Father's smoking during pregnancy tied to asthma in kids

[ad_1]

(Reuters Health) - Children who are exposed to tobacco smoke from their fathers while they’re in the womb may be more likely than those who are not to develop asthma by age 6, according to a study of chemical changes to DNA.

While prenatal smoke exposure has long been linked to an increased risk of childhood asthma, the current study offers fresh evidence that it’s not just a pregnant mother’s smoking that can cause harm.

Researchers followed 756 babies for six years. Almost one in four were exposed to tobacco by fathers who smoked while the child was developing in the womb; only three mothers smoked.

Overall, 31% of kids with fathers who smoked during pregnancy developed asthma by age 6, compared with 23% of kids without fathers who smoked, the study found.

Asthma was also more common among kids whose fathers were heavier smokers, senior study author Dr. Kuender Yang of the National Defense Medical Center in Taipei said by email.

“Children with prenatal paternal tobacco smoke exposure corresponding to more than 20 cigarettes per day had a significantly higher risk of developing asthma than those with less than 20 cigarettes per day and those without prenatal paternal tobacco smoke exposure,” Yang said.

About 35% of the kids with fathers who were heavier smokers developed asthma, compared with 25% of children with fathers who were lighter smokers and 23% of kids with fathers who didn’t smoke at all during pregnancy.

Smoking by fathers during pregnancy was also associated with changes in methylation - a chemical code along the DNA strand that influences gene activity - on portions of genes involved in immune system function and the development of asthma.

Researchers extracted infants’ DNA from cord blood immediately after birth and examined methylation along the DNA strand. The more fathers smoked during pregnancy, the more methylation increased on stretches of three specific genes that play a role in immune function.

Children who had the greatest methylation increases at birth, affecting all three of these genes, had up to almost twice the risk of having asthma by age 6 as other kids in the study.

While smoking by fathers during pregnancy was linked to childhood asthma, it didn’t appear to impact children’s sensitivity to allergens or total levels of IgE, an antibody associated with asthma.

This suggests that the risk of asthma from tobacco exposure is unlike allergic asthma, which is driven by allergies or allergic sensitization via IgE antibody, said Dr. Avni Joshi, a researcher at the Mayo Clinic Children’s Center in Rochester, Minnesota, who wasn’t involved in the study.

The study wasn’t designed to prove whether or how prenatal smoking exposure might directly cause so-called epigenetic changes, or how those changes cause asthma in children.

It’s not yet clear how the alterations seen along the DNA strand where methylation increased might cause asthma, the study team notes in Frontiers in Genetics.

Still, the message to parents should be clear, Joshi said by email.

“Smoking is bad at ANY point in time: before the baby is born and after the baby is born,” Joshi said. “Many parents defer quitting until the baby is born, but this study stresses that the prenatal exposure to tobacco creates changes to the unborn child’s immune system, hence it is best to quit as a family decides to have children, even before the conception happens.”

SOURCE: bit.ly/2WG9lhM Frontiers in Genetics, online May 31, 2019.

Our Standards:The Thomson Reuters Trust Principles.

[ad_2]

Source link

Many epinephrine self-injectors still potent long after expiration date

[ad_1]

(Reuters Health) - EpiPens and other autoinjectors filled with epinephrine to treat severe allergic reactions may still be potent enough to work many months past their labeled expiration date, according to a new study that concludes patients might need expensive refills less often.

These autoinjectors contain a pre-set dose of epinephrine, a life-saving drug used by people at risk of experiencing anaphylaxis, a severe allergy attack. Untreated, anaphylactic shock can be fatal because blood pressure can drop suddenly and airways can narrow, making it difficult to breathe.

Patients who need these life-saving devices must carry at least one with them at all times and have access to one everywhere they go. Soaring prices and out-of-pocket costs for the autoinjectors have made it increasingly difficult for many patients to keep throwing out and replacing unused devices when they expire, researchers note in the Journal of Allergy and Clinical Immunology: In Practice.

The U.S. Food and Drug Administration (FDA) requires autoinjector expiration dates to ensure that the devices never contain less than 90% of the original dose of epinephrine, the study team notes.

For the study, researchers tested the contents of 46 different autoinjectors to see how much epinephrine remained after the expiration dates on the labels. Half of the devices were tested at least two years after their labeled expiration date. At this point, 80% of the devices still retained 90% or more epinephrine, indicating they were still effective under the FDA rules.

“If the expiration dating on these devices was changed, this means that patients would not need to replace their auto-injectors as frequently, limiting cost to them, their insurance, and the healthcare system, while still feeling secure that they have access to adequate treatment for anaphylactic reactions,” said lead study author Lynn Kassel of Drake University College of Pharmacy & Health Sciences in Des Moines, Iowa.

Devices six months past their labeled expiration date in the study still had 100% of the original epinephrine dose. One year after the labeled expiration date, devices still had 95% of the original epinephrine dose.

And all of the autoinjectors tested that were up to 30 months beyond their labeled expiration date still had 90% of the dose remaining.

The study tested far too few devices to help determine with certainty whether all epinephrine autoinjectors in the U.S. might be safely used past their expiration dates, Kassel said by email.

The authors also note that they did not test the expired injectors’ effectiveness in stopping an anaphylaxis episode.

“Until the FDA changes the expiration dating guidance for these devices, patients with anaphylactic allergies should carry auto-injectors that have not yet expired,” Kassel advised.

“The greatest risk of using an expired auto-injector is that the epinephrine is no longer potent enough to combat the anaphylactic reaction, and this could result in death or critical illness.”

Right now, the expiration date is 18 months from the time the product is manufactured, a duration that is shorter than the expiration date for most other medications, said Dr. Kao-Ping Chua of the C.S. Mott Children’s Hospital and the University of Michigan Medical School in Ann Arbor.

While the study results build on a growing body of evidence suggesting that expiration dates for epinephrine autoinjectors could be extended, in the meantime, patients should use the devices as labeled, Chua, who wasn’t involved in the study, said by email.

“I don’t think anyone should postpone refilling an epinephrine auto-injector if they can afford it,” Chua said. “In a life-or-death situation, you want to have as much certainty as possible that the rescue medication is going to work.”

SOURCE: bit.ly/2F7WrTT Journal of Allergy and Clinical Immunology: In Practice, online May 28, 2019.

Our Standards:The Thomson Reuters Trust Principles.

[ad_2]

Source link