Endocrinology · USMLE Step 1 and Step 2

Diabetes Mellitus Type 1 song

Type 1 Diabetes - Pathophysiology & Findings, as a song. Hear the short teaser here. The full song is on YouTube and Spotify.

Diabetes Mellitus Type 1

Full song on YouTube ↗Spotify ↗

Key points in this song10

Type 1 DM results from autoimmune destruction of pancreatic beta cells, leading to absolute insulin deficiency.
HLA-DR3 and HLA-DR4 alleles confer the strongest genetic susceptibility; presence of both dramatically increases risk.
Autoantibodies against islet cell antigens — including anti-GAD65, anti-insulin (IAA), and anti-IA-2 — appear years before clinical onset and serve as early biomarkers.
CD8+ cytotoxic T cells are the primary mediators of beta cell destruction; CD4+ T helper cells amplify the inflammatory response.
The process is chronic and progressive — symptoms appear only after approximately 80–90% of beta cell mass is destroyed.
Absence of insulin leads to unopposed glucagon activity, driving gluconeogenesis, glycogenolysis, lipolysis, and ketogenesis — culminating in diabetic ketoacidosis.
Environmental triggers such as Coxsackievirus B4 infection are implicated via molecular mimicry, where viral antigens resemble beta cell proteins.
Unlike Type 2 DM, Type 1 is characterized by low C-peptide levels, reflecting absent endogenous insulin secretion.
Patients require exogenous insulin for survival; without it, ketoacidosis develops rapidly and is life-threatening.
Type 1 DM is associated with other autoimmune conditions, including Hashimoto thyroiditis, Graves disease, and Addison disease (polyglandular autoimmune syndrome).