El riesgo de cáncer de próstata asociado a la obesidad variaría según la raza – correofarmacéutico.com
En el estudio, liderado por la investigadora Wendy Barrington, se realizó un seguimiento a un total de 3.398 hombres afroamericanos y 22.673 de raza blanca no hispanos de 2001 a 2011, todos ellos de 55 años al inicio del estudio.
Al cabo de seis años, los investigadores encontraron 270 casos de cáncer de próstata entre los afroamericanos y 1.453 entre los blancos, lo que en comparación con la muestra utilizada reflejaba un riesgo de desarrollar estos tumores en la población afroamericana un 58 por ciento mayor que entre la población blanca.
Cuando se analizó el índice de masa corporal (IMC) de los participantes, vieron que la obesidad se asoció a un mayor riesgo de cáncer de próstata sólo entre la población afroamericana pero no entre los blancos.
Así, si los afroamericanos con un peso normal tenían un 28 por ciento más de riesgo, entre los obesos las probabilidades de desarrollar estos tumores era un 103 por ciento mayor.
Del mismo modo, la relación entre la obesidad, el cáncer de próstata y la raza también variaba dependiendo de la agresividad de la enfermedad, según vieron los investigadores.
Los autores no saben explicar las causas de este mayor riesgo entre la población afroamericana, de ahí que ahora el siguiente paso sea ver el papel que juegan las diferencias biológicas. “Realmente no lo sabemos”, ha admitido Barrington, que tampoco puede probar si este riesgo también varía en otras razas no estudiadas.
March 26, 2015Obesity and drinking alcohol increase the risk for liver cancer, and coffee consumption decreases the risk, according to a new report called Diet, Nutrition, Physical Activity and Liver Cancer.
The report was released by the American Institute for Cancer Research (AICR) and the World Cancer Research Fund’s Continuous Update Project (CUP) on March 25.
“This is the first time there’s been such a clear signal from a rigorous, systematic review on the links between obesity increasing risk of liver cancer and coffee decreasing risk,” CUP panel member Stephen Hursting, PhD, MPH, commented in a press release. Dr Hursting is a researcher at the University of North Carolina at Chapel Hill.
The CUP report analyzed 34 studies on research about how lifestyle factors affect the risk for liver cancer. The studies included more than 8 million people and more than 24,600 liver cancer cases. An independent panel of international experts reviewed the results.
Liver cancer is the second most common cause of death from cancer worldwide, and rates of the disease are increasing, according to World Health Organization statistics cited in the report. Because liver cancer is usually diagnosed at an advanced stage, it is associated with a poor 5-year survival rate. The disease affects men more often than women and is more common in people living in developing countries (because of hepatitis) than those in industrialized regions.
The report found that drinking coffee “probably” protects against liver cancer. The mechanism behind coffee’s protective effect is not entirely understood. Some evidence points to compounds in coffee that may help with detoxification, antioxidant defence, DNA damage, cell apoptosis, and the expression of genes involved in inflammation.
Link With Obesity “Getting Stronger”
The analysis found “strong evidence” linking higher BMI to increased risk for liver cancer.
“The evidence on obesity and cancer is only getting stronger,” Dr Hursting emphasized in the press release.
We’re looking at a tsunami of obesity-related cancer coming. Dr Stephen Hursting
“We’re looking at a tsunami of obesity-related cancer coming. People really need to be aware of this issue, and we need more research on weight loss strategies and understanding the mechanisms so that we can break this connection,” he emphasized.
Other cancers linked to being overweight include ovarian, colorectal, postmenopausal breast, advanced prostate, endometrial, esophageal, kidney, pancreatic, and gallbladder.
Body fatness increases insulinlike growth factors and estrogens, according to the report. This process stimulates inflammatory responses and creates a procarcinogenic environment. Moreover, body fatness increases the risk for type 2 diabetes, a known risk factor for liver cancer. Body fatness also increases the risk for nonalcoholic steatohepatitis, which can progress to cirrhosis and increase the risk for liver cancer.
Link With Alcohol Confirmed
The report also confirms the well-known link between alcohol consumption and liver cancer, and provides the first quantification about how much alcohol is too much, in terms of liver cancer risk.
“We now have a little more precision on the alcohol-liver cancer link,” Dr Hursting also said in the press release. “Above three drinks a day seems to dramatically impact the tumorigenic process and increase risk.”
Alcohol predisposes to cirrhosis, a risk factor for liver cancer, according to the report.
Finally, the report found “limited” though “consistent” evidence that physical activity and fish consumption could decrease the risk for liver cancer, though further research is needed.
The most common hypothesis, according to the report, explains that n-3 fatty acids found in fatty fish and fish oils ― especially the long-chain polyunsaturated fatty acids ― inhibit carcinogenesis by inhibiting eicosanoid production.
Physical activity may protect against liver cancer, the report explained, by improving insulin sensitivity and body fatness, as well as decreasing chronic inflammation and oxidative stress.
“Lifestyle factors are important contributors to the development of liver cancer, and even moderate changes in diet, alcohol consumption, and exercise can prevent it,” CUP panel member Hillel Tobias, MD, PhD, said in the press release. Dr Tobias is clinical professor in the Department of Gastroenterology at New York University Langone Medical Center and cochair of the American Liver Foundation’s National Medical Advisory Committee.
“But liver cancer can also occur because of uncontrolled forms of hepatitis, including hepatitis C, which affects millions of people worldwide,” he pointed out.
Other factors that contribute to the development of liver cancer include viral hepatitis, type 2 diabetes, cirrhosis, smoking, oral contraceptives with high doses of estrogen and progesterone, and aflatoxins.
The report was developed in partnership with the World Cancer Research Fund International Continuous Update Project (CUP) and the American Institute for Cancer Research.
Continuous Update Project. Diet, Nutrition, Physical Activity and Liver Cancer. 2015. Full text
Eres ‘manzana’ o ‘pera’ según el gen Plexin D1 – correofarmacéutico.com
Ana Callejo Mora | email@example.com
| 30/03/2015 00:00
Eres ‘manzana’ o ‘pera’ según el gen Plexin D1 – correofarmacéutico.com
En la práctica clínica el objetivo para los pacientes con fenotipo “manzana” es corregir el sobrepeso u obesidad y reducir el riesgo cardiovascular, indica Alonso. “Conviene intervenir en estas personas para generar un balance energético negativo y que pierdan peso. De hecho, el tratamiento con dieta mediterránea daría muy buenos resultados. El estudio Predimed ya ha demostrado que este patrón alimentario reduce el número de episodios cardiovasculares en pacientes de alto riesgo cardiaco. También hay que fomentar la práctica de ejercicio físico en estas personas”.
Características del fenotipo manzana, que acumula la grasa alrededor de las vísceras.
– En el fenotipo manzana la grasa se infiltra alrededor de las vísceras, en la zona abdominal.
– El acúmulo de grasa visceral confiere un mayor riesgo de enfermedades cardiovasculares y de diabetes tipo 2.
– Una forma cuantitativa de medir la distribución de la grasa es el índice cintura/cadera.
– Conviene intervenir en estas personas para generar un balance energético negativo.
– Tratar con dieta mediterránea daría muy buenos resultados.
– Los lácteos que consuman estos individuos deben ser desnatados.
– A estos pacientes también hay que recomendarles la práctica de ejercicio físico.
Las zonas teñidas de color amarillo destacan la localización de las células de la grasa, o adipocitos, en este par de peces cebra. En el pez adulto de la parte superior de la imagen, que mide aproximadamente 10 milímetros, la grasa se deposita en todo el cuerpo, sobre todo subcutáneamente en los costados. El pez cebra de la parte inferior de la imagen, más joven y de 4,5 milímetros de tamaño, sólo tiene adiposidad en el abdomen y alrededor de éste. Gracias al estudio de estos animales, los investigadores de la Universidad de Duke han descubierto que un gen llamado Plexin D1 controla dónde se almacena la grasa y cómo se forman los adipocitos.
El gen Plexin D1, conocido por dar instrucciones para construir vasos sanguíneos, controlaría los lugares donde la grasa es almacenada y revelaría cómo se forman los adipocitos.ç
En el fenotipo manzana la grasa se equivoca, y en vez de acumularse subcutáneamente en zonas como las caderas como reserva energética, se infiltra alrededor de las vísceras.
El pez cebra sin el gen Plexin D1 presentaba un mejor manejo de la glucosa, de manera que dicho gen puede estar implicado en el desarrollo de resistencia a la insulina.
Un índice cintura/cadera más alto es indicativo de acúmulo abdominal de grasa, mientras que un índice menor confiere menos riesgo de diabetes tipo 2, hipertensión y dislipemia.
El objetivo para los pacientes con fenotipo “manzana” es corregir el sobrepeso u obesidad y reducir el riesgo cardiovascular. Se puede intervenir con la dieta mediterránea.
March 05, 2015GENEVA (Reuters) – Adults and children must cut the amount of sugar they consume by as much as half in North America and Western Europe and even more in other areas to lower risk of obesity and tooth decay, the World Health Organization said on Wednesday.
New guidelines meant people should reduce the amount to less than 10% of their daily energy intake – or to about 50 grams or 12 teaspoons of sugar for adults, experts at the U.N. body told Reuters.
A cut to less than 5% would be even better, they added.
The WHO’s recommendations to health ministries cover free sugars such as glucose and fructose, and sucrose or table sugar added to processed foods and drinks as well as sugar naturally present in honey, syrups and fruit juices.
The current average in North and Central America was 95 grams per adult per day, in South America about 130 grams, and in Western Europe about 101 grams, said Dr. Francesco Branca, Director of WHO’s Department of Nutrition for Health and Development.
“A single can of sugar-sweetened soda contains up to 40 grams (around 10 teaspoons) of free sugar,” the WHO said.
Evidence showed adults and children who consume less sugars have lower body weight, according to the announcement.
Current rates of sugar consumption varied widely according to age and area, it added. Intake in Europe ranged from about 7-8% of daily energy intake in Hungary and Norway to 16-17% in countries like Spain and Britain.
Data showed rates among children in Portugal were as high as 25% of daily energy intake.
“We have solid evidence that keeping intake of free sugars to less than 10% of total energy intake reduces the risk of overweight, obesity and tooth decay,” Branca said in a statement.
March 09, 2015SAN DIEGO — The so-called “love hormone” oxytocin could turn out even more lovely if it proves to be an effective weight-loss drug.
In a first step, a study found that an intranasal formulation of oxytocin cut food consumption by an average of 122 kcal in a single-meal test involving 25 healthy men of varying body mass indexes (BMIs). The results were reported March 8 here at the annual meeting of the Endocrine Society, ENDO 2015, by Elizabeth A Lawson, MD, from Massachusetts General Hospital and Harvard Medical School, Boston.
“This study suggests that oxytocin may reduce the amount of food that people eat and improve the way that the body handles blood sugar. It will be important to do more studies to find out whether we could use oxytocin to treat obesity and [type 2] diabetes,” Dr Lawson told Medscape Medical News.
Oxytocin, a hormone produced in the brain, is available in the United States as an intravenous drug for the induction of labor. The synthetic intranasal version used in this study is on the market in Europe, to induce lactation, but is not available in the United States.
In animal studies, oxytocin has been shown to reduce food intake and produce weight loss — presumably through effects on appetite pathways in the brain — as well as increase energy expenditure and improve handling of blood glucose. A small trial of intranasal oxytocin over 8 weeks in humans resulted in weight loss, but mechanisms were not studied, Dr Lawson said.
Session moderator Daniel H Bessesen, MD, from the University of Colorado, Denver, who was not involved in the study, told Medscape Medical News, “For anything to go from an idea to a product is a long, long road. There are definitely animal data to suggest oxytocin affects appetite, but I think most people would not consider it to be a central hormone in appetite regulation. Its main functions are in reproduction. But that doesn’t mean it wouldn’t have a role. So, I think it’s a good thing to study and this…is a very first step.”
Interestingly, oxytocin has also been reported to be of benefit in the eating disorder anorexia nervosa, as well as in other psychiatric disorders.
Men Ate Less
The randomized, double-blind, placebo-controlled crossover study used a single dose of 24-IU intranasal oxytocin (Syntocinon, Novartis) in 13 normal-weight (BMI 18.5–24.9 kg/m2) and 12 overweight or obese (BMI 25–40 kg/m2) men aged 18 to 45 years.
“We decided to start with men only because fluctuating hormone levels in women could affect the response to oxytocin. It will be important to study women to determine whether oxytocin has similar effects on food intake and metabolism,” Dr Lawson explained.
The subjects were asked to track food intake for 72 hours prior to their first visit and to eat the same foods in the days leading up to the second visit. They came for study visits in the morning after fasting for 12 hours. Food intake leading up to the visits didn’t differ among the subjects.
After receiving either oxytocin or placebo, the men selected breakfast from a menu and were offered double portions. Caloric content was calculated, and resting energy expenditure and respiratory quotient (use of carbohydrates and fats as fuel) were assessed. Fasting appetite and appetite-regulating hormones were measured before and after oxytocin or placebo.
While oxytocin didn’t affect the number of calories ordered from the menu, it did decrease the total caloric intake by 122 kcal and fat intake by 8.7 g. The effect didn’t differ by BMI status, Dr Lawson noted.
There were no significant differences in intake of protein or carbohydrates, in measures of appetite, or in levels of the appetite-regulating hormones leptin, ghrelin, or peptide tyrosine-tyrosine (PYY). Resting energy expenditure also didn’t change with oxytocin administration.
Oxytocin resulted in a shift in fuel source to provide energy to the body, decreased carbohydrate utilization, and increased fat utilization. It reduced insulin levels and Homeostatic Model Assessment of Insulin Resistance but had no effect on glucose levels, indicating an improvement in insulin sensitivity among the nondiabetic study subjects, Dr Lawson said.
Oxytocin did not affect blood pressure or heart rate. There were few adverse events in the study. Dizziness, drowsiness, nasal irritation, and abdominal pain were seen, but none were severe, and these did not differ between oxytocin and placebo.
Sustained Over Time?
Dr Lawson pointed out that if the effect of oxytocin is equivalent over three meals per day and sustained over time, the finding of a decrease in food intake of 122 kcal/meal translates to 366 kcal/day, which is about 4 kg over 12 weeks, or more than 17 kg over a year.
By contrast, current Food and Drug Administration (FDA)-approved medications for obesity lead to approximately a 3- to 9-kg weight loss at 1 year.
And, she told Medscape Medical News, the intranasal spray used 3 times a day would cost only about $275/month based on the current cost of the spray in the European Union.
But Dr Bessesen said that the “sustained over time” part is a big question mark. “This was a single-meal test. Weight is regulated over long periods of time….As the weight starts to fall, the body responds to that….There are adaptive responses. When we eat less, we get hungry. The idea that a caloric deficit over a single meal would persist at that level for a year is unrealistic.”
However, he said, “The design is good: a randomized, controlled crossover trial. The fact that they find that effect suggests that there’s something real here.…Here’s a medicine that has been tried in humans before and doesn’t seem to have a lot of side effects.…I think it’s an interesting first observation.”
In response to a reporter’s question about other positive effects that have recently been attributed to oxytocin, Dr Lawson said, “It’s a hot hormone right now. It has social effects, improves social interactions, increases trust, and improves accurate perception of social cues. I think these effects are independent of what we’re seeing.”
But given that oxytocin also appears to improve anxiety and depression, which could also curb eating, she said “I think we really need to do more studies.”
The study was funded by the National Institutes of Health, the Boston Nutrition Obesity Research Center, and Massachusetts General Hospital Claflin Distinguished Scholar Award. There was no funding from industry. Dr Lawson and coauthors report no relevant financial relationships. Dr Bessesen runs the data safety and monitoring board for Enteromedics.
ENDO 2015: The Endocrine Society Annual Meeting. Abstract OR40-2, presented on March 8, 2015.
El sedentarismo, culpable de la obesidad infantil – DiarioMedico.com
Isabel Gallardo. Madrid | firstname.lastname@example.org
| 25/02/2015 13:57
El sedentarismo, culpable de la obesidad infantil – DiarioMedico.com
La deficiencia de vitamina D está más vinculada a la diabetes que a la obesidad – DiarioMedico.com
January 15, 2015Fresh evidence that just a little bit of exercise, such as 20 minutes walking a day, is extremely beneficial — regardless of whether people are overweight/obese or not — has emerged from a large European study.
In fact, the most pronounced reduction in premature death risk was observed among individuals who were normal weight/abdominally lean and “moderately inactive,” compared with those of the same build who were completely inactive, which was defined as having a sedentary job with no reported recreational physical activity.
Looking at this another way, the study — in more than 330,000 men and women — showed that twice as many premature deaths may be attributable to lack of physical activity compared with the number of deaths attributable to obesity, the researchers say.
The results are published online January 14 in the American Journal of Clinical Nutrition by Dr Ulf Ekelund (University of Cambridge, United Kingdom), Dr Heather A Ward (Imperial College London, United Kingdom), and a long list of collaborators on the European Prospective Investigation into Cancer and Nutrition (EPIC).
“This is a simple message: just a small amount of physical activity each day could have substantial health benefits for people who are physically inactive,” said Dr Ekelund in a statement. “Although we found that just 20 minutes would make a difference, we should really be looking to do more than this — physical activity has many proven health benefits and should be an important part of our daily life,” he added.
Another of the authors stressed that encouraging movement is something that doctors can easily do, especially in light of research published earlier this week, which showed that primary-care physicians, at least in the United Kingdom, seldom provide access to weight-management interventions.
“Helping people to lose weight can be a real challenge, and while we should continue to aim at reducing population levels of obesity, public-health interventions that encourage people to make small but achievable changes in physical activity can have significant health benefits and may be easier to achieve and maintain,” commented Dr Nick Wareham (Medical Research Council Epidemiology Unit, University of Cambridge).
Is Effect of Physical Activity Independent of BMI, Waist Circumference?
In their paper, Dr Ekelund and colleagues note that physical inactivity has consistently been associated with an increased risk for all-cause mortality independent of general adiposity as defined by body mass index (BMI).
And prior research that has examined associations between physical activity, BMI, and mortality suggests that activity protects against premature death but does not eliminate the increased risk associated with high BMI.
But these studies had numerous limitations, they observe, and while it may seem logical that physical activity exerts its influence on mortality indirectly through reducing adiposity, this is by no means clear.
So they set out to examine the relationship between physical activity and all-cause mortality and to look at whether BMI and waist circumference modified these associations in a large sample of 334,161 men and women followed for more than 12 years from the EPIC study, in which both BMI and waist circumference were measured at baseline.
As a secondary aim, they estimated how many deaths could theoretically be avoided if inactive or obese individuals were active or nonobese, respectively, and calculated the years of gain in life expectancy from avoiding physical inactivity, high BMI (>30 kg/m2), and high waist circumference (> 88 cm in women and > 102 cm in men), separately and combined in the cohort.
Physical activity was measured using self-assessment. Just under a quarter (22.7%) of participants were categorized as inactive, reporting no recreational activity in combination with a sedentary occupation.
Impact of Physical Activity Greatest Among Those of Normal Weight
Over the 12 years of follow-up, 21,438 participants died.
The greatest reduction in risk for premature death occurred in the comparison between inactive and moderately inactive groups.
All-cause mortality was reduced by 16% to 30% in the moderately inactive group compared with those categorized as inactive, across all strata of BMI and waist circumference.
The authors estimate that doing exercise equivalent to just a 20-minute brisk walk each day — burning between 90 and 110 kcal — would take an individual from the inactive to moderately inactive group and thereby reduce the risk for premature death by this same amount (ie, between 16% and 30%).
The impact was greatest among normal-weight individuals, but even those with higher BMI saw a benefit of physical activity.
The researchers say that data from the United States have suggested that physical activity reduces but does not eliminate the increased risk of adiposity on all-cause mortality when cross-classifying activity and BMI groups.
Emerging evidence is accumulating indicating that substantial health benefits may be achieved by fairly small increases in physical activity.
Other research has shown that exercising for 15 minutes per day is associated with a 14% reduction in risk of all-cause mortality compared with inactivity in an Asian population.
“Our results extend these previous observations to also include European men and women and suggest that, within each strata for BMI and waist circumference, the hazard of all-cause mortality was substantially reduced when the inactive group was compared with the moderately inactive group,” they state.
“Thus, emerging evidence is accumulating indicating that substantial health benefits may be achieved by fairly small increases in physical activity.”
Using the most recent available data on deaths in Europe, the researchers estimate that 337,000 of the 9.2 million deaths among European men and women were attributable to obesity: however, double this number of deaths (676,000) could be attributed to physical inactivity.
Simply moving from one category to another (eg, inactive to moderately inactive) would be sufficient to dramatically reduce premature deaths, they stress. “Efforts to encourage even small increases in activity in inactive individuals may be of public-health benefit,” they conclude.
The authors have reported no relevant financial relationships.
Am J Clin Nutr. Published online January 24, 2015. Article