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Effects of Obesity on Autophagy and mTORC1 Signalling in Skeletal Muscle

17 de agosto de 2026 actualizado por: Nathan Hodson, University of Birmingham

Understanding the Effects of Obesity on Autophagic and mTORC1 Signalling Following Resistance Exercise and Protein Ingestion in Skeletal Muscle.

It is well known that individuals living with overweight or obesity are not able to activate skeletal muscle growth processes to the same extent as lean individuals following activities such as weightlifting (resistance exercise) or protein ingestion. However, the underlying cell signalling pathways which may be regulating these impairments are not fully understood. This study aims to understand if skeletal muscle signalling responses to resistance exercise and protein intake differ between lean individuals and those living with overweight or obesity. The investigators will recruit a cohort of lean individuals and a cohort of individuals living with overweight/obesity who will undertake a bout of single-leg resistance exercise and consume a protein-rich drink. Before and after this, muscle samples will be obtained from each leg of participants at different timepoints to understand the effects of exercise and feeding combined (exercised leg) and feeding alone (rested leg) on different cellular processes which regulate muscle growth. This will allow the investigators to understand if their are specific pathways within skeletal muscle which could be targeted in future interventions to overcome impaired protein metabolism in those living with overweight/obesity.

Descripción general del estudio

Estado

Reclutamiento

Condiciones

Intervención / Tratamiento

Descripción detallada

As skeletal muscle is a major contributor to basal metabolic rate and glucose control, increasing the quality of skeletal muscle in those living with obesity could improve the long-term success of subsequent weight loss programs. There are two main activities which are often recommended to improve skeletal muscle quality, resistance exercise (i.e. weightlifting) and adequate protein intake, however, recent research has suggested that individuals living with obesity do not respond as well to these activities as a non-obese person. This research project aims to investigate if certain processes within muscle cells, which regulate muscle size and quality, are reduced in people living with obesity following a single session of resistance exercise and a protein-rich drink. This will hopefully identify processes we can target specifically to improve skeletal muscle quality. The project involves participants attending the lab and completing a session of single-leg resistance exercise and ingesting a protein drink. Before and after this the investigators will take a number of blood samples and small pieces of muscle from each thigh to understand how muscle reacts to exercise/feeding and whether this differs between individuals with and without obesity. Following the visit investigators will the conduct a variety of laboratory analysis on these samples to understand the responses. Overall, this project has the potential to help design future programmes which can improve skeletal muscle quality in those living with obesity, improving general health and increasing success of weight loss interventions.

To date, the acute effects anabolic stimulation by resistance exercise and protein ingestion in individuals with obesity have been shown to be blunted. However, the mechanisms responsible for this have scarcely been investigated. We intend to build on current evidence by identifying what causes this blunted response to anabolic stimulation in individuals with obesity.

This project aims to determine whether individuals with obesity exhibit differential mTORC1-lysosomal translocation in response to anabolic signaling following a single bout of resistance exercise combined with protein ingestion.

Tipo de estudio

De observación

Inscripción (Estimado)

24

Contactos y Ubicaciones

Esta sección proporciona los datos de contacto de quienes realizan el estudio e información sobre dónde se lleva a cabo este estudio.

Estudio Contacto

  • Nombre: Jennifer Barrett, PhD
  • Número de teléfono: +447875713844
  • Correo electrónico: j.s.barrett@bham.ac.uk

Ubicaciones de estudio

  • Reino Unido
      • Birmingham, Reino Unido, B152TT
        • Reclutamiento
        • School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham
        • Contacto:
        • Contacto:
        • Investigador principal:
          • Nathan Hodson, PhD
        • Sub-Investigador:
          • Jennifer Barrett, PhD
        • Sub-Investigador:
          • Jordan Acheson, MSc

Criterios de participación

Los investigadores buscan personas que se ajusten a una determinada descripción, denominada criterio de elegibilidad. Algunos ejemplos de estos criterios son el estado de salud general de una persona o tratamientos previos.

Criterio de elegibilidad

Edades elegibles para estudiar

  • Adulto

Acepta Voluntarios Saludables

Sí

Método de muestreo

Muestra no probabilística

Población de estudio

Participants will be recruited from around the West Midlands area via recruitment media.

Descripción

Inclusion Criteria:

  • Age - 18-45yrs
  • BMI - 18.5-24.9kg/m2 OR >28kg/m2 (self-declaration, or calculated by research team based on height and weight)
  • Weight Stable i.e. no change in weight of more than 5% in previous 6 months
  • Meeting UK Physical activity guidelines (150 mins moderate or 75 mins vigorous activity/wk)
  • Not involved in structured exercise training in previous 6 months
  • No other diagnosed metabolic or neuromuscular conditions (self-declaration)

Exclusion Criteria:

  • Currently using anti-diabetes medication (insulin, metformin, sulphonylureas, meglitinides, thiazolidinediones, DPP- 4 inhibitors, GLP-1 inhibitors).
  • Currently taking cholesterol lowering medications (statins)
  • Currently engaged in active weight loss programmes or using weight loss medication
  • Chronic kidney disease (moderate to severe reduction in kidney function), defined as eGFR <30 ml/min/1.73m2 identified by self declaration.
  • Pregnant or breast feeding
  • Currently using anti-coagulation medication
  • Hypothyroidism
  • Type 1 diabetes
  • Current or recent weakness/injury to either leg that may affect muscle function or ability to exercise
  • Current gastrointestinal issue/condition that may affect digestion and absorption of protein drink
  • Individuals who follow a vegan diet or have intolerance/allergies to Whey protein.
  • Previous adverse reaction to local anaethetic (lidocaine or marcaine).

Plan de estudios

Esta sección proporciona detalles del plan de estudio, incluido cómo está diseñado el estudio y qué mide el estudio.

¿Cómo está diseñado el estudio?

Detalles de diseño

Cohortes e Intervenciones

Grupo / Cohorte
Intervención / Tratamiento
Lean Individuals
This cohort will be aged between 18-45yrs and have a Body Mass index (BMI) of 18.5-25.9kg/m2. They will also have been weight-stable (<5% bodyweight change in previous 6 months).
Procedimiento: Skeletal muscle biopsy
On five occasions throughout the experimental visit, skeletal muscle biopsies will be obtained from the vastus lateralis of participants (3 in rested leg, 2 in exercised leg). These will be completed under local anaesthetic using the Bergstrom needle technique, modified for suction.
Procedimiento: venous blood sampling
Upon arrival at the experimental visit, participant will have a cannula inserted into their antecubital vein for repeated blood sampling. 12 blood samples will then be taken throughout the course of the experimental trial from which both plasma and serum will be isolated.
Suplemento dietético: Protein-Rich Beverage
Following completion of the acute, single-leg resistance exercise bout, participants will consumed a protein-rich beverage containing 0.25g/kg bodyweight whey protein (dissolved in 300ml water).
Otro: Single-leg resistance exercise
During the experimental visit, participants will complete an acute bout of single-leg knee extensions on a randomised leg. This will be comprised of 6 sets of knee extensions at 80% of participants pre-determined 1 repetition maximum (1RM), with each set completed to volitional failure separated by a 2 minute rest interval.
Radiación: Dual-Energy X-ray Absorptiometry (DEXA) Scan
During Visit 1 of the study, participants will undergo a whole-body DEXA scan to assess body composition (body fat and fate-free mass). This short, painless scan exposes participants to a small amount of radiation which is equivalent to the amount exposed to during a transatlantic flight.
Otro: Maximal Strength Testing
During Visit 1 of the study, participants will undergo maximal knee extension strength testing using a randomised leg (which will complete exercise during experimental trial). This will involve increasing the weight on the knee extension machine until the participant can no longer complete a single repetition. This weight will then be used to calculate the workload at which the participant will complete the exercise bout during the experimental trial.
Otros nombres:
  • 1RM testing
Individuals with Overweight or Obesity
This cohort will be aged between 18-45yrs and have a Body Mass index (BMI) of >28kg/m2. They will also have been weight-stable (<5% bodyweight change in previous 6 months).
Procedimiento: Skeletal muscle biopsy
On five occasions throughout the experimental visit, skeletal muscle biopsies will be obtained from the vastus lateralis of participants (3 in rested leg, 2 in exercised leg). These will be completed under local anaesthetic using the Bergstrom needle technique, modified for suction.
Procedimiento: venous blood sampling
Upon arrival at the experimental visit, participant will have a cannula inserted into their antecubital vein for repeated blood sampling. 12 blood samples will then be taken throughout the course of the experimental trial from which both plasma and serum will be isolated.
Suplemento dietético: Protein-Rich Beverage
Following completion of the acute, single-leg resistance exercise bout, participants will consumed a protein-rich beverage containing 0.25g/kg bodyweight whey protein (dissolved in 300ml water).
Otro: Single-leg resistance exercise
During the experimental visit, participants will complete an acute bout of single-leg knee extensions on a randomised leg. This will be comprised of 6 sets of knee extensions at 80% of participants pre-determined 1 repetition maximum (1RM), with each set completed to volitional failure separated by a 2 minute rest interval.
Radiación: Dual-Energy X-ray Absorptiometry (DEXA) Scan
During Visit 1 of the study, participants will undergo a whole-body DEXA scan to assess body composition (body fat and fate-free mass). This short, painless scan exposes participants to a small amount of radiation which is equivalent to the amount exposed to during a transatlantic flight.
Otro: Maximal Strength Testing
During Visit 1 of the study, participants will undergo maximal knee extension strength testing using a randomised leg (which will complete exercise during experimental trial). This will involve increasing the weight on the knee extension machine until the participant can no longer complete a single repetition. This weight will then be used to calculate the workload at which the participant will complete the exercise bout during the experimental trial.
Otros nombres:
  • 1RM testing

¿Qué mide el estudio?

Medidas de resultado primarias

Medida de resultado
Medida Descripción
Periodo de tiempo
mTORC1-lysosomal translocation
Periodo de tiempo: From completion of experimental testing/biosample collection until end of study, an average of 1 year.
The translocation of the mTORC1-lysosomal complex toward the cell periphery following resistance exercise and/or protein ingestion will be assessed in skeletal muscle cross sections via immunofluorescence microscopy.
From completion of experimental testing/biosample collection until end of study, an average of 1 year.

Medidas de resultado secundarias

Medida de resultado
Medida Descripción
Periodo de tiempo
mTORC1 activation
Periodo de tiempo: From completion of experimental testing/biosample collection until end of study, an average of 1 year.
Markers of mTORC1 activation (phosphorylation of downstream signalling targets) will be assessed via immunoblotting on homogenised skeletal muscle samples.
From completion of experimental testing/biosample collection until end of study, an average of 1 year.
Autophagic Flux
Periodo de tiempo: From completion of experimental testing/biosample collection until end of study, an average of 1 year.
Skeletal muscle autophagic flux will be assessed on skeletal muscle samples using a novel ex vivo assay followed by immunoblotting.
From completion of experimental testing/biosample collection until end of study, an average of 1 year.
Lysosomal Content
Periodo de tiempo: From completion of experimental testing/biosample collection until end of study, an average of 1 year.
Skeletal muscle lysosomal content will be assessed via immunoblotting for markers of the lysosome on homogenised skeletal muscle samples
From completion of experimental testing/biosample collection until end of study, an average of 1 year.

Otras medidas de resultado

Medida de resultado
Medida Descripción
Periodo de tiempo
Circulating Amino Acids Concentrations
Periodo de tiempo: From completion of experimental testing/biosample collection until end of study, an average of 1 year.
Amino acid concentrations will be assessed via high performance liquid chromatography to determine how much of the protein ingested arrives in circulation
From completion of experimental testing/biosample collection until end of study, an average of 1 year.
Circulating Hormone Concentrations
Periodo de tiempo: From completion of experimental testing/biosample collection until end of study, an average of 1 year.
Hormones associated with glycaemic control (glucose & insulin) will be assessed in plasma/serum samples via colorometric assay or ELISA
From completion of experimental testing/biosample collection until end of study, an average of 1 year.

Colaboradores e Investigadores

Aquí es donde encontrará personas y organizaciones involucradas en este estudio.

Patrocinador

University of Birmingham

Investigadores

  • Investigador principal: Nathan Hodson, University of Birmingham

Fechas de registro del estudio

Estas fechas rastrean el progreso del registro del estudio y los envíos de resultados resumidos a ClinicalTrials.gov. Los registros del estudio y los resultados informados son revisados ​​por la Biblioteca Nacional de Medicina (NLM) para asegurarse de que cumplan con los estándares de control de calidad específicos antes de publicarlos en el sitio web público.

Fechas importantes del estudio

Inicio del estudio (Actual)

15 de abril de 2026

Finalización primaria (Estimado)

1 de diciembre de 2026

Finalización del estudio (Estimado)

1 de diciembre de 2027

Fechas de registro del estudio

Enviado por primera vez

12 de agosto de 2026

Primero enviado que cumplió con los criterios de control de calidad

17 de agosto de 2026

Publicado por primera vez (Actual)

19 de agosto de 2026

Actualizaciones de registros de estudio

Última actualización publicada (Actual)

19 de agosto de 2026

Última actualización enviada que cumplió con los criterios de control de calidad

17 de agosto de 2026

Última verificación

1 de agosto de 2026

Más información

Términos relacionados con este estudio

Palabras clave

Términos MeSH relevantes adicionales

Otros números de identificación del estudio

  • RG_25-084

Plan de datos de participantes individuales (IPD)

¿Planea compartir datos de participantes individuales (IPD)?

SÍ

Descripción del plan IPD

IPD used in publications arising from the project will be shared upon request

Marco de tiempo para compartir IPD

IPD will be available upon request following publication of the IPD with no end date

Criterios de acceso compartido de IPD

Qualified researchers with an approved scientifically sound research proposal from recognized academic, clinical, or commercial institutions can request IPD from the principal investigator. In such cases, the de-identified data long with the study protocol will be provided via a secure cloud-based research environment.

Tipo de información de apoyo para compartir IPD

  • PROTOCOLO DE ESTUDIO

Información sobre medicamentos y dispositivos, documentos del estudio

Estudia un producto farmacéutico regulado por la FDA de EE. UU.

No

Estudia un producto de dispositivo regulado por la FDA de EE. UU.

No

Esta información se obtuvo directamente del sitio web clinicaltrials.gov sin cambios. Si tiene alguna solicitud para cambiar, eliminar o actualizar los detalles de su estudio, comuníquese con register@clinicaltrials.gov. Tan pronto como se implemente un cambio en clinicaltrials.gov, también se actualizará automáticamente en nuestro sitio web. .

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