Copeptin and Nonalcoholic Fatty Liver Disease

Participants: As a pilot study, the investigators will recruit 30 obese adults with NAFLD based upon ultrasound echogenicity within 6 months of enrollment, and 30 obese adults without NAFLD based upon ultrasound (US) echogenicity for comparison.

Screening Visit/Study Visit: Patients in the investigator's Obesity clinic will be approached about the study and consented if interested at the screening. Participants will have a chart review for their history and physical Exam and medication review for inclusion and exclusion criteria. Qualified participants will be invited for a screening visit to be scheduled in conjunction with the labs and procedures performed as Standard of Care (SOC) in the obesity clinic. At the screening visit, following consent, participants will have vitals (blood pressure, Body Mass Index (BMI), waist circumference) and a physical examination performed. Participants' Standard of Care (SOC) labs including fasting lipid panel, HbA1c (unless done within last 3 months), comprehensive metabolic panel, titers for hepatitis b and c, and complete blood count will be drawn, along with the following research labs: insulin, glucagon, free fatty acids, adiponectin and a 24-hour urine cortisol collection. Those who have not had an abdominal US will have a SOC US performed to delineate non-NAFLD or NAFLD status. US will not be performed if already done within 6 months of enrollment. All ultrasound studies will be interpreted by one University of Colorado Denver radiologist to categorize the patient as NAFLD or non-NAFLD to limit inter-reader variability. Those with NAFLD present on US will also have a SOC Fibroscan done to assess severity of steatosis (based upon Controlled Attenuation Parameter or CAP Score) and fibrosis (based upon elastography). Given limitations of ultrasound to accurately detect significant steatosis unless >30%, the investigators will in addition perform Fibroscan (all particpants regardless of US) to assess steatosis, so as to confirm if significant steatosis and compare copeptin levels on a continuum of level of steatosis as part of research procedure. Fibroscan can detect steatosis (based upon Controlled Attenuation Parameter or CAP Score) and fibrosis (based upon elastography). FIbroscan with M probe has been found to have AUROC 0.823 for a cutoff of value of 248 dB/m for no steatosis vs steatosis (with other cutoffs at 268 dB/m between S1 and S2-S3 and 280 dB/m between S1-S2 and S3 disease).