The Physiology of Human Brown Adipose Tissue

Inclusion criteria

• Healthy participants between age 18 and 75 years undergoing planned clinically indicated procedure at BIDMC.

Exclusion Criteria

• Body mass index (BMI) greater than or equal to 40 kg/m2
• History of any local or systemic infectious disease with fever or requiring antibiotic within four weeks of drug administration;
• Diabetes, either previously diagnosed or hemoglobin A1c greater than or equal to 6.5%
• Use of oral or parenteral corticosteroids (epidural permitted) or other medication known to cause insulin resistance in the previous 6 weeks.
• Willingness to provide informed consent and follow study procedures, including attending scheduled visits.
• Chronic kidney disease stage 4 or 5 (including end-stage renal disease);
• Hepatic disease, including serum alanine aminotransferase (ALT) or aspartate transaminase (AST) greater than or equal to 3 times the upper limit of normal; hepatic synthetic insufficiency as defined as serum albumin \< 3.0 g/dL; or serum bilirubin > 2.0;
• Active malignancy (except squamous or basal cell carcinoma of skin)
• Bleeding disorder, treatment with anticoagulants (if not discontinued prior to surgery), or platelet count \<50,000;
• Current addiction to alcohol or substances of abuse;
• Mental incapacity, unwillingness or language barriers precluding adequate understanding or cooperation;
• Use of an investigational drug within 30 days prior to screening.
• There will be no involvement of special vulnerable populations such as fetuses, neonates, pregnant women, children, prisoners, institutionalized or incarcerated individuals, or others who may be considered vulnerable populations.
• Because the goal is to study adult human brown adipose tissue, children are not eligible to participate.