Updated on November 6, 2024 Overview Type I Diabetes Mellitus (T1DM): Caused by autoimmune destruction of beta cells. Always requires insulin. Lean patient with early onset. Type II Diabetes Mellitus (T2DM): Caused by insulin resistance. Controlled by appropriate diet and exercise and/or oral meds. May require insulin. Chronically overweight/obese patient. Both T1DM and T2DM have...