Aldosterone and Glucose Homeostasis

Not Applicable

Completed

Conditions: Diabetes Mellitus

Interventions: Drug: Aldosterone infusion (A)
Drug: Vehicle Infusion (V)
Other: High Sodium Diet (HS)
Other: Low Sodium Diet (LS)

Registration Number: NCT00732160

Lead Sponsor: Vanderbilt University

Brief Summary: Determine the effect of aldosterone on how the body handles glucose (sugar).

Detailed Description: Determine the effect of aldosterone on glucose metabolism in humans.

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 34

Inclusion Criteria

Ambulatory subjects, 18 to 70 years of age, inclusive
For female subjects, the following conditions must be met:

a postmenopausal status for at least 1 year, or b status-post surgical sterilization, or c if of childbearing potential, utilization of adequate birth control and willingness to undergo urine beta-hcg testing prior to drug treatment and on every study day
Metabolic Syndrome as defined by the presence of > 3 of the following:

a Systolic Blood Pressure > 130 mm Hg OR Diastolic Blood Pressure > 85 mm Hg. b Glucose Intolerance (Fasting Plasma Glucose > 100 mg/dL) c Increased triglyceride level > 150mg/dL (1.7mmol/L) d Decreased levels of HDL cholesterol For males, less than 40 mg/dL For females, less than 50 mg/dL e Waist circumference For males, greater than 40 inches (102 cm) For females, greater than 35 inches (89 cm).

Exclusion Criteria

Previously diagnosed Type I Diabetes , or the use of anti-diabetic medication. Subjects with type II diabetes not on medication will be allowed to participate if fasting blood glucose is <200mg/dL.
Prior allergies to medications used in the study protocol (e.g. L-arginine, potassium chloride).
Screening plasma potassium <3.5 mmol/L or use of chronic potassium supplements for the treatment of hypokalemia
Use of hormone replacement therapy
If on statin therapy for hypercholesterolemia, a change in dose within the past 6 months.
Breast-feeding
Cardiovascular disease such as prior myocardial infarction, presence of angina pectoris, significant arrhythmia, congestive heart failure (LV hypertrophy acceptable), deep vein thrombosis, pulmonary embolism, second or third degree heart block, mitral valve stenosis, aortic stenosis or hypertrophic cardiomyopathy
Treatment with anticoagulants
History of serious neurologic disease such as cerebral hemorrhage, stroke, seizure, or transient ischemic attack
History or presence of immunological or hematological disorders
Diagnosis of asthma requiring use of inhaled beta agonist >1 time per week
Clinically significant gastrointestinal impairment that could interfere with drug absorption
Impaired hepatic function [aspartate amino transaminase (AST) and/or alanine amino transaminase (ALT) >2.0 x upper limit of normal range]
Impaired renal function [estimated glomerular filtration rate (eGFR) of <60ml/min] as determined by the four-variable Modification of Diet in Renal Disease (MDRD) equation, where serum creatinine (Scr) is expressed in mg/dl and age in years:
eGFR <60 ml/min
Hematocrit <35%
Any underlying or acute disease requiring regular medication which could possibly pose a threat to the subject or make implementation of the protocol or interpretation of the study results difficult, such as arthritis treated with non-steroidal antiinflammatory drugs
Treatment with chronic systemic glucocorticoid therapy (more than 7 consecutive days in 1 month)
Treatment with lithium salts
History of alcohol or drug abuse
Treatment with any investigational drug in the 1 month preceding the study
Mental conditions rendering the subject unable to understand the nature, scope and possible consequences of the study
Inability to comply with the protocol, e.g., uncooperative attitude, inability to return for follow-up visits, and unlikelihood of completing the study

Study & Design

Study Type: INTERVENTIONAL

Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
HS-V/A; LS-V/A	Aldosterone infusion (A)	High Sodium diet- Vehicle infusion then Aldosterone infusion Low Sodium diet- Vehicle infusion then Aldosterone infusion
HS-A/V; LS-A/V	Vehicle Infusion (V)	High Sodium diet- Aldosterone infusion then Vehicle infusion Low Sodium diet- Aldosterone infusion then Vehicle infusion
HS-V/A; LS-V/A	Vehicle Infusion (V)	High Sodium diet- Vehicle infusion then Aldosterone infusion Low Sodium diet- Vehicle infusion then Aldosterone infusion
HS-V/A; LS-V/A	High Sodium Diet (HS)	High Sodium diet- Vehicle infusion then Aldosterone infusion Low Sodium diet- Vehicle infusion then Aldosterone infusion
LS-V/A; HS-V/A	High Sodium Diet (HS)	Low Sodium diet- Vehicle infusion then Aldosterone infusion High Sodium diet- Vehicle infusion then Aldosterone infusion
LS-A/V; HS-A/V	High Sodium Diet (HS)	Low Sodium diet- Aldosterone infusion then Vehicle infusion High Sodium diet- Aldosterone infusion then Vehicle infusion
HS-A/V; LS-A/V	Aldosterone infusion (A)	High Sodium diet- Aldosterone infusion then Vehicle infusion Low Sodium diet- Aldosterone infusion then Vehicle infusion
HS-A/V; LS-A/V	High Sodium Diet (HS)	High Sodium diet- Aldosterone infusion then Vehicle infusion Low Sodium diet- Aldosterone infusion then Vehicle infusion
LS-V/A; HS-V/A	Aldosterone infusion (A)	Low Sodium diet- Vehicle infusion then Aldosterone infusion High Sodium diet- Vehicle infusion then Aldosterone infusion
LS-A/V; HS-A/V	Aldosterone infusion (A)	Low Sodium diet- Aldosterone infusion then Vehicle infusion High Sodium diet- Aldosterone infusion then Vehicle infusion
HS-V/A; LS-V/A	Low Sodium Diet (LS)	High Sodium diet- Vehicle infusion then Aldosterone infusion Low Sodium diet- Vehicle infusion then Aldosterone infusion
LS-V/A; HS-V/A	Vehicle Infusion (V)	Low Sodium diet- Vehicle infusion then Aldosterone infusion High Sodium diet- Vehicle infusion then Aldosterone infusion
LS-V/A; HS-V/A	Low Sodium Diet (LS)	Low Sodium diet- Vehicle infusion then Aldosterone infusion High Sodium diet- Vehicle infusion then Aldosterone infusion
HS-A/V; LS-A/V	Low Sodium Diet (LS)	High Sodium diet- Aldosterone infusion then Vehicle infusion Low Sodium diet- Aldosterone infusion then Vehicle infusion
LS-A/V; HS-A/V	Vehicle Infusion (V)	Low Sodium diet- Aldosterone infusion then Vehicle infusion High Sodium diet- Aldosterone infusion then Vehicle infusion
LS-A/V; HS-A/V	Low Sodium Diet (LS)	Low Sodium diet- Aldosterone infusion then Vehicle infusion High Sodium diet- Aldosterone infusion then Vehicle infusion

Primary Outcome Measures

Name	Time	Method
Insulin Secretion	3 hours	Acute Insulin response during Hyperglycemic clamp (delta insulin uU/mL, t=0-10)

Secondary Outcome Measures

Name	Time	Method
Insulin Sensitivity	3 hours	Insulin sensitivity index (ISI) was calculated by dividing the average glucose infusion rate (mg glucose infusion/kg body weight/min) by the average insulin concentration (uU/mL) from 90 to 120 minutes. This was multiplied by 100 (thus, x100 in units description), per reporting convention in literature.