The Effect of Menstrual Phase and Oral Contraceptives on Muscle Protein Metabolism
Trial Snapshot
- Phase
- Not Applicable
- Status
- Recruiting
- Sponsor
- University of Toronto
- Enrollment
- 10
- Locations
- 1
- Primary Endpoint
- Protein Synthesis (Murine Cell-Based Experiments, ex-vivo experiments)
Study Overview
Brief Summary
Despite comprising half the population, females are often left out of muscle research due to the impact of changing hormones during the menstrual cycle and when using oral contraceptives. This makes it hard to perform costly and invasive studies involving tracers to study muscle protein metabolism. Consequently, we lack a clear understanding of how these hormonal changes affect muscle growth.
There is a need for less invasive methods to study how sex hormones and oral contraceptives influence muscle protein metabolism. Ex vivo models, where serum from participants is applied to mouse muscle cell cultures, mimic the conditions of human muscle cells and can provide initial insights.
Detailed Description
The aim of the study is to develop a non-invasive model using serum from both oral contraceptive users and non-users at various stages of their cycles, to understand if different cycle or pill stages affect how muscles process proteins.
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Crossover
- Primary Purpose
- Other
- Masking
- None
Eligibility Criteria
- Ages
- 18 Years to 35 Years (Adult)
- Sex
- Female
- Accepts Healthy Volunteers
- Yes
Inclusion Criteria
- •BMI between 18.5-29.9 kg/m2 (I.e., non-obese).
- •For OC users: on monophasic OCs for > 3 months prior to study enrollment
- •For non-OC users: regular menstrual cycles length (25-35 days) for at least 3 months prior to study and at least 6 months off of OCs.
Exclusion Criteria
- •Chronic disease diagnosis (cardiovascular, thyroid, diabetes)
- •Current or recent remission of cancer
- •Regular use of NSAID (except low-dose aspirin), anticoagulants
- •Use of prescription drugs that would impact metabolism, e.g. Statins, Lithium, Attention-Deficit/Hyperactivity Disorder (ADHD) medication.
- •Insertion of intrauterine device (IUD) - exception: copper
- •Use of ergogenic aids such as creatine
- •Regular Tabacco use
- •Use of illicit drugs (growth hormones, testosterone)
- •For non-OC users: Use of oral contraceptives for > 6 months prior to study enrollment - to ensure return to regular menstrual cycle.
Arms & Interventions
Mid-Follicular Phase
7-11 days after onset of menses.
Intervention: Protein tracer drink (Behavioral)
Mid-Luteal Phase
5-9 days after ovulation (as confirmed with ovulation test kits).
Intervention: Protein tracer drink (Behavioral)
Active pill phase
10-20 days after starting new pill cycle.
Intervention: Protein tracer drink (Behavioral)
Withdrawal phase
48hrs after last pill (during placebo pill phase).
Intervention: Protein tracer drink (Behavioral)
Outcomes
Primary Outcomes
Protein Synthesis (Murine Cell-Based Experiments, ex-vivo experiments)
Time Frame: 60 minutes
Investigators will use human serum obtained from fasted and fed timepoints (-15, 20, 40 and 60 minutes following beverage consumption) to condition cell culture media (20% volume). To determine the effects of using fasted and/or fed 'human-conditioned' culture media on cell protein synthesis, puromycin incorporation (measure of protein synthesis) will be measured via western blot and expressed relative to a no-serum control. A two-way repeated measures ANOVA will be used to analyze outcomes with cycle stage and group (OC vs non-OC) used as factors
Secondary Outcomes
- Whole-body protein synthesis(6 hours)
- Urinary Measures (Muscle Protein Breakdown)(6 hours)
Investigators
Daniel Moore
Associate Professor
University of Toronto