Beta-blockers heal the heart via the brain

Heart failure treated 'in the brain'

Beta-blockers heal the heart via the brain when administered during heart failure, according to a new study by UCL (University College London). Up to now, it was thought that beta-blockers work directly on the heart, but the new study shows that the drugs may also act via the brain, suggesting that future therapies to treat cardiovascular disease could be targeting the central nervous system.

Heart failure patients are routinely given beta-blockers, although doctors do not know exactly how these drugs boost cardiac performance and reduce the risk of death. The UCL study, based on the rat model of postmyocardial infarction-induced heart failure and published in the journal Circulation Research, has discovered that the beta-adrenoceptor blocker metoprolol acts directly in the brain to slow the progression of heart failure. The action seems to be localised to a group of brain cells that UCL researchers have identified previously as being crucial in the control of blood pressure and heart rate.

Professor Mike Spyer, UCL Vice-Provost and co-author of the study, says: "Our study shows the importance of the brain in regulating the cardiovascular system. This is often ignored by cardiologists who concentrate on the dynamics of cardiac contraction and the receptors on the heart that influence this, rather than how the nervous innervation of the heart is regulated."

Millions of heart failure patients worldwide are routinely treated with beta-blockers, which were pioneered in the 1970s for the treatment of arterial hypertension and are one of the most important advances in heart failure therapy. However, it has not entirely been clear how long-term treatment with beta-blockers slows the development of heart failure, improves heart function and exercise capacity and reduces the risk of sudden cardiac death.

Dr Alexander Gourine, UCL Department of Neuroscience, Physiology and Pharmacology, says: "Many people have assumed that beta-blockers have a direct salutary influence on the heart, but our findings challenge this view, suggesting that beta-blockers may act directly in the brain and this action could underlie their beneficial effect on the failing heart. This study suggests that novel ways might be found to treat cardiovascular disease aimed at sites within the brain."

University College London, March 26, 2008 
http://www.brightsurf.com/news/

AHA dietary guidelines - Metabolic syndrome

Burgers, fries, diet soda: Metabolic syndrome blue-plate special

January 23, 2008 - American Heart Association rapid access journal report
Otherwise-healthy adults who eat two or more servings of meat a day - the equivalent of two burger patties - increase their risk of developing metabolic syndrome by 25 percent compared with those who eat meat twice a week, according to research published in Circulation: Journal of the American Heart Association.

Metabolic syndrome is a cluster of cardiovascular disease and diabetes risk factors including elevated waist circumference, high blood pressure, elevated triglycerides, low levels of high-density lipoprotein (HDL or "good") cholesterol and high fasting glucose levels. The presence of three or more of the factors increases a person's risk of developing diabetes and cardiovascular disease.

But it's not just meat that adds inches to the waist, increases blood pressure and lowers HDL - "it's fried foods as well," said Lyn M. Steffen, Ph.D., M.P.H., R.D., co-author of the study and an associate professor of epidemiology at the University of Minnesota.

Dairy products, by contrast, appeared to offer some protection against metabolic syndrome.

Steffen said that, "Fried foods are typically synonymous with commonly eaten fast foods, so I think it is safe to say that these findings support a link between fast-food consumption and an increase in metabolic risk factors."

The findings emerged from an analysis of dietary intake by 9,514 participants in the Atherosclerosis Risk In Communities (ARIC) study. ARIC is a collaborative study funded by the National Heart, Lung, and Blood Institute.

Unlike other researchers who have investigated relationships between nutrients and cardiovascular risk, "we specifically studied food intake. When making recommendations about dietary intake it is easier to do so using the framework of real foods eaten by real people," Steffen said.

Researchers assessed food intake using a 66-item food frequency questionnaire. From those responses, they categorized people by their dietary preferences into a Western-pattern diet or a prudent-pattern diet.

In general, the Western-pattern diet was heavy on refined grains, processed meat, fried foods, red meat, eggs and soda, and light on fish, fruit, vegetables and whole grain products.

Prudent diet eating patterns, by contrast, favored cruciferous vegetables (e.g., cabbage, radish and broccoli), carotenoid vegetables (e.g., carrots, pumpkins, red pepper, cabbage, broccoli and spinach), fruit, fish and seafood, poultry and whole grains, along with low-fat dairy.

Researchers also assessed associations with individual food items: fried foods, sweetened beverages (regular soda and fruit drinks), diet soda, nuts and coffee.

After nine years of follow-up, 3,782 (nearly 40 percent) of the participants had three or more of the risk factors for metabolic syndrome.

At baseline, participants were 45 to 64 years old - ages at which many people gain weight.

Steffen said that weight gain over the years of follow-up might explain some of the cases of metabolic syndrome. But "after adjusting for demographic factors, smoking, physical activity and energy intake, consumption of a 'Western' dietary pattern was adversely associated with metabolic syndrome," she said.

"One surprising finding was while it didn't increase the risk of metabolic syndrome, there was no evidence of a beneficial effect of consuming a prudent diet either. I had expected to find a beneficial effect because we have seen that in other studies."

When Steffen and colleagues analyzed the results by specific foods, they found that meat, fried foods and diet soda were all significantly associated with increased risk of metabolic syndrome, but consumption of dairy products was beneficial.

The study did not address the mechanisms involved in the increased risk of metabolic syndrome seen with certain foods, but Steffen speculated that "it may be a fatty acid mechanism since saturated fats are a common link and certainly overweight and obesity are contributing to the development of metabolic syndrome." She also said more research on the relationship between diet soda and its association to metabolic syndrome is needed.

The fact that 60.5 percent of the ARIC population had metabolic syndrome at the start of the study or developed it during nine years of follow-up is troubling, researchers said.

Steffen said the study's results are clear: Too much meat, fried foods and diet soda, do not add up to a healthy life.

American Heart Association dietary guidelines for healthy Americans age 2 and older include:

* Limit saturated fat, trans fat, cholesterol and sodium in the diet.
* Minimize the intake of food and beverages with added sugars.
* Eat a diet rich in vegetables, fruits and whole-grain foods.
* Select fat-free and low-fat dairy.
* Eat fish at least twice per week.
* Emphasize physical activity and weight control.
* Avoid use of and exposure to tobacco products.
* Achieve and maintain healthy cholesterol, blood pressure and blood glucose levels.

American Heart Association
http://www.brightsurf.com/news/

Seasonal changes in weight

Seasonal weight changes linked to metabolic syndrome

January 23, 2008 - Seasonal changes in weight increase the risk for metabolic syndrome, a group of scientists from National Public Health Institute, Helsinki, Finland, reports in a study published in the January 23 issue of the online, open-access journal PLoS ONE.

This finding was based on analysis of 8,028 individuals, representative of the general population aged over 30, who attended a nationwide health examination survey.

According to the current study, individuals with metabolic syndrome have more seasonal changes in their mood and behavior. The study concludes that the seasonal changes in weight in particular are linked to metabolic syndrome.

People having winter blues the risk of metabolic syndrome is heightened by 56 per cent. The negative effect of the seasonal changes equals to the protective effect against metabolic syndrome gained with regular physical exercise.

Because of easy assessment the scoring of seasonal changes in weight might be taken as a routine part of health status examination in persons being at risk of or currently having metabolic syndrome. If there were these changes, treatment options including scheduled exposures to light and regular physical exercise need to be considered.

"Disruption of circadian rhythms has been implicated in the pathogenesis of metabolic disorders. Our results give support to the hypothesized links between the metabolic and circadian cycles generated and guided by the circadian clock", says Timo Partonen, MD, academy research fellow of the group. "Our findings herein now extend these links to include relationships between the metabolic and seasonal fluctuations."

The current findings now suggest that abnormalities in the circadian clockwork predispose to seasonal changes in weight and to metabolic syndrome. This means that the circadian clockwork may well be a key to public health.

Obesity is an increasing problem concerning public health. High caloric intake or low physical exercise for example may lead not only to obesity but also to hypertension, insulin resistance and abnormal circulating lipid levels. These abnormalities tend to coincide and contribute to the term metabolic syndrome.

Public Library of Science
http://www.brightsurf.com/news/

Metabolic syndrome in US teens

Metabolic syndrome affects nearly 1 in 10 US teens

Lack of standard definition of risk factors makes measuring problem difficult

About nine percent of teenagers may have metabolic syndrome, a clustering of risk factors that put them on the path toward heart disease and diabetes in adulthood. This shocking statistic represents some of the first concentrated efforts to define and measure metabolic syndrome in children and adolescents - a necessary starting point for combating the problem, but one that has proven even trickier in youth than it has been in adults.

With the number of obese children in the United States rising at an alarming rate, pediatricians, family practitioners and researchers are concerned about what it means to for children's future health. The U.S. cholesterol guidelines have defined the metabolic syndrome for adults who have a cluster of risk factors, including increased waist circumference (central adiposity), hypertension (or elevated blood pressure), low HDL cholesterol, elevated triglycerides and an elevated fasting glucose. Even though these same components can be found in children, they have not been developed into a universal definition or diagnosis. In fact, they have only recently gained attention with the first publication on the syndrome by Stephen Cook, M.D., M.P.H., assistant professor of Pediatrics at the University of Rochester Medical Center, in 2003, which was based on national data from 1988 to 1994.

In the summer of 2006, a handful of national experts were convened by the National Institutes of Health with a task to define the metabolic syndrome for children and adolescents. The Pediatric Metabolic Syndrome Working Group (PMSWG) chose to tackle this problem affecting overweight and obese youth, tapping Cook to participate. The National Institute of Child Health and Human Development, National Heart, Lung, and Blood Institute, National Institute of Diabetes and Digestive and Kidney Diseases and the National Institutes of Health Office of Rare Diseases sponsored the conference.

As part of the committee, Cook performed a study, published with a collection of reports from the working group in February's Journal of Pediatrics, which analyzes how many teens in the U.S. could be considered to have the metabolic syndrome based on four different definitions of it.

Based on the most recently available data from the National Health and Nutrition Examination Survey from 1999 to 2002, the study shows that the definition Cook developed in Rochester (a waist circumference at or above the 90th percentile for age and sex; blood pressure at or above the 90th percentile; a high triglyceride level at or above 10 mg/dL; a low HDL cholesterol level at or above 40 mg/dL; and an impaired glucose metabolism at or above 100 mg/dL), reveals that 2.9 million teens - 9.4 percent of teens overall, and over a third of obese teens - meet the definition of the metabolic syndrome.

The original work by Cook and colleagues published in 2003 showed only 4 percent of teens meet this definition and that the increased prevalence is driven by the rise in obesity.

Using two other well-reported definitions with more stringent cut points, the study also reports rates as low as 2 percent (or 600,000 teens); using analyses that apply the U.S. adult definitions, it reported rates of 1.8 million teens -5.8 percent of all teens, and 25 percent of obese teens.

"Even if there is no consensus on a pediatric-specific definition, the fact that 1 in 4 obese teens meet the adult definition for this clustering of cardiovascular disease risk factors is enough of a concern," said Cook, who is a pediatrician and adult-internist at Golisano Children's Hospital at Strong. "Many longitudinal studies have shown that adults with this definition are at increased risk for developing type 2 diabetes, heart disease and dying prematurely from heart disease."

While one goal of the committee was to define the metabolic syndrome in pediatric populations, the bigger picture was to recognize the importance of obesity on cardiovascular risk for pediatric populations.

"We are not saying that adolescents who meet a definition for metabolic syndrome are going to develop diabetes or have a heart attack in the next few years, but some of the longitudinal studies presented at this meeting showed they were at very high risk for developing diabetes or heart disease in their 30s," Cook said. "When you consider all the success we've had with lowering the death rate from heart disease for middle aged and older adults, it's really disheartening to see actual data showing heart disease going up in young adults."

Cook said there have been advances in technology, pharmaceuticals and tremendous public health victories seen with reductions in tobacco use and exposure, so the increased rates in cardiovascular risk factors in young adults must be considered "the first wave of severe consequences of the modern obesity epidemic."

January 25, 2008
University of Rochester Medical Center
http://www.brightsurf.com/news/headlines/35557/Metabolic_syndrome_affects_nearly_1_in_10_US_teens.html

Christmas Blessings for all!

Christmas Blessings for all!