Medications such as diuretics, phenytoin, niacin, and high-dose corticosteroids can produce hyperglycemia that is reversible once the drugs are discontinued or when diuretic-induced hypokalemia is corrected. Chronic pancreatitis or subtotal pancreatectomy reduces the number of functioning B cells and can result in a metabolic derangement very similar to that of genetic type 1 diabetes except that a concomitant reduction in pancreatic A cells may reduce glucagon secretion so that relatively lower doses of insulin replacement are needed. Insulin-dependent diabetes is occasionally associated with Addison’s disease and autoimmune thyroiditis ( Schmidt’s syndrome , or polyglandular failure syndrome ). This occurs more commonly in women and represents an autoimmune disorder in which there are circulating antibodies to adrenocortical and thyroid tissue, thyroglobulin, and gastric parietal cells.
Urate precipitates as needle-shaped monosodium urate (MSU) crystals, which are deposited extracellularly in cartilage tendons, tendon sheaths, ligaments, walls of bursae and skin around cooler distal joints and tissues (eg, ears). In severe, long-standing hyperuricemia, MSU crystals may be deposited in larger central joints and in the parenchyma of organs such as the kidney. At the acid pH of urine, urate precipitates readily as small plate like or irregular crystals that may aggregate to form gravel or stones, which may cause obstruction . Tophi are MSU crystal aggregates that most often develop in joint and cutaneous tissue.