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Calcium-Channel Blockers No Better Than Diuretics for Treating Hypertension

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Diuretics are just as effective as calcium-channel blockers, alpha-blockers or angiotensin-converting enzymes (ACE) inhibitors when treating hypertension among patients with metabolic syndrome, according to a report in the Archives of Internal Medicine.

Metabolic syndrome is defined as hypertension with at least two of the following factors: high glyceride levels, diabetes, a body mass index (BMI) of at least 30, and low levels of "good cholesterol." Patients with metabolic syndrome are at high risk for complications of cardiovascular disease.

While some alpha-blockers, ACE inhibitors and calcium channel blockers have more favorable short-term effects on blood glucose or blood cholesterol levels, they have been promoted over beta-blockers and diuretics to treat patients with metabolic syndrome.

Researchers at Case Western Reserve University, Cleveland, analyzed data from the Antihypertensive and Lipid- Lowering Treatment to Prevent Heart Attack Trial (ALLHAT). 42,418 hypertension patients with at least one other risk factor for heart disease were randomly picked to take either a diuretic (chlorthalidone -15,255 patients), a calcium channel blocker (doxazosin mesylate – 9,061 patients), or an ACE inhibitor (lisinopril – 9,054 patients).

Other drugs could be added if necessary to control blood pressure, and patients were checked for an average of 4.9 years for all drugs administered except the alpha-blocker. Followup of this drug was discontinued after 3.2 years, because increased rates of cardiovascular disease were noted, including nearly twice the rate of heart failure, compared with the group taking diuretics. A total of 23,077 ALLHAT participants (54.4%) met criteria for metabolic syndrome.

"No differences were noted among the four treatment groups, regardless of race or metabolic syndrome status for the primary end point (non-fatal myocardial infarction [heart attack] and fatal coronary heart disease)," the authors write.

Among patients with the metabolic syndrome (7,327 black and 15,750 white patients), the calcium channel blocker, ACE inhibitor and alpha-blocker had higher rates of heart failure compared with the diuretic; the ACE inhibitor and the alpha-blocker also had an increased risk of combined cardiovascular disease.

"The lack of benefit of the agents with the most favorable metabolic profile (i.e., ACE inhibitors and alpha-blockers) was especially marked in the black participants with metabolic syndrome," the authors write. "The magnitude of the excess risk of end-stage renal disease (70 percent), heart failure (49 percent) and stroke (37 percent) and the increased risk of combined cardiovascular disease and combined coronary heart disease strongly argue against the preference of ACE inhibitors over diuretics as the initial therapy in black patients with metabolic syndrome. Similar higher risk was noted for those randomized to the alpha-blocker vs. the diuretic."

"These findings fail to provide support for the selection of alpha-blockers, ACE inhibitors, or calcium channel blockers over thiazide-type diuretics to prevent cardiovascular or renal outcomes in patients with metabolic syndrome, despite their more favorable metabolic profiles," the authors conclude.

This study was supported by a contract from the National Heart, Lung, and Blood Institute and by Pfizer Inc. (ALLHAT).

Source: Arch Intern Med. 2008;168[2]:207-217.

Sedentary Lifestyle Likely Contributes to Aging, Says Study

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People whose leisure time is filled with physical activity appear to be biologically younger than people with a sedentary lifestyles, according to a recent report. “A sedentary lifestyle increases the propensity to aging-related diseases and premature death. Inactivity may diminish life expectancy not only by predisposing to age-related diseases but also because it may influence the aging process itself,” the authors write.

Questionnaires on physical activity level, smoking habits, and socioeconomic status were sent to 2,401 caucasian twins. The twins also gave a blood sample from which DNA was extracted. Also checked were the length of telomeres in the twins’ white blood cells. Telomeres progressively shorten over time and may serve as a measurement of biological age.

People who were less physically active in their leisure time had shorter leukocyte telomeres than those who were more active. “Such a relationship between leukocyte telomere length and physical activity level remained significant after adjustment for body mass index, smoking, socioeconomic status and physical activity at work,” the authors write, “and the most active subjects had telomeres the same length as sedentary individuals up to 10 years younger, on average.”

Sedentary lifestyles can also shorten telomeres by allowing oxidative stress. Physical activity may reduce psychological stress, lessening its effect on telomeres and the aging process.

“The U.S guidelines recommend that that 30 minutes of moderate-intensity physical activity at least five days a week can have significant health benefits’ the authors write. “Our results underscore the vital importance of these guidelines. They also show that adults who partake in regular physical activity are biologically younger than sedentary individuals.”

Source: Arch Intern Med. 2008;168[2]:154-158.

Snoring May be Linked to Chronic Bronchitis

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According to a report in the January issue of Archives of Internal Medicine, chronic bronchitis is more likely to develop in habitual snorers.

From 2001 to 2003, Inkyung Baik, Ph.D., of the Korea University Ansan Hospital, Republic of Korea, and colleagues monitored 4,270 people—52% men, 48% women. The men and women gave demographic information, health conditions, family disease history and lifestyle, and how often they snored. They were re-interviewed every year through 2006, and were classified as developing chronic bronchitis if they reported having a cough and sputum on most days for at least three months per year, for at least two years.

314 people developed chronic bronchitis during four years of follow-up. Individuals who snored regularly were more likely to develop bronchitis than those who did not.

Source: Arch Intern Med. 2008;168[2]:167-173

Childrens’ Brain Development Not Affected By Amalgam Fillings

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Dental amalgam fillings do not adversely affect brain development in children, or their neurological status, according to a recent report published in the Journal of the American Dental Association. Dental amalgam contains elemental mercury, plus silver, copper, tin, and zinc to form a stable alloy, and has long been used to save dacaying teeth.

A seven year study of 507 Portuguese children, aged 8 through 12 years, who had received amalgam or resin-based composite fillings, conducted routine neurological tests for hard and soft neurological damage to the children, and for the presence of tremor.

There was no difference between the two groups of children after seven years with regard to the presence or absence of tremor. Neither was there any difference in the presence, absence or severity of soft signs. And since these were healthy children, any neurological sot signs diminished as they grew older.

"Even at the levels of amalgam exposure in this study (a mean of 7.7-10.7 amalgam surfaces per subject across the seven years of follow-up)," the authors write, "[we] conclude that exposure to mercury from dental amalgam does not adversely affect neurological status.

"These data indicate the absence of a generalized negative effect on children’s nervous system functions stemming from the presence of dental amalgam," they continue, "and while we cannot rule out potential adverse reactions in individual children, we found no indications of any."

Source: American Dental Association (ADA)

Heart Disease Appears Early in Obese Children

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A new study published in the Winter 2007 issue of the Journal of Cardiometabolic Syndrome finds that early signs of heart disease  appear in obese children or in children at risk for obesity.

"Based on this study, these subtle markers can help us predict who could be at risk for heart disease and heart attacks," said Angela Sharkey, M.D., associate professor of pediatrics at Washington University School of Medicine and a pediatric cardiologist at St. Louis Children’s Hospital.

Nationally, 19% of children in the 6 to 11 age group and 17% of children aged 12 to 19 are overweight, which amounts to an epidemic says the Centers for Disease Control (CDC). Being overweight during childhood means a higher risk of adult obesity, with the possibility of diabetes, elevated blood pressure and heart disease.

Dr. Sharkey and Dr. Steven M. Lorch of the University of Texas Health Science Center at Houston reviewed data from 168 children aged 10 to 18 who suffer from heart murmur, chest pain, acid reflux or hiogh blood cholesterol. CDC guidelines for BMIA indicated that 33 patients were obese, 20 had a BMIA putting them at risk for obesity, and 115 were considered normal.

The obese children’s hearts were evaluated by Drs. Sharkey and Lorch using a new tissue Doppler imaging technique called vector velocity imaging. This tracks the movement of the heart’s muscular wall: changes in the rate of motion of heart muscle were averaged within each group and compared to the normal rate of motion.

"In the patients who are obese, the rate of motion of heart muscle changed," Sharkey said. "As a child’s BMIA increases, we see alterations in both the relaxation and contraction phase of the heartbeat. Many of these changes that have been seen in adults were assumed to be from long-standing obesity, but it may be that these changes start much earlier in life than we thought."

The results of the study, said Dr. Sharkey, help physicians in counseling patients and parents about the risks of obesity and the importance of achieving a normal weight.

"Even in teenagers, obesity leads to decreased myocardial performance and abnormal diastolic function," she said.

Source: Washington University in St. Louis

Hormonal Components in Some Dietary Supplements May Promote Progression of Prostate Cancer

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A recent study by researchers at UT Southwestern Medical Center concludes that hormonal components in over-the-counter dietary supplements may actually accelerate the progression of prostate cancer, at the same time decreasing the effectiveness of anti-cancer drugs.

The study, published in the January 11, 2008 issue of Clinical Cancer Research, strongly advises patients to tell their doctor if they are taking any herbal or hormonal dietary supplements. It is also recommended that the use of such supplements is routinely documented as part of the patient’s health assessment.

"Physicians need to ask their patients not only about the prescription drugs they may be taking, but—perhaps even more importantly—about the over-the-counter drugs and supplements, which may have a profound impact on certain health conditions," said Dr. Claus Roehrborn, chairman of urology at UT Southwestern and one of the study’s authors.

The research commenced when two UT Southwestern patients developed aggressive prostate cancer mere months after starting daily use of the same dietary supplement—one for muscular development, the other for sexual enhancement. When Dr. Roehrborn and Dr.Shariat, a resident in urology and the study’s lead author, and their colleagues analyzed the product (not named in the study) they found that the label listed ingredients not present, misrepresented the concentrations of the ingredients that were present, and did not list all the steroid hormones in the product.

Hormone analysis showed the presence of testosterone and estradiol, a sex hormone. Testing of the product’s effect on human prostate cancer-cell lines revealed that the product was a more potent stimulator of cancer-cell growth than testosterone. Use of the anti-cancer drug bicalutamide, in increasing concentrations, proved ineffective.

"Bicalutamide is an oral nonsteroidal anti-androgen used to treat prostate cancer," Dr. Shariat said. "The fact that this supplement caused the drug to be less effective is very troubling." The researchers filed an adverse event report with the Food and Drug Administration, which in turn issued a warning letter to the manufacturer, who withdrew the product from the market.

"Unlike prescription and over-the-counter drugs, the law does not require nutritional supplements to undergo pre-market approval for safety and efficacy," Dr. Shariat said. "The current FDA regulatory system provides little oversight or assurances that dietary supplements will have predictable pharmacological effects or even that product labels provide accurate information for consumers."

It is estimated that 42% – 69% of U.S. adults use dietary supplements, at an estimated cost of $34 billion. People often use supplements in the belief that these natural products are safe and drug-free. The sale of androgenic steroids meanwhile is increasing exponentionally, with 2004 sales U.S. expenditures on testosterone supplements totalling an estimated $425 million.

"Given that testosterone supplements are in high demand, there is significant concern that supplements, in addition to the one we evaluated, may pose an urgent human health risk," Dr. Shariat said.

Researchers from Baylor College of Medicine in Houston also contributed to the research.

"The current FDA regulatory system provides little oversight or assurances that dietary supplements will have predictable pharmacological effects or even that product labels provide accurate information for consumers."

Many Doctors Inadequately Trained for Prescribing Medicine to Children

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Research published in Archives of Disease in Childhood suggests that inadequate training among healthcare professionals increases the risk of prescribing errors for childrens’ medicines. Children are especially vulnerable to mistaken prescribing because formulations are not designed specifically for them, and doses have to be individually figured.

Existing research revealed that junior doctors did not know what to prescribe for chest infections or anaphylaxis. The authors were able to find only two studies relevant to the teaching of prescribing skills, and these showed that the error rate fell after the introduction of specific techniques; but the conclusions did not show which had been most effective.

The survery generated a response rate of 57%, with 319 out of 559 questionnaires returned. They showed that training in the avoidance of mistakes in prescribing childrens’ medications was brief, and primarily veral with little practical training.

Eleven centers taught doctors how to complete a drug chart, with another seven reviewing common errors. Only one center offred a computer-based prescribing course showing the correct calculaton of drug doses. In thirteen centers the training amounted to a presentation by specialist pharmacists, of between 30 and 60 minutes, while another ten centers simply gave trainees an induction pack with written information. Only three centers tested prescribing competency.

This research may not present a complete picture of current prescribing training, say the authors, but meanwhile there are no national standards on the teaching of prescribing medicines for children. So that finding which teaching methods are most effective in reducing errors, if any, has geat mportance.

Source: (em>First Arch Dis Child 2007; doi: 10.1136/adc.2007.127761

Can Daily Aspirin for Heart Attack Prevention be Dangerous?

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Nearly 250,000 Americans may suffer from bleeding complications each year because they take an adult-sized aspirin daily to prevent heart attack, rather than baby aspirin. That is the conclusion of University of Kentucky heart disease researchers following a study that found that the commonly-prescribed 325 mg adult tablet may be more than many people need each day.

Published in the Journal of the American Medical Association, the study showed that doses higher than a baby aspirin (75 to 81 mg) are associated with increased risk of gastrointestinal bleeding and are no more effective at preventing cardiovascular events long-term.

Gill Heart Institute cardiologists and University of Kentucky College of Medicine faculty Dr. Charles Campbell, Dr. Steven R. Steinhubl and Dr. Susan Smyth, along with Dr. Gilles Montalescot of the Instjtut de Cardiologie-Centre Hospitalier Universitaire Pitié-Salpêtrière in Paris, France, systematically reviewed published data regarding clinical studies involving aspirin dosing. Even in patients with diabetes, who may be more difficult to treat, they found no large-scale studies that support higher doses of aspirin.

"While aspirin is an effective drug for the prevention of clots," said Campbell, lead author of the report, "the downside of aspirin therapy is an increased tendency for bleeding (particulary from the GI tract). We believe the minimum effective dose should be utilized (75-81 mg)." However, Campbell notes, "We also believe more study in this area is warranted to determine if the minimum dose is effective for everyone, or if dose should be adjusted from person to person."

Thirty-six percent of the adult population in the U.S. take 10 to 20 billion aspirin tablets annually to prevent clots, the main cause fo heart attacks and strokes.

"Patients should check with their doctor to be sure, but there is almost no one who needs to take more than 81 mg of aspirin a day for protection from heart attacks," Campbell said. Meanwhile, physicians face the challenge of identifying the best blood-thinning regimen for their patients.

Source: University of Kentucky

Gastric Inhibitory Polypeptide (GIP) Can Reverse Diabetes and Promote Weight Loss

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A new study was designed to find whether prolonged receptor antagonism using daily injections of GIP was capable of reversing diet-induced obesity and related metabolic abnormalities in an animal model.

The 8-week old mice selected for the study were given access to drinking water and a high fat diet—20% protein and 35% protein, percent of total energy 26.15kg/g. Control mice were fed a standard rodent maintenance diet—10% fat, 30% protein, 60% carbohydrate, percent of total energy of 12.99.

Before the study, mice were fed a high-fat diet for 160 days. Another set of mice were given a high-fat diet for 112 days before measuring circulating GIP and GLP-1 levels. For both samples, obesity and diabetes were unmistakably evident.

Among the key findings were that consumption of the high-fat diet produced progressive weight gain and elevations of plasma and gyrated hemoglobin, resulting in impaired insulin sensitivity and glucose intolerance within 10 days. (Pro3)GIP countered many of the detrimental effects of high fat diet on body weight and indices of glucose and lipid metabolism.

This study showed that blocking GIP activity using (Pro3)GIP in mice with established, high fat diet-induced obesity and diabetes results in significant weight loss, improvement of insulin resistance and amelioration of diabetes. These findings represent an interesting new approach to the treatment of obesity and metabolic disturbances.

Nigel Irwin, PH.D., of the research team said that possible parallels exist with the benefits of gastric bypass surgery in treating gross obesity and diabetes in people. In this procedure nutrients surgically bypass the area of the small intestine, resulting in a deficiency of circulating GIP.

Source: American Physiological Society (APS)

Hospitals Slow to Check Catheter-related Infections

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Twenty-five percent of Americans in hospital are given a urinary catheter, but a new study shows that hospitals are slow to prevent UTIs (urinary tract infections), which are the most common hospital acquired infections and represent 40% of such infections.

The study was published in the January issue of the journal Clinical Infectious Diseases by a team of safety experts from the University of Michigan Health System and the VA Ann Arbor Healthcare System, It shows that almost half of all hospitals do not have any way of knowing which patients currently have a catheter, and three quarters lack a system which tell them how long a patient has had a catheter, or whether one has been removed. Close to one third of hospitals do not monitor the UTI rates among their patients.

A method of reducing UTI rates and the time patients spend with catheters—
a simple daily reminder for doctors to check whether a catheter is needed—
is used by less than 10% of hospitals. “Until now, we haven’t had national data to tell us what hospitals are doing to prevent this common and costly patient-safety problem,” says lead author Sanjay Saint, M.D., MPH, the director of the U-M/VA Patient Safety Enhancement Program, and leader of several other studies on catheter-related issues. “Now that we have these data, it’s clear that there’s no one dominant practice that’s being used, including physician reminders, which have proven benefit and make a lot of common sense.”

Continues Saint, who is also a U-M professor of internal medicine and a research scientist at VA Ann Arbor, “The bottom line for hospitalized patients and their families is, if you have a catheter, ask the doctor or nurse every day if you really still need it.”

Source: University of Michigan Health System