Diagnosing Natriuretic Peptide Deficiency

Inclusion criteria: * Men and women ages 18-50 years * BMI 18.5 to \<25 kg/m\^2 Exclusion Criteria: * Significant use of systemically-absorbed glucocorticoids currently or for an extended period of time during the prior 6 months * Current use of antihypertensive medications * Current use of metformin, or any antidiabetic medications (which could affect glucose and insulin levels) * Current use of medications known to affect dexamethasone metabolism, including phenytoin, rifampin, carbamazepine, troglitazone, and barbiturates * Active, clinically significant infection at time of visit * History of adrenal insufficiency or Cushing's syndrome * Prior or current cardiovascular disease, renal disease, or liver disease * Diabetes mellitus, pre-diabetes, impaired fasting glucose, or impaired glucose tolerance * Atrial fibrillation * Bleeding disorder or anemia * Elevated Liver Functions Tests \> 2 times upper limit of normal * Estimated glomerular filtration rate \< 60 ml/min * HbA1c \> 5.7 * Abnormal sodium or potassium level * Positive pregnancy test, women of child-bearing age not practicing birth control, women who are breastfeeding