title: Relationship Between Aerobic Fitness, the Serum IGF-1 Profiles of Healthy Young Adult African American Males, and Growth of Prostate Cancer Cells.
abstract: The growth of prostate tumors is mediated by the bioavailability of androgens and insulin-like growth factors. This study tested the hypothesis that healthy young adult African American men exhibiting low aerobic capacity (fitness) have serum insulin-like growth Factor-1 (IGF-1) and testosterone levels that promote growth of prostate cancer cells. A cross-sectional data research design was used to study groups of 18- to 26-year-old healthy men exhibiting low and moderate aerobic fitness, based on their peak oxygen consumption (VO2peak). The individual serum levels of IGF-1, IGF-1 binding protein-3 (IGFBP-3), and testosterone were measured. In vitro growth of androgen-dependent LNCaP prostate tumor cells was measured after incubation in culture medium fortified with each subject's serum. Aerobic capacity was significantly greater in the moderate-fitness group than in the low-fitness group without an intergroup difference in body mass index. The serum IGF-1 concentration was significantly higher in the low-fitness group in the absence of an intergroup difference in serum testosterone. The serum IGFBP-3 concentration was significantly lower in the low-fitness group. Prostate tumor cell growth was significantly greater in the cultures incubated in media containing the sera of the low-fitness group than in the sera of the moderate-fitness group. These findings suggest that moderate aerobic fitness in young adults may decrease the circulating levels of free IGF-1 and lower the potential to support growth of prostate cancer cells.
authors.affiliation: 1 Howard University, Washington, DC, USA.
authors.forename: Rajagopalan
authors.initials: R
authors.lastname: Sridhar
authors.affiliation: 1 Howard University, Washington, DC, USA.
authors.forename: Vernon
authors.initials: V
authors.lastname: Bond
authors.affiliation: 1 Howard University, Washington, DC, USA.
authors.forename: Jacquelyn
authors.initials: J
authors.lastname: Dunmore-Griffith
authors.affiliation: 1 Howard University, Washington, DC, USA.
authors.forename: Valerie M
authors.initials: VM
authors.lastname: Cousins
authors.affiliation: 1 Howard University, Washington, DC, USA.
authors.forename: Renshu
authors.initials: R
authors.lastname: Zhang
authors.affiliation: 2 The American University of Antigua College of Medicine, St. John's, Antigua & Barbuda.
authors.forename: Richard M
authors.initials: RM
authors.lastname: Millis
keywords: African Americans; IGF-1; IGFBP-3; aerobic capacity; prostate cancer; testosterone