This document summarizes key aspects of diabetes mellitus and the metabolic syndrome from a chapter in a medical textbook. It discusses the roles of insulin and glucagon in regulating anabolism and catabolism. It also summarizes the different types of diabetes, including type 1, type 2, and gestational diabetes. Additionally, it outlines acute complications like diabetic ketoacidosis and chronic complications that can arise from long-term high blood glucose levels, such as nephropathy, retinopathy, and neuropathy.