Effect of Hypoglycemia on β-Adrenergic Sensitivity in Normal and Type 1 Diabetic Subjects

摘要: OBJECTIVE The purpose of this study was to assess the potential role reduced tissue sensitivity catecholamines in pathogenesis hypoglycemia unawareness patients with type 1 diabetes. RESEARCH DESIGN AND METHODS effect a single episode on β-adrenergic studied 10 diabetic apparently normal awareness (age 29 ± 5 years, diabetes duration 13 8 HbA 1c 7.3 0.9%) and age-matched healthy control subjects. measured isoproterenol test after hyperinsulinemic euglycemic clamp hypoglycemic clamp. expressed as dose intravenous that increased heart rate by 25 beats/min (IC25). RESULTS During hypoglycemia, subjects had an impaired plasma epinephrine response compared (16.7 5.0 vs. 40.1 6.8 ng/ml, P = 0.02). In subjects, IC25 lower than euglycemia (0.83 0.22 1.13 0.21 μg, 0.02) indicating increase sensitivity. other hand, greater (1.00 0.26 0.65 0.14 μ, 0.04), decrease CONCLUSIONS increases contrast, reduces These results provide evidence patients, some maladaptation contributes development unawareness. A unifying hypothesis is presented for incorporating concepts both catecholamine adrenergic