Higher levels of leptin, a protein that controls weight and appetite, are found to be associated with a lower incidence of Alzheimer’s disease and dementia, perhaps opening new pathways for preventive and therapeutic interventions.
Given the rapid aging of developed and developing societies, it is projected that the prevalence of dementia will dramatically increase during the next five decades. Therefore, it is a public health priority to explore pathophysiological pathways underlying the development of dementia and its most common cause, Alzheimer’s.
According to researchers at Boston University School of Medicine, a growing body of evidence suggests that leptin has beneficial effects on brain development and function. It appears to mediate structure and functional changes in the hippocampus and to improve memory function. Leptin also has been shown to reduce brain concentrations of B-amyloid, the major component of the neuritic plaques that are a hallmark of Alzheimer’s disease.
The researchers measured leptin concentrations in 785 persons without dementia. A sub-sample of 198 dementia-free survivors underwent volumetric brain magnetic resonance imaging (MRI) between 1999 and 2005, approximately 7.7 years after leptin levels were measured. Two measures of brain aging, total cerebral brain volume and temporal horn volume, were assessed. The researchers found that elevated leptin level was associated with higher total cerebral brain volume and lower temporal horn volume and that higher leptin levels were associated with a lower incidence of Alzheimer’s and dementia.
“Over a 12-year follow-up, this corresponds to an absolute Alzheimer’s risk of 25 percent for persons with the lowest levels of leptin compared to a 6 percent risk for persons with the highest levels,” senior author Sudha Seshadri, M.D. and associate professor of neurology at Boston University School of Medicine, was quoted as saying. “If our findings are confirmed by others, leptin levels in older adults may serve as one of several possible biomarkers for healthy brain aging and, more importantly, may open new pathways for possible preventive and therapeutic intervention.”
This article was written with source material from the Journal of the American Medical Association’s December 16, 2009 eddition.