Health Briefs

March 8, 2004

The class of drugs referred to as “statins” has revolutionized the treatment of patients with adverse blood cholesterol levels. These drugs appear to exert their beneficial effects not only by lowering elevated levels of LDL (the “bad cholesterol”) and raising levels of HDL (the “good cholesterol”), but also by reducing inflammation within the heart’s arteries. However, the optimal utilization of these powerful drugs has not been clear to date. There are several statin drugs currently approved by the FDA for the treatment of elevated blood cholesterol, and different doses of each drug have been recommended by different experts. A new double-blind, prospective, randomized study in this week’s Journal of the American Medical Association compared moderate versus intensive treatment with statins, and the results of this study are very interesting, indeed.

The study was conducted at 34 different medical centers, and compared the effects of “moderate-dose” pravastatin (40 mg per day) and “high-dose” atorvastatin (80 mg per day) on the progression of known coronary artery disease. The 654 patients in this study took either pravastatin or atorvastatin for 18 months. A tiny ultrasound probe was threaded up into the coronary arteries of 502 of these study participants initially upon entering the study, and again following 18 months of statin therapy.

Although both groups of patients experienced a significant improvement in their blood cholesterol values (as well as a significant reduction in the inflammatory marker protein, c-reactive protein), the patients who took the high-dose atorvastatin experienced a significantly greater improvement in LDL, HDL and c-reactive protein levels when compared to the patients taking pravastatin. More importantly, the high-dose statin group experienced no significant progression of their coronary artery plaques over the 18-month duration of the study, while the moderate-dose statin patients continued to experience progression of their artery-clogging plaques. The precise mechanism whereby the high-dose statin stopped progression of coronary artery plaques was not directly assessed by this study. However, the markedly greater improvements seen in the HDL, LDL and c-reactive protein levels in patients receiving the high-dose statin regimen imply, at least, that these favorable changes in known markers of coronary artery disease risk are probably directly involved in halting the progression of already established cardiovascular disease.

ANTIBACTERIAL HOME PRODUCTS & THE RISK OF INFECTION

Virtually every manufacturer of personal and home cleaning products is marketing one or more products with “antibacterial” properties. Despite concerns within the medical world about the explosion of antibiotic-resistant bacteria, these products are heavily hyped as effective agents in destroying bacteria, viruses or, simply, “germs on contact.” A new study in the Annals of Internal Medicine looked at the impact of these antibacterial cleaning products on the incidence of infectious diseases in households that use such products. This randomized, double-blinded study encompassed 238 primarily Hispanic households in Manhattan. Participating households were given unlabeled cleaning products for household cleaning, laundry and hand-washing. Each household was randomly assigned to either antibacterial products or non-antibacterial products. Hygiene practices and symptoms of infectious diseases were then monitored by weekly phone surveys, monthly home visits, and quarterly interviews, for a total of 48 weeks.
The study determined that there was no significant difference in the incidence of infectious diseases between the households that used the antibacterial cleaning products and the households that used the non-antibacterial products. Specifically, there was no significant difference in the incidences of respiratory infections, vomiting, diarrhea or skin infections between the two groups. The study concluded that the antibacterial cleaning products did not appear to reduce the incidence of common household infectious diseases when compared to non-antibacterial products. As the majority of the observed infectious diseases were likely viral in origin, the authors did point out that even if the antibacterial products did indeed kill bacteria, they did not appear to have any effect on the viruses that cause the overwhelming majority of infectious diseases among healthy people at home. In view of the continuing emergence of disease-causing bacteria that are resistant to multiple antibiotics, it is difficult to justify the addition of antibacterial agents to home and personal cleaning products. The results of this study add further support to this conclusion.

“CAMERA-INSIDE-A-PILL” IDENTIFIES ABNORMALITIES INSIDE YOUR INTESTINES

Capsule endoscopy (CE) offers a new method of visualizing the interior of the small intestine. The esophagus, stomach, and first part of the small intestine (the duodenum) can be directly visualized by flexible fiberoptic scopes (endoscopes). The rectum and colon can also be inspected and biopsied using an endoscope during colonoscopy. However, the 20 to 25 feet of small intestine between the duodenum and the colon cannot be easily visualized by endoscopes. Radiologists can provide some details about the interior of the small intestines by performing an “upper GI series,” but such radiographic studies do not provide the level of detail available with endoscopes. CE utilizes a miniaturized digital camera and wireless transmitter within a capsule that can be swallowed by the patient. As the capsule passes through the GI tract, it repeatedly captures images of the lining of the intestines and transmits them to a recording device worn by the patient. Although seen as a promising new GI imaging technology, very little scientific study of the merits of this amazing new technology has been performed to date.

A study in the current issue of the journal Gastroenterology looked at the sensitivity of CE in detecting the causes of blood loss from this endoscopically silent area of the GI tract. A total of 100 patients with a history of GI tract bleeding were enrolled in the study. All patients first underwent upper and lower GI tract endoscopy without identifying a cause for the patients’ GI bleeding. Twenty-six of the patients presented with ongoing active GI bleeding (Group A), while 31 presented with a prior history of active bleeding that had since stopped (Group B). A third group, consisting of 43 patients, presented without direct active bleeding, but with positive occult blood stool tests and iron deficiency anemia (Group C). All three groups of patients underwent CE. Among Group A patients, CE revealed the cause of their active bleeding in 92% of cases, while CE identified the cause of recent GI bleeding in only 13% of cases among Group B patients. Among the Group C patients, CE identified the cause for occult GI blood loss in 44% of cases. Overall, CE proved to be extremely sensitive in detecting intestinal pathology resulting in GI bleeding, picking up the actual abnormalities in about 90% of cases. In 87% of cases, CE picked up abnormalities that resulted in specific treatments directed at the causes of GI bleeding in Group A patients (i.e., patients who were actively bleeding at the time of CE). The capsule had to be surgically removed in 5 patients, but in 4 of those 5 cases, the capsule became stuck as a result of abnormalities that required surgery anyway. The authors concluded that CE is a highly sensitive and accurate method of identifying the causes of active small intestinal bleeding in patients with normal upper and lower GI endoscopy, and in patients with chronic occult GI bleeding and normal upper and lower GI endoscopy. While there is a small risk of the capsule getting hung-up within the GI tract, thus necessitating surgical removal, almost all of these cases occurred due to intestinal abnormalities that require surgical treatment anyway. CE represents an important new advance in our ability to photographically image the longest segment of the GI tract, and an area of our bodies that has, until now, been largely invisible except for the limited and largely unimproved radiographic imaging that radiologists have been performing for decades.

DIETARY FOLATE & OVARIAN CANCER INCIDENCE

Several previous studies have suggested that low dietary intake of the B-vitamin folate in the diet is associated with an increased risk of colorectal and breast cancer. This increased risk of cancer in people with folate-deficient diets appears to be especially significant among alcohol drinkers. (Heavy alcohol consumption is associated with reduced blood levels of folate.) Folate, or folic acid, plays a crucial role in the repair of damaged DNA within our cells, and a deficiency of this vital nutrient may impair our cells’ ability to recover from genetic damage that may, in turn, predispose us to an increased risk of cancer. A new Swedish study, reported in the current issue of the Journal of the National Cancer Institute, examined the link between dietary folate, alcohol intake and the incidence of ovarian cancer in 61,084 women, aged 38 to 76 years. These women were part of a large prospective study of mammography, the Swedish Mammography Cohort study.

All study volunteers completed dietary surveys, allowing researchers to tease-out dietary risk factors for specific cancers. Overall, a low dietary folate intake was only weakly associated with an increase in the risk of ovarian cancer (these results were not statistically significant). However, among women who consumed two or more alcoholic drinks per week, there was a strong and statistically significant increase in the incidence of ovarian cancer among women with low levels of folate in their diets. The women with the lowest dietary folate intake experienced a 74% increase in the relative risk of developing ovarian cancer during this more than decade-long study. At the same time, there was no difference in the incidence of ovarian cancer among women who consumed 2 or fewer alcoholic drinks per week, irrespective of their folate intake. Thus, the authors conclude, high levels of dietary folate may reduce the risk of ovarian cancer in women, and particularly among women who consume two or more alcoholic drinks per week.

In addition to a possible role in the prevention of cancer, adequate folate intake also appears to offer some protection against heart disease (by lowering levels of homocysteine in the blood), and against certain birth defects (e.g., spina bifida, cleft palate, cleft lip, heart anomalies and limb malformations). In view of the critical health benefits of dietary folate, the FDA mandated, in 1996, that rice, pasta, cornmeal, and other grain products be fortified with 140 micrograms of folate per 100 grams of food product.

Dr. Robert A. Wascher