All Posts tagged clinical

Vegetarian diet helps with kidney disease

Chronic kidney disease (CKD) patients who consume a diet high in vegetables rather than meat may prevent the accumulation of toxic phosphorus levels, according to a study published online Dec. 23 in the Clinical Journal of the American Society of Nephrology.Sharon M. Moe, M.D., of the Indiana University School of Medicine in Indianapolis, and colleagues conducted a crossover trial in nine patients with a mean estimated glomerular filtration rate of 32 ml/min to compare vegetarian and meat diets containing equivalent nutrients prepared by clinical research staff.

The investigators found that one week of a vegetarian diet led to lower serum phosphorus levels, decreased phosphorus excretion in the urine, and reduced fibroblast growth factor-23 levels compared with a meat diet, despite equivalent protein and phosphorus concentrations in the two diets.

“In summary, this study demonstrates that the source of protein has a significant effect on phosphorus homeostasis in patients with CKD. Therefore, dietary counseling of patients with CKD must include information on not only the amount of phosphate but also the source of protein from which the phosphate derives,” the authors write.

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Fruit & Veg may not help allergy

Eating more fruits and vegetables may not protect children from developing allergies, according to a large Swedish study that questions earlier hints of benefit. Fruits and vegetables are rich in antioxidants, which are thought to reduce airway inflammation. So recent studies reporting less asthma, wheezing and hay fever among children who consumed more produce appeared to make sense.

But not all research has found that link, and the studies that did may have had a surprising flaw, said Helen Rosenlund of Karolinska Institutet in Stockholm, who led the new study. She said some proteins in fruits like apples and pears resemble the pollen parts that trigger hay fever, meaning that kids might react to both. In other words, existing allergies may have caused them to eat around the produce, rather than the other way around. “This could confuse research findings,” explained Rosenlund, “falsely suggesting that diets with fewer fruits and vegetables result in more allergic disease.”

To find out if this was the case, Rosenlund and her colleagues looked at data on nearly 2,500 eight-year-olds who had participated since birth in a larger Swedish study. Based on blood tests and questionnaires filled out by parents, the researchers found that seven percent of the children had asthma. The rates of hay fever and skin rashes were more than twice as high. The average child ate between one and two servings of fruit, and between two and three servings of vegetables each day.

At first glance, some produce did seem helpful: Kids with the biggest appetite for fruit had less than two-thirds the odds of developing hay fever than those who ate the least amount. Apples, pears and carrots appeared to be particularly helpful, the researchers report in the Journal of Allergy and Clinical Immunology, but there was no such link for vegetables overall. However, it turned out that half the children with hay fever were sensitive to birch tree pollen, one of the pollens known to resemble the proteins in apples and carrots. And sure enough, after the team repeated their analysis excluding the 122 kids with food-related allergy symptoms, the hay fever link disappeared as well. “Fruits do not seem to offer protection against allergic if diet modifications are considered,” say Rosenlund.

The researchers say more studies are needed, particularly in other parts of the world that may have a different variety of allergy triggers, or allergens. And they advise those studies should not forget to look at how allergies might influence what participants eat. “Studying diet it is not so easy when it comes to the relation with allergic disease,” Rosenlund said, “because it is such a complex disease pattern.”

SOURCE: bit.ly/g3DpI7 The Journal of Allergy and Clinical Immunology, online January 10, 2011.

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Studies support 3 glasses of milk daily

Individuals who drink three glasses of milk a day decrease their risk of cardiovascular disease by 18 percent, according to new research published in the American Journal of Clinical Nutrition.Researchers at Wageningen University and Harvard University examined 17 studies from the United States, Europe and Japan and found no link between the consumption of regular or low fat dairy and any increased risk of heart disease, stroke or total mortality. “Milk and dairy are the most nutritious and healthy foods available and loaded with naturally occurring nutrients, such as calcium, potassium and protein, to name a few,” said Cindy Schweitzer, technical director of the Global Dairy Platform. “It's about going back to the basics; maintaining a healthy lifestyle doesn't have to be a scientific equation.”

Schweitzer said during the past three decades as research sought to understand influencers of cardiovascular disease, simplified dietary advice including consuming only low fat dairy products emerged. However, in 2010 alone, a significant amount of new research was published from all over the world, supporting the health benefits of dairy. From dispelling the myth that dairy causes heart disease, to revealing dairy's weight loss-benefits, the following is a roundup of select dairy research conducted in 2010:

  • U.S. researchers examined 21 studies that included data from nearly 350,000 and concluded that dietary intakes of saturated fats are not associated with increases in the risk of either coronary heart disease or cardiovascular disease. The study was published in the American Journal of Clinical Nutrition.
  • A study published in the American Journal of Epidemiology examined 23,366 Swedish men and revealed that intakes of calcium above the recommended daily levels may reduce the risk of mortality from heart disease and cancer by 25 percent.
  • An Australian study published in the European Journal of Clinical Nutrition concluded that overall intake of dairy products was not associated with mortality. The 16-year prospective study of 1,529 Australian adults found that people who ate the most full-fat dairy had a 69-percent lower risk of cardiovascular death than those who ate the least.
  • A Danish study published in Physiology & Behavior concluded that an inadequate calcium intake during an energy restricted weight-loss program may trigger hunger and impair compliance to the diet.
  • An Israeli study published in the American Journal of Clinical Nutrition showed that a higher dairy calcium intake is related to greater diet-induced weight loss. The study sampled more than 300 overweight men and women during two years and found those with the highest dairy calcium intake lost 38-percent more weight than those with the lowest dairy calcium intake.

The amount of dairy recommended per day varies by country and is generally based on nutrition needs and food availability. “In the US and some European countries, three servings of dairy foods are recommended daily, said Dr. Schweitzer.”

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Denufosol improves Cystic Fibrosis in clinical trials

Cystic fibrosis is a genetic disease that causes a thick, sticky mucus to build up in the lungs and digestive tract. A clinical trial of a new drug called denufosol found that those given the medication for six months prevented some of the accumulation and improved performance on lung tests.

The Cystic Fibrosis Foundation estimates that about 30,000 children and adults in the United States have the condition that clogs the lungs and leads to life-threatening lung infections. The mucus also obstructs the pancreas and stops natural enzymes from helping the body break down and absorb food.

Cystic fibrosis is caused by a genetic mutation that disrupts the cystic fibrosis transmembrane regulator (CFTR) protein, an ion channel. Denufosol tetrasodium inhalation solution works by correcting ion transport in patients to enhance airway hydration and mucus clearance by increasing chloride secretion, inhibiting sodium absorption and increasing ciliary beat frequency.

Frank J. Accurso MD of the University of Colorado and colleagues included about 350 children with cystic fibrosis aged five and older in the study called TIGER-1, The Transport of Ions to Generate Epithelial Rehydration. All had a forced expiratory volume (FEV1) at least 75% of normal, indicating normal to mildly impaired lung function characteristic of early cystic fibrosis.

The patients were randomized to receive either 60 milligrams of inhaled denufosol three times daily or a matching placebo for 24 weeks. This was followed by another 24-week open-label safety extension phase.

The patients on the new medication had increase in FEV1 of 0.048 L, approximately 2% over baseline. In addition, the researchers found further lung improvement by 0.115L by the end of the open-label phase. The placebo group, when switched over to denofusol in the open-label phase, also improved by a mean 0.078 L in FEV1.

Big improvements weren't expected, says Accurso, because the drug is primarily designed to prevent or delay loss of lung function rather than act as a rescue therapy.

Denufosol appeared to be safe without serious adverse events or impaired growth of the young patients, suggesting it could be suitable as an early intervention. Intervention for cystic fibrosis early in its course has the potential to delay or prevent progressive changes that lead to irreversible airflow obstructions, the researchers say in their study published in the American Journal of Respiratory and Critical Care Medicine.

A second phase III trial, which is called TIGER-2, is ongoing which will incorporate a longer placebo-controlled treatment phase. Inspire Pharmaceuticals is targeting a potential US commercial launch of the drug for 2012, pending FDA approval.

Source reference:
Accurso FJ, et al “Denufosol Tetrasodium in Patients with Cystic Fibrosis and Normal to Mildly Impaired Lung Function” Am J Respir Crit Care Med 2011.

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Wholegrains help lower blood pressure

Starting the morning with a bowl of porridge and eating a whole-grain sandwich at lunchtime can help cut the risk of high blood pressure, according to new research. A study carried out by scientists from Aberdeen University which involved more than 200 volunteers revealed that eating three portions of whole-grain foods every day lowers the risk of high blood pressure, a major risk factor for heart disease and stroke. A good deal of research has suggested that a whole-grain diet is good for your health, but this study is one of the first to test the theory in a well-designed clinical trial.

Volunteers in the study ate three servings a day of whole-grain foods, which were either wheat, or a mixture of both wheat and oats. The whole-grain diets were compared with one that contained the same amounts of refined cereals and white bread. The study used foods widely available in supermarkets to make the diet easy to follow, without having to make any changes to their usual lifestyle. Apart from the whole-grain and the equivalent refined cereal foods, the volunteers were encouraged to continue with their normal food choices.

Dr Frank Thies, senior lecturer at The Rowett Institute of Nutrition and Health, who led the study, said: “We observed a decrease in systolic blood pressure of 5-6 mm Hg in the volunteers who ate the whole-grain foods, and this effect is similar to that you might expect to get from using blood pressure-lowering drugs. “This drop in systolic blood pressure could potentially decrease the incidence of heart attack and stroke disease by at least 15 and 25 per cent respectively. The scientists also added that wholegrain wheat and oat-based recipes should be on everyone's festive menu this Christmas.

The findings are published in the American Journal of Clinical Nutrition.

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US NIAID Issues Food Allergy Management Guidelines

A coordinating committee representing 34 professional organizations, advocacy groups and federal agencies oversaw the development of the guidelines. The coordinating committee selected a 25-member expert panel, chaired by Joshua Boyce, M.D., co-director of the Inflammation and Allergic Disease Research Section at Boston's Brigham and Women's Hospital. The panel used an independent, systematic literature review of food allergy and their own expert clinical opinions to prepare draft guidelines. Public comments were invited and considered as well during the development of the guidelines.

“These guidelines are an important starting point toward a goal of a more cogent, evidence-based approach to the diagnosis and management of food allergy,” says Dr. Boyce. “We believe that they provide healthcare professionals with a clear-cut definition of what constitutes a food allergy and a logical framework for the appropriate use of diagnostic testing and accurate interpretation of the results.”

Additional topics covered by the guidelines include the prevalence of food allergy, natural history of food allergy and closely associated diseases, and management of acute allergic reactions to food, including anaphylaxis, a severe whole-body reaction. They also identify gaps about what is known about food allergy.

“The food allergy guidelines provide a rigorous assessment of the state of the science, and clearly identify the areas where evidence is lacking and where research needs to be pursued,” says Daniel Rotrosen, M.D., director of the Division of Allergy, Immunology and Transplantation at NIAID. “This information will help shape our research agenda for the near future.”

Food allergy has become a serious health concern in the United States. Recent studies estimate that food allergy affects nearly 5 percent of children younger than 5 years old and 4 percent of teens and adults. Its prevalence appears to be on the rise. Not only can food allergy be associated with immediate and sometimes life-threatening consequences, it also can affect an individual's health, nutrition, development and quality of life. While several potential treatments appear promising, currently no treatments for food allergy exist and avoidance of the food is the only way to prevent complications of the disease.

More information on the guidelines may be found at http://www.niaid.nih.gov/topics/foodAllergy/clinical/Pages/default.aspx

 

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Tylenol linked to asthma

A new study shows that adolescents who take acetaminophen, better known as Tylenol, have a higher risk of asthma, allergic nasal conditions and the skin disorder eczema.

Acetaminophen is widely viewed as a very safe drug—one reason why hospitals use it routinely as a painkiller instead of aspirin or ibuprofen. The major problem associated with it is liver damage caused by overdoses. Recently, however, there has been a growing drumbeat about possible dangers from the drug. One study, for example, found that acetaminophen increased the risk of hearing loss in men. And some others have hinted that the drug is linked to asthma in newborns whose mothers used the drug during pregnancy and in young children exposed to it.

The new findings were reported in the American Journal of Respiratory and Critical Care Medicine by researchers in the International Study of Asthma and Allergies in Childhood. The team, headed by epidemiologist Richard Beasley of the Medical Research Institute in Wellington, New Zealand, gave written questionnaires to 322,959 13- and 14-year-olds in 50 countries exploring their use of acetaminophen, other drugs, and asthma symptoms. They were also shown a video containing five scenes of clinical asthma and asked whether they had experienced any symptoms similar to those shown. About 73% of the teens said they had used acetaminophen at least once in the previous year and 30% said they had used it monthly.

Taking into account maternal education, smoking, diet and siblings, the team found that those subjects who had used the drug at least once per year were 43% more likely to have asthma, while those who used it at least monthly were 2.5 times as likely to suffer from the condition. The risk of rhinoconjunctivitis (a severe nasal congestion) was 38% higher for those who used it once per year and 2.39 times as high for those who used it at least monthly. The comparable increases in risk for eczema were 31% and 99%, respectively.

Overall, the increased risk of asthma associated with acetaminophen was 41%, the authors found. That could, at least in part, explain why there has been an increase in the prevalence of asthma in the 50 years since the drug was introduced. Given the widespread use of the drug, it could also represent a large public health problem.

But—and it is a very big but—the study shows only an association, not causality. That could only be determined by a randomized clinical trial, which the authors recommend. Furthermore, the study relies on the recall of teenagers. Recall is notoriously inaccurate in adults, and it is probably worse in adolescents, clouding the results. For the time being then, you can probably continue to feel comfortable giving the drug to your children.

In a statement, McNeil Consumer Healthcare, which manufactures Tylenol, said that the drug “has over 50 years of clinical history to support its safety and effectiveness” and that no clinical trial has demonstrated that the drug causes asthma.

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Meat Lovers Gain More Weight Over Time

Heavy meat-eating could be part of an overall unhealthy diet or unhealthy lifestyle, Vergnaud and her team note.

Because meat is “energy-dense” (meaning it packs more calories by weight than veggies or fruits, for example), it could influence appetite control, they add. However, the researchers did attempt to take overall dietary pattern into account, as well as education, physical activity level, whether or not people smoked, and their total calorie intake.

Based on the findings, a person who cut their meat consumption by 250 grams daily (about a half-pound) could conceivably reduce their 5-year weight gain by around 4 pounds.

While this is a relatively small amount of weight from an individual's point of view, the researchers add, gaining an average of 4 pounds in 5 years “could have an important effect from a population perspective.”

“More importantly,” they add, “our results do not support that a high-protein diet prevents obesity or promotes long-term weight loss, contrary to what has been advocated.”

SOURCE: American Journal of Clinical Nutrition, online June 30, 2010.

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Benefits of Calcium and Vitamin D

Led by researchers at Copenhagen University in Denmark, Robbins and an international team of colleagues analyzed the results of seven large clinical trials from around the world to assess the effectiveness of vitamin D alone or with calcium in reducing fractures among people averaging 70 years or older. The researchers could not identify any significant effects for people who only take vitamin D supplements.

Among the clinical trial results analyzed was Robbins' WHI research, which was part of a 15-year, national program to address the most common causes of death, disability and poor quality of life in postmenopausal women such as cardiovascular disease, cancer and osteoporosis. Those trials were primarily designed to study the effect of calcium and vitamin D supplementation in preventing hip fractures, with a secondary objective of testing the supplements on spine and other types of fractures, as well as on colorectal cancer. The results were published in the Feb. 16, 2006 edition of the New England Journal of Medicine.

Fractures are a major cause of disability, loss of independence and death for older people. The injuries are often the result of osteoporosis, or porous bone, a disease characterized by low bone mass and bone fragility. The National Osteoporosis Foundation estimates that about 10 million Americans have osteoporosis; 80 percent of them are women. Four of 10 women over age 50 will experience a fracture of the hip, spine or wrist in their lifetime, and osteoporosis-related fractures were responsible for an estimated $19 billion in health-related costs in 2005.

“This study supports a growing consensus that combined calcium and vitamin D is more effective than vitamin D alone in reducing a variety of fractures,” said Robbins. “Interestingly, this combination of supplements benefits both women and men of all ages, which is not something we fully expected to find. We now need to investigate the best dosage, duration and optimal way for people to take it.”

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Wine Does Not Boost Heart Health

Where did the story come from?

The study was carried out by researchers from Hopital de la Pitie and the IPC (Investigations Preventives et Cliniques) Center in Paris, France. It was funded by French public health bodies, the Caisse Nationale d'Assurance Maladie (CNAM) and the Caisse Primaire d'Assurance Maladie de Paris (CPAM-Paris). The study was published in the peer-reviewed European Journal of Clinical Nutrition.

This research was generally covered well by the media, with most stories making it clear that alcohol had not been found to improve health, but rather that people who drank moderately also had better health and social status. The messages from some headlines were more misleading, however, with Metro claiming that “Drinking wine makes you happier” and The Sun suggesting that booze “aids the body”.

The Daily Mail featured particularly clear coverage, with both its headline and article clearly explaining that the good health of moderate drinkers is more likely to be down to healthier diet, exercise and work–life balance rather than any supposed benefits of alcohol.

What kind of research was this?

This cross-sectional study analysed the relationship between alcohol intake, other cardiovascular risk factors and health status in a large French population. The aim was to evaluate potential confounding factors that may be behind the supposed cardiovascular benefits of alcohol.The researchers looked at data on the clinical and biological characteristics of nearly 150,000 people, which were gathered as part of a large ongoing cohort study.

Several observational studies have shown an association between moderate alcohol intake and a lower risk of cardiovascular disease. The lower risk is often attributed to alcohol having beneficial effects on blood levels of lipids, such as cholesterol, or on other factors, such as the effect of the antioxidants in alcoholic drinks. The researchers point out that addressing the underlying message implied by previous data, that moderate alcohol intake is good for health, is particularly important in France, which has one of the highest average individual alcohol intakes in the world.

The researchers also stress that the findings from observational studies need to be viewed with caution, so they assessed a number of key factors not taken into account by previous research. These key, but generally unexplored, factors included mental wellbeing, subjective health status and social factors.

What did the research involve?

All the people in the study underwent a clinical examination between 1999 and 2005, which included measurements blood pressure, waist circumference, cholesterol, respiratory function and heart rate. Also recorded were tobacco use, physical activity, personal medical history, current medications, social status and occupation. Stress and depression scores were assessed using validated questionnaires, and people were also asked to estimate their own health status.

Alcohol intake was quantified as the number of standardised glasses of pure alcohol (10g a glass) consumed each day, and different types of alcoholic drink were also recorded. People were divided into four groups according to their alcohol consumption: never, low (less than 1 glass a day), moderate (1-3 glasses a day) or high (more than 3 glasses a day). Former drinkers were analysed as a separate group. Established statistical techniques were used to analyse the relationship between alcohol intake and all the other factors. The results were adjusted to account for the influence of age and were also broken down by gender.

What were the basic results?

The researchers found that:

13.7% of men and 23.9% of women did not drink at all. Total alcohol intake increased with age in both sexes. Apart from people aged under 30, most people drank wine. They found that women who drank moderate amounts of alcohol had lower body mass index, waist circumference, blood pressure and blood lipids, including LDL (“bad”) cholesterol. Men who drank moderately had lower body mass index, heart rate, blood pressure, some blood lipids (triglycerides) and fasting glucose levels, plus lower stress and depression scores.

Men who drank little or moderately were also more likely to have better self-assessed health status, social status and respiratory function. In both sexes, alcohol intake was strongly associated with higher levels of HDL (“good”) cholesterol, a finding which was independent of the type of alcoholic beverage consumed.

How did the researchers interpret the results?

The researchers concluded that moderate and low consumption of alcohol was strongly associated with several clinical, social and biological characteristics that point to overall better health status and a lower risk of cardiovascular disease. Importantly, they say, few of these factors seem causally related to alcohol consumption.

They point out that social status was “strikingly different” across the groups, with moderate alcohol consumption being a “powerful general indicator” of social status. Risk factors that have never been taken into account before, such as social and professional status, anxiety score and heart rate, were all more favourable in moderate consumers.

Their results, they say, raise the possibility that the seemingly protective effects of moderate alcohol consumption found in previous research may have been due to the researchers not fully taking account of possible confounders.

Conclusion

This research adds a note of caution to the results of previous studies. It concludes that moderate alcohol consumption may be a marker of better health and lower cardiovascular risk rather than a cause of these improvements.

The study's strength is that it is based on a relatively large cohort and that standardised, validated methods were used to collect clinical and biological information. The main weakness of the study is its cross-sectional design, which means that people were not followed up over time to see if they developed disease. This also meant that deaths from heart disease, for example, were not reported.

Another limitation is that alcohol intake was based on self–reported data. This leaves a possibility for error as accurate recall of alcohol consumption is notoriously hard in this type of study. Future research in this area will ideally follow people over time and carefully measure possible risk factors to establish whether alcohol has any direct, causal role in protection from heart disease.

Overall, this study has implications for public health. As the researchers say, its results suggest that it is premature to promote alcohol consumption as an independent factor for cardiovascular protection, as some have proposed based on past research.

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