Elevated glucose levels in melanoma patients - a real-world analysis.

Aim: To assess the glycemic status of consecutive melanoma patients undergoing standardized capillary fasting blood glucose (cFBG) assessment prior to fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) examination. Methods: This retrospective study included 336 consecutive melanoma patients at the University Hospital Zurich, Switzerland. Fasting cFBG levels were measured prior to FDG PET/CT and classified according to American Diabetes Association guidelines. Multivariable linear regression analysis was performed to identify independent predictors of cFBG levels. Sensitivity analyses were performed on patients examined before 11 AM and fasting for 8 h as well as patients without known diabetes. Results: The cohort included 336 melanoma patients with a median age of 67 years (IQR 57-76), 36 % female (122/336), and 12 % (40/336) with known diabetes mellitus. The median cFBG was 103 mg/dL (IQR 94-112; 5.7 mmol/L, IQR 5.2-6.2). Overall, 58 % (194/336) of patients had non-normal cFBG levels (≥100 mg/dL; ≥5.6 mmol/L), consistent with findings from a sensitivity analysis of patients presenting before 11 AM, where 58 % (115/198) exhibited non-normal levels. Excluding patients with known diabetes, 56 % (165/296) of patients had non-normal cFBG levels, with 7 % (20/210) having levels ≥126 mg/dL (≥7.0 mmol/L), indicative of possible undiagnosed diabetes mellitus. Multivariable linear regression analysis identified male gender, active disease, and subcutaneous fat as independent predictors of cFBG levels, whereas traditional risk factors such as BMI, visceral fat, hypertension or lack of exercise were not independent predictors. Conclusion: More than half of melanoma patients have elevated cFBG levels, even in those without known diabetes, highlighting the need for improved glycemic screening and management.