Hyperinsulinemia: A Merging History with Idiopathic Tinnitus, Vertigo, and Hearing Loss.

The history of neurootology and the history of diabetes mellitus have their earliest but separate recognition in ancient Egyptian medicine. Both the polyuric condition resembling diabetes and "humming in the ear" now known as tinnitus were described. Yallow's refinement of a radioimmunoassay for insulin demonstrated increased insulin (hyperinsulinemia) in known diabetics. Glucose-insulin tolerances corroborated Yallow's findings. Specific hyperinsulinemia patterns of non-insulin-dependent diabetes mellitus, type II (NIDDM) have been identified. Hyperinsulinemia precedes hyperglycemia. Hyperinsulinemia with normal glucose tolerance is the earliest identifier of NIDDM. In 1977, Updegraff identified hyperinsulinemia with idiopathic Menière's disease. Sustained clinical response was achieved in all who maintained nutritional management. This finding was the first major impact of hyperinsulinemia in the clinical arena. Subsequently, Updegraff's studies were substantiated by others. As a result, the clinical pathology of hyperinsulinemia has become a major factor in multiple medical disciplines. The hyperinsulinemia associated with idiopathic tinnitus, vertigo, and hearing loss and the hyperinsulinemia of NIDDM, without regard for glycemia status, are one and the same entity. The merging relationship preceded the clinical recognition of both entities. A retrospective relationship to ancient Egyptian medicine and before is considered to be most probable.