Diabetes secondary to pancreatic diseases: clinical and diagnostic aspects

The advance of metabolic endocrinology, gastroenterology, and clinical pathology in Brazil has highlighted the complex correlation between the structural integrity of the pancreatic parenchyma and glycemic homeostasis. The pancreas is an organ with a dual physiological function, whose exocrine and endocrine compartments share an intimate microcirculation and integrated cellular signaling pathways. In patients affected by primary pancreatic disorders, such as chronic pancreatitis, recurrent acute pancreatitis, pancreatic neoplasms, cystic fibrosis, and hemochromatosis, the progressive or sudden destruction of the glandular tissue culminates in the development of a specific form of glucose intolerance. This disorder, classified by the World Health Organization as type 3c diabetes mellitus (T3cDM) or pancreatogenic diabetes, represents a challenging clinical scenario of high pathophysiological complexity that remains widely underdiagnosed in Brazilian medical practice. Although type 2 diabetes mellitus dominates screenings and care flows within the country's healthcare networks, T3cDM presents a unique biochemical and clinical signature, marked not only by the loss of insulin-producing beta cells but also by the synchronous collapse of alpha and PP cells, resulting in the absence of glucagon and pancreatic polypeptide, which leads to extreme glycemic instability that is difficult to therapeutically manage. Given the urgent need to consolidate and standardize national scientific evidence on specific diagnostic criteria, adaptive molecular mechanisms, and current propedeutic pitfalls in the country, this study aims to analyze and synthesize, through a systematic review of the Brazilian medical and biomedical literature, diabetes secondary to pancreatic diseases, addressing its clinical and diagnostic aspects. To fulfill this purpose, a structured methodological survey based on PRISMA guidelines was conducted in the SciELO, LILACS, and PubMed electronic databases for original Brazilian articles and national clinical consensus published in the last decade (2016-2026). The results reveal that the definitive diagnosis of T3cDM requires proof of concomitant exocrine insufficiency (via reduced fecal elastase-1), altered structural pancreatic imaging, and the absence of typical type 1 diabetes autoantibodies. It is concluded that active screening and the systematic application of integrated diagnostic algorithms in secondary and tertiary care within the Unified Health System constitute essential preventive interventions to optimize therapeutic prognosis, mitigate episodes of severe hypoglycemia, and qualify the survival and overall health of the affected population throughout the national territory.(AU)