(Press-News.org) When doctors give heart drugs to patients, the time of day can make a big difference, according to new research by University of Guelph scientists.
Many doctors prefer to give heart drugs to patients in the morning. But the study revealed that angiotensin-converting enzyme (ACE) inhibitors – commonly given to patients with high blood pressure or after a heart attack or during heart failure – improve heart structure and function when given at sleep time. In fact, when administered during wake time, ACE inhibitors are no more effective than a placebo, the study found.
The research was conducted on mice with high blood pressure.
Guelph professors Tami Martino, Department of Biomedical Sciences, Jeremy Simpson, Department of Human Health and Nutritional Sciences and Nazneen Tata conducted the study in the laboratory of Dr. Michael Sole at the Peter Munk Cardiac Centre and the Heart and Stroke Richard Lewar Centre of Excellence in Toronto.
The study will appear May 17 in the Journal of the American College of Cardiology.
"Heart drugs are often given to patients in the morning for convenience without considering biological rhythms or time-related risks of adverse effects," said Martino. "But if they're given at bedtime, it's better."
That is because the drug affects a natural hormone involved in heart remodeling. Hormone levels increase at night and cause the heart to enlarge, which damages the organ in cardiac patients, said Martino.
"The sleep-time benefit of giving the ACE inhibitor correlates with the biological rhythm of this hormone," she said. "By targeting those hormones when they're highest during sleep, you're dropping their levels so they're not doing so much damage."
It's known that heart attacks and sudden cardiac death peak in early morning and night-shift workers with disturbed circadian rhythms have higher risk of heart disease and worse outcomes, said Sole, who is a cardiologist at the Toronto General Hospital.
"Earlier studies our group has worked on suggest that the heart repairs and renews itself during sleeping hours," he added.
These findings led the researchers to explore whether the effectiveness of ACE inhibitors is impacted by the time of day it's administered. The team used a short-acting version of the drug and studied the effects during wake and sleep time in a mouse model designed with high blood pressure.
Besides administering the drug to patients before bed, study results also suggest doctors should consider using a short-acting version of the drug, said Martino.
"Since the drug is most effective during sleep hours, it's not necessary to have its effects last throughout the span of an entire day. Using a short-acting version of the drug may help to reduce side effects."
Other researchers have also looked at using biological rhythms for drug treatment of other diseases, such as insulin release in diabetes and chemotherapy for cancer patients, she added.
"We are now starting to learn that biological and physiological rhythms play an important role in health and disease."
###
Contacts:
Professor Tami Martino
Department of Biomedical Sciences
University of Guelph
519-824-4120, Ext. 54910
tmartino@uoguelph.ca
Professor Jeremy Simpson
Department of Human Health and Nutritional Science
University of Guelph
519-824-4120, Ext. 56629
jeremys@uoguelph.ca
Nicole Bodnar
Public Affairs & Communications
Peter Munk Cardiac Centre
416-340-4800, Ext. 3417
nicole.bodnar@uhn.on.ca
For media questions, contact Communications and Public Affairs: Lori Bona Hunt, 519-824-4120, Ext. 53338, lhunt@uoguelph.ca, or Deirdre Healey, Ext. 56982, dealey@uoguelph.ca.
Heart medication best at bedtime, study reveals
2011-05-10
ELSE PRESS RELEASES FROM THIS DATE:
New study reveals autism prevalence in South Korea estimated to be 2.6 percent or 1 in 38 children
2011-05-10
New York, N.Y. (May 9, 2011) – In the first comprehensive study of autism prevalence using a total population sample, an international team of investigators from the U.S., South Korea, and Canada estimated the prevalence of autism spectrum disorders (ASD) in South Korea to be 2.64%, or approximately 1 in 38 children, and concluded that autism prevalence estimates worldwide may increase when this approach is used to identify children with ASD. "Prevalence of Autism Spectrum Disorder in a Total Population Sample," published today online in the American Journal of Psychiatry ...
Vanderbilt biologists discover a new class of insect repellent
2011-05-10
NASHVILLE, Tenn. – Imagine an insect repellant that not only is thousands of times more effective than DEET – the active ingredient in most commercial mosquito repellants – but also works against all types of insects, including flies, moths and ants.
That possibility has been created by the discovery of a new class of insect repellant made in the laboratory of Vanderbilt Professor of Biological Sciences and Pharmacology Laurence Zwiebel and reported this week in the online Early Edition of the Proceedings of the National Academy of Sciences.
"It wasn't something we ...
Zombie ants have fungus on the brain, new research reveals
2011-05-10
New research has revealed how infection by a parasitic fungus dramatically changes the behavior of tropical of carpenter ants (species Camponotus leonardi), causing them to become zombie-like and to die at a spot that has optimal reproduction conditions for the fungus. The multinational research team studied ants living high up in the rainforest canopy in Thailand. A paper describing the research will be published in the BioMed Central open-access journal BMC Ecology on 9 May 2011.
"The behavior of these infected zombie ants essentially causes their bodies to become an ...
Cheap-TV-Spots.com Tops 190 International Awards for Affordable TV Ads
2011-05-10
The affordable, internet-based TV advertising agency Cheap TV Spots is proud to announce it has won the prestigious Gold Award at the 2011 Worldfest International Film Festival. The advertising agency's amazing award count now stands at over 190 international awards.
Worldfest is the one of the longest running international film and TV festivals in North America, and Cheap-TV-Spots.com is the longest-operating producer of original, discount-priced TV commercials for the international market.
What do all of these awards mean to you, the business owner? Your high quality ...
CIC nanoGUNE develops Nano-FTIR-nanoscale infrared spectroscopy with a thermal source
2011-05-10
Researchers from the Basque nanoscience research center CIC nanoGUNE and Neaspec GmbH (Germany) have developed an instrument that allows for recording infrared spectra with a thermal source at a resolution that is 100 times better than in conventional infrared spectroscopy. In future, the technique could be applied for analyzing the local chemical composition and structure of nanoscale materials in polymer composites, semiconductor devices, minerals or biological tissue. The work is published in Nature Materials.
The absorption of infrared radiation is characteristic ...
Social learning
2011-05-10
Online social networking sites, such as Facebook, can help students become academically and socially integrated as well as improving learning outcomes, according to a study by researchers in China and Hong Kong. Writing in the International Journal of Networking and Virtual Organisations, explain that Facebook usage is around 90% across campuses and many educational institutions offer new students orientation on how to capitalize on social networking to improve their experience of their course and their final results.
Many previous studies of social networking have focused ...
OzeVision Web Hosting Awarded Two Web Hosting Awards In April 2011
2011-05-10
OzeVision Web Hosting has been presented with 14th position amongst the "Top 25 Most Poplar" web hosting companies in the category "Australian Web Hosting Directory" by WebHostDir.com and 5th position in the category "Australian Dedicated Servers Directory" by DedicatedServerDir.com for the month of April 2011. The awards pages can be viewed at:
http://ozevision.com/web_hosting/top-25-most-popular-webhosting-awards.html
http://ozevision.com/web_hosting/top-25-most-popular-dedicated-awards.html
On monthly basis, WebHostDir.com and DedicatedServerDir.com ...
Most nurses don't use recommended intramuscular injection site despite potential risks
2011-05-10
Seven out of ten hospital nurses who took part in a Canadian study used the dorsogluteal (DG) buttock site to administer intramuscular injections - despite the potential risks of sciatic nerve injury - with only 14% using the ventrogluteal (VG) hip site recommended by the nursing literature.
The research, published in the May issue of the Journal of Advanced Nursing, found that younger, newer nurses were significantly more likely to follow the latest VG site advice than their older, experienced colleagues. It also discovered that more than one in four nurses using ...
Study of health in Brazil highlights major progress
2011-05-10
Major progress has been made in reducing the burden of infectious diseases in Brazil as part of a "remarkable" success story for health in the South American country, according to researchers on a series of papers published in The Lancet.
After decades of marked social change, including the introduction of unified healthcare for all, Brazil can also celebrate a reduction in mortality from chronic diseases and huge inroads into improving maternal and child health. But the nation still faces problems – including some infectious diseases such as dengue and leishmaniasis, ...
Blood test for colon cancer screening beneficial for some seniors, but not for many others
2011-05-10
CHAPEL HILL, N.C. – A new study of U.S. veterans ages 70 and older finds that the healthiest get the most benefit from current colon cancer screening methods. However, for many less healthy veterans the burdens of screening may outweigh the benefits.
"This study shows that we really need to target screening in older adults, so that those who will benefit do get screened and followed-up while those who won't benefit aren't exposed to unnecessary burdens," said Christine E. Kistler, MD, assistant professor of Family Medicine at the University of North Carolina at Chapel ...