Noutati stiintifice

* hipertiroidia predispune la fracturi

April 2, 2011 — Levothyroxine dose is linked to fracture risk in older adults, according to the results of a nested case-control study reported online April 28 in the BMJ.

"Chronic hyperthyroidism may increase the risk of fractures, particularly in older people and postmenopausal women who already have a higher risk of osteoporosis and fractures," write Marci R. Turner, from the Department of Medicine, University of Toronto, Toronto, Ontario, Canada, and colleagues.

* sarea

"What our study basically shows is that it might not be right to impose a general reduction on sodium intake," senior author Dr Jan A Staessen (University of Leuven, Belgium) told heartwire . "We are not negating previous studies, and I think sodium restriction is meaningful for patients who already have hypertension and perhaps for patients with heart failure, but there are very few arguments showing that reducing salt intake in the general population would result in substantial benefit."

 

* cafeaua si efortul...

 

Coffee, Vigorous Exercise May Trigger Aneurysm

May 5, 2011 — Dutch researchers have identified and quantified 8 potential trigger factors for intracranial aneurysm rupture, including consumption of coffee or cola, straining for defecation, and vigorous physical activity.

 

Dr. Monique H. Vlak "Reducing caffeine consumption or treating constipated patients with unruptured intracranial aneurysm with laxatives may lower the risk of subarachnoid hemorrhage [SAH]," Monique H. Vlak, MD, of University Medical Center Utrecht, the Netherlands, and colleagues write in the journal Stroke, published online May 5.

However, "We do not advise them to refrain from physical exercise, since this also is an important factor in lowering the risk of other cardiovascular diseases," she emphasized in comments to Medscape Medical News.

"These factors are not surprising," said Y. Jonathan Zhang, MD, a neurosurgeon with the Methodist Neurological Institute in Houston, Texas, who was not involved in the study.

"They are well-known anecdotes." However, he cautioned, that "at most, they may be associated with the aneurysm rupture, but it is very premature to conclude that they actually caused the rupture."

 Incidental Findings Roughly 2% of the population has an intracranial aneurysm, but only a few rupture. Through neuroimaging techniques, more incidental intracranial aneurysms are being detected.

Knowledge of the activities that might play a role in triggering rupture of these aneurysms is limited.

To investigate, Dr. Vlak and colleagues asked 250 patients with aneurysmal SAH about their usual frequency of exposure to 30 potential trigger factors in the year before SAH and also about exposure to these trigger factors in the hour before SAH (hazard period). Using a case crossover design, the researchers assessed relative risks for rupture after exposure to triggers and calculated population-attributable risks. They identified a total of 8 factors that increased the risk for aneurysm rupture.

Coffee drinking and vigorous physical activity had the greatest population-attributable risks.

 Table.

 Relative Risks for 8 Trigger Factors Risk Factor RR (95% CI) PAR, %

 Coffee 1.7 (1.2 – 2.4) 10.6

 Cola 3.4 (1.5 – 7.9) 3.5

 Nose-blowing 2.4 (1.3 – 4.5) 5.4

 Straining to defecate 7.3 (2.9 – 19) 3.6

 Startling 23.3 (4.2 – 128) 2.7

 Anger 6.3 (1.6 – 25) 1.3

 Sexual intercourse 11.2 (5.3 – 24) 4.3

 Physical exercise* 2.4 (1.4 – 4.2) 7.9

 CI = confidence interval; RR = relative risk; PAR = population-attributable risk; *Metabolic equivalent of task of 6 or higher.

 

 Mechanism Unclear Dr. Vlak and colleagues note in their report that all of these triggers cause a short-lasting and sudden increase in blood pressure, "which seems a possible common cause for aneurysmal rupture." But Dr. Zhang is wary, citing autoregulation of the brain. "The brain's circulation is highly regulated, and unless a patient has a severe abnormality, we know that when the systemic blood pressure goes up, the blood pressure in the brain is not directly affected," he said. Limitations of the study, the researchers say, include its retrospective design and the average 3-week period between SAH and completion of the questionnaire. Dr. Zhang also made the point that the data are "self-reported and bias may be introduced." Clearly, more study is needed. In the meantime, Dr. Zhang hopes the results will not fuel "unnecessary medical paranoia among family physicians, or even general neurologists, and unnecessarily increase the anxiety of patients and unnecessarily limit the patients activity and enjoyment of life." The study was funded by the Julius Center for General Health and Primary Care and the Department of Neurology of the University Medical Center Utrecht. The study authors and Dr. Zhang have disclosed no relevant financial relationships.

* Clozapine/clorpromazine

The study authors compared the 9-year outcomes of 160 individuals with  treatment-naive, first-episode schizophrenia or schizophreniform  disorder treated in a mental health center in Beijing, China. They were  initially randomly assigned to clozapine or chlorpromazine (with  benztropine) treatment for up to 2 years followed by up to an additional  7 years of naturalistic treatment. Individuals in both groups spent  essentially equal amounts of time in remission during the follow-up time  period (78%). There were no significant differences on other measures  of illness severity. There were no significant differences between the 2  groups on other secondary efficacy outcomes. However, the clozapine  group was more likely than the chlorpromazine group to remain on the  medication to which they were originally assigned (26% vs 10%; <i>P</i> = .01), with a number-needed-to-treat advantage of 7