Newswise — New research shows cerebral microbleeds, which are
lesions in the brain, are more common in people over 60 than previously
thought. The study is published in the April 1, 2008, issue of Neurology®, the medical journal of the American Academy of Neurology.
“We found a three-to-four-fold higher overall prevalence of cerebral microbleeds compared to other studies,” according to study author Monique M.B. Breteler, MD, PhD, with the Erasmus MC University Medical Center in Rotterdam, the Netherlands. “These findings are of major importance since cerebral microbleeds likely reflect cerebrovascular pathology and may be associated with an increased risk of cerebrovascular problems.”
Cerebral microbleeds are lesions that can be seen on brain scans, such as an MRI brain scan. The lesions are deposits of iron from red blood cells that have presumably leaked out of small brain vessels.
For the study, 1,062 healthy men and women who were an average age of 70 underwent an MRI to scan for the presence of cerebral microbleeds. Of the participants, 250 were found to have cerebral microbleeds.
The study found overall prevalence of cerebral microbleeds was high and increased with age from 18 percent in people age 60 to 69 to 38 percent in people over age 80. People with the e4 allele of the APOE gene, which is known to increase the risk of Alzheimer’s disease and of cerebral amyloid angiopathy, had significantly more microbleeds than people without this genetic variant.
“We also found that the risk factors for cerebral microbleeds appear to vary according to the location of the microbleed,” said Breteler. “Our results show people with high blood pressure and a history of smoking had microbleeds in a different location in the brain than people with the APOE e4 allele, suggesting different causes for microbleeds in different locations.”
The study was supported by the Erasmus MC University Medical Center and Erasmus University Rotterdam, the Netherlands Organization for Scientific Research, and the Netherlands Organization for Health Research and Development.
The American Academy of Neurology, an association of more than 21,000 neurologists and neuroscience professionals, is dedicated to improving patient care through education and research. A neurologist is a doctor with specialized training in diagnosing, treating and managing disorders of the brain and nervous system such as stroke, Alzheimer’s disease, epilepsy, Parkinson’s disease, and multiple sclerosis.
Sciatica pain occurs when a protruding (herniated) spinal disk pushes against the sciatic nerve.
Newswise — For patients with moderate to severe chronic kidney
disease (CKD), treatment with activated vitamin D may reduce the risk
of death by approximately one-fourth, suggests a study in the August Journal of the American Society of Nephrology.
Many patients with advanced CKD take the drug calcitriol, an oral form of activated vitamin D, to treat elevated levels of parathyroid hormone. "Although activated vitamin D is known to influence many biological processes, previous clinical knowledge is limited to its effect on parathyroid hormone levels," explains Dr. Bryan Kestenbaum of the University of Washington in Seattle, one of the study authors.
The study included 1,418 patients who had stage 3 to 4 CKD, which means moderately to severely reduced kidney function. All patients also had high parathyroid hormone levels (hyperparathyroidism), which can contribute to weakening of the bones in CKD. The researchers identified one group of patients who were being treated with calcitriol to lower their parathyroid hormone levels and another group who were not receiving calcitriol.
During a two-year follow-up period, mortality rates were compared for patients who were and were not taking calcitriol. "We then adjusted for differences in age, kidney function, parathyroid hormone levels, other illnesses, and other medications," says Dr. Kestenbaum.
In the adjusted analysis, the overall risk of death was about 26 percent lower for patients taking calcitriol. Patients on calcitriol were also less likely to develop end-stage renal disease, requiring dialysis to replace lost kidney function.
Overall, treatment with calcitriol was associated with a 20 percent reduction in the risk of either death or dialysis. The reduction in mortality with calcitriol was unrelated to its effect on parathyroid hormone levels.
"Recently, there has been an increased focus on the effects of vitamin D beyond those on bone health," Dr. Kestenbaum comments. "Vitamin D deficiency has been associated with risk factors for cardiovascular disease , such as high blood pressure, diabetes, and inflammation." Previous studies have suggested that treatment with intravenous vitamin D can improve survival in patients on hemodialysis.
The new results suggest that treatment with oral activated vitamin D may also improve survival in patients with CKD who do not yet require dialysis. "Randomized clinical trials are needed to test the hypothesis that vitamin D therapy can improve cardiovascular health and survival in CKD," Dr. Kestenbaum adds. "Future studies should also examine the role of non-activated vitamin D, which is less expensive and less toxic."
The study has some important limitations, including a lack of data on other factors that may have affected survival in patients taking calcitriol. Also, since the study included mainly older, white men, the results may not apply to younger, more ethnically diverse populations with CKD.
This study was supported by a Career Development Award (K23 DK63274-01) from the National Institutes of Health.