More study needed to see if IGF-1 readings can predict risk
WEDNESDAY, March 3 (HealthDay News) -- High levels of a hormone called insulin-like growth factor 1 (IGF-1) are associated with an increased risk of cancer death in older men, a new study has found.
The findings, published in the March issue of the Journal of Clinical Endocrinology & Metabolism, suggest that IGF-1 may prove a useful biomarker for predicting cancer risk.
IGF-1, which is similar in structure to insulin, is regulated by growth hormone. Levels of growth hormone and IGF-1 decline as men and women age and this decrease is believed to be linked to health problems associated with old age. In an attempt to counter this, some people take supplemental growth hormone to elevate levels of IGF-1, according to background information in an Endocrine Society news release about the study.
"This is the first population-based study to show an association of higher IGF-1 levels with increased risk of a cancer-related death in older men," study corresponding author Gail Laughlin, of the University of California, San Diego, said in the news release. "Although the design of this study does not explicitly show that the higher IGF-1 levels caused the cancer death, it does encourage more study as well as a re-examination of the use of IGF-1 enhancing therapies as an anti-aging strategy."
The study included 633 men, aged 50 and older, whose IGF-1 levels were measured between 1988 and 1991. During 18 years of follow-up, men whose IGF-1 levels were above 100 nanograms per milliliter at the start of the study were nearly twice as likely to die of cancer as those with lower levels of the hormone.
"In this study, the increased risk of cancer death for older men with high levels of IGF-1 was not explained by differences in age, body size, lifestyle or cancer history," lead author Jacqueline Major said in the news release. "If these results are confirmed in other populations, these findings suggest that serum IGF-1 may have potential importance as a biomarker for prognostic testing."
The U.S. National Cancer Institute has more about cancer risk factors.
-- Robert Preidt
SOURCE: The Endocrine Society, news release, March 1, 2010
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