Which of the following is a complication of pancreatitis?

The complication associated with pancreatitis that presents as a direct result of the disease process is diabetes mellitus. Pancreatitis, particularly when chronic, can lead to inadequate production of insulin due to damage to the pancreatic cells responsible for insulin secretion. This inadequacy can result in glucose intolerance and ultimately diabetes mellitus, which may manifest during or after episodes of pancreatitis.

The other options, while they could be associated with various health issues and complications in a broader sense, do not directly stem from pancreatitis itself. Heart failure, chronic kidney disease, and hypertension represent different disease processes and risk factors rather than direct complications arising from pancreatic inflammation or damage. The close relationship of the pancreas to metabolic processes makes diabetes mellitus the most relevant and direct complication of pancreatitis.