PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Review of 90 studies confirms that men's sperm quality declines with age

2014-12-01
(Press-News.org) Conflicting evidence about the extent to which men's semen quality declines with age--likely lowering their fertility--is being cleared up by new University of Otago, New Zealand, research that has collated and reviewed data from 90 previous studies from around the world.

After conducting a systematic review and meta-analysis of the studies' data, researchers from the University's Departments of Zoology and Anatomy found consistent age-related declines in semen volume and sperm performance and increases in malformed and DNA-damaged sperm. Semen quality is regarded as a proxy for how fertile a male is.

Study lead author Dr Sheri Johnson says that understanding how age affects fertility is becoming increasingly important as couples delay childbearing toward later stages of their lives.

"While female age is well known to have negative effects on fertility, reproductive success and the health of offspring, the influence of male age on a couple's fertility has been largely neglected.

"The effects of declining semen traits with increasing male age have largely been ignored due to inconsistencies in the literature, but our work now suggests that male age affects a variety of traits. It is well recognised that reduced sperm performance can affect pregnancy success, but it is less well known that the quality of the sperm, particularly DNA quality, could affect the development and health of the offspring," Dr Johnson says.

Dr Johnson and her co-authors synthesised the current state of knowledge from 90 individual studies, spanning around 94,000 volunteers/patients from more than 30 countries. Their Marsden-funded study appears in the international journal, Ageing Research Reviews.

"Our study made no attempt to estimate the rate of decline, but some well-controlled clinic-based studies have observed consistent declines with increasing age, whereas others project declines after age 35 for some traits and after age 40 for others" she says.

Professor Neil Gemmell, a co-author on the paper, says the consistency in its findings suggests that further awareness of the potential consequences of male age on reproductive outcomes is needed.

"Older males contribute to increased risk of obstetric complications, miscarriage, and offspring disorders such as autism, Down syndrome, epilepsy, and schizophrenia. In addition, increasing male age may be an overlooked component of couple infertility, leading to our increased use and dependency on fertility treatments, such as IVF."

Overall, the authors advise that clinicians and the general public need to be aware of the risks associated with male age on fertility outcomes.

The authors suggest that clinical analysis of the percentage of DNA-fragmented sperm cells and a greater focus on how well sperm swim may lead to better patient outcomes during fertility treatments of ageing couples.

"These are likely more accurate and consistent predictors of a man's fertility status than commonly clinically measured traits such as semen volume, sperm concentration and total sperm count," Dr Johnson says.

INFORMATION:



ELSE PRESS RELEASES FROM THIS DATE:

Singapore scientists uncover gene associated with an aggressive breast cancer

2014-12-01
Singapore--Scientists at A*STAR's Genome Institute of Singapore (GIS), in collaboration with local clinicians and colleagues in the USA, have identified a biomarker which is strongly associated with triple negative breast cancer (TNBC), a highly aggressive carcinoma that often has early relapse and metastasis following chemotherapy. The newly identified biomarker, a gene called RASAL2, provides a target for developing new therapeutics designed to treat this often deadly disease. TNBC is deadly because, unlike other types of breast cancers such as estrogen receptor (ER) ...

Genes and environment: Complex interactions at the heart of personalized medicine

2014-12-01
Personalized medicine uses methods of molecular analysis, especially genetic sequencing and transcription, in order to simultaneously identify genetic mutations to evaluate each individual's risk of contracting a given disease. It seems that there is more than a single mechanism at hand, as proven by the work of a team of geneticists at the University of Geneva's (UNIGE) Faculty of Medicine, and the Swiss Institute for Bioinformatics (SIB). They have sequenced the RNA of 400 pairs of twins; with this information, they can quantify the roles of both genetic and environmental ...

Taking the 'mute' off silenced gene may be answer to Angelman syndrome

2014-12-01
HOUSTON -- (Dec. 1, 2014) - Most genes are inherited as two working copies, one from the mother and one from the father. However, in a few instances, a gene is imprinted, which means that one copy is silenced. This is called genomic imprinting. If the active copy is mutated, then disease results, even though the silenced gene copy may be normal. Angelman syndrome, which causes learning difficulties, speech problems, seizures, jerky movements and an unusually happy disposition, results when a gene inherited from the mother in a particular area of chromosome 15 is mutated ...

Penn study points to new therapeutic strategy in chronic kidney disease

Penn study points to new therapeutic strategy in chronic kidney disease
2014-12-01
PHILADELPHIA-- Chronic kidney disease (CKD) affects at least one in four Americans who are older than 60 and can significantly shorten lifespan. Yet the few available drugs for CKD can only modestly delay the disease's progress towards kidney failure. Now, however, a team led by researchers at the Perelman School of Medicine at the University of Pennsylvania, has found an aspect of CKD's development that points to a promising new therapeutic strategy. "We found that a defect in energy production in affected kidney cells plays a key role in CKD development," says Katalin ...

Neuronal encoding of the switch from specific to generalized fear

2014-12-01
"I can't get the memories out of my mind!... I am right back in Vietnam, in the middle of the monsoon season at my guard post. My hands are freezing, yet sweat pours from my entire body...I smell a damp sulfur smell. Suddenly I see what's left of my buddy Troy, his head on a bamboo platter, sent back to our camp by the Viet Cong."i This veteran of the US army, who served in Vietnam, has intense flashbacks of his decapitated friend whenever he hears a clap of thunder, touches a bamboo mat, or sees an Oriental woman. Although the traumatic incident happened decades ago in ...

Scientists discover why bowel cancer sometimes outsmarts treatment

2014-12-01
A new study* that challenges the prevailing view of how bowel cancer develops in the large intestine is published today in Nature Medicine. Cancer Research UK scientists have discovered that bowel cancer may not be restricted to starting its journey in the stem cells in the lining of the intestines as previously thought. The researchers, based at the Wellcome Trust Centre for Human Genetics, studied a hereditary faulty gene which can cause bowel cancer in middle age. The faulty gene causes normal cells to behave like immortal stem cells and develop tumours of their ...

New research highlights the key role of ozone in climate change

2014-12-01
Many of the complex computer models which are used to predict climate change could be missing an important ozone 'feedback' factor in their calculations of future global warming, according to new research led by the University of Cambridge and published today (1 December) in the journal Nature Climate Change. Computer models play a crucial role in informing climate policy. They are used to assess the effect that carbon emissions have had on the Earth's climate to date, and to predict possible pathways for the future of our climate. Increasing computing power combined ...

Fighting malnutrition with a 'stronger' chickpea

2014-12-01
This news release is available in French. Micronutrient malnutrition affects more than 2 billion people. Researchers working at the Crop Development Centre at the University of Saskatchewan are seeking long term solutions to help to alleviate the increasing micronutrient malnutrition problem by enriching food grains with essential micronutrients through breeding and appropriate management practices, collectively known as biofortification. Chickpea (Cicer arietinum L.) is considered an excellent whole food as source of dietary proteins, carbohydrates, micronutrients ...

Study links sleep apnea to impaired exercise capacity

2014-12-01
DARIEN, IL - A new study shows that obstructive sleep apnea is associated with impaired exercise capacity, which is an indicator of increased cardiovascular risk. Results show that the predicted peak oxygen uptake, a measure of aerobic physical fitness, was significantly lower in people with moderate to severe obstructive sleep apnea than in controls. Further analysis found that sleep apnea severity alone explained 16.1 percent of this variability. "We found a significant association indicating that there is likely a very strong independent relationship between obstructive ...

Warning to bariatric surgery patients: Take your supplements, for eye's sake

2014-12-01
Obese patients who have undergone bariatric surgery to shed weight should take the supplements prescribed to them to protect their eyes. Taking in too little Vitamin A, in particular, could in some cases actually cause night blindness, dry eyes, corneal ulcers, and in extreme cases total blindness. This advice comes from Rui Azevedo Guerreiro and Rui Ribeiro of the Centro Hospitalar de Lisboa Central in Portugal, who reviewed what little research there currently is on the occurrence of eye conditions following bariatric surgery. The review is published in Springer's journal ...

LAST 30 PRESS RELEASES:

Exercise as an anti-ageing intervention to avoid detrimental impact of mental fatigue

UMass Amherst Nursing Professor Emerita honored as ‘Living Legend’

New guidelines aim to improve cystic fibrosis screening

Picky eaters by day, buffet by night: Butterfly, moth diets sync to plant aromas

Pennington Biomedical’s Dr. Leanne Redman honored with the E. V. McCollum Award from the American Society for Nutrition

CCNY physicists uncover electronic interactions mediated via spin waves

Researchers’ 3D-printing formula may transform future of foam

Nurture more important than nature for robotic hand

Drug-delivering aptamers target leukemia stem cells for one-two knockout punch

New study finds that over 95% of sponsored influencer posts on Twitter were not disclosed

New sea grant report helps great lakes fish farmers navigate aquaculture regulations

Strain “trick” improves perovskite solar cells’ efficiency

How GPS helps older drivers stay on the roads

Estrogen and progesterone stimulate the body to make opioids

Dancing with the cells – how acoustically levitating a diamond led to a breakthrough in biotech automation

Machine learning helps construct an evolutionary timeline of bacteria

Cellular regulator of mRNA vaccine revealed... offering new therapeutic options

Animal behavioral diversity at risk in the face of declining biodiversity

Finding their way: GPS ignites independence in older adult drivers

Antibiotic resistance among key bacterial species plateaus over time

‘Some insects are declining but what’s happening to the other 99%?’

Powerful new software platform could reshape biomedical research by making data analysis more accessible

Revealing capillaries and cells in living organs with ultrasound

American College of Physicians awards $260,000 in grants to address equity challenges in obesity care

Researchers from MARE ULisboa discover that the European catfish, an invasive species in Portugal, has a prolonged breeding season, enhancing its invasive potential

Rakesh K. Jain, PhD, FAACR, honored with the 2025 AACR Award for Lifetime Achievement in Cancer Research

Solar cells made of moon dust could power future space exploration

Deporting immigrants may further shrink the health care workforce

Border region emergency medical services in migrant emergency care

Resident physician intentions regarding unionization

[Press-News.org] Review of 90 studies confirms that men's sperm quality declines with age