Glucose intolerance in sarcoma patients
Twenty-seven otherwise healthy patients with localized sarcoma were examined to determine if glucose intolerance can be detected before the appearance of clinical signs of cachexia. No patient had lost weight or demonstrated severe malnutrition. Fasting plasma samples for glucose, insulin, glucagon, and free fatty acids (FFA) were obtained, and a standard intravenous glucose tolerance test performed. Glucose disappearance rate (K) was calculated between 5 and 60 minutes. K levels were compared to those of normal controls and to those of patients with more extensive cancer (statistics obtained from the literature). Levels for K were compared to tumor volume measurements following surgery. Fasting glucose, insulin, and glucagon levels were normal. Fasting FFA levels were slightly elevated. K levels for sarcoma patients were significantly lower than in control patients (P = 0.04), and higher than in patients with advanced cancer (P less than 0.0001). The subset of patients who weighed less than the ideal had a significantly lower K level than did the rest of the sarcoma population. K levels correlated inversely with tumor volume (r = -0.34; P = 0.04). These data indicate that mild glucose intolerance (reduction in clearance of a glucose load) occurs early in untreated sarcoma patients, is most prevalent in patients who maintain less than the ideal weight, correlates with tumor burden, and occurs before other signs of cachexia appear.