Abstract
BACKGROUND Although diabetes mellitus is a risk factor for cancer, the relationship of an increased glucose concentration at a non-diabetic glucose level with cancer mortality is yet to be determined. OBJECTIVE The aim was to observe whether an increased glucose concentration and/or glucose intolerance at the non-diabetic glucose level can predict cancer mortality. METHODS Population-based prospective cohort studies evaluating cancer mortality at the non-diabetic level (defined as fasting plasma glucose <7.0 mmol/L and two-hour plasma glucose <11.1mmol/L following an oral glucose tolerance test) were collected via a PubMed search with an additional Google scholar search between 1 January 1966 and 31 July 2016. RESULTS We identified seven studies, which met the defined criteria. Studies examining fasting/casual states indicated an increase in cancer mortality with a slight increase in fasting/casual glucose levels in men in particular. Not all, but some studies using a glucose tolerance test indicated an increase in cancer mortality with impaired glucose tolerance/prediabetes. Concerning cause-cancer mortality, glucose intolerance states appeared to have an increase in mortality, particularly due to the stomach, liver and pancreatic cancers. CONCLUSION In these studies reviewed, cancer mortality increased in individuals with an increased glucose concentration and an increased potential was seen in those patients with glucose intolerance even at non-diabetic glucose levels. The outcome of these findings is promising and forms the basis for further studies to directly address the relevance of increased (non-diabetic) glucose and glucose intolerance as a prognostic indicator of cancer mortality.
