Link between Breast Cancer Risk and Insulin Resistance?
4th April 2013
In a study published in 2010 researchers found a link between breast cancer and the presence of the metabolic syndrome — a syndrome that predisposes to cardiovascular and other diseases, which is characterized by abdominal obesity, high levels of triglycerides and low concentrations of HDL cholesterol, increased blood pressure and insulin resistance.
The same researchers have now confirmed those findings in a new study, which focuses on the contribution of insulin resistance to breast cancer development. When tissues become resistant to the action of insulin – which occurs often in obese people – a balancing mechanism further increases insulin production leading to a chronic hyperinsulinemia. Such high insulin levels can be detrimental to the body because insulin not only regulates glucose metabolism but has more functions such as stimulating cell proliferation and survival. Therefore the continuous activation of insulin pathways can contribute to cancer development by fuelling cancer cell growth.
By analyzing a cohort of 410 patients and 565 healthy women, the researchers found that 49% of patients were insulin resistant compared with 34% of controls – indicating that insulin resistance can indeed increase the risk of developing breast cancer. Most of the insulin resistant patients were postmenopausal but, interestingly, most of them had fasting plasma glucose and/or fasting plasma levels in the normal range. It was only through the application of the homeostasis model assessment of insulin resistance (HOMA-IR) that the authors were able to identify a subset of patients with a subclinical insulin resistance but an increased cancer risk.
The HOMA-IR method takes into account both fasting plasma glucose and fasting plasma levels and is widely used in epidemiological studies to determine insulin resistance.
Overall these findings further support the hypothesis that metabolic syndrome, and particularly abdominal fat (waist circumference more than 88cm) and insulin resistance, can be considered risk factors for developing breast cancer after menopause.
Capasso I et al., Homeostasis model assessment to detect insulin resistance and identify patients at high risk of breast cancer development: national cancer institute of Naples experience. Journal of Experimental & Clinical Cancer Research, 2013; 32 (1): 14 DOI: 10.1186/1756-9966-32-14
Capasso I et al., Metabolic syndrome affects breast cancer risk in postmenopausal women: National Cancer Institute of Naples experience. Cancer Biology & Therapy, 2010; 10 (12): 1240 DOI: 10.4161/cbt.10.12.13473
Categories: Hormonal Health, Weight Management, Metabolic Health