The Glucose Ketone Index Calculator: A Simple Tool to Assess Therapeutic Efficacy for Metabolic Management of Brain Cancer

Abstract

Metabolic therapy using ketogenic diets (KD) is emerging as an alternative or complementary approach to the current standard of care for management of brain and other malignant cancers. This therapeutic strategy targets the aerobic fermentation of glucose (Warburg effect), which is the common metabolic malady of most tumors. The KD targets tumor energy metabolism by lowering blood glucose and by elevating blood ketones (β‐hydroxybutyrate). Brain tumor cells, unlike normal brain cells, cannot use ketone bodies effectively for energy when glucose becomes limiting. Although plasma levels of glucose and ketone bodies have been used alone to predict the therapeutic success of metabolic therapy, daily glucose levels can fluctuate widely in brain cancer patients. This can create difficulty in linking changes in blood glucose and ketones to efficacy of metabolic therapy. A program was developed (Glucose Ketone Index Calculator, GKIC) that tracks the ratio of blood glucose to ketones as a single value. We have termed this ratio the Glucose Ketone Index (GKI). The GKIC was used to compute the GKI for data published on blood glucose and ketone levels in humans and mice with brain tumors. The results showed a clear relationship between the GKI and therapeutic efficacy using ketogenic diets and calorie restriction. Hence, the GKIC is a simple tool that can help assess the efficacy of metabolic therapy in animal models and patients with malignant brain tumors and possibly other cancers that express aerobic fermentation. The GKI may also be useful in treating other disorders that are responsive to metabolic intervention, such as epilepsy.This work was supported by NIH grant NS055195 and the Jasse Walsh Scholarship.