Painkillers Increase Risk of Erectile Dysfunction

 

Regularly taking prescription painkillers, commonly called opioids, is linked to a greater risk of erectile dysfunction (ED) in men, according to a new study published in Spine.

Over 11,000 men suffering from back pain were involved in the research. The health records of the participants were analyzed to determine whether males taking prescription opioids were more likely to also receive prescriptions for testosterone replacement or ED medications.

The investigators found that over 19% of males who took high-dose opioids for 4 months or more were also given ED prescriptions, while fewer than 7% of males who did not take painkillers received prescriptions for ED.

Over 12% of men who took low-dose opioids for four months or more also received ED prescriptions or testosterone replacement.

Age was the factor most notably linked to receiving ED prescriptions. The men in the study over the age of 60 had a much higher probability of receiving ED prescriptions.

"Men 60 to 69 (years old) were 14 times more likely to receive prescriptions for ED medication than men 18 to 29," the researchers said.

Depression, other health problems (other than back pain), and use of sedative hypnotics, such as benzodiazepines, also raised the probability that men would receive prescriptions for ED.

However, the authors explained, even after adjusting for those factors, men with high-dose opioid use and males with long-term opioid use still had a 50% increased likelihood of recieving ED prescriptions than those who did not take opioids.

Leading author Richard A. Deyo, MD, MPH, investigator with the Kaiser Permanente Center for Health Research and Professor of Evidence-based Family Medicine at Oregon Health & Science University, said:

"Men who take opioid pain medications for an extended period of time have the highest risk of ED. This doesn't mean that these medications cause ED, but the association is something patients and clinicians should be aware of when deciding if opioids should be used to treat back pain."

According to the CDC (Centers for Disease Control and Prevention), the use of prescription painkillers is on the rise in the U.S. The Mortality and Morbidity Report by the CDC revealed that prescription opioid sales experienced a fourfold increase between 1999 and 2010.

A different report, published in the journal Pain, indicated that about 4.3 million Americans use opioid drugs on a regular basis.

The most commonly used prescription opioids include:

• oxycodone
• morphine
• hydrocodone

Deyo said:

"There is no question that for some patients opioid use is appropriate, but there is also increasing evidence that long-term use can lead to addiction, fatal overdoses, sleep apnea, falls in the elderly, reduced hormone production, and now erectile dysfunction."

A CDC report from 2011 found that more Americans die each year from prescription painkiller overdoses than the combined total for cocaine and heroin.

Deyo and his team studied 11,327 men in Oregon and Washington registered for the Kaiser Permanente health plan who saw a doctor for back pain during 2004.

The subjects' pharmacy records for 6 months before and after their doctor's visit for back pain were analyzed to determine whether they had received prescriptions for opioids and for ED or testosterone replacement.

Prescription painkiller use was categorized as:

• none - men who did not receive an opioid prescription
• acute - men who took opioids for 3 months or less
• episodic - men who took opioids for longer than 3 months, but less than 4 months and with fewer than 10 refills
• long-term - men who took opioids for at least four months, or more than 3 months with 10 or more refills

High-dose use was considered anything over 120 mg of morphine equivalent, and low-dose use was considered under 120 mg.

A 2011 study published in the British Journal of Urology International showed that erectile dysfunction is linked to how many different medications are taken.

Hysterectomy Does Not Raise Heart Risk

 

 Contrary to some previous research, a new study from the US finds women's risk of cardiovascular disease does not go up after having a hysterectomy in mid-life, with or without ovary removal. The risk is no higher than that faced by women who reach the menopause naturally, says the new study.

Lead author Karen A. Matthews of the University of Pittsburgh, and colleagues, write about their findings in a report due to be published online this week in the Journal of the American College of Cardiology.

Matthews, who is a distinguished professor of psychiatry and professor of epidemiology and psychology at Pittsburgh, declares in a press statement that the results should be encouraging to middle-aged women considering a hysterectomy:

"... our results suggest that increased levels of cardiovascular risk factors are not any more likely after hysterectomy relative to after natural menopause," says Matthews.

Hysterectomy and Risk of Cardiovascular Disease

Hysterectomy is a common surgical procedure that removes a woman's uterus. Sometimes she also has her ovaries removed, usually to reduce risk of ovarian cancer.

However, while the need for such a procedure may be obvious, for instance because of cancer, prolapsed uterus, fibroids, or because of very heavy and painful periods, as with all surgery, the benefits have to be weighed against the risks.

Because of changes to hormones, one of the effects of having a hysterectomy before the menopause is that it usually brings on the menopause earlier.

Some previous studies have suggested hysterectomy raises long term risk of cardiovascular disease, which is the number one killer of women. And they have inferred that the risk is even higher if ovaries are also removed.

But there are objections to this view, mainly because those studies tended to evaluate cardiovascular disease risk factors years after hysterectomy and/or ovary removal without taking into account what they might have been before surgery.

What the Researchers Did

For this new study, Matthews and colleagues followed 3,302 premenopausal women in the US for 11 years. The women were taking part in the Study of Women's Health across the Nation (SWAN).

At the start of the study period, when the women enrolled on SWAN, they were between 42 and 52 years of age, had an intact uterus, at least one ovary, and were not taking hormone therapy.

They underwent assessments every year over the follow up, during which time the majority reached the menopause naturally, some had hysterectomy with ovary removal, and some had hysterectomy without ovary removal.

The main reasons for hysterectomy were fibroids, heavy periods, and chronic pelvic pain.

The researchers assessed cardiovascular disease risk factors in the participants before and after hysterectomy, and compared this to the risk factors before and after the final menstrual period in those who went through the menopause naturally.

Matthews and colleagues say their study is the first multiethnic study to track prospective annual changes in cardiovascular disease risk factors relative to hysterectomy or natural menopause.

What They Found

The analysis showed that while some of the before and after individual cardiovascular risk factors changes were different for hysterectomy compared to natural menopause, overall, the pattern of changes did not suggest an increase in cardiovascular risk following hysterectomy say the researchers. And this was the same in all ethnic groups.

Plus, this was the case even after adjusting for possible influencers like Body Mass Index (BMI), which did go up after hysterectomy with ovary removal.

What the Reasons Might Be

Mathews says they are not sure why their findings disagree with earlier studies that suggest hysterectomy raises cardiovascular disease risk.

One reason could be because they did not include younger women, and hysterectomy that occurs earlier in life may result in higher cardiovascular disease risk.

Another reason, says Matthews, could be that this study excluded women who had hysterectomies because of cancer.

SWAN is co-sponsored by the National Institute on Aging, the National Institute of Nursing Research, the National Institutes of Health, Office of Research on Women's Health, and the National Center for Complementary and Alternative Medicine.

In 2011, writing in the journal Archives of Internal Medicine, researchers from the University of California at San Francisco reported finding women who underwent hysterectomy with ovary removal had a reduced risk of developing ovarian cancer, and no higher risk of developing other types of cancer, heart disease or hip fractures.

Researchers Develop An Algorithm To Predict How And When Proteins Misfold

Several neurodegenerative diseases - including Alzheimer's and ALS (Lou Gehrig's disease) - are caused when the body's own proteins fold incorrectly, recruit and convert healthy proteins to the misfolded form, and aggregate in large clumps that gum up the works of the nervous system. "For Star Trek fans, this is like the Borg, [a fictional race of cyborgs that abduct and assimilate humans and other species]," says Steven Plotkin, a biophysicist at the University of British Columbia in Vancouver who studies the process of protein misfolding. 

Plotkin's team has developed an algorithm that can predict which regions of a protein are prone to exposure upon misfolding, and how mutations in the protein and changes in the cellular environment might affect the stability of these vulnerable regions. These predictions help scientists gain a better understanding of protein dynamics, and may one day help in developing treatments to effectively combat currently incurable neurodegenerative diseases. The team will present its findings at the 56th Annual Meeting of the Biophysical Society (BPS), held Feb. 25-29 in San Diego, Calif. 

The algorithm developed by Plotkin's group uses the energy equations of thermodynamics to calculate the likelihood that certain stretches of protein will be displayed when the protein misfolds. Since the exposed regions are specific to the misfolded version of the protein, researchers can use these regions as targets for diagnostic and therapeutic treatments. The algorithm can be adapted for different proteins and predicts several potential target regions for each protein. The group has used it to study neurodegenerative disease-causing proteins as well as misfolded proteins that have been implicated in some cancers. 

More recently, the research group used computer simulations to manipulate proteins in a virtual environment, testing out how easy it is for mutated proteins to misfold and propagate. Using this tool has helped the team predict the progression of hereditary ALS disease. 

"The fact that we can predict the lifetime of an individual diagnosed with hereditary ALS from simulations of a protein's mechanical properties is something that is both satisfying and that gives one pause," says Plotkin. "We hope that such information might give some clues as to how to develop effective therapies for this disease." 

Stem Cell Development Triggers Memory

Researchers at the RIKEN-MIT Center for Neural Circuit Genetics have discovered an answer to the long-standing mystery of how brain cells can both remember new memories while also maintaining older ones.

They found that specific neurons in a brain region called the dentate gyrus serve distinct roles in memory formation depending on whether the neural stem cells that produced them were of old versus young age. 

The study will appear in the March 30 issue of Cell and links the cellular basis of memory formation to the birth of new neurons - a finding that could unlock a new class of drug targets to treat memory disorders. 

The findings also suggest that an imbalance between young and old neurons in the brain could disrupt normal memory formation during post-traumatic stress disorder (PTSD) and aging. "In animals, traumatic experiences and aging often lead to decline of the birth of new neurons in the dentate gyrus. In humans, recent studies found dentate gyrus dysfunction and related memory impairments during normal aging," said the study's senior author Susumu Tonegawa, 1987 Nobel Laureate and Director of the RIKEN-MIT Center. 

Other authors include Toshiaki Nakashiba and researchers from the RIKEN-MIT Center and Picower Institute at MIT; the laboratory of Michael S. Fanselow at the University of California at Los Angeles; and the laboratory of Chris J. McBain at the National Institute of Child Health and Human Development. 

In the study, the authors tested mice in two types of memory processes. Pattern separation is the process by which the brain distinguishes differences between similar events, like remembering two Madeleine cookies with different tastes. In contrast, pattern completion is used to recall detailed content of memories based on limited clues, like recalling who one was with when remembering the taste of the Madeleine cookies. 

Pattern separation forms distinct new memories based on differences between experiences; pattern completion retrieves memories by detecting similarities. Individuals with brain injury or trauma may be unable to recall people they see every day. Others with PTSD are unable to forget terrible events. "Impaired pattern separation due to the loss of young neurons may shift the balance in favor of pattern completion, which may underlie recurrent traumatic memory recall observed in PTSD patients," Tonegawa said. 

Neuroscientists have long thought these two opposing and potentially competing processes occur in different neural circuits. The dentate gyrus, a structure with remarkable plasticity within the nervous system and its role in conditions from depression to epilepsy to traumatic brain injury - was thought to be engaged in pattern separation and the CA3 region in pattern completion. Instead, the MIT researchers found that dentate gyrus neurons may perform pattern separation or completion depending on the age of their cells. 

The MIT researchers assessed pattern separation in mice who learned to distinguish between two similar but distinct chambers: one safe and the other associated with an unpleasant foot shock. To test their pattern completion abilities, the mice were given limited cues to escape a maze they had previously learned to negotiate. Normal mice were compared with mice lacking either young neurons or old neurons. The mice exhibited defects in pattern completion or separation depending on which set of neurons was removed. 

"By studying mice genetically modified to block neuronal communication from old neurons -- or by wiping out their adult-born young neurons - we found that old neurons were dispensable for pattern separation, whereas young neurons were required for it," co-author Toshiaki Nakashiba said. "Our data also demonstrated that mice devoid of old neurons were defective in pattern completion, suggesting that the balance between pattern separation and completion may be altered as a result of loss of old neurons." 

The Number Of GP Visits Before Cancer Patients Are Referred To Specialists Examined By Study

More than three quarters (77%) of cancerpatients who first present to their family doctors (GPs) with suspicious symptoms are referred to hospital after only one or two consultations, a new study has found. However, the new research also shows a wide variation in the number of times a cancer patient sees their general practitioner before they are referred to a specialist, with the most pre-referral consultations occurring when the cancer was one of the less common types, or when the patient was either female, young, or an older person from an ethnic minority. The research was published 24 February, in the journalThe Lancet Oncology. 

The study, led by researchers at the University of Cambridge, found that patients with breast,melanoma, testicular and endometrial cancers are more likely to be referred to a specialist after just one or two consultations. However, patients with some less common cancers such asmultiple myeloma, pancreatic, stomach and ovarian cancer, as well as patients with lung andcolon cancers and lymphomas are more likely to require three or more visits to their family doctor before they are referred to a hospital specialist. Patients with multiple myeloma, a blood cancer that is notoriously difficult to diagnose since it mimics many other conditions, are 18 times more likely to require three or more pre-referral consultations compared with patients withbreast cancer. 

"These findings highlight limitations in current scientific knowledge about these cancers," said lead investigator Dr Georgios Lyratzopoulos, Clinical Senior Research Associate at the University of Cambridge. "Medical research in recent decades has prioritised improving cancer treatments, but knowledge about the 'symptom signature' of common cancers and practical solutions on how best to diagnose them is still emerging. Hopefully, our study will stimulate investment into research, focusing on patients with cancers and characteristics where the potential to improve the experience of diagnosis of cancer is greatest." 

The researchers have also found that the diagnosis of cancer is more challenging among young patients, women, and older ethnic minority patients - all of these three groups are known to have a lower risk of developing cancer compared with older, male and white patients in the United Kingdom. 

These findings amplify similar patterns first reported by co-author Dr Richard Neal, Senior Lecturer in General Practice at Bangor University, among cancer patients who took part in a similar survey that was carried out in 2000. Dr Neal said: "The fact that the diagnosis of cancer may be more challenging in some patient groups and for some cancers can help us to tailor diagnostic efforts. The findings will also inform the forthcoming update of the NICE Guidelines for Referral of Suspected Cancer, which will have an important impact on policy and practice." 

The researchers proposed some explanations as to why some of the patient groups were less likely to receive a prompt referral:

• As differences in ethnic minorities were only apparent for older patients, they indicate that communication difficulties may be responsible.
• For bladder cancer, women were more than twice as likely as men to have required three or more consultations with their doctor before a decision to refer to hospital was made. In women, there may be difficulties in discriminating symptoms and signs of bladder cancer from those of benign gynaecological conditions or bladder infection.
• As young people have a lower rate of cancer, the researchers believe GPs are less likely to consider cancer as a possibility.

The research used data from more than 41,000 patients with 24 different cancers who took part in the English National Cancer Patient Experience Survey 2010. (The UK government has indicated that patient experience is a critical aspect of measuring care quality.) The researchers examined variation in the number of general practitioner consultations with cancer symptoms before hospital referral to diagnose cancer. 

"Whilst doctors may have concerns about the accuracy of patient-reported data, we have good reasons to believe the validity of our findings", said co-author Greg Rubin, Professor of General Practice and Primary Care at Durham University. "This is because they correlate well with data collected by general practitioners who took part in the independent National Audit of Diagnosis of Cancer in Primary Care. We hope further strides towards diagnosing cancer earlier will be made through the use of both patient experience and clinical audit data." 

In order to improve the promptness of referrals, the study makes recommendations for both clinicians and policy makers. For clinicians, they highlight the need to be more aware of some of the patient groups and cancers which tended to be diagnosed less promptly and the need to participate in data collection to benchmark their practice. They also suggest that policy makers 'should explore and evaluate physician-level educational interventions, further development of point-of-care decisions aids, risk calculators and diagnostic tests, and system re-design to enable greater appropriate and timely use of specialist diagnostic tests (such as imaging or endoscopy)'. 

Although the researchers are based in the UK, they believe their findings have implications for other countries as well, as they reflect the difficulties of diagnosis cancers with non-specific symptoms and signs more generally. Most patients subsequently diagnosed with cancer first see a doctor in the community regardless of where they live.