MayoClinic.org - High-definition colonoscopy is much more sensitive than standard colonoscopy in finding polyps that could morph into cancer, say researchers at the Mayo Clinic campus in Florida.

They say their findings, presented at the annual meeting of the American College of Gastroenterology in San Diego, are not only important because a large group (2,430) of patients participated, but they resulted from the only study to date that has compared these two methods in a general clinical practice setting, among all the patients who needed a colonoscopy and with all the physicians who performed it.

“There hasn’t been a definitive trial to see whether high-definition (HD) colonoscopy detects more polyps or not, and this was a natural experiment, designed to ask if use of one endoscope or another makes a difference in day-to-day clinical practice,” says the study’s senior investigator, gastroenterologist Michael Wallace, M.D., a professor of medicine at the College of Medicine, Mayo Clinic.

“Based on these results, it appears that high-definition colonoscopy detects more precancerous polyps,” he says. This study - funded by the Mayo Clinic - was conducted between September 2006 and December 2007 when Mayo Clinic in Florida was switching its six colonoscopy procedure rooms from standard colonoscopy endoscopes to high-definition endoscopes.

An endoscope is the lighted tube inserted into the colon and rectum to look for, and remove, polyps. A high-definition endoscope uses both a high-definition video chip and HD monitors (like HD television) that increase the resolution of the image, Dr. Wallace says.

Patients were not assigned to one scope or the other. Instead, they were placed in whatever room was available and assigned a gastroenterologist who was on duty at the time. “So there was a natural randomization of patients to either standard or high-definition endoscopes, and physicians were not able to cherry-pick their patients,” Dr. Wallace says. “No doctors used high definition more than any other and, in this way, you can eliminate most of the variables that can bias results of a clinical trial.”

Researchers found that the rate of detection of adenomas - polyps that are likely to become cancerous - was 29 percent among patients who were scanned with high-definition endoscopes, versus 24 percent for those in which standard endoscopes were used.

“That is an increase of 20 percent,” Dr. Wallace says. “While that may seem small, in light of the 14 million colonoscopies that are performed each year, even small differences add up to important improvements.”

All three Mayo Clinic sites (Florida, Minnesota, and Arizona) now only use high-definition endoscopes to perform colonoscopies, Dr. Wallace says. Many clinics in the country have both kinds of endoscopes “so it will not be that hard to move to the newer, and better, technology,” he says.

Low vitamin D levels may account for nearly 60 percent of the elevated risk of end-stage renal disease (ESRD) in African Americans, according to a report in the December 2009 Journal of the American Society of Nephrology (JASN). “Our study adds to previous evidence linking vitamin D deficiency to the progression of kidney disease and the need for dialysis,” comments Michal L. Melamed, MD, of Albert Einstein College of Medicine (Bronx, NY). “It also explains a fair amount of the increased risk of ESRD in African Americans.” Vitamin D is obtained from sun exposure, food and food supplements.

Melamed and colleagues analyzed a nationwide sample of 13,000 Americans, including measurements of the vitamin D metabolite 25(OH)D [25-hydroxyvitamin D]. Medicare data were used to identify participants who eventually required dialysis therapy for ESRD. “We found that the participants with the lowest 25(OH)D levels were 2.6 times as likely to end up on dialysis compared to those with higher levels,” says Melamed.

The researchers then tested whether 25(OH)D levels could contribute to the higher risk of ESRD in African Americans, compared to whites. “African Americans have lower 25(OH)D levels and a higher risk of ESRD,” Melamed explains. “We found that 25(OH)D deficiency was responsible for about 58 percent of the excess risk for ESRD experienced by African Americans.”

Vitamin D deficiency is a very common problem in the United States. In recent years, studies have linked low vitamin D to many different health problems, including diabetes, high blood pressure, cancers, and heart disease. The new results add to previous evidence that low 25(OH)D levels are an important risk factor for ESRD. “This is another good reason to make sure that people get enough vitamin D,” Melamed adds.

Although it can’t prove any cause-and-effect relationship, the study also suggests that vitamin D deficiency is a key contributor to the high risk of ESRD in African Americans. More research is needed to confirm these findings, and to determine whether treatment to raise low vitamin D levels can help to preserve kidney function. “We are currently in the process of enrolling for a clinical trial of vitamin D repletion in patients with chronic kidney disease to further test these hypotheses,” says Melamed.

Dr. Melamed’s research is being presented during ASN Renal Week in October 2009. This poster presentation is entitled, “25-Hydroxyvitamin D Levels and Progressive Kidney Disease: Contribution to the Excess Risk of ESRD in Non-Hispanic Blacks” (Newswise).

The study entitled, “25-Hydroxyvitamin D Levels, Race, and the Progression of Kidney Disease,” is to be published in JASN, and online at http://jasn.asnjournals.org (doi 10.1681/ASN.2009030283).

Athletes - especially bodybuilders - who use anabolic steroids may gain muscle mass and strength, but they can destroy their kidney function and cause serious kidney damage, according to a paper being presented at the American Society of Nephrology’s 42nd Annual Meeting and Scientific Exposition in San Diego, CA. The findings indicate that the habitual use of steroids has serious harmful effects on the kidneys that were not previously recognized.

Reports of professional athletes who abuse anabolic steroids are increasingly common. Most people know that using steroids is not good for your health, but until now, their effects on the kidneys have not been known. Leal Herlitz, MD (Columbia University Medical Center) and her colleagues recently conducted the first study describing injury to the kidneys following long-term abuse of anabolic steroids. The investigators studied a group of 10 bodybuilders who used steroids for many years and developed protein leakage into the urine and severe reductions in kidney function. Kidney tests revealed that nine of the ten bodybuilders developed a condition called focal segmental glomerulosclerosis (FSGS), a type of scarring within the kidneys. This disease typically occurs when the kidneys are overworked. The kidney damage in the bodybuilders has similarities to that seen in morbidly obese patients, but appears to be even more severe.

When the bodybuilders discontinued steroid use their kidney abnormalities improved, with the exception of one individual with advanced kidney disease who developed end-stage kidney failure and required dialysis. Also, one of the bodybuilders started taking steroids again and suffered a relapse of severe kidney dysfunction.

The researchers propose that extreme increases in muscle mass require the kidneys to increase their filtration rate, placing harmful levels of stress on these organs. It’s also likely that synthetic steroids have direct toxic effects on the kidneys. “Athletes who use anabolic steroids and the doctors caring for them need to be aware of the potentially serious risks to the kidney,” said Dr. Herlitz (Newswise).

The study abstract, “Development of FSGS Following Anabolic Steroid Use in Bodybuilders,” (TH-PO163) is being presented during the American Society of Nephrology’s Annual Meeting and Scientific Exposition in San Diego, CA.

A diet high in fructose increases the risk of developing high blood pressure (hypertension), according to a paper being presented at the American Society of Nephrology’s 42nd Annual Meeting and Scientific Exposition in San Diego, California. The findings suggest that cutting back on processed foods and beverages that contain high fructose corn syrup (HFCS) may help prevent hypertension.

Over the last 200 years, the rate of fructose intake has directly paralleled the increasing rate of obesity, which has increased sharply in the last 20 years since the introduction of high fructose corn syrup. Today, Americans consume 30 percent more fructose than 20 years ago and up to four times more than 100 years ago, when obesity rates were less than 5 percent. While this increase mirrors the dramatic rise in the prevalence of hypertension, studies have been inconsistent in linking excess fructose in the diet to hypertension.

Diana Jalal, MD (University of Colorado Denver Health Sciences Center), and her colleagues studied the issue in a large representative population of US adults. They examined 4,528 adults 18 years of age or older with no prior history of hypertension. Fructose intake was calculated based on a dietary questionnaire, and foods such as fruit juices, soft drinks, bakery products, and candy were included. Dr. Jalal’s team found that people who ate or drank more than 74 grams per day of fructose (2.5 sugary soft drinks per day) increased their risk of developing hypertension. Specifically, a diet of more than 74 grams per day of fructose led to a 28 percent, 36 percent, and 87 percent higher risk for blood pressure levels of 135/85, 140/90, and 160/100 mmHg, respectively. (A normal blood pressure reading is below 120/80 mmHg.)

“These results indicate that high fructose intake in the form of added sugars is significantly and independently associated with higher blood pressure levels in the US adult population with no previous history of hypertension,” the authors concluded. Additional studies are needed to see if low fructose diets can normalize blood pressure and prevent the development of hypertension.

The study abstract, “Increased Fructose Intake is Independently Associated with Elevated Blood Pressure. Findings from the National Health and Nutrition Examination Survey (2003-2006),” will be presented during the American Society of Nephrology’s Annual Meeting and Scientific Exposition this week in San Diego, CA (Newswise).

JHSPH.edu - Children of mothers who had received an iron and folic acid supplement during pregnancy had dramatically reduced mortality through age 7, according to researchers at the Johns Hopkins Bloomberg School of Public Health. Researchers found that other supplement combinations, including the multiple micronutrient supplement, did not confer the same benefit. Nearly 40 percent of pregnant women worldwide are estimated to be anemic. Although there is an international policy for antenatal iron-folic acid supplementation, coverage and use of this antenatal intervention is low in many developing countries. The results of the NIH-funded study are featured in the September 24, 2009 issue of the American Journal of Epidemiology.

“In a setting where maternal iron deficiency and anemia are common, we found a 31 percent reduction in childhood mortality due to maternal antenatal and postnatal supplementation with iron-folic acid compared to a control,” said Parul Christian, DrPH, MSc, lead author of the study and an associate professor in the Bloomberg School’s Department of International Health. “A reduction in mortality resulting from an intervention, such as iron-folic acid supplementation during pregnancy, provides a new and previously unreported evidence of benefit to offspring during childhood. To our knowledge this is the first time the long-term effects of maternal iron-folic acid supplementation on childhood survival have been examined.”

Christian and colleagues examined the long-term impact of micronutrient supplementation on childhood survival, growth, and early markers of chronic disease among the offspring of women who received micronutrient supplementation. The study is a follow-up to a 1999 to 2001 randomized, double-masked trial of the administration of micronutrients during pregnancy to women in the rural southern plains district of Sarlahi, Nepal. At the time the team examined folic acid; folic acid-iron; folic acid-iron-zinc, as well as a multiple micronutrients that contained the foregoing plus 11 other micronutrients. Vitamin A alone was provided in the control group and each of the four supplement groups also contained vitamin A. They found that iron-folic acid supplementation relative to the control significantly reduced the prevalence of low birth weight by 16 percent and the prevalence of maternal anemia during pregnancy and the postpartum period by 50 percent.

“Supplementation with iron and folic acid during pregnancy is a common policy in many low- and middle-income countries, although implementation is typically not very good,” said James Tielsch, PhD, professor and associate chair for academic programs at the Bloomberg School of Public Health. “This policy has been motivated primarily by the beneficial effects of supplementation on anemia in pregnancy and maternal iron stores. Following their previous demonstration that iron-folic acid supplementation during pregnancy increased birth weight, Christian, et al., have now provided unique data on the critical importance of this intervention for improving child survival. This strong evidence should reenergize programs for the delivery of this critical intervention for maternal and child health.” The folate and iron supplement study was also funded by the Bill & Melinda Gates Foundation.

Reference: “Antenatal and Postnatal Iron Supplementation and Childhood Mortality in Rural Nepal: A Prospective Follow-up in a Randomized, controlled Community Trial” by Parul Christian, et al. September 24, 2009 edition of the American Journal of Epidemiology.

A new study published in the journal Paediatric and Perinatal Epidemiology reveals that anxiety in pregnant women impacts their babies’ size and gestational age. Specifically, women with more severe and chronic anxiety during pregnancy are more likely to have smaller babies.

Shahla M. Hosseini, Minhnoi W. Biglan, Cynthia Larkby, Maria M. Brooks, Michael B. Gorin, and Nancy L. Day studied a sample of low-income women, half of whom were African American and the other half Caucasian. The group already had well-known risk factors such as alcohol and cigarette use. The authors demonstrated that the mother’s anxiety during pregnancy impacts birth outcomes over and beyond factors such as drug use, education, and race.

Anxiety during the third trimester predicted women delivering significantly smaller babies. In the first and second trimesters, the effects of anxiety were significant only among those women who had severe anxiety.

Low to moderate levels of anxiety in women during either the first or second trimester did not significantly affect the birth outcomes, but women who are severely anxious during much of their pregnancy should be considered for anxiety-reducing interventions for special prenatal care for prevention purposes.

“One way to prevent health problems in children and adults is to focus care on the prenatal period,” the authors note. “It is key to pursue further research which addresses interventions to ameliorate the effects that a woman’s trait anxiety has on the development of fetuses” (Courtesy of EurekAlert!, a service of AAAS).