Adrenergic Contribution to Glucose Counterregulation in Islet Transplantation
概览
- 阶段
- 早期 1 期
- 状态
- 已完成
- 入组人数
- 9
- 试验地点
- 2
- 主要终点
- C-PEPTIDE suppression during hyperinsulinemia euglycemia.
概览
简要总结
To determine the effect of sympathetic neural and hormonal (epinephrine) input on islet cell hormonal responses to insulin-induced hypoglycemia in type 1 diabetic recipients of intrahepatic islet transplantation. We hypothesize that α-adrenergic (neural) blockage will abolish insulin-mediated suppression of C-peptide, attenuating α-cell glucagon secretion during hypoglycemia, and that β-adrenergic (hormonal) blockage will have no effect. Glucose counterregulatory responses will be measured during hyperinsulinemic euglycemic-hypoglycemic clamps on three occasions with randomized, double-blind administration of the α-adrenergic blocker phentolamine, the β-adrenergic blocker propranolol, or placebo. The demonstration of neural rather than hormonal regulation of the transplanted islet cell response to hypoglycemia is critical for understanding the mechanism for protection from hypoglycemia afforded by intrahepatically transplanted.
详细描述
This study is designed to test the hypothesis that α-adrenergic (neural) blockade will abolish insulin-mediated suppression of C-peptide, attenuating α-cell glucagon secretion during hypoglycemia, and that β-adrenergic (hormonal) blockade will have no effect. Glucose counterregulatory responses will be measured during hyperinsulinemic euglycemic-hypoglycemic clamps on three occasions with randomized, double-blind administration of the α-adrenergic blocker phentolamine, the β-adrenergic blocker propranolol, or placebo. The demonstration of neural rather than hormonal regulation of the transplanted islet cell response to hypoglycemia is critical for understanding the mechanism for protection from hypoglycemia afforded by intrahepatically transplanted islets.
Glucose counterregulation has not been studied in type 1 diabetic recipients of extrahepatic islet transplantation. Comparison of glucose counterregulatory responses measured during hyperinsulinemic euglycemic-hypoglycemic clamps will be compared to those obtained from type 1 diabetic recipients of intrahepatic islet transplantation studied under the placebo condition above.
Glucose counterregulation has not been directly compared between recipients of intrahepatic auto- and allo-islet transplantation. Direct comparison of glucose counterregulatory responses under the same experimental conditions is required to understand whether mechanisms other than the glucagon response may be important to the reported hypoglycemia affecting pancreatectomized recipients of islet auto-transplantation.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Factorial
- 主要目的
- Basic Science
- 盲法
- Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
盲法说明
Conditions of testing for "Group 1" (intra-hepatic islet recipients) will remain double-blind for each subject until their completion of all testing visits, unless for safety concerns, either the PI or Medical Monitor request an unblinding. Groups "2" and "3" will have no masking.
入排标准
- 年龄范围
- 21 Years 至 65 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Male and female subjects age 21 to 65 years of age.
- •Subjects who are able to provide written informed consent and to comply with the procedures of the study protocol.
- •Clinical history compatible with type 1 diabetes with onset of disease at \< 40 years of age and insulin-dependent for \> 10 years at the time of islet transplantation \> 6 months before study.
- •Stable islet graft function defined by C-peptide \> 0.5 ng/ml and insulin-independent or insulin-dependent with daily insulin requirement \< 0.2 units/kg•d to maintain HbA1c \< 7.0%.
- •Use of standard immunosuppression consisting of tacrolimus with or without sirolimus or mycophenolic acid. Substitutions of tacrolimus with cyclosporine, and of sirolimus or mycophenolic acid with azathioprine are permissible if stable for over 3 months. Prednisone is allowable if no more than 5 mg daily.
排除标准
- •BMI ≥ 30 kg/m
- •Insulin requirement of ≥ 0.2 units/kg•day.
- •HbA1c ≥ 7.0%.
- •Uncontrolled hypertension: systolic blood pressure \> 160 mmHg or diastolic blood pressure \> 100 mmHg.
- •History of cardiovascular disease, including coronary artery, cerebrovascular or peripheral vascular disease, or current use of β-blocker therapy.
- •Bronchial asthma.
- •Abnormal kidney function: Estimated glomerular filtration rate (eGFR) \< 60 ml/min/1.73 m
- •Abnormal liver function: persistent elevation of liver function tests \> 1.5 times the upper limit of normal.
- •Untreated hypothyroidism, Addison's disease, or Celiac disease.
- •Anemia: baseline hemoglobin concentration \< 11 g/dl in women and \< 12 g/dl in men.
研究组 & 干预措施
Group 1-Propranolol Intra-hepatic islet
The dose of propranolol will be 0.48 μg/kilogram•minute, which will provide a total dose of 0.10 mg/kg. It will be administered 1 x only via intravenous infusion over 3.5 hours, starting 30 min before conduct of a hyperinsulinemic euglycemic (90 min) followed by hypoglycemia (90 min) clamp.
干预措施: Propranolol (Drug)
Group 1- Placebo Intra-hepatic islet
Placebo in 100mL NSS. Infuse Intravenously at 0.0095 ML/KG/MIN. 1 x only via intravenous infusion over 3.5 hours, starting 30 min before conduct of a hyperinsulinemic euglycemic (90 min) followed by hypoglycemia (90 min) clamp.
干预措施: Placebo (Drug)
Group 2 - Extra-hepatic islet
Hyperinsulinemic euglycemic (90 min) followed by hypoglycemia (90 min) clamp only.
Group 3 - Intra-hepatic auto islet
Hyperinsulinemic euglycemic (90 min) followed by hypoglycemia (90 min) clamp only.
Group 1-Phentolamine Intra-hepatic islet
The dose of phentolamine will be 0.95 μg/kg•min, which will provide a total dose of 0.20 mg/kg. It will be administered 1 x only via intravenous infusion over 3.5 hours, starting 30 min before conduct of a hyperinsulinemic euglycemic (90 min) followed by hypoglycemia (90 min) clamp.
干预措施: Phentolamine (Drug)
结局指标
主要结局
C-PEPTIDE suppression during hyperinsulinemia euglycemia.
时间窗: For C-peptide at the 60-90 time-point during the hyperinsulinemic euglycemic-hypoglycemic clamp.
The primary outcome measures will be the levels of C-peptide during hyperinsulinemia euglycemia.
GLUCAGON activation during hyperinsulinemia hypoglycemia.
时间窗: For Glucagon at the 150-180 minute time-point during the hyperinsulinemic euglycemic-hypoglycemic clamp.
The primary outcome measures will be the levels of glucagon during hyperinsulinemia hypoglycemia.
C-PEPTIDE Suppression During Hyperinsulinemia Euglycemia.
时间窗: For C-peptide at the 60-90 minute time-point during the hyperinsulinemic euglycemic-hypoglycemic clamp.
The primary outcome measures will be the levels of C-peptide during hyperinsulinemia euglycemia.
GLUCAGON Activation During Hyperinsulinemia Hypoglycemia.
时间窗: For Glucagon at the 150-180 minute time-point during the hyperinsulinemic euglycemic-hypoglycemic clamp.
The primary outcome measures will be the levels of glucagon during hyperinsulinemia hypoglycemia.
次要结局
- EPINEPHRINE during hyperinsulinemia hypoglycemia.(During metabolic testing in the 150-180 minute time-point of the hyperinsulinemic euglycemic-hypoglycemic clamp.)
- Rates of ENDOGENOUS GLUCOSE PRODUCTION during hyperinsulinemia hypoglycemia.(During metabolic testing in the 150-180 minute time-point of the hyperinsulinemic euglycemic-hypoglycemic clamp.)
- AUTONOMIC SYMPTOMS during hyperinsulinemia(During metabolic testing; this symptom questionnaire will be asked at the following time points: -15min, -1min, 30min, 60min,75min, 90min,120min, 150min, 165min, 180min.)
- EPINEPHRINE During Hyperinsulinemia Hypoglycemia.(During metabolic testing in the 150-180 minute time-point of the hyperinsulinemic euglycemic-hypoglycemic clamp.)
- Rates of ENDOGENOUS GLUCOSE PRODUCTION During Hyperinsulinemia Hypoglycemia.(During metabolic testing in the 150-180 minute time-point of the hyperinsulinemic euglycemic-hypoglycemic clamp.)
- AUTONOMIC SYMPTOMS During Hyperinsulinemia Hypoglycemia(The autonomic symptom score was calculated as the mean of scores at the two hypoglycemic time points during the clamp (165 and 180 minutes).)
研究者
Michael R. Rickels, MD, MS
Michael R. Rickels, M.D., M.S. Associate Professor of Medicine Division of Endocrinology, Diabetes & Metabolism Director, Translational Research Program Institute for Diabetes, Obesity & Metabolism University of Pennsylvania Perelman School of Medicine
University of Pennsylvania