Suppression of hGH may ward of cancer, diabetes -- LA Times

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Suppression of human growth hormone may ward off cancer, diabetes

A study of a population with a genetic mutation that shuts off receptors to

HGH finds they almost never get cancer or diabetes, suggesting a downside

for people taking the hormone as an anti-aging treatment.

By Eryn Brown, Los Angeles Times, Feb 17th, 2011

Anyone seeking the fountain of youth should think twice before turning to

growth hormone

<http://www.latimes.com/topic/health/human-body/hormones-metabolism-HHA00003

0.topic> , a fast-growing trend in anti-aging

<http://www.latimes.com/topic/health/physical-conditions/aging-HEPHC000002.t

opic> fringe medicine. If conclusions from a study of an obscure population

living in Ecuador

<http://www.latimes.com/topic/intl/ecuador-PLGEO00000135.topic> prove true,

less growth hormone - not more - may help prevent cancer

<http://www.latimes.com/topic/health/diseases-illnesses/cancer-HEDAI0000010.

topic> and diabetes

<http://www.latimes.com/topic/health/diseases-illnesses/diabetes-HEDAI000002

2.topic> in old age.

The discovery, published Wednesday in the journal Science Translational

Medicine, backs up earlier research showing that yeast, flies and rodents

live longer - in some species, as much as 10 times longer - when they grow

slowly.

" There are a lot of people giving human growth hormone to fight aging, " said

Dr. Nir Barzilai, a researcher at the Albert Einstein

<http://www.latimes.com/topic/science-technology/albert-einstein-PECLB001542

..topic> College of Medicine in New York, who was not involved in the

research. " The question is, will you live longer and healthier? I think

these studies suggest maybe not. "

The discovery hinged on a group of extended relatives living in the Andes in

Ecuador, many of whom share a genetic

<http://www.latimes.com/topic/health/human-body/genes-chromosomes-HHA000024.

topic> mutation that shuts off receptors to human growth hormone. The

hormone helps regulate metabolism throughout the body and the way that cells

change as they age.

The mutation, called E180, is one of several that cause Laron syndrome, a

disorder that stunts growth after birth by about 50%.

The most obvious effects of the disorder are negative, said study coauthor

Dr. Guevara-Aguirre of the Institute of Endocrinology, Metabolism and

Reproduction in Quito, Ecuador. These include short stature - people with

Laron grow to be about 3 to 4 feet tall - and high infant mortality.

But Guevara-Aguirre, who treats Laron patients, saw a positive side too:

Virtually none of them got cancer or diabetes.

He eventually joined forces with study senior author Valter Longo, a USC

<http://www.latimes.com/topic/education/colleges-universities/university-of-

southern-california-OREDU000019271.topic> cell biologist who researches

aging. Longo's team had been looking at yeast and mice that also lacked

growth genes. Both organisms were about half the normal size; the yeast

lived three times longer than normal and the mice lived 40% longer.

Longo's team had found that cells from the mutant yeast and mice were

protected against DNA

<http://www.latimes.com/topic/health/human-body/dna-HHA000078.topic>

damage. The Laron patients provided an opportunity to see if the same held

true in humans.

The researchers collected health histories of 99 patients over age 10 and

death statistics of 53 other Ecuadoreans with Laron who died before

Guevara-Aguirre began his work in the 1980s. They also collected data on

more than 1,600 unaffected relatives of the Laron patients.

There were 30 deaths in the Laron group: eight from heart disease

<http://www.latimes.com/topic/health/diseases-illnesses/heart-disease-HEDAI0

000026.topic> , one from stroke and 21 from non-age-related causes,

including an unusual number from convulsive disorders, accidents or

alcohol-related issues.

Only one person got cancer. She did not die from it. Cancer accounted for

about 20% of deaths of relatives without Laron.

None of those with Laron had diabetes, even though 21% of the Laron patients

were obese. Diabetes caused 5% of relatives' deaths.

The team took serum taken from patients and unaffected relatives and added

them to human cells. They found that the serum from Laron patients protected

DNA from breakage that can contribute to cancer. Serum from unaffected

relatives did not.

The Laron serum also promoted a kind of suicide among damaged cells. This,

Longo said, might protect against cancer by killing off cells that are about

to turn rogue.

" The results are about as clear as you can get, " said Andrzej Bartke of the

Southern Illinois University School of Medicine in Springfield

<http://www.latimes.com/topic/us/illinois/sangamon-county/springfield-PLGEO1

00101101011274.topic> , Ill., who has seen similar results in his work on

aging in mice.

Experts said the study casts doubt on the use of human growth hormone

injections to combat aging. Though the treatment has been shown to improve

muscle mass, doctors have worried that it may raise the risk for diabetes

and cancer.

Dr. Perls, a professor of medicine and geriatrics

<http://www.latimes.com/topic/health/medical-specialization/geriatrics-HEMSP

00004.topic> at Boston University and a critic of the growth hormone

industry, said the research provided " yet more dramatic evidence that growth

hormone does the opposite of what the hucksters and the anti-aging industry

promote. " He was not involved with the study.

In 2009, Americans spent $1.35 billion on growth hormone treatments, filling

431,000 prescriptions, according to the healthcare information and

consulting company IMS Health

<http://www.latimes.com/topic/economy-business-finance/ims-health-incorporat

ed-ORCRP007709.topic> .

Longo said the research might lead to drugs that suppress growth hormone to

prevent many diseases of aging, much the way statin drugs are used to lower

cholesterol and prevent cardiac disease.

The goal of such prevention wouldn't be to live longer, but to live

disease-free for as long as possible, he said.

" These mice and the Laron patients don't seem to have chronic conditions, "

he added. " They live long lives, and then they drop dead. "