Asthma and diabetes mellitus: a biochemical basis for antithetical features

Diabetes mellitus and asthma have many antipodal features. Although both are common disorders, concurrence occurs less often than would be predicted. When co-existence does occur, the cases are generally mild, and effective treatment of one disease frequently exacerbates the other. The hypothesis is advanced that basilar membrane concentrations of heparan sulfate differ in these two diseases and that this difference may account for the antithetical features. An experimental basis for postulating increased concentrations of extracellular heparan sulfate in asthma and diminished concentrations in diabetes is cited. A rationale for tying these differences to the polar activities of cholinergic transmission and atherogenesis in the two diseases is advanced. Diminished heparan sulfate concentrations in diabetes may down-regulate the transmission of vagal impulses to insulin-producing pancreatic cells, and thereby impair both the continued vitality of these cells, and the acetylcholine modulated potentiation of glucose-induced insulin release.