GLYCEMIC CONTROL AND CARDIOPULMONARY FUNCTION IN PATIENTS WITH INSULIN-DEPENDENT DIABETES-MELLITUS

BACKGROUND: We studied cardiopulmonary function during exercise in you ng subjects with long-standing insulin-dependent diabetes mellitus (ID DM) who have no clinical cardiopulmonary disease to determine the rela tionships of aerobic capacity, gas exchange, ventilatory power require ment, and cardiac output to chronic glycemic control. METHODS: Eightee n subjects with IDDM and 14 normal control subjects were studied. Nine diabetic subjects received twice daily insulin injections and had chr onically elevated levels of glycosylated hemoglobin (hyperglycemic gro up); 9 other diabetic subjects received insulin via continuous infusio n pumps and maintained chronic near-normal levels of glycosylated hemo globin (normoglycemic group). At the end of at least 7 years of regula r follow-up, aerobic capacity was determined by cycle ergometry. Lung volume, diffusing capacity, and cardiac output during exercise were me asured by a rebreathing technique. Ventilatory power was measured by t he esophageal balloon technique. RESULTS: Maximal work load and oxygen uptake were markedly impaired in chronically hyperglycemic diabetic p atients associated with significant restrictions of lung volume, lung diffusing capacity, and stroke index during exercise. Membrane diffusi ng capacity was significantly reduced at a given cardiac index. The no rmoglycemic patients consistently showed less impairment than the hype rglycemic patients. CONCLUSION: Physiologically significant cardiopulm onary dysfunction develops in asymptomatic patients with long-standing IDDM. Chronic maintenance of near-normoglycemia is associated with im proved cardiopulmonary function. (C) 1997 by Excerpta Medica, Inc.