Mutation That Causes Growth-Hormone Deficiency Prevents Cancer and Diabetes

A mutation causing abnormally low growth-hormone activity appears to be responsible for eliminating diabetes and cancer in an isolated community located on the slopes of the Andes Mountains of Ecuador.

A study published in the February 16, 2011, issue of the journal Science Translational Medicine reported results obtained by observing the population of growth hormone-deficient individuals for more than 22 years. During this period, health profiles of 100 individuals with Laron syndrome – caused by deficiency in a gene that prevents the body from using growth hormone - and 1,600 relatives of normal stature were monitored.

The results revealed that during 22 years of observation no cases of diabetes and only one nonlethal case of cancer were found in the Laron syndrome subjects. In comparison, among normal sized relatives living in the same towns during the same period, 5% were diagnosed with diabetes and 17% with cancer. Reduced insulin concentrations and a very low HOMA-IR (homeostatic model assessment–insulin resistance) index in Loran syndrome, indicating higher insulin sensitivity, could explain the absence of diabetes in these subjects.

Serum from Loran syndrome subjects reduced DNA breaks but increased apoptosis in cultures of human mammary epithelial cells treated with hydrogen peroxide. Furthermore, serum from these subjects also caused changes that promoted cellular protection and life-span extension in model organisms.

"The growth hormone receptor-deficient people do not get two of the major diseases of aging. They also have a very low incidence of stroke, but the number of deaths from stroke is too small to determine whether it is significant,” said senior author Dr. Valter Longo, professor of cellular and molecular biology at the University of Southern California (Los Angeles, USA). "Although all the growth hormone deficient subjects we met appear to be relatively happy and normal and are known to have normal cognitive function, there are a lot of strange causes of death, including many that are alcohol related.”

Related Links:
University of Southern California