Clinical Briefs
Clinical Briefs
Elevated Homocysteine Level Possible Risk for Alzheimer’s
By Joan Unger, RN, MS, ARNP-C
Researchers hypothesized that B12 deficiencies are more common in senile dementia of the Alzheimer’s type (SDAT) and might be revealed by an elevated total serum homocysteine (tHcy). In a prospective case-controlled survey, investigators studied 164 patients, all over age 55, with a clinical diagnosis of Alzheimer’s disease. The diagnosis was confirmed histologically in 76 subjects.
Serum total tHcy levels were found to be significantly higher in patients with confirmed SDAT than in the 108 control subjects, while serum folate and vitamin B12 were significantly lower. Study subjects in the top third for tHcy were 4½ times as likely to have SDAT as those in the bottom third. Subjects in the lowest thirds for vitamin B12 and folate were 4.3 and 3.3 times (respectively) more likely to have SDAT as those in the top thirds.
Researchers concluded low levels of folate and vitamin B12 and elevated tHcy levels were associated with SDAT. They suspect a vascular trigger exists for SDAT, but they caution that additional research is needed to confirm this and the justification for vitamin supplementation.
Source Clarke R, Smith D, Jobst K. Elevated homocysteine levels a possible risk factor for Alzheimer’s. Arch Neurol 1998;55: 1449-55.
Hepatitis A Shot Urged for Children in 11 States
Members of the Advisory Committee on Immunization Practices (ACIP) from the Centers for Disease Control and Prevention (CDC) in Atlanta recommend that children ages 2 through 18 in states where hepatitis A is considered endemic be vaccinated against the disease. Between 1987 and 1997, 11 states were found to have an annual hepatitis A infection rate at least twice that of the national average. The states with rates higher than 20 cases per 100,000 people were Arizona, Alaska, California, Idaho, Nevada, New Mexico, Oklahoma, Oregon, South Dakota, Utah, and Washington.
The ACIP recommends routine vaccination for children in states where hepatitis A infection exceeds 20/100,000 or the average annual rate during the 10-year period was at least 10/100,000. Vaccines are encouraged for adults in endemic states and travelers to developing nations. The vaccine is considered effective and safe; studies are under way to determine safety and efficacy in children under 2 with a goal of vaccination for all U.S. children. — JU
Source Centers for Disease Control and Prevention. Advis ory Com mittee on Immunization Practices. Feb. 17, 1999: www.cdc.gov/ncidod.
Antihypertensives and Risk of Gastrointestinal Bleeding
A nested case-control study design within a population-based cohort of 34,074 new users of beta blockers, angiotensin-converting enzyme (ACE) inhibitors, or calcium channel blockers was used to determine if these categories of antihypertensive drugs increased the risk of gastrointestinal (GI) bleeding. All 311 study subjects had been hospitalized because of GI bleeding. Each subject was matched to 10 (total of 3110) randomly selected controls. When compared with control subjects with no current use of antihypertensive drugs, the adjusted rate ratio of GI bleeding for current use of calcium channel blockers was 1.1 and for beta blockers, 0.66.The adjusted rate ratio for ACE inhibitor use was 1.0 and for diuretic use, 1.4. Investigators were surprised to find the use of beta-blockers associated with a 33% reduction in risk of hospitalization for GI bleeding. Equally unexpected was the finding that diuretic use seemed to increase risk of hospitalization for GI bleeding by 40%.
The authors concluded the use of calcium channel blockers did not appear to increase the risk of GI bleeding during the first five years of treatment, while beta blockers prevented the adverse event. They noted the need for additional research to further evaluate the elevated risk associated with the use of diuretics. — JU
Source Suissa S, Bourgault C, Barkun A, et al. Antihypertensive drugs and the risk of gastrointestinal bleeding. Am J Med 1998;105:230-35.
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