jueves, 11 de septiembre de 2014

Cannabis use in adolescence has negative impact on education

A study looks to add more fuel to the heated debate around the use of marijuana, as researchers have linked the frequent use of cannabis among adolescents with reduced educational attainment. The study also links frequent use of the drug with other negative health outcomes, such as suicide attempts.

The study's lead author, Dr. Edmund Silins, says that the results "provide strong evidence that the prevention or delay of cannabis use is likely to have broad health and social benefits."
The team, comprised of researchers from Australia and New Zealand, received funding from the Australian Government National Health and Medical Research Council, and the study has been published in The Lancet Psychiatry.

Many researchers are pushing for cannabis to be used in a therapeutic capacity, as a form of pain relief or to alleviate symptoms of conditions such as multiple sclerosis (MS) and post-traumatic stress disorder(PTSD).
However, study author Richard Mattick believes that moves toward the decriminalization and legalization of cannabis also contribute toward "raising the possibility that the drug might become more accessible to young people."
Outside of legal avenues, cannabis is the most widely used illicit drug worldwide. The National Institute on Drug Abuse (NIDA) report that around 7% of US high-school seniors are daily or near-daily cannabis users, with around 46% having tried the drug at some point during their lifetime.
Although the study uses data from adolescents in Australia and New Zealand, the authors state that the rates of cannabis use are similar across high-income countries. For example, they cite that the rates of cannabis use among adults in Australia and New Zealand are 10% and 15% respectively, compared with a rate of 15% in the US.

Does early cannabis use compromise education?

For the study, the researchers utilized the data of 3,765 participants from three large, long-term longitudinal studies, tracking cannabis use alongside several developmental outcomes from before the age of 17 up to the age of 30.
They recorded the frequency of cannabis use as never, less than monthly, monthly or more, weekly or more, or daily. The researchers chose to record the following developmental outcomes:
  • Cannabis dependence
  • Completing high school
  • Depression
  • Obtaining a university degree
  • Suicide attempts
  • Use of other illicit drugs
  • Welfare dependence.
The researchers found significant associations between the frequency of adolescent cannabis use and all of the designated developmental outcomes. After adjusting for potential confounding factors such as socioeconomic status and mental illness, they found that five of the associations remained significant.
Individuals who had used cannabis daily before the age of 17 were 60% less likely to complete high school or obtain a degree than those who had never used cannabis. They were also 18 times more likely to become dependent on cannabis, eight times more likely to use other illicit drugs and seven times more likely to attempt suicide by the age of 25.
Most significantly, the researchers found that the risk of negative developmental outcomes increased relative to the frequency of the cannabis dose. Daily cannabis users experienced the strongest effects of the association.

Impact on reforming legislation

In a linked commentary, Prof. Merete Nordentoft, of the University of Copenhagen, Denmark, explains why these results may have occurred:
"Persistent cannabis use has adverse effects, such as low energy and initiative, and impairment of cognitive functions, and these factors are likely to mediate the harmful effect of cannabis on educational attainment."
The authors say that these findings are consistent with the results of previous studies investigating early cannabis use alongside these developmental outcomes. They suggest that preventing or delaying cannabis use in adolescents could have far-reaching benefits, both socially and with regard to health.
One measure that the authors suggest could be implemented is screening for cannabis use in adolescents as standard practice during visits to doctors, child psychiatrists, school nurses and other health care practitioners. This is due to an estimated lack of self-reporting among adolescent cannabis users.
"Efforts to reform cannabis legislation should be carefully assessed to ensure they reduce adolescent cannabis use and prevent potentially adverse effects on adolescent development," says Dr. Silins.
In spite of this, the authors also acknowledge that within US states where cannabis has been made increasingly available for medical use, there has been no reported increase in use among young people.
The study still urges caution. The landscape is undeniably changing with regard to how cannabis is perceived and utilized, and the authors believe that as this framework changes, the needs of the youth must always be considered in order to prevent adverse developmental outcomes.
Tomado de: Medical News Today. Written by James McIntosh

martes, 9 de septiembre de 2014

Inflammatory marker signals diabetic nephropathy development

Measuring serum levels of high-sensitivity C-reactive protein (hs-CRP) could help to predict which patients with Type 2 diabetes will develop renal disease, research suggests.

Results of a prospective cohort study conducted in Japan show that patients with the highest hs-CRP levels were more likely to develop microalbuminuria than those with the lowest levels.
Over a median follow-up of 0.94 years, 197 patients developed diabetic nephropathy, with an incidence ratio of 155.4 per 1000 person–years. Adjusted hazard ratios (HR) for the risk of developing nephropathy associated with the second, third and fourth hs-CRP quartiles versus the first quartile were 1.31, 1.55 and 1.57, respectively.
However, hs-CRP levels did not appear to be associated with the progression from microalbuminuria to macroalbuminuria. During the same follow-up period, 109 patients experienced diabetic nephropathy progression, with an incidence ratio of 92.4 per 1000 patient–years. Adjusted HRs were 0.59, 1.14 and 1.03, respectively, for the lowest versus the second, third and fourth highest quartiles of hs-CRP, respectively.
“Our study identifies new information regarding CRP and disease outcomes”, observe Yasuaki Hayashino, from Tenri Hospital in Nara, Japan, and co-authors.
“There is a temporal association between elevated levels of hs-CRP and the subsequent risk of developing, not progressing, diabetic nephropathy”, they write in Diabetes Care, adding that this association is seen “even after adjusting for possible confounders, including medication use which may influence the natural course of renal function.”
Longitudinal data on 2518 patients with Type 2 diabetes were obtained from the Diabetes Distress and Care Registry at Tenri study to look at the association between baseline hs-CRP and subsequent risk of development or progression of diabetic nephropathy at 1 year.
Development of diabetic nephropathy was defined as the transition from normoalbuminuria (urinary albumin-to-creatinine ratio [UACR]  menor 3.4 mg/mmol) to microalbuminuria (UACR 3.4–33.9 mg/mmol), and progression as the transition from microalbuminuria to macroalbuminuria (UACR mayor o igual a33.9 mg/mmol).

Hayashino et al note that their results were obtained from studying patients seen at a single diabetes centre in Japan, and so it remains to be seen if they apply to multi-ethnic populations in North American and Europe.
“More research is needed to examine if there is an effective strategy to reduce the risk of diabetic nephropathy in a group of patients with diabetes and elevated levels of hs-CRP”, they conclude.

Tomado de:medwireNews (www.medwirenews.com

miércoles, 3 de septiembre de 2014

Noninvasive DNA Test for Colorectal Cancer Gets FDA Thumbs-up

Among cancers that affect both men and women, colorectal cancer is the third most common cancer and the second leading cause of cancer-related death in the United States, according to the CDC. The agency estimates that if everyone age 50 or older participated in recommended colorectal cancer screening(www.cdc.gov), at least 60 percent of colorectal cancer deaths could be avoided.
Now, family physicians and other clinicians have a singular new option for detecting this life-threatening condition. Moreover, CMS has already laid the groundwork for Medicare coverage for the test.
On Aug. 11, the FDA approved Cologuard, a stool-based colorectal screening test that detects red blood cells and DNA mutations that can indicate the presence of abnormal, possibly precancerous growths, according to an FDA news release(www.fda.gov). It is the first fecal DNA test for colorectal cancer to receive the agency's thumbs-up; previous candidates have lacked adequate sensitivity and specificity.
Specifically, Cologuard detects hemoglobin and mutations associated with colorectal cancer in DNA of cells shed by advanced adenomas as stool moves through the large intestine and rectum. Patients who receive a positive test result are advised to undergo a diagnostic colonoscopy.
"This approval offers patients and physicians another option to screen for colorectal cancer," said Alberto Gutierrez, Ph.D., director of the Office of In Vitro Diagnostics and Radiological Health at the FDA's Center for Devices and Radiological Health (CDRH), in the news release. "Fecal blood testing is a well-established screening tool, and the clinical data showed that (Cologuard) detected more cancers than a commonly used fecal occult test."
The FDA's approval of Madison, Wisc.-based Exact Sciences' Cologuard expands the options for colorectal cancer screening but does not change current related guidelines. The U.S. Preventive Services Task Force (USPSTF) does not recommend stool DNA testing as a method to screen for colorectal cancer. The USPSTF's current screening recommendation(www.uspreventiveservicestaskforce.org) for average-risk adults ages 50 to 75 calls for using fecal occult blood testing (FOBT), sigmoidoscopy or colonoscopy.
However, the USPSTF currently is reviewing its colorectal cancer screening recommendations; evaluation of fecal DNA screening was specifically included in the systematic evidence review(www.ncbi.nlm.nih.gov) the task force is using to inform that update.

Cologuard Study

A recent study(www.nejm.org) published in the New England Journal of Medicineexamined the safety and effectiveness of Cologuard, screening almost 10,000 asymptomatic participants ages 50 to 84 who were at average risk for colorectal cancer and were scheduled to undergo a screening colonoscopy. The trial compared Cologuard to fecal immunochemical testing (FIT).
Compared with FIT, Cologuard was more accurate in detecting colorectal cancers (92 percent versus 74 percent) and advanced adenomas (42 percent versus 24 percent). It was less accurate than FIT, however, at correctly identifying subjects negative for colorectal cancer or advanced adenomas (87 percent versus 95 percent).
Family physician Richard Wender, M.D., who is chair of the National Colorectal Cancer Roundtable and chief cancer control officer for the American Cancer Society (ACS), told AAFP News he was impressed with the sensitivity of Cologuard in the clinical trial. He added that a precursor to Cologuard had at one time been on an ACS-recommended list of colorectal cancer screening options, but the test is no longer available.
"Cologuard has more robust data than the older stool DNA test and better performance," Wender said, "so a good argument for including the test in guidelines can be made."

CMS Coverage

Cologuard is the first product to be reviewed through a joint FDA-CMS pilot program for parallel review,(www.fda.gov) under which the agencies concurrently review certain premarket medical devices to reduce the time between FDA approval and Medicare coverage.
"Parallel review allows the last part of the FDA process to run at the same time as the CMS process, cutting as many as six months from the time of study initiation to coverage," said Nancy Stade, CDRH's deputy director for policy, in the news release.
CMS proposes to cover the Cologuard test once every three years for asymptomatic individuals ages 50 to 85 who are at average risk of developing colorectal cancer.
"This new process (of parallel review) is a good step in developing a more efficient and streamlined approach to test approval," Wender said. "I applaud the FDA and CMS for developing this innovative process to accelerate the availability of the test.
"I think it is fair to say that having both agencies join in approving the test and paying for the test does constitute additional endorsement of the test."

The Future for Cologuard

For Cologuard to become widely used, it will need to be added to the USPSTF and other major colorectal cancer screening guidelines, Wender said. Otherwise, the test may not be covered by some commercial insurers.
As to Cologuard's limitations, Wender said that although CMS has decided to pay for the test every three years, the ideal testing interval has not yet been determined. Furthermore, at a cost of $500 (the preliminary payment amount established by CMS), the test is likely to be cost-effective but its relative cost-effectiveness compared to other screening options is unclear. Finally, the acceptability of the test to clinicians and patients also is not fully known.
Wender said it's important for physicians to remember that there are already two widely used screening options: colonoscopy every 10 years or FIT every year. He added that high-sensitivity guaiac FOBT and CT colonoscopy are additional options to consider. The variety of options should help the ACS reach its "80% by 2018"(nccrt.org) initiative's goal to have 80 percent of adults ages 50 and older screened for colorectal cancer by 2018.
"In short, we already have both more and less invasive, more and less costly options to screen everyone for colorectal cancer," said Wender. "We can achieve the 80 percent goal using available tests. But it is conceivable that having Cologuard available and approved may place the 80 percent goal more within our reach."
Tomado de: http://www.aafp.org/

viernes, 29 de agosto de 2014

APA: Regular marijuana use bad for teens' brains

As presented at the Annual Convention of the American Psychological Association

Frequent marijuana use can have a significant negative effect on the brains of teenagers and young adults, including cognitive decline, poor attention and memory, and decreased IQ, according to psychologists discussing public health implications of marijuana legalization at at APA, held in Washington, D.C., in August. 
     “It needs to be emphasized that regular cannabis use, which we consider once a week, is not safe and may result in addiction and neurocognitive damage, especially in youth,” said Krista Lisdahl, PhD, director of the brain imaging and neuropsychology lab at University of Wisconsin-Milwaukee. 
Brain imaging studies of regular marijuana users have shown significant changes in their brain structure, particularly among adolescents, Dr. Lisdahl said. Abnormalities in the brain’s gray matter, which is associated with intelligence, have been found in 16- to 19-year-olds who increased their marijuana use in the past year, she said. These findings remained even after researchers controlled for major medical conditions, prenatal drug exposure, developmental delays, and learning disabilities, she added. 
     “When considering legalization, policymakers need to address ways to prevent easy access to marijuana and provide additional treatment funding for adolescent and young adult users,” she said. She also recommended that legislators consider regulating levels of tetrahydrocannabinol, or THC, the major psychoactive chemical in marijuana, in order to reduce potential neurocognitive effects. 
Tomado de: Reportes de Congresos.  Univadis.com

jueves, 28 de agosto de 2014

Obesity: exploring the causes, consequences and solutions

The World Health Organization estimates that global levels of obesity have doubled since 1980. In 2012, more than 40 million children under the age of 5 were estimated to be overweight or obese, which is an issue of serious concern as excess body weight is believed to be the driver of many non-communicable diseases, namely type 2 diabetes, cardiovascular disease and some types of cancer.
To tackle what is, in most cases, a preventable condition, there is increasing focus on research into understanding the mechanisms behind obesity, including our genetics and the influence of lifestyle and the environment. There is also now increased focus on introducing public health initiatives to aid long-term weight loss, which range from improving public, patient and healthcare provider education to policy reform regarding the sale of pre-packaged and processed foods.
To focus on these issues, BMC Medicine has launched an article collection that aims to explore the main contributing factors and possible solutions to tackle the worldwide impact of obesity.

Which are the culprits – sugars, starches or fats?

How much of what we eat makes us fat? This is an ongoing debate, fuelled most recently byRobert Lustig and his focus on sugar. On the question of sugar, a further debate arises – is itsucrose or fructose that has the most impact on obesity?
In an editorial to introduce the article collection in BMC MedicineJack Winkler, former Professor of Nutrition Policy at London Metropolitan University, and currently Director of Food & Health Research, discusses why it is so hard to measure which food components are associated with obesity.
Prof Winkler explains one of the many problems with this field is that data derived from large-scale studies depends on reliable and consistent reporting. However, this is a limiting factor simply because these studies rely on self-reported energy intake surveys, and as Prof Winkler reminds us, people are good at lying about how much they are actually eating.

The lies people tell about their food may be white lies, but they are large lies….. In one study of soft drinks, subjects in the National Diet and Nutrition Survey claimed to be drinking barely a quarter of the products that manufacturers reported they were selling

The consequences of obesity

There is no question that obesity places a burden on healthcare services. Earlier this year,Gillian Reeves and colleagues showed that elevated body mass index (BMI) in UK women is associated with increased hospital admissions equating to around 420,000 extra admissions annually, indicating that current obesity levels are directly impacting UK healthcare services.
Primary care physicians are usually the first in line to treat patients with obesity related diseases, although patients may not be visiting their GP to directly ‘treat’ their obesity. As David Haslam, a GP and physician specializing in obesity at the Centre for Obesity research explains, the role of primary care in managing obesity is complicated in the UK by ineffective or contradictory policies. In his commentary published as part of this article collection, Prof Haslam starkly points out:
“Obesity prevention has failed. If nobody in the UK gains another single ounce, there are enough already obese people to make epidemics of diabetes, then heart disease then premature death inevitable.”
Prof Haslam, who also serves as Chair of the National Obesity Forum, highlights that obesity can be most effectively managed by individualization of care, which should be implemented through effective screening and risk management. After all, not all patients will benefit from weight loss. Prof Haslam discusses the obesity paradox in his commentary, and recent evidence on this includes a meta-analysis we published this year by Wie Nie and colleagues, showing that an obesity paradox exists for pneumonia – i.e. obese individuals have an increased risk of pneumonia but a decreased risk of pneumonia mortality, indicating a survival advantage for obese individuals.
However, in most cases, obesity and diet are considered as a causal risk factor for chronic diseases such as type 2 diabetes. Recently, Elin Hall and colleagues showed that exposing pancreatic islet cells to the free fatty acid palmitate results in differential gene expression and epigenetic modifications, which may influence type 2 diabetes risk through impaired insulin secretion in these treated cells.
In an Opinion article, Naveed Sattar and Jason Gill discuss the plausible link between type 2 diabetes and ectopic fat around organs such as the liver and pancreas. In their article, they explain that studies have shown accumulation of ectopic fat around the liver leads to insulin resistance, and they also hypothesize that fat around the pancreas could lead to β-cell dysfunction. Prof Sattar and Dr Gill ask a very provocative question: can type 2 diabetes be reversed by loss of ectopic fat around key organs?

Taking action on obesity

So, what should be done about the rising levels of obesity? One of the physicians leading the issue is John Wass, a consultant physician and endocrinologist, and also Chair of the Working Party for Action on Obesity.
I interviewed Prof Wass about the goals of the working party, which aims to tackle the rise of obesity in the UK  by filling current gaps in knowledge and support within the healthcare and medical education systems. Prof Wass highlights that educating the public about healthy eating, and collaborations with the food industry on how to responsibly sell and label foods, is key to improving public health.
There is also ongoing debate about whether or not obesity should be considered as a disease. On this, Prof Wass explains that as obesity is a condition that needs to be actively managed it can be labelled as a disease, and unless it is recognized as such, prevention and management strategies will not be taken seriously.

Tomado de: 

miércoles, 27 de agosto de 2014

‘Prostate cancers’ not ‘prostate cancer’ – revealing the many faces of ‘one’ disease

New research published today in Genome Biology shows that RNA sequencing could lead the way towards more personalized treatments for prostate cancer. In this guest post, Dr Iain Frame, Director of Research at Prostate Cancer UK discusses what this could mean for patients and health services, and what more is needed to provide effective support and treatment for men with prostate cancer.
We are used to hearing and talking about prostate cancer as a single disease.  Albeit a disease with its tigers and pussycats – the tigers being the aggressive cancers that move out of the prostate gland to other parts of the body, and the pussycats being those cancers that may never cause any harm and won’t go on to kill.  But it’s never quite as simple as that is it?
More and more we hear clinicians and research scientists talk about ‘prostate cancers’ plural. This is largely down to the introduction of genomic sequencing which has allowed researchers to identify and examine large numbers of prostate tumors, which initiate and progress in different ways. Add to this, the genomic variations in the men themselves, and suddenly the world of detecting and treating cancers of the prostate becomes a lot more complicated – not that it was ever simple to begin with!
What the paper published today by Drs Collins and Wyatt from the Vancouver Prostate Centre does so well is apply state-of-the art RNA sequencing technology to a real life situation. So on top of the information we know at the whole genome level, they looked at which genes were being used and disrupted at the point when the tumor was collected. Being able to match this up with how these men and their tumors had responded to different treatments meant that the researchers could then see which treatments work best for the different tumor types.
So in theory, by knowing more about the tumor and the man who has the tumor, researchers will be able to develop more personalized or tailored treatments for individuals. As a result, clinicians will be armed with a much clearer idea as to which treatments will work most effectively and speculation will be a thing of the past.
However, there is a ‘but’.  The researchers here only looked at 25 tumors and were surprised by the sheer number of genomic differences between them. Forty-thousand  men are newly diagnosed with prostate cancer each year in the UK and there are 250,000 men in this country living with the disease – so how much variation will there be when the number of tumors examined in this way increases?
The challenge lies in how we translate this fantastically elegant research into real life benefits for these men and those at risk of prostate cancer.  And what’s more – let’s not kid ourselves that it is only prostate cancer that is looking to tailor treatments – every other disease is working to the same aim, putting tremendous pressure on health services, which will need to cope with the increased expense of diagnosing and managing disease at an individual level.
At Prostate Cancer UK, we strongly support the development of new tailored treatments for men with prostate cancer. However, allied to that aim is an ambition to be able to take some men out of the system – those men whose cancer will never spread.
We feel that alongside developing better treatments, the global research community needs to develop a more robust risk assessment tool that can be used in multi-ethnic populations, delivered through primary care reasonably simply and in a cost-effective way. By doing this in prostate cancer we should be able to concentrate limited healthcare resources on those who need it most – those with, or at high risk of, aggressive prostate cancers.
There is absolutely no doubt that this is a really exciting time for prostate cancer research.  The results from this research will help build a better picture of what is going on and I’m confident that in the future it can lead to important health benefits for men with, and at high risk of, aggressive prostate cancer.
But that fight needs resources – both financial and human – to succeed.  It is clear that we must keep building on research successes such as the one reported here,  but for this to be possible, more funding is needed to support more scientists through their research endeavors in order to achieve real benefits for men.

Tomado de blogs.biomedcentral.com