- Type I or II diabetes (by World Health Organization criteria). The following medications and drug therapies will disqualify subjects from participating in the study: beta-adrenergic antagonists, maintenance alpha-adrenergic blockers, Methyldopa, thiazide and loop diuretics, parasympatholytic agents, zinc, estrogen/hormone replacement therapy excluding oral contraceptives, insulin-sensitizing drugs, aspirin, and non-steroidal anti-inflammatory drugs.