A recently published study has shown that men who are obese or have high levels of insulin secretion are more likely to die from their prostate cancer. Men who were both obese and had high levels of insulin secretion were found to be at even higher risk. Men with both of these risk factors were shown to have a risk of dying of their prostate cancer that was four times the normal.
Many studies in the past have linked obesity with higher mortality rates from prostate cancer, but this new study is the first to show a reason why this association may exist. The secretion of insulin into the bloodstream is one of the ways that the body tries to maintain a steady level of blood sugar. Insulin works to lower blood sugar (for instance, after meals). Many men who are obese develop a relative tolerance to the effects of insulin within their bodies. This causes the body to secrete more and more insulin in an effort to control blood sugar levels.
This study that was recently released, in addition to the finding that obesity and high insulin levels led to higher mortality rates, also showed that mice with higher levels of insulin secretion showed faster cancer growth than normal mice. The researchers believe that prostate cancer cells may have a high number of tiny receptors on their surfaces to which insulin attaches. The insulin then causes the cells to grow at a faster rate and the higher levels of insulin found in obese men result in even faster cell growth.
This study is further evidence yet that there is a strong link between lifestyle issues such as obesity and prostate cancer.
Ma J, Li H, Giovanucci E, et al. "Prediagnostic body-mass index, plasma C-peptide concentration, and prostate cancer-specific mortality in men with prostate cancer: a long-term survival analysis" Lancet Oncol 2008.