Amyloid-β peptide Aβ42 is implicated in the pathogenesis of Alzheimer disease. In a phase 2 trial, tarenflurbil—a selective Aβ42-lowering agent—was associated with a slower rate of cognitive decline among patients with mild Alzheimer disease. In the Tarenflurbil Phase 3 Study, a multicenter trial in which patients with mild Alzheimer disease were randomly assigned to receive tarenflurbil (800 mg, twice a day) or placebo for 18 months, Green and colleagues Article found that compared with placebo, tarenflurbil did not slow cognitive decline or the loss of activities of daily living in patients with mild Alzheimer disease. In an editorial, Montine and Larson Article discuss the challenge of finding effective therapies to delay, slow, or prevent Alzheimer disease and other dementias.
Overweight and obesity have been associated with poorer cognitive function in some studies, and leptin—an adipokine produced in adipose tissue—has been suggested as a possible mediator of the effect. In an analysis of data from the Framingham Study cohort, Lieb and colleagues Article assessed the association of plasma leptin levels in 1990-1994 with incident Alzheimer disease and magnetic resonance imaging measures of brain aging during follow-up. The authors report that persons with higher levels of leptin at baseline had a lower risk of incident dementia and Alzheimer disease and had higher cerebral brain volume during a median follow-up of 8.3 years (range, 0-15.5 years). In an editorial, Montine and Larson Article discuss leptin biology and neurodegeneration.
Some studies suggest a decline in the incidence of births of children with cystic fibrosis, but the data are inconsistent across populations. In a retrospective analysis of data from 2 regions in northeastern Italy, Castellani and colleagues Article assessed the association between carrier screening and cystic fibrosis birth incidence. The authors found a time-related decrease in the birth of children with cystic fibrosis that correlated with an increase in the number of screened carriers. Specifically, the decrease was greater in the region where carrier tests were offered to relatives of patients and carrier screening was offered to infertile couples and couples of reproductive age than in the region where only relatives of patients or couples planning in vitro fertilization were offered carrier testing. In an editorial, Liou and Rubenstein Article discuss carrier screening for cystic fibrosis and the choices and challenges facing prospective parents of a child with cystic fibrosis.
Heterogeneity is ubiquitous in complex systems—both biological and societal—and accounting for heterogeneity in the design and analysis of clinical and health services research and in the application of research outcomes at the level of the individual patient or individual practice site is challenging. In a discussion of 2 healthcare improvement initiatives, Davidoff considers the influence of participant and social system heterogeneity in study design and analysis, and the benefits of acknowledging heterogeneity in new models of program evaluation.
‘”Please, Doctor, no more surgery. I don't want to live in the dark.’” From “Jobs.”
Citing recent studies linking vitamin D insufficiency with poorer health outcomes, some researchers say that recommended intake levels for the vitamin should be increased.
Health insurance cooperatives
Reduce global disparities in breast cancer treatment
Authors are invited to submit manuscripts for a JAMA theme issue.
Join Hussein Hollands, MD, MSc, Wednesday, January 20, from 2 to 3 pm to discuss acute-onset floaters and flashes and risk of retinal detachment. To register, go to http://www.ihi.org/AuthorintheRoom.
How would you manage a 43-year-old man who has exertional nausea, elevated troponin levels, and lateral ST depression on ECG? Go to www.jama.com, read the case, and submit a response by January 3, which may be selected for online publication.
For your patients: Information about magnetic resonance imaging.
This Week in JAMA . JAMA. 2009;302(23):2513. doi:10.1001/jama.2009.1859