The purpose of this study is to analyze the relationship between sebum excretion rate and the following factors:
- Hormone levels (testosterone, dehydroepiandrosterone sulfate)
- Expression of 5-α-reductase type 1 (a protein in sebaceous glands that transforms a hormone (testosterone) into another one that strongly stimulates sebum production)
- Sun and ultraviolet light exposure.
- Facial washing routine
- Sleep patterns (time when you start sleeping and total sleep time)
This study will analyze the relationship between sebum excretion rate and the various factors that may influence it in approximately 40 subjects. It will be conducted in one center located in Montreal. All devices are known and have already been used in the past.
Primary Outcome Measures:
- Intra subject variability of sebum excretion rate [ Time Frame: 7 Days ]
To study the relationship between intra-subject variability in sebum excretion rate and androgen levels, expression of 5-α-reductase type 1, diet, UV exposure and sleep patterns
Secondary Outcome Measures:
- Inter subject variability in sebum excretion rate [ Time Frame: 7 Days ]
To study the relationship between inter-subject variability in sebum excretion rate and androgen levels, expression of 5-α-reductase type 1, diet, UV exposure and sleep patterns
| Study Start Date:
| Study Completion Date:
| Primary Completion Date:
||September 2012 (Final data collection date for primary outcome measure)
A total of 40 subjects with a sebum excretion rate of at least 4 will be included. Subjects will be seen at Day 0 and Day 7. Casual sebum measurements will be performed at least 2 hours after washing the face in the morning with a Sebumeter® following a 30-second application of a Sebumeter® Measurement Cartridge to the forehead. Sebum excretion rates will be measured with Sebutape® applied to the right and left forehead at each visit. Each Sebutape® will be scanned and the area covered by sebum, seen as gray-black dots on the scanned Sebutape®, will be measured by an image analysis software. Circulating levels of free testosterone and DHEAS will be measured at each visit. A skin biopsy behind an ear will be performed at Day 0 and Day 7 to measure gene expression of the 5-α-reductase type 1. On Day 0 and Day 7, subjects will be required to take a 24-hour recall questionnaire. On Day 0 and Day 7, subjects will be questioned about the time of sleep induction, their total sleep time for the night preceding the visit, facial washing routine and the number of hours of direct and indirect UV exposure in the past 24 hours. On Day 0 and Day 7, subject's forehead skin temperature will be measured.