Investigating the Stability, Variability and Mechanism of Incorporation of Lipid Mediators Into Eccrine Sweat

The purpose of this study is to see what the differences are in sweat (amount and small molecule content) collected from different sites of the body and by different methods of sweat stimulation. Additionally, the investigators want to know whether the amount and small molecule content of the sweat is the same in an individual over time, and the same across individuals at a given time. Finally, the investigators want to know how consumption of over-the-counter anti-inflammatory drugs such as ibuprofen will affect the inflammatory mediator content of sweat and how that compares to blood. This information will help to better understand the composition and behavior of sweat and assess its potential utility as a routine clinical tool in skin research.

Study Overview

• Status: Completed
• Conditions: Stability & Variability of Lipid-derived Molecules in Sweat
• Intervention / Treatment: Drug: Ibuprofen; Other: Physiological induction of sweating; Drug: Pilocarpine

Detailed Description

Subjects will participate in 4 study day visits that will be scheduled about 1- week apart. During the first study visit, the investigators will compare sweat collected following pharmacological stimulation of sweating (using the drug pilocarpine) to sweat collected following physiological stimulation of sweating (using a stationary bicycle). During the second study visit, the investigators will collect sweat following stimulation of sweating by the drug pilocarpine from the inner part of the forearm (near the wrist) and also the upper surface of the thigh (near the knee). During the third study visit, the investigators will collect sweat following stimulation of sweating by the drug pilocarpine from the inner part of both forearms (near the wrist). During the fourth study visit, the investigators will collect a sweat sample following stimulation of sweating by the drug pilocarpine from the inner part of the forearm (near the wrist) and a blood sample (about one teaspoon) from the other arm. After blood and sweat collection, participants will consume 400 mg (two tablets) of ibuprofen. The investigators will then collect blood and sweat from 30 minutes, 2 hours and 4 hours after participants consume the ibuprofen.

• Study Type: Interventional
• Enrollment (Actual): 14
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • California
    • Davis, California, United States, 95616
      • Western Human Nutrition Research Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 20 years to 40 years (Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: Male

Description

Inclusion Criteria:

• 20-40 y
• Male
• Weight > 110 pounds

Exclusion Criteria:

• Diagnosed active chronic diseases for which the individual is currently taking daily medication, including but not limited to:

  • Diabetes mellitus
  • Cardiovascular disease
  • Cancer
  • Gastrointestinal disorders
  • Kidney disease
  • Liver disease
  • Bleeding disorders
  • Asthma
  • Autoimmune disorders
  • Hypertension
  • Osteoporosis
• Recent minor surgery (within 4 wk) or major surgery (within 16 wk)
• Recent antibiotic therapy (within 4 wk)
• Recent hospitalization (within 4 wk)
• Use of over-the-counter or prescription medications at the time of the study that directly affect endpoints of interest (e.g. hyperlipidemia, glycemic control, steroids, statins, anti-inflammatory agents, and weight loss aids)
• Adults who are not able to consent
• Under current medical supervision
• Ibuprofen intolerance or allergy
• Those with a bleeding disorder
• Current enrollee in a clinical research study.
• Individuals with blood clotting or platelet defect disorders
• Individuals with orthopedic limitations or cardiovascular risk that preclude participation in the physiological stimulation of sweat by light exercise portion of the study
• Individuals who are trained athletes or that regularly perform physical activity defined as "vigorous" by the Centers for Disease Control and Prevention

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Single group; All subjects will participate in 4 study day visits in the same order.; compare sweat collected following pharmacological stimulation of sweating (using the drug pilocarpine) to sweat collected following physiological induction of sweating (exercise using a stationary bicycle).; compare sweat collected following stimulation of sweating by the drug pilocarpine from the inner part of the forearm (near the wrist) to upper surface of thigh (near the knee).; collect sweat following stimulation of sweating by the drug pilocarpine from the inner part of both forearms (near the wrist).; collect blood and sweat samples before and 30 minutes, 2 hours and 4 hours after consumption of 400 mg of ibuprofen.

Drug: Ibuprofen; 400 mg ibuprofen given to inhibit cyclooxygenase metabolism; Other: Physiological induction of sweating; 15 minutes exercise at 60-80% oxygen consumption to induce sweating; Other Names: Exercise; Drug: Pilocarpine; Iontophoresis with a 1.5 milliampere (mA) current using a gel disc containing a 5% pilocarpine nitrate solution to induce sweating; Other Names: Pilogel

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Volar Forearm Sweat Lipid Mediator Concentrations Following Pilocarpine Stimulation	Approximately 150 lipid mediators will be measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Assayed lipid mediators include oxygenated lipids, endocannabinoids and endocannabinoid-like molecules, and sphingolipids.	measured at study visit 1, 2 and 3; detected lipid mediator concentrations for study visit 1 reported
Volar Forearm Sweat Lipid Mediator Concentrations Following Exercise	Approximately 150 lipid mediators will be measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Assayed lipid mediators include oxygenated lipids, endocannabinoids and endocannabinoid-like molecules, and sphingolipids.	measured at study visit 1, detected lipid mediator concentrations reported
Lower Back Sweat Lipid Mediator Concentrations Following Pilocarpine Stimulation	Approximately 150 lipid mediators will be measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Assayed lipid mediators include oxygenated lipids, endocannabinoids and endocannabinoid-like molecules, and sphingolipids.	measured at study visit 1, detected lipid mediator concentrations reported
Anterior Distal Thigh Sweat Lipid Mediator Concentrations Following Pilocarpine Stimulation	Approximately 150 lipid mediators will be measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Assayed lipid mediators include oxygenated lipids, endocannabinoids and endocannabinoid-like molecules, and sphingolipids.	measured at study visit 2, detected lipid mediator concentrations reported
Change in Plasma Lipid Mediator Concentrations Before and After Oral Ibuprofen Administration	Approximately 100 lipid mediators will be measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Assayed lipid mediators include oxygenated lipids, endocannabinoids, and endocannabinoid-like molecules.	measured at four timepoints at study visit 4, detected lipid mediator concentrations for first timepoint reported

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Pilocarpine-stimulated Sweat Lipid Mediator Concentrations Before and After Oral Ibuprofen Administration	Approximately 100 lipid mediators will be measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Assayed lipid mediators include oxygenated lipids, endocannabinoids, and endocannabinoid-like molecules.	measured at four timepoints at study visit 4, detected lipid mediator concentrations for first timepoint reported
Change in Plasma Ibuprofen Concentrations	Plasma concentration of ibuprofen prior to and 30 min, 2 hr and 4 hr after oral administration	measured at four timepoints at study visit 4
Change in Sweat Ibuprofen Concentrations	Sweat concentration of ibuprofen prior to and 30 min, 2 hr and 4 hr after oral administration	measured at four timepoints at study visit 4

Collaborators and Investigators

• Sponsor: USDA, Western Human Nutrition Research Center
• Collaborators: University of California, Davis
• Investigators: Principal Investigator: John W. Newman, Ph.D., USDA-ARS-Western Human Nutrition Research Center

Study record dates

Study Major Dates

• Study Start (Actual): November 28, 2016
• Primary Completion (Actual): June 8, 2017
• Study Completion (Actual): June 8, 2017

Study Registration Dates

• First Submitted: October 12, 2016
• First Submitted That Met QC Criteria: October 13, 2016
• First Posted (Estimate): October 18, 2016

Study Record Updates

• Last Update Posted (Actual): June 1, 2018
• Last Update Submitted That Met QC Criteria: April 30, 2018
• Last Verified: April 1, 2018

More Information

Terms related to this study

• Keywords: endocannabinoids; oxygenated lipids; metabolic profiling; sphingoid bases; ceramides; non-invasive sampling
• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Neurotransmitter Agents; Molecular Mechanisms of Pharmacological Action; Autonomic Agents; Peripheral Nervous System Agents; Cholinergic Agents; Enzyme Inhibitors; Analgesics; Sensory System Agents; Anti-Inflammatory Agents, Non-Steroidal; Analgesics, Non-Narcotic; Anti-Inflammatory Agents; Antirheumatic Agents; Cyclooxygenase Inhibitors; Cholinergic Agonists; Miotics; Muscarinic Agonists; Ibuprofen; Pilocarpine
• Other Study ID Numbers: 929370

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO