Bill Kraus, MD
Office Phone (919) 681-6733

Kim Huffman, MD, PhD
Office Phone (919) 668-1644

Johanna Johnson, MS
Office Phone (919) 660-6766


Brian Andonian, MD
Kelsey Belski, MS
William Bennett, MS
Florence Briones, RN
Julie Counts, MS, RD, LDN
Brian Duscha, MS
Lorrie Elliott-Penry, RN
Liezl Fos, MS
Leslie Kelly, RT
Megan Reaves, MS
Leslie Willis, MS
Alyssa Zidek, MS



Duke Center for Living
3475 Erwin Rd.
Durham, NC  27705

Map and Directions


The Human Physiology Testing (HPT) Core offers clinical procedures related to the biochemical and physical functions of the human body, including physical fitness assessment, physical activity monitoring, energy expenditure measurement, evaluation of glucose metabolism, body composition measurement, phlebotomy and nursing services, and muscle biopsy procedures. Located on the Center for Living campus with its convenient free patient parking, the HPT Core is ideal for conducting outpatient research with human subjects. The HPT Core contains facilities in both the Duke Aesthetics Center and the Sarah W. Stedman Nutrition and Metabolism Center buildings.

In addition to offering testing services, HPT Core staff can assist with protocol development, subject recruitment, scheduling study appointments, general nursing services, data analysis, and other aspects of study design and management. In addition to the three physician specialists on staff, the HPT Core staff members conducting the clinical procedures are all master’s level degree or higher professionals, most of whom have more than 10 years of clinical research experience at Duke. While the HPT Core does not provide laboratory analyses, samples can be stored in ultra-low temperature freezers or easily transferred to another facility that provides these services.


  • Cardiopulmonary exercise (CPX) test: In this sensitive but non-invasive stress test, subjects exercise on a treadmill to maximal exertion, while their  expired air is collected and evaluated to determine peak oxygen consumption. Trained personnel monitor the subject’s electrocardiogram (ECG), blood pressure and perceived exertion. The results provide an assessment of the subject’s fitness level and cardiovascular response to exercise stress.
  • Resting metabolic rate (RMR) test: This test measures the amount of energy the body uses while at rest. During this procedure, the participant lies down for 40-50 minutes while a large, clear plastic hood is placed over his/her head and neck. A metabolic cart collects and analyzes exhaled air while the participant breathes freely.
  • Oral glucose tolerance test (OGTT): The OGTT is a standard clinical procedure for those at risk for diabetes. A venous catheter is placed in the subject’s arm and baseline blood samples are taken. Subjects then drink a glucose solution followed by additional blood draws taken at specific times following the glucose consumption.  The OGTT provides a robust measure of glucose tolerance, such as glucose area under the curve, and insulin sensitivity via the Matsuda formula and/or insulin area under the curve.
  • BODPOD body composition test:
    This test requires the participant to sit in a BODPOD® chamber which uses air displacement to measure one’s body volume. Through a series of calculations, the participant’s fat mass, lean body mass and percent body fat are determined. Spandex clothing and a swim cap are required and will be provided by the study staff. Body circumference and skinfold measures can also be obtained.
  • Intravenous glucose tolerance test (IVGTT): The IVGTT procedure evaluates carbohydrate metabolism and insulin sensitivity. Glucose and insulin are administered through a catheter in each arm, with blood samples drawn at specific time intervals over a three-hour period.
  • Muscle biopsy services: This outpatient surgical procedure removes a small muscle tissue sample via needle or small incision while the subject is under local anesthetic. Muscle biopsy services can provide tissue for multiple types of assays including muscle histology, protein, DNA, gene expression and metabolic analyses.
  • Phlebotomy services: Trained nursing staff can collect blood samples for analysis or provide IV placement services.
  • mHealth (Wearable) physical activity monitoring services: The HPT Core offers various wearable devices to monitor subjects’ physical activity levels on a continual basis in a real-world setting. Frequently used devices include Actigraph accelerometers, Garmin wristbands, or FitBit® tracking devices.

Research teams interested in requesting services should contact Johanna Johnson, MS at (919) 660-6766 or johanna.johnson@duke.edu.