 1.21-1.60; P <.001) but not with other studied common diseases.

In addition, higher BPA concentrations were associated with clinically abnormal concentrations of the liver enzymes gamma -glutamyltransferase (OR per 1-SD increase in BPA concentration, 1.29; 95% CI, 1.14-1.46; P < .001) and alkaline phosphatase (OR per 1-SD increase in BPA concentration, 1.48; 95% CI, 1.18-1.85; P = .002).

Conclusion: Higher BPA exposure, reflected in higher urinary concentrations of BPA, may be associated with avoidable morbidity in the community-dwelling adult population.

JAMA. 2008;300(11):1303-1310

Antibiotics given to delay labour can harm baby

Another disgraceful attempt to worry pregnant women. The report below is a very partial summary of two papers that were published simultaneously. This paper found no effect of antibiotic use while this paper found no effect of antibiotic use on anything other than rate of cerebral palsy, which was rare in any case. It's just data dredging. If you look at enough variables, you will find differences by chance alone. The real conclusion should be that antibiotics in pregnancy are almost certainly safe

Giving women antibiotics to delay premature labour may increase the risk of developmental problems for the baby, a study suggests. The study by the University of Leicester, published in The Lancet, assessed seven-year-olds whose mothers had been involved in a clinical trial at the time of their birth. The children of those given an antibiotic were much more likely to have cerebral palsy. The Health Department has written to doctors asking them to discontinue the practice, which is not routine.

Experts say that the more common use of antibiotics for pregnant women who show signs of an infection when their waters break early can be lifesaving, and should be continued.

Many new mothers get too little postnatal support, a poll of 6,000 mothers by found. Six out of ten felt they had not seen their health visitor enough during the first year of their child's life.


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