The Effect of Sleep on Tendon Cellular Adaptation (TSS)

The Effect of Sleep on Human Tendon Cellular Remodeling: a ex Vivo Pilot Study.

The goal of this observational study is to evaluate the effect of hormones which surge or diminish during different stages of sleep on collagen turnover in tendon cells. The main questions it aims to answer are:

1. To evaluate the effect of serum taken from participants overnight on human tendon cell-derived collagen expression in a cell culture model.
2. To evaluate whether tendon cell-derived collagen expression in a cell culture model is driven by changes in collagen synthesis or breakdown.

To evaluate the effect of sleep on tendon adaptation, blood will be taken from human participants overnight and used to treat a tendon cell culture model.

Study Overview

• Status: Recruiting
• Conditions: Sleep; Cell Culture Techniques; Collagen Turnover; Tendon

Detailed Description

Recent clinical evidence has linked poor sleep with increased risk of musculoskeletal injury while evidence from basic biological models indicates that growth hormone and cortisol may regulate the turnover of collagen, a key structural protein in tendons. Growth hormone concentration in the blood surges during deep sleep (~1-2 hr after sleep onset), while cortisol concentration reaches a nadir at this same time. It remains unclear whether serum containing these hormones, collected during sleep itself, can modulate collagen turnover processes. Therefore, the purpose of this study is to evaluate the effect of hormones which surge or diminish during different stages of sleep on collagen turnover in tendon cells.

This study will use a within-subjects design to collect serum for ex vivo experiments. The total study duration will be ~8 days. Participants will first be screened to ensure compliance with our inclusion and exclusion criteria. Written informed consent will be obtained from participants that pass screening. Twelve participants will be recruited in total (6 male, 6 female). Participants will complete a 7 night sleep diary while wearing two wearable devices (an accelerometer to measure physical activity and basic sleep outcomes, worn on the waist; a Fitbit to estimate sleep stages and sleep onset). After the sleep diary, participants will arrive at the laboratory following an overnight fast for a resting venous blood collection. They will return to the laboratory to sleep overnight in the Nutrition and Metabolism Research Group's Bed Rest Facility. Approximately 95 minutes following sleep onset, participants will be briefly awoken for a venous blood draw (i.e., deep sleep sample), before returning to sleep. Four hours after the deep sleep sample, participants will be briefly woken up for a venous blood draw (i.e., REM sleep sample). Participants will then be allowed to finish their night of sleep in the facility.

Commercially available human tenocytes will be treated with serum from the different timepoints (morning, deep/early sleep, REM/late sleep) for 7 days. Following the 7 day treatment period, tenocytes will be collected and collagen I and III expression will be assessed by immunoblot while stable isotope tracers will be used to quantify collagen synthesis and breakdown.

The primary objective of the study is to evaluate the effect of the nocturnal biochemical milieu on human tenocyte-derived collagen expression in vitro. The secondary objectives of the study is to assess whether changes in collagen expression are due to altered collagen synthesis and/or breakdown.

• Study Type: Observational
• Enrollment (Estimated): 12

Contacts and Locations

• Study Contact: Name: Paul L Babits, MSc; Phone Number: 647-609-4710; Email: paul.babits@mail.utoronto.ca
• Study Contact Backup: Name: Dan R Moore, PhD; Phone Number: 416-946-4088; Email: dr.moore@utoronto.ca

Study Locations

• Canada
  • Ontario
    • Kingston, Ontario, Canada, K7L 3N6
      • Recruiting
      • School of Kinesiology and Health Studies Building
      • Contact: Chris McGlory, PhD; Phone Number: 75410 613-533-6000; Email: chris.mcglory@queensu.ca

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 35 years (Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Resident of Kingston, Ontario

Description

Inclusion Criteria:

• healthy (determined using a medical screening questionnaire)
• between the ages of 18 and 35
• participants must be a non-smoker
• self-reported moderately active (>150 minutes of moderate-to-vigorous physical activity per week)
• self-reported weight stable (< 2 kg increase or decrease in weight over the previous 6 months)
• sleep ≥ 7 hours per night
• female participants must have a stable menstrual cycle (>3 months of 21-35 day cycle length).

Exclusion Criteria:

• have a BMI <18.5 or >29.9 kg/m2
• have a history of clinically diagnosed insomnia (>7 on the Insomnia Severity Index) or other sleep disorder (e.g., sleep apnea)
• use a hormonal contraceptive (oral or IUD)
• consume 7+ standard drinks per week (high risk range)
• use cannabis >1 time per week
• have any concurrent medical, orthopedic, or psychiatric condition that, in the opinion of the investigators, would compromise the ability to comply with the study requirements
• regularly use anti-inflammatory and/or analgesic medication, whether prescription or not; use any medications known to affect collagen metabolism (e.g., glucocorticoids, acetaminophen, non-steroidal anti-inflammatory medication, or prescription strength acne medication, ACE inhibitors, proton pump inhibitors, growth hormone, GLP-1 receptor agonists);
• participated in a study involving a phenylalanine stable-isotope tracer in the previous year

Study Plan

How is the study designed?

Design Details

• Observational Models: COHORT
• Time Perspectives: PROSPECTIVE

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort
Healthy, young males and females.; Healthy, recreationally active, young adults (18-35) regularly getting > 7 h of sleep per night are the target population. There is no intervention for this study.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Collagen Expression	Tenocyte-derived collagen expression will be assessed following a 7 day treatment period using daytime, early/deep sleep, and late/REM sleep by immunoblot.	Ex vivo experiments and immunoblot analysis will conclude approximately 12 weeks following serum collection.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Collagen Synthesis	On the last day of the 7 day serum incubation, cells will be treated with a stable-isotope tracer for 6hrs to measure incorporation of this tracer into tenocyte collagen and thus collagen synthesis.	Ex vivo experiments and immunoblot analysis will conclude approximately 12 weeks following serum collection.
Collagen breakdown	Cells will be treated with a stable isotope tracer during a 7 day serum incubation. Six hours prior to collection, tracer will be withdrawn and tracer release into the media will be measured to estimate collagen breakdown.	Ex vivo experiments and immunoblot analysis will conclude approximately 12 weeks following serum collection.

Collaborators and Investigators

• Sponsor: University of Toronto
• Collaborators: Tanenbaum Institute for Science in Sport
• Investigators: Principal Investigator: Chris McGlory, PhD, Queen's University; Principal Investigator: Dan R Moore, PhD, University of Toronto

Study record dates

Study Major Dates

• Study Start (Estimated): November 10, 2026
• Primary Completion (Estimated): February 1, 2027
• Study Completion (Estimated): May 1, 2027

Study Registration Dates

• First Submitted: November 5, 2026
• First Submitted That Met QC Criteria: November 5, 2026
• First Posted (Actual): November 12, 2026

Study Record Updates

• Last Update Posted (Actual): November 12, 2026
• Last Update Submitted That Met QC Criteria: November 5, 2026
• Last Verified: November 1, 2026

More Information

Terms related to this study

• Keywords: Sleep; Tendon; Collagen Turnover; Cell Culture Techniques
• Other Study ID Numbers: TSS; TISS FKPE Seed Grant (Other Grant/Funding Number: Tanenbaum Institute for Science in Sport)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES

IPD Plan Description

This study is a collaboration between the McGlory and Moore research groups. Therefore, sleep and activity data will be shared between groups. Serum collected from sleep trials at the McGlory lab will also be shared with the Moore lab where ex vivo experiments will be conducted. However, no identifying information collected by the McGlory lab will be shared with the Moore lab.

IPD Sharing Time Frame

IPD collected by the McGlory lab will be made available to collaborators at the Moore lab following completion of data collection (estimated October 2026) until the time of publication (estimated November 2027).

IPD Sharing Access Criteria

Paul Babits and Dr. Daniel Moore will have access sleep, activity data as well as serum collected during overnight trials. Electronic data will be shared via secure servers. Serum will be shipped between sites following the completion of data collection.

• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No