Male Hypogonadism

Stephen J. Winters, MD, Professor of Medicine, Chief, Division of Endocrinology, Metabolism and Diabetes, University of Louisville, Louisville, KY, USAIlpo Huhtaniemi, MD, PhD, Professor Emeritus of Reproductive Endocrinology, Institute of Reproductive and Developmental Biology, Department of Surgery & Cancer, Imperial College London, Hammermith Campus, London, UK