Adrenergic beta-Antagonists--adverse effects Angiotensin-Converting Enzyme Inhibitors--therapeutic use Antihypertensive Agents--therapeutic use Atenolol--therapeutic use Captopril--therapeutic use Diabetes Complications Diabetes Mellitus--drug therapy Diabetes Mellitus, Type 1--complications Diabetes Mellitus, Type 2--complications Humans Hypoglycemia--chemically induced Randomized Controlled Trials as Topic Risk Factors Time Factors