Menopause does not adversely affect diabetes risk or strategies to prevent diabetes in women who already have an increased risk for the disease, investigators reported.

Neither natural menopause nor oophorectomy-induced menopause increased diabetes risk as compared with premenopausal women. In fact, bilateral oophorectomy was associated with a decreased risk of diabetes (HR 0.19) among women who also made lifestyle changes to reduce their risk of the disease, according to a report published online in Menopause.

“The present report has clinical and public health relevance, showing that natural menopause does not modify the impact of diabetes prevention interventions among women at high risk for diabetes,” Catherine Kim, MD, MPH, of the University of Michigan in Ann Arbor, and coauthors wrote in conclusion.

“Bilateral oophorectomy may have different effects on response to lifestyle interventions than natural menopause, but the role of hormone therapy needs to be assessed,” they added.

In the big picture, however, a decreased risk of diabetes leads to a decreased risk in cardiovascular disease. Heart disease and stroke are the leading causes of death and disability among people with type 2 diabetes. In fact, at least 65% of people with diabetes die of some form of heart disease or stroke. And adults with diabetes are two to four times more likely to die of heart disease than adults without diabetes, according to the American Heart Association.

In the current study, the authors noted that some evidence suggests that menopause might accelerate progression of glucose intolerance. Whether menopause affects diabetes risk in women at high risk for the condition had remained unclear.

Data from the Diabetes Prevention Program (DPP) afforded an opportunity to examine more closely the relationship between menopause and diabetes.

The DPP evaluated the impact of lifestyle interventions and metformin in middle-age men and women who were at high risk for diabetes because of impaired fasting glucose and impaired glucose tolerance.

Kim and colleague used the DPP database to compare diabetes risk in pre- and postmenopausal women and to determine whether menopausal status modified the effect of DPP interventions on various metabolic parameters.

The analysis included 1,237 women ages 40 to 65, of whom 708 were premenopausal, 328 had undergone natural menopause, and 201 were surgically postmenopausal (bilateral oophorectomy). Follow-up averaged 3.2 years.

The premenopausal women had an unadjusted diabetes rate of 11.8 per 100 person-years in the placebo group, 6.6 in the metformin group, and 6.8 in the lifestyle group. Postmenopausal women had case rates of 11.5 per 100 person-years in the placebo group, 8.9 in the metformin group, and 3.2 in the lifestyle group.

Naturally postmenopausal women had diabetes case rates of 10.5 per 100 person-years in the placebo arm of the DPP, 5.0 in the metformin arm, and 4.3 in the lifestyle arm. Corresponding rates among surgically postmenopausal women were 12.9, 10.3, and 1.1 per 100 person-years.

None of the differences between pre- and postmenopausal women achieved statistical significance in the unadjusted analysis or after adjustment for age, race/ethnicity, family history of diabetes, history of gestational diabetes, waist circumference, fasting insulin, and corrected insulin response.

The only significant difference between pre- and postmenopausal women occurred in the adjusted analysis of surgically postmenopausal women randomized to the lifestyle intervention arm of the DPP (HR 0.19, 95% CI 0.04-0.94).

Stratification by hormone use also showed no significant difference in diabetes risk, overall or in separate analyses of naturally and surgically postmenopausal women. The significant difference observed in surgically postmenopausal women assigned to lifestyle intervention did not persist in those with hormone therapy.

Acknowledging limitations of the study, Kim and coauthors pointed out that bilateral oophorectomy was self-reported and that study participants were queried only at baseline about menopausal status. The investigators could not account for women who might have transitioned from pre- to postmenopausal status during the three years of follow-up.

Use of oral contraceptives to manage perimenopausal symptoms might have affected progression to diabetes in premenopausal women, but only 6% of women reported OC use.

The authors had no relevant disclosures.

The National Institutes of Health provided funding for the Diabetes Prevention Program. Bristol-Myers Squibb and Parke-Davis provided medication. These companies donated materials, equipment or medications for concomitant conditions: LifeScan, Health O Meter, Hoechst Marion Roussel, Merck-Medco Managed Care, Merck, Nike Sports Marketing, Slim Fast Foods, and Quaker Oats. McKesson BioServices, Matthews Media Group, and the Henry M. Jackson Foundation provided support services.

BOSTON, Jan. 12 — An endoscopic surgical procedure to treat symptomatic gastroesophageal reflux disease (GERD) was safe and effective over a three-year follow-up, found researchers here and at four other centers.

A full-thickness plication in the gastric cardia 1 cm below the gastroesophageal junction reduced the need for medication and improved quality of life, according to Douglas Pleskow, M.D., of Beth Israel Deaconess Medical Center, and colleagues.

Moreover, the improvements were stable from 12 months after the procedure to 36 months, Dr. Pleskow and colleagues reported online in Surgical Endoscopy.

The finding comes from a follow-up of a study conducted five years ago to test the efficacy and safety of endoscopic plication using a device called the Plicator, manufactured by NDO Surgical, Inc., of Mansfield, Mass.

The procedure restores the anti-reflux barrier, which Dr. Pleskow described in a statement as “a fold over the top part of the stomach that acts to prevent acid and other stomach contents from going up into the esophagus.”

Restoring the barrier reduces the symptoms of GERD, he said.

After the one-year follow-up of the original study, the researchers at five centers were able to recruit 29 of the original 64 patients for a continued three-year follow-up, Dr. Pleskow said.

At the end of the initial study, he said, “59% of the patients who had had plication at one year (were) completely symptom-free.”

“What the data shows now at three years,” he added, “is that 55% of the original patient population had complete symptom relief.”

Of the 29 patients in the follow-up, 28 were daily users of proton pump inhibitors to control their GERD symptoms before the surgery, and the remaining patient was using a histamine-2 receptor antagonist on a daily basis.

At the end of three years, the researchers reported, 16 of the 28 (or 57%) remained off daily proton pump inhibitor therapy. Two patients were on non-daily, on-demand proton pump inhibitor therapy, so that complete cessation was achieved in half the patients.

The patient who had been on baseline daily histamine-2 receptor antagonist therapy was not taking any anti-secretory therapy three years later, they said.

The researchers also found that median GERD-health related quality of life scores remained significantly improved at 36 months compared with baseline scores without medication. Specifically, the median score at baseline was eight on the 45-point scale, compared to 19 at three years, a change that was significant at P

It may be hard to think of radiation as a present and serious environmental health concern in the United States, much less one with the potential to affect nearly every home in the country.

But a radioactive gas known as radon is responsible for an estimated 21,000 lung cancer deaths every year, according to the U.S. National Cancer Institute.

“It’s the second leading cause of lung cancer, and, for non-smokers, it is the leading cause of lung cancer,” said Kristy Miller, a spokeswoman for the indoor environments division of the U.S. Environmental Protection Agency. “It is invisible and odorless. It causes no symptoms. You possibly may be breathing in high levels and not even know it.”

Radon gas is created by the breakdown of uranium in rocks, soil and water. It seeps up through the ground and into homes through foundation cracks and crawl spaces.

“It’s a naturally occurring decay product of uranium,” said Dr. Michael Thun, vice president of epidemiology and surveillance research for the American Cancer Society. “Radon is one of the avoidable known carcinogens to which many people are exposed at a range of levels. Compared to cigarette smoking, it’s a very small risk, but across the population, it is a significant risk. And, it is avoidable.”

Outside, radon seeping up from the ground floats away into the atmosphere, causing no harm. But a building acts as a container for any radon seeping up from beneath it, capturing the gas and allowing it to concentrate.

Houses in the Northeast and Midwest tend to have higher radon levels than those elsewhere in the United States, Thun said.

And don’t think that new homes are less likely to have dangerous levels of radon. “Any type of home, regardless of its age or where it’s located, has the potential of having high levels,” Miller said. “If your home has contact with the earth, which most homes do, then your home has a chance of having a high level of radon.”

The best bet for protecting yourself and your family from long-term radon gas exposure is to check for high levels in the house.

“If one lives in an area where radon is prevalent, it’s a good idea to have your home tested,” Thun said.

The EPA recommends a two-level test for radon. First, a homeowner should buy a short-term test kit, a small device that is left in the house for two days to 90 days, depending on the kit.

The test kit, Miller said, should be put:

In a spot where it will have access to the same air that’s inhaled by the home’s occupants.
Away from doors and windows.
At a level that’s not too high nor too low.
On a shelf or someplace where it won’t be jostled.

At the end of the testing period, the homeowner sends the radon kit to a lab for analysis, Miller said.

If the test shows that the radon level registers at 4 picocuries per liter of air, a second test should be done, according to EPA recommendations. The follow-up test can be another short-term test or a long-term test, which takes more than 90 days. If the average of the two tests remains above 4 pCi/L, then the homeowner should consider having the house fixed.

This process, called radon mitigation, can cost from $800 to $2,500, depending on what must be done to the house, Miller said.

Workers will go through the house to seal up places through which radon can enter, including:

Cracks in walls and solid floors.
Gaps in construction joints and suspended floors.
Gaps around pipes.
Cavities inside walls.

Radon also can be vented away from the home using PVC pipes that are sunk into the ground. “You want to take that soil gas and vent it from underneath your home or foundation before it ever gets inside,” Miller said.

People should re-test their houses for radon regularly, he said, particularly if something happens to disturb either the house or the ground beneath it. A new addition may have been built, renovations done or excavation performed, or the homeowner may simply have noticed that the foundation has shifted.

People having a new house built can take preemptive measures against potential radon contamination by asking for certain construction techniques and features that reduce the risk of radon.

“It’s most cost-effective to do it when you’re building a new home,” Miller said. “Ask your builder to include radon-resistant features.”

The most important thing to remember, the experts say, is that radon is just about everywhere.

“Radon is a natural substance within the Earth’s crust,” Miller said. “It’s there in the soil. The issue is, is your particular home going to allow it to seep in?”

More information

The U.S. Environmental Protection Agency offers more information in A Citizen’s Guide to Radon.

A companion article has more on detecting radon.

How Radon Leads to Lung Cancer

WHEELING, W.Va., July 24 — Sequencing of two genes associated with restless legs syndrome (RLS) revealed a functional mutation in some patients with the condition — the first ever found, researchers said.
The mutation was found in the MEIS1 gene, a member of the homeobox gene family thought to play a critical role in development, reported Carles Vilari?±o-G??ell, PhD, of the Mayo Clinic in Jacksonville, Fla., and colleagues in the July issue of Neurology.
Although the mutation appears to be rare, even among RLS patients, it was found in all affected members of one family, suggesting a causative role.
“Replication in independent datasets is warranted to evaluate [the mutation] as a pathogenic cause of familial RLS,” the researchers wrote.

MEIS1 and another gene, BTBD9, were found in several previous studies to harbor variants that were significantly more common in familial RLS patients than in the general population.

But all the mutations identified in those studies were located “deep in intronic regions and are not thought to be functional,” the researchers said.

Those studies did not actually sequence the two genes, leaving open the possibility that functional mutations may have been present but escaped detection.

In the current study, Dr. Vilari?±o-G??ell and colleagues sequenced the MEIS1 and BTBD9 genes in a so-called discovery group of 71 familial RLS probands. These individuals were part of a larger North American cohort that totaled 378 patients and 528 controls.

No variants in coding regions or within 10 bases of exon-intron boundaries were found in the BTBD9 genes in the discovery group.

However, one individual showed a mutation in MEIS1, called p.R272H, in which a histidine residue was substituted for the normal arginine at the beginning of the gene’s highly conserved TALE (three-amino acid loop extension) domain.

Studies in other contexts have shown that the mutation creates a loss of function for the MEIS1 homeobox protein product, the researchers said, though how it may be related to RLS remains unclear.

Genotyping in the entire cohort failed to identify this mutation in any additional patients or controls. One instance was later found in a group of 325 Europeans controls, a 64-year-old Irish man with no history of neurological disease.

But when Dr. Vilari?±o-G??ell and colleagues performed a segregation analysis for the mutation in six members of a family in which RLS was prominent, it was found in all three members diagnosed with RLS. The mutation was also present in one healthy family member, a parent who had children with RLS.

“If pathogenic, p.R272H does not appear to be fully penetrant, nor a common cause of disease,” the researchers acknowledged.

But Dr. Vilari?±o-G??ell added that the finding was important as a lead for better understanding of RLS pathology.

He said the mutation “is the first that we think can be a real candidate for causing or promoting” RLS, he said in a press statement.

The study received support from the National Institute of Neurological Disorders and Stroke and internal Mayo Clinic funds.

No potential conflicts of interest were reported.

Primary source: Neurology

Source reference:
Vilari?±o-G??ell C, et al., “MEIS1 p.R272H in familial restless legs syndrome” Neurology 2009; 73: 243-45.

A Mexican study has confirmed that younger people were more likely to become infected with the pandemic H1N1 influenza virus but that older people were more likely to die from it.

The majority of confirmed infections (56%) occurred in individuals 10 to 39 years old, with only 10.2% occurring in people 40 and older, according to Victor Borja-Aburto, PhD, of the Mexican Institute for Social Security in Mexico City, and colleagues.

“The high incidence of infection in young people could show not only their different exposure related to their daily activities but also that people older than 60 years might have some immunity against the H1N1 virus,” they wrote online in The Lancet.

However, the death rate was highest among those 70 and older, at 10.3%. The death rate was 2% or less for all age groups younger than 40.

The findings are consistent with previous epidemiological studies of the ongoing pandemic.

“Some researchers believe, with the information available up to now, that the present H1N1 influenza virus will not cause a pandemic on the scale of those during the 20th century,” the researchers said. “This pandemic might not be the one we expected; however, the virus is evolving and the threat continues.”

Borja-Aburto and his colleagues examined data obtained at Mexican clinics between April 28 and the end of July.

Over that time, 63,479 cases of influenza-like illness — characterized by fever, cough, headache, muscular pain, and rhinorrhea — were reported, with 6,945 cases of H1N1 confirmed.

Risk of confirmed H1N1 infection was significantly reduced in patients who had received a seasonal influenza vaccine in the past year (OR 0.65, 95% CI 0.55 to 0.77).

The researchers acknowledged that the potential for the seasonal vaccine to protect against the pandemic strain remains controversial and said that the association deserves further study.

Anne Schuchat, MD, director of the CDC’s National Center for Immunization and Respiratory Diseases, has said seasonal flu vaccines are unlikely to provide meaningful protection against the pandemic strain. (See Older Population Might Have Immunity to H1N1 Swine Flu)

Of the confirmed cases, 92% received outpatient treatment, 7% were hospitalized and survived, and less than 1% (63 patients) died.

Mortality rates were low until age 40, after which they steadily climbed with increasing age.

Each day of delay in hospital admission was associated with about a 20% increased risk of death (OR 1.19, 95% CI 1.11 to 1.28).

Consistent with other studies, the presence of chronic diseases such as hypertension, diabetes, and obesity was linked to a greater risk of dying (OR 6.1, 95% CI 2.37 to 15.99).

Pregnant women accounted for 6.3% of the deaths from confirmed H1N1 infection, which is slightly lower than the 8% rate observed in the U.S. during a similar time frame.

“In Mexico, all pregnant workers were sent home during the peak of the pandemic, which probably accounts for this difference,” the researchers said.

None of the pregnant women who died received antivirals during first 48 hours after symptom onset, as recommended by the CDC, and none had received a seasonal flu vaccine.

“Treatment should begin immediately after onset of symptoms in this group,” the researchers said, “and vaccination during pregnancy is not contraindicated and therefore can be considered.”

Borja-Aburto and his colleagues acknowledged that the study was limited by incomplete data and use of information provided by staff who were not necessarily trained to handle epidemics.

In an accompanying comment, V. Alberto Laguna-Torres, MD, of the U.S. Naval Medical Research Center Detachment in Lima, Peru, and Jorge Gomez Benavides, PhD, of San Marcos University in Lima and the Peruvian Ministry of Health, said the study was also limited because some patients eligible for treatment at clinics included in the study could have sought care elsewhere.

Influenza surveillance in general also has shortcomings because not all patients with flu-like illness seek treatment or are sampled during a pandemic, and diagnosis depends on access to laboratories, they added.

“All of these factors contribute to a bias in incidence rates,” they declared.

There was no funding source for the study.

Both the study authors and the editorialists reported that they had no conflicts of interest.

WASHINGTON — The FDA approved Merck’s Gardasil vaccine against human papillomavirus (HPV) for boys and men, the same day that it okayed a competing vaccine for use in females.

Gardasil was approved for males ages 9 to 26 for prevention of genital warts. The approval did not address claims that the vaccine in this population may help prevent transmission to girls and women.

Earlier Friday, the agency also approved the first competitor for Gardasil since the latter came on the market in 2006. GlaxoSmithKline’s Cervarix was cleared for use in girls and women, 9 to 26 years old. (See FDA Okays Second HPV Vaccine)

The new indication for Gardasil was based on two trials: a randomized trial in 4,055 males ages 16 through 26 testing the vaccine’s effectiveness in preventing genital warts, and a study in boys ages 9 to 15 that measured immune responses.

The second trial showed that the immune response was as good as that found in the older age group, indicating that the vaccine should have similar effectiveness, the FDA said.

In September, the FDA’s advisory committee on vaccines voted to recommend Gardasil’s approval for males when it also backed Cervarix. (See FDA Panel Votes to Approve Second HPV Vaccine)

Merck is to conduct postmarketing studies aimed at collecting more data on the vaccine’s safety and efficacy in males.

Gardasil is given as three injections over a six-month period. Headache, fever, pain at the injection site, itching, redness, swelling, and bruising were the most common side effects observed in the clinical studies.

SEATTLE, Aug. 23 — The theory that autism is caused by the brain growing too large and maturing too quickly may not hold water, according to an imaging study here.

Although the brains of autistic children are definitely larger than typical children’s brains, they also seem to suffer from developmental delay rather than an excess of growth and maturation, said Stephen R. Dager, M.D., of the University of Washington, and colleagues, in the Aug. 22 issue of Neurology.

Using an MRI technique that measures the physical properties of water in brain tissue, Dr. Dager and colleagues found molecular signs of developmental delay in the gray matter, but not the white matter, of young autistic children.

The study involved 60 children age two to four diagnosed with autism spectrum disorder. Brain images of these children were compared with those of 16 age-matched children with idiopathic developmental delay and 10 normal children.

The study focused on “T2 transverse relaxation time” — a measurement of how fast certain electrons in water molecules change their spin orientation when subjected to radio frequency pulses. The T2 time indicates how much cellular versus extracellular water tissue contains and to what degree this water is “bound” to surrounding molecules.

A shorter T2 time indicates more bound water and, in terms of child brain development, a more mature brain. A longer T2 time indicates more free water in the brain tissue and suggests a less-developed brain, the authors said.

Gray matter T2 time was longer in autistic children versus normal children (119 ms versus 118 ms; P=0.009), indicating less maturation. White matter T2 time was about 101 ms for both groups (P=not significant).

For comparison, T2 time was longer in both the gray and white matter of developmentally delayed children compared with typical children (120 ms versus 118 ms for gray matter [P=0.008] and 103 ms versus 101 ms for white matter [P=0.003]).

The study found no significant correlations between T2 times in gray or white matter and the children’s IQ scores for any of the three groups.

These findings are not consistent with the so-called “overgrowth” theory, which suggests that abnormally fast brain maturation ends up causing damage that leads to autism, Dr. Dager said in an interview. “Our findings suggest delayed growth, not accelerated growth,” he said.

One possible suspect for that delayed growth is inflammation, possibly due to autoimmune activity in the brain, Dr. Dager and colleagues speculated. “Our T2 gray matter findings in the children with autism spectrum disorder, studied soon after clinical diagnosis was established, may reflect brain mechanisms involving neuroinflammation, which have been implicated in this disorder,” they wrote.

“Such processes are typically accompanied by edema and would result in increased T2 relaxation,” they added.

Other possible mechanisms include deficits in the neuroregulatory protein Reelin or an overabundance of serotonin, which has been linked to aberrations in brain development and connectivity, they suggested.

The study’s findings may be consistent with another theory about the underlying cause of autism — that faulty connections between the brain’s parts may be responsible, Dr. Dager said. “Our findings suggest disruption in the cellular architecture of the brain, and that disruption could affect connectivity,” he said.

The authors plan to focus future imaging studies on specific areas of the brain, including the hippocampus, amygdala, and thalamus, “to aid in further understanding the gray and white matter microstructural differences in autism.”

The T2 time measurement can not be used to diagnose autism, Dr. Dager stressed. However, if the technique provides a clearer understanding of the biological mechanism underlying autism, then the genes involved may be identified. These genes could in turn become targets for new therapies, he speculated.

Primary source: Neurology

Source reference:
Petropoulos, H et al. “Gray matter abnormalities in autism spectrum disorder revealed by T2 relaxation.” Neurology 2006; 67:632-636.

Just over a third of patients (33.9%) who underwent a revisional bariatric operation at a single center had complications within three months, a prospective case series showed.

And nearly one-quarter (23.2%) had a complication more than 90 days after their revision, Fotis Kalfarentzos, MD, of the University Hospital of Patras in Rion, Greece, and colleagues reported in the February issue of Archives of Surgery.

But, “although revisional bariatric surgery is associated with higher risk of perioperative complications compared with the primary procedures, it appears to be safe and effective when performed in experienced centers,” the researchers wrote.

“New concepts and improved techniques by well-trained surgeons in properly organized institutions coupled with cautious patient selection represent the cornerstone for achieving favorable results and for extending patients’ longevity.”

As the use of bariatric surgery becomes more widespread, revisions due to complications or unsatisfactory weight loss are becoming more common.

Reported rates of bariatric revisions vary widely, from 5% to 56% of all procedures.

To evaluate the safety and effectiveness of revisional procedures, Kalfarentzos and colleagues prospectively analyzed data from their institution.

From 1995 to 2008, there were 1,161 bariatric operations performed; of those, 56 (4.8%) were revisions, all performed by Kalfarentzos.

Most of the patients who had a revision (69.6%) had had unsatisfactory weight loss with the initial procedure. Another 26.8% had protein malnutrition. Two patients (3.6%) had stomal obstruction and stenosis.

In the group that had unsatisfactory weight loss, 90% of original procedures were either vertical banded gastroplasty (stomach stapling) or gastric banding.

All of the patients in the group with protein malnutrition had a biliopancreatic diversion with Roux-en-Y gastric bypass.

Of the last two patients, one had a standard Roux-en-Y gastric bypass and one had a biliopancreatic diversion with gastric bypass.

All of the revisional operations were open procedures.

The most common revisions were conversion to a variant of biliopancreatic diversion with Roux-en-Y reconstruction (62.5%) and elongation of the common limb at the expense of the biliopancreatic limb after a biliopancreatic diversion (26.7%).

Through a mean follow-up of eight-and-a-half years, there were no deaths among the patients.

However, 33.9% had a complication within 90 days, including two cases of acute renal failure, five anastomotic leaks, eight cases of pneumonia, and one case each of wound infection, incisional dehiscence, bile leak, and small-bowel obstruction.

Another 23.2% had complications longer than 90 days after the revision, including two cases of stenosis of the gastrojejunal anastomosis, two cases of hypoalbuminemia, and nine cases of incisional herniation.

In the largest group of patients — those who had unsatisfactory weight loss from the original procedure — body mass index decreased from a mean of 55.4 kg/m2 to 35 kg/m2 (P<0.05) following the revision. A mean of 68.9% of excess weight was lost.

Among the patients who were undergoing a revision because of protein malnutrition, weight did not significantly change following the revision, but there was a total resolution of hypoalbuminemia with no complications.

The researchers said both patients who underwent a revision because of mechanical complications had favorable outcomes.

The authors did not make any financial disclosures.

Smoke-free laws covering public spaces in entire counties are associated with less exposure to secondhand smoke among children living there, a large, cross-sectional study showed.

Among children from a nonsmoking home, the prevalence of detectable levels of urinary cotinine — a metabolite of nicotine — was significantly lower in those living in a county with extensive smoke-free laws than in those living in an area with no smoke-free legislation (prevalence ratio 0.61, 95% CI 0.48 to 0.78), according to Melanie Dove, DSc, MPH, of Harvard School of Public Health, and colleagues.

Extensive coverage was not associated with lower cotinine levels among children from a smoking home, the researchers reported in the July issue of Pediatrics.

“These results suggest that smoke-free laws are an effective strategy for reducing cotinine in youth without home secondhand smoke exposure,” they wrote.

Because children from homes in which someone smoked did not appear to benefit from smoke-free laws, Dove and her colleagues wrote, “interventions designed to reduce or prevent adults from smoking around children are needed, such as parental counseling by physicians to stop smoking.”

The number of local smoke-free laws affecting workplaces, restaurants, and bars increased from 0 in 1988 to 175 in 2006, according to the researchers.

These laws have been associated with reductions in cotinine levels in adults, but the issue hadn’t been explored in children and teens.

So Dove and her colleagues turned to the National Health and Nutrition Examination Survey (NHANES) for 1999 to 2006. They included data from 11,486 children ages 3 to 19, all of whom were nonsmokers according to serum cotinine levels and self-reported status.

The participants came from 117 U.S. counties — 26 had at least one smoke-free law that covered the entire county population (extensive coverage), 11 did not have a law that covered the entire population but had at least one city within the county with such a law (limited), and 80 did not have any coverage from a smoke-free law.

The percentage of children with detectable levels of cotinine in their urine (≥0.05 ng/mL) increased from 32.7% in counties with extensive smoke-free law coverage to 49.6% in those with limited coverage to 64.6% in those with no coverage.

About one-fifth (21%) of children came from a smoking home, and nearly all (98%) of these children had detectable levels of cotinine. Fewer than half (45.4%) of children from nonsmoking homes had detectable levels.

The prevalence of detectable levels of cotinine among children was significantly lower with extensive smoke-free law coverage among children from nonsmoking homes only after adjustment for survey cycle, gender, age, race, ratio of family income to poverty, region, restaurant visits per week, and adult county smoking prevalence.

The association was not significant for children from smoking homes or for areas with only limited coverage from smoke-free laws.

The findings were consistent with two Scottish studies evaluating the effect of smoke-free laws in that country.

Dove and her colleagues said misclassification of exposure to smoke-free laws was possible because county-level laws may not reflect individual exposure to those laws.

The study was funded by the Flight Attendants Medical Research Institute Clinical Innovator Award. Dove was supported in part by a National Institute of Environmental Health Sciences Training Program in Environmental Epidemiology grant.

The authors reported no conflicts of interest.

MINNEAPOLIS, Jan. 25 – If carbon monoxide poisoning causes heart muscle injury, it can double the risk of death in the next decade, investigators here reported.

In a prospective cohort study of 230 people with carbon monoxide poisoning treated with hyperbaric oxygen at the Hennepin Country Medical Center, about 37% suffered myocardial injury, according to Timothy Henry, M.D., of the Minneapolis Heart Institute.

After a median follow-up of 7.6 years, 38% of those patients had died, compared with 15% of those whose hearts were not injured during the carbon monoxide poisoning, Dr. Henry and colleagues reported in the Jan. 25 issue of the Journal of the American Medical Association.

Heart muscle damage during carbon monoxide poisoning is “much more common than people realize,” Dr. Henry said in an interview, “and if you have it it’s a bad thing.”

Dr. Henry added there are two key take-home messages from the study: People in general, he said, should take steps to prevent carbon monoxide poisoning in the first place and physicians treating victims should be aware of the potential for myocardial damage.

“Personally,” he said, “I’m treating them as if they are patients who came to me with abnormal heart muscle function or congestive heart failure” – including follow-up with repeated echocardiograms and therapy with beta-blockers and ACE inhibitors.

The report came as 26-year-old Randal McCloy – who survived extensive carbon monoxide poisoning in the Sago, W.Va., mine explosion — continues to make a slow recovery. Doctors upgraded his condition to fair Tuesday, but he is still not fully conscious, said a spokesman for Ruby Memorial Hospital in Morgantown, W.Va.

McCloy suffered extensive tissue damage that affected several organs including his heart, although his doctors now say his heart rhythm and function are normal.

The attention in McCloy’s case has been focused on his neurological condition, which Dr. Henry says is standard in carbon monoxide poisoning. “Physicians focus on that,” he said, because the most striking symptoms of carbon monoxide poisoning are things like dizziness and loss of consciousness.

In the Minnesota study, he said, myocardial injury was diagnosed by elevations in the enzymes troponin I or creatine kinase-MB, alterations on diagnostic electrocardiograms, or both.

The study found:

85 of the 230 patients had evidence of heart muscle injury.
At a median follow-up of 7.6 years — ranging from just the hospital stay to 11.8 years — in the community, there were 54 deaths, 12 of them in hospital as a result of a combination of burns and anoxic brain injury, or cardiac arrest and anoxic brain injury.
Among the 85 patients who sustained myocardial injury, 32 eventually died from all causes, compared with 22 of 145 patients who did not have heart muscle injury.
The hazard ratio for death was 2.1, with a 95% confidence interval from 1.2 to 3.7.

Primary source: Journal of the American Medical Association

Source reference:
Henry CR et al. Myocardial Injury and Long-term Mortality Following Moderate to Severe Carbon Monoxide Poisoning. JAMA. 2006; 295: 398 – 402.