Higher levels of protein hormone associated with lower risk of dementia, Alzheimer's disease

Dec 15, 2009

Persons with higher levels of leptin, a protein hormone produced by fat cells and involved in the regulation of appetite, may have an associated reduced incidence of Alzheimer disease and dementia, according to a study in the December 16 issue of JAMA.

Previous studies have shown that overweight and in mid-life are associated with poorer cognitive function in the general population and an increased risk of . There has been evidence that leptin exerts additional functions on the brain outside the hypothalamus (a region of the brain that controls body temperature, hunger, and thirst), according to background information in the article.

Wolfgang Lieb, M.D., of the Framingham Heart Study, Framingham, Mass., and colleagues examined the relationship between measurements of plasma leptin concentrations and incidence of dementia and Alzheimer disease (AD). For this study, plasma leptin concentrations were measured in 785 persons without dementia (average age, 79 years; 62 percent female), who were in the original Framingham study group at the 22nd examination cycle (1990-1994). A subsample of 198 dementia-free survivors underwent volumetric brain magnetic resonance imaging (MRI) between 1999 and 2005, approximately 7.7 years after leptin was measured. Two measures of were assessed: total cerebral brain volume and temporal horn (a region of the brain) volume, both of which are markers of early AD pathology and subsequent dementia risk. The researchers conducted follow-up for new cases of dementia and AD until Dec. 2007. During a median (midpoint) follow-up of 8.3 years, 111 participants developed dementia; 89 of them were diagnosed with AD.

The researchers found that higher leptin levels were associated with a lower incidence of all-cause dementia and AD. The incidence of decreased gradually across increasing levels of leptin: a person with a baseline leptin level in the lowest quartile group had a 25 percent risk of developing AD after 12 years of follow-up, whereas the corresponding risk for a person in the top quartile group was only 6 percent.

Higher leptin levels were also associated with higher total cerebral brain volume. Lower temporal horn volume was not significantly related to leptin levels.

"These findings are consistent with recent experimental data indicating that leptin improves memory function in animals through direct effects on the hippocampus and strengthens the evidence that leptin is a hormone with a broad set of actions in the central nervous system. Due to the exploratory character of the present analyses, we did not adjust for multiple comparisons and acknowledge that our findings require confirmation in independent samples," the authors write.

"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. Further exploration of the molecular and cellular basis for the observed association may expand our understanding of the pathophysiology underlying aging and the development of AD."

Explore further: West Africa's Ebola outbreak prompts changes in I.Coast cuisine

More information: JAMA. 2009;302[23]:2565-2572.

add to favorites email to friend print save as pdf

Related Stories

Hunger hormone linked to memory

Jul 20, 2005

Scottish scientists say they've determined the hormone that controls the body's hunger pangs may also boost one's memory.

A link between obesity and memory?

Jun 14, 2006

Scientists have wondered why obese patients who have diabetes also may have problems with their long-term memory. New Saint Louis University research in this month's Peptides provides a clue.

Obesity: Perhaps not all hot fudge sundaes

Apr 10, 2006

University of Pittsburgh scientists say it may not be all hot fudge sundaes and french fries that cause obesity -- it might also be due to brain chemistry.

Recommended for you

Two expats die of MERS in Saudi commercial hub

16 hours ago

Two foreigners died of MERS in the Saudi city of Jeddah, the health ministry said Saturday, as fears rise over the spreading respiratory virus in the kingdom's commercial hub.

UAE reports 12 new cases of MERS

16 hours ago

Health authorities in the United Arab Emirates have announced 12 new cases of infection by the MERS coronavirus, but insisted the patients would be cured within two weeks.

Filipino tests negative for Middle East virus

Apr 19, 2014

A Filipino nurse who tested positive for the Middle East virus has been found free of infection in a subsequent examination after he returned home, Philippine health officials said Saturday.

User comments : 0

More news stories

Cancer stem cells linked to drug resistance

Most drugs used to treat lung, breast and pancreatic cancers also promote drug-resistance and ultimately spur tumor growth. Researchers at the University of California, San Diego School of Medicine have discovered ...

Making graphene in your kitchen

Graphene has been touted as a wonder material—the world's thinnest substance, but super-strong. Now scientists say it is so easy to make you could produce some in your kitchen.