(Press-News.org) ATS 2013, PHILADELPHIA ─ A new study from researchers in Japan indicates that obstructive sleep apnea (OSA) is independently associated with visceral (abdominal) fat accumulation only in men, perhaps explaining gender differences in the impact of OSA on cardiovascular disease and mortality.
"Visceral fat accumulation, which is a risk factor for cardiovascular disease, is also associated with OSA, and gender differences in mortality related to sleep apnea have been reported in some studies. Accordingly, we examined if the relationship between OSA and visceral fat accumulation differed by gender," said Drs. Yuka Harada, MD and Kazuo Chin MD.PhD, of the Kyoto University Graduate School of Medicine. "We found that visceral fat accumulation was associated with OSA in men, but not in women."
The study results will be presented at the ATS 2013 International Conference in Philadelphia.
The study enrolled 271 male and 100 female patients who were evaluated for OSA between October 2008 and December 2010.
Body mass index (BMI) and waist circumference were similar in men and women. Compared with women, men had greater visceral fat accumulation, more severe OSA, and more severe dyslipidemia.
Statistical analyses of the relationships between OSA and fat accumulation revealed that in men, age, BMI, and two indicators of OSA (minimum oxygen saturation during sleep and alveolar-arterial oxygen difference) were independently associated with visceral fat accumulation, while in women, only BMI was associated with visceral fat accumulation.
Measurements of subcutaneous fat were related to BMI in both men and women, but were not related to OSA parameters.
"The complex relationship between OSA and obesity is well documented," said Drs Harada and Chin. "If our findings that visceral fat accumulation is associated with OSA only in men are confirmed in further studies, it may help in the development of new prognostic tools and treatment approaches in this population."
* Please note that numbers in this release may differ slightly from those in the abstract. Many of these investigations are ongoing; the release represents the most up-to-date data available at press time.
Type: Scientific Abstract
Category: 16.04 - Sleep Disordered Breathing: Epidemiology, Genetics and Outcomes (SRN)
Authors: Y. Harada1, T. Oga1, Y. Chihara2, S. Hamada1, M. Azuma1, Y. Toyama1, K. Murase1, K. Tanizawa1, C. Yoshimura1, T. Hitomi1, T. Handa1, M. Mishima1, K. Chin1; 1Graduate School of Medicine, Kyoto University - Kyoto/JP, 2Otsu Red Cross Hospital - Otsu/JP
RATIONALE: Gender difference in mortality from obstructive sleep apnea (OSA) is an important issue. Visceral fat accumulation, a significant risk factor for cardiovascular disease (CVD), was reported to be closely related to OSA. Thus, we hypothesized that the association between OSA and visceral fat differed by gender, possibly affecting gender differences in OSA-related CVD and mortality. We examined by gender which factors were independently associated with visceral fat accumulation in OSA.
METHODS: Subjects were 271 males and 100 females consecutively hospitalized for examination of OSA from October 2008 to December 2010. In the first 308 subjects, relationships were analyzed between fat areas by computed tomography, comorbidity, polysomnographic data, arterial blood gas, pulmonary function and venous blood data. Multiple regression analyses were performed to identify those variables independently associated with visceral fat area (VFA) and subcutaneous fat area (SFA) for each gender. Additionally, we devised prediction formulas for VFA and SFA from our results and validated these formulas in the latter 63 subjects.
RESULTS: Despite similar body mass index (BMI) and waist circumference, men had larger VFA, more severe OSA and more severe dyslipidemia than women. Multiple regression analyses revealed that in men, not only age and BMI but also minimum oxygen saturation (contribution rate (R2) = 4.7%) during sleep, and alveolar-arterial oxygen difference (R2 = 6.3%) were independently associated with VFA. Conversely, VFA was only associated with BMI in women. In both genders, SFA were associated with BMI, not with OSA-related parameters (Figure 1) . Moreover, values of predicted VFA and SFA from multiple regression function were very close to actual measured values in the latter subjects (r = 0.6-0.9, p < 0.001).
CONCLUSIONS: Only in men was OSA independently associated with VFA. The lesser effect of OSA on visceral fat in women might account for lower impact of OSA on CVD or mortality in women. END
OSA is associated with less visceral fat accumulation in women than men
ELSE PRESS RELEASES FROM THIS DATE:
Migraine and depression together may be linked with brain size
MINNEAPOLIS – Older people with a history of migraines and depression may have smaller brain tissue volumes than people with only one or neither of the conditions, according to a new study in the May 22, 2013, online issue of Neurology®, the medical journal of the American Academy of Neurology. "Studies show that people with migraine have double the risk of depression compared to people without migraine," said study author Larus S. Gudmundsson, PhD, with the National Institute on Aging and the Uniformed Services University of the Health Sciences, in Bethesda, Md. Gudmundsson ...
Ants and carnivorous plants conspire for mutualistic feeding
An insect-eating pitcher plant teams up with ants to prevent mosquito larvae from stealing its nutrients, according to research published May 22 in the open access journal PLOS ONE by Mathias Scharmann and colleagues from the University of Cambridge and the University Brunei Darussalam. The unusual relationship between insect-eating pitcher plants and ants that live exclusively on them has long puzzled scientists. The Camponotus schmitzi ants live only on one species of Bornean pitcher plants (Nepenthes bicalcarata), where they walk across slippery pitcher traps, swim ...
Captive-bred wallabies may carry antibiotic resistant bacteria into wild populations
Endangered brush-tail rock wallabies raised in captive breeding programs carry antibiotic resistance genes in their gut bacteria and may be able to transmit these genes into wild populations, according to research published May 22 in the open access journal PLOS ONE by Michelle Power and colleagues from Macquarie University in New South Wales, Australia. Brush-tail rock wallabies are currently being raised in species recovery programs and restored to the wild to bolster populations of this endangered species. Here, researchers found that nearly half of fecal samples ...
New cave-dwelling arachnids discovered in Brazil
Two new species of cave-dwelling short-tailed whipscorpions have been discovered in northeastern Brazil, and are described in research published May 22 in the open access journal PLOS ONE by Adalberto Santos, from the Federal University of Minas Gerais (Brazil) and colleagues. The reddish-brown short-tailed whipscorpions inhabit cool, humid limestone caves in an otherwise arid region. Both new species, Rowlandius ubajara and Rowlandius potiguara, were found deep within the limestone caves, which are also home to bats. Bat guano and seed deposits harbor springtails and ...
Baby's life saved with groundbreaking 3-D printed device that restored his breathing
Ann Arbor, Mich. – Every day, their baby stopped breathing, his collapsed bronchus blocking the crucial flow of air to his lungs. April and Bryan Gionfriddo watched helplessly, just praying that somehow the dire predictions weren't true. "Quite a few doctors said he had a good chance of not leaving the hospital alive," says April Gionfriddo, about her now 20-month-old son, Kaiba. "At that point, we were desperate. Anything that would work, we would take it and run with it." They found hope at the University of Michigan, where a new, bioresorbable device that could help ...
Fetch, boy! Study shows homes with dogs have more types of bacteria
New research from North Carolina State University and the University of Colorado shows that households with dogs are home to more types of bacteria – including bacteria that are rarely found in households that do not have dogs. The finding is part of a larger study to improve our understanding of the microscopic life forms that live in our homes. "We wanted to know what variables influence the microbial ecosystems in our homes, and the biggest difference we've found so far is whether you own a dog," says Dr. Rob Dunn, an associate professor of biology at NC State and ...
Calorie information in fast food restaurants used by 40 percent of 9-18 year olds when making food choices
A new study published online today (Thursday) in the Journal of Public Health has found that of young people who visited fast food or chain restaurants in the U.S. in 2010, girls and youth who were obese were more likely to use calorie information given in the restaurants to inform their food choices. It also found that young people eating at fast food or chain restaurants twice a week or more were half as likely to use calorie information as those eating there once a week or less. Childhood obesity has tripled in recent decades. One potential contributing factor is fast ...
Enzyme-activating antibodies revealed as marker for most severe form of rheumatoid arthritis
In a series of lab experiments designed to unravel the workings of a key enzyme widely considered a possible trigger of rheumatoid arthritis, researchers at Johns Hopkins have found that in the most severe cases of the disease, the immune system makes a unique subset of antibodies that have a disease-promoting role. Reporting in the journal Science Translational Medicine online May 22, the Johns Hopkins team describes how it found the novel antibodies to peptidylarginine deiminase 4, or PAD4, in blood samples from people with aggressive inflammation and connective tissue ...
Mega genomes of spruce species decoded
Canadian and Swedish scientists today released genome sequences of two of the most economically important forest trees in the world. Conifers supply raw materials for the Canadian forestry industry, which accounted for $23.7 billion in Canada's economy in 2011. Gross output of the forest sector in Sweden in 2009 was $29.7 billion. At 20-30 billion base-pairs and up to 10 times larger than the human genome, the white spruce genome, published in Bioinformatics, and the Norway spruce genome, published in Nature, are also the largest genome sequence assemblies to date. ...
NIH researchers conduct first genomic survey of human skin fungal diversity
While humans have harnessed the power of yeast to ferment bread and beer, the function of yeast or other types of fungi that live in and on the human body is not well understood. In the first study of human fungal skin diversity, National Institutes of Health researchers sequenced the DNA of fungi at skin sites of healthy adults to define the normal populations across the skin and to provide a framework for investigating fungal skin conditions. Human skin surfaces are complex ecosystems for microorganisms, including fungi, bacteria and viruses, which are known collectively ...