Immunosenescence, Aging
Conditions
Keywords
Aerobic exercise, Elderly, Aging, Institutionalized, Immune system, Immunosenescence
Brief summary
Background: Immunosenescence is an age-related decline in immune function, associated with chronic low-grade inflammation, increased morbidity, and functional impairment in older adults. Aerobic exercise has been proposed as an effective non-pharmacological strategy to counteract these alterations; however, evidence from randomized-controlled trials (RCTs), particularly in institutionalized elderly populations, remains scarce and methodologically limited. Objective: This study protocol aims to investigate the effects of short- and medium-term aerobic exercise programs on immunosenescence in institutionalized older adults, as well as to analyze the impact of a detraining period and a subsequent reintervention. Methods: A stratified RCT will be conducted with institutionalized adults aged ≥60 years, randomly allocated to an aerobic exercise group or a control group. The intervention consists of a supervised 12-week moderate-intensity aerobic exercise program (three sessions/week), followed by a 4-week detraining period and a 4-week reintervention. Assessments will be performed at five time points. Primary outcomes include immunological and analytical parameters assessed by spectral flow cytometry and multiplex cytokine analysis. Secondary outcomes include anthropometry, functional capacity, hemodynamic parameters, heart rate variability, and psychological indicators. Expected Results: Aerobic exercise is expected to induce favorable immunological adaptations, partially reverse immunosenescence, and improve functional and psychosocial outcomes.
Detailed description
This investigation will be based on a stratified randomized intervention. Participants will initially be stratified according to clinical conditions. Within each stratum, a 1:1 randomization will be performed to the experimental group (AERG) and control group (CG) using software SPSS. The randomization sequence will be generated using variable-size permuted blocks to ensure a balance in the number of participants in each group and reduce the risk of allocation predictability. Randomization will be performed by a researcher external to the data collection and intervention implementation process. The randomization will be stored in an encrypted file until the start of the intervention, ensuring allocation concealment. An aerobic exercise program (12 weeks) will be implemented, followed by a detraining period (4 weeks) and the implementation of a second intervention (4 weeks). Primary outcomes include analysis of analytical parameters and cellular assessment. Secondary outcomes include anthropometric analysis, functional capacity, hemodynamic parameters, and psychological parameters. All participants will be assessed at five distinct time points, as shown in Figure 1: before the intervention (T0), at 6 weeks (T6) and at 12 weeks (T12) of intervention, after the detraining period (T16), and after the second intervention (T20).
Interventions
BEHAVIORALAerobic exercise program
Supervised moderate-intensity aerobic exercise program based on ACSM and WHO recommendations. Sessions will be delivered 3 times per week for 60 minutes, fully supervised by a certified exercise professional. Each session includes: (1) 5-10 min warm-up (joint mobility and light walking), (2) 30-50 min continuous aerobic exercise (primarily walking) targeting large muscle groups at 50-70% HRmax (Borg RPE 5-7), and (3) 5-10 min active recovery and static stretching. Intensity and progression will follow ACSM guidance, starting at light-to-moderate intensity and increasing continuous aerobic duration by \~5 min/week during the first 4 weeks, with subsequent individualized adjustments according to participants' adaptations. Adherence will be tracked via attendance logs, with ≥80% session attendance required for adequate compliance. Safety will be ensured through continuous monitoring for adverse events (e.g., chest pain, palpitations, abnormal dyspnea) with immediate session interruption an
Sponsors
Instituto Politécnico de Castelo Branco
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
DOUBLE (Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
60 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
Participants must be aged 60 years or older and institutionalized. Studying institutionalised older adults ensures greater uniformity in diet, daily routines, behaviours, and environmental exposures, thereby minimising the impact of external factors other than the exercise intervention.
Exclusion criteria
Participants will be excluded if they have acute conditions that may affect their immune or inflammatory responses. These conditions include recent trauma or surgery (within the previous six months), recent blood transfusions (within the previous month), acute infections (such as respiratory, gastrointestinal, or urinary infections), recent vaccinations, and the use of medications that may interfere with immune responses (such as immunomodulators, systemic corticosteroids, methotrexate, and biologics).
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Sodium | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Serum sodium concentration measured from peripheral blood samples. Unit of measure: mmol/L |
| Potassium | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Serum potassium concentration measured from peripheral blood samples. Unit of measure: mmol/L |
| Chloride | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Serum chloride concentration measured from peripheral blood samples. Unit of measure: mmol/L |
| Calcium | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Total serum calcium concentration measured from peripheral blood samples. Unit of measure: mg/dL |
| Phosphorus | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Serum phosphorus concentration measured from peripheral blood samples. Unit of measure: mg/dL |
| Magnesium | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Serum magnesium concentration measured from peripheral blood samples. Unit of measure: mg/dL |
| Aspartate aminotransferase (AST) | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Serum AST activity measured from peripheral blood samples. Unit of measure: U/L |
| Alanine aminotransferase (ALT) | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Serum ALT activity measured from peripheral blood samples. Unit of measure: U/L |
| Gamma-glutamyl transferase (GGT) | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Serum gamma-glutamyl transferase activity measured from peripheral blood samples. Unit of measure: U/L |
| Total bilirubin | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Total bilirubin concentration measured from peripheral blood samples. Unit of measure: mg/dL |
| Direct bilirubin | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Direct bilirubin concentration measured from peripheral blood samples. Unit of measure: mg/dL |
| Alkaline phosphatase | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Serum alkaline phosphatase activity measured from peripheral blood samples. Unit of measure: U/L |
| Lactate dehydrogenase (LDH) | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Serum lactate dehydrogenase activity measured from peripheral blood samples. Unit of measure: U/L |
| Total cholesterol | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Total cholesterol concentration measured from peripheral blood samples. Unit of measure: mg/dL |
| HDL cholesterol | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | High-density lipoprotein cholesterol concentration measured from peripheral blood samples. Unit of measure: mg/dL |
| LDL cholesterol | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Low-density lipoprotein cholesterol concentration measured from peripheral blood samples. Unit of measure: mg/dL |
| Triglycerides | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Serum triglyceride concentration measured from peripheral blood samples. Unit of measure: mg/dL |
| Amylase | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Serum amylase activity measured from peripheral blood samples. Unit of measure: U/L |
| Urea | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Serum urea concentration measured from peripheral blood samples. Unit of measure: mg/dL |
| Creatinine | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Serum creatinine concentration measured from peripheral blood samples. Unit of measure: mg/dL |
| Uric acid | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Serum uric acid concentration measured from peripheral blood samples. Unit of measure: mg/dL |
| Total proteins | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Total serum protein concentration measured from peripheral blood samples. Unit of measure: g/dL |
| Albumin | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Serum albumin concentration measured from peripheral blood samples. Unit of measure: g/dL |
| Glucose | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Fasting blood glucose concentration measured from peripheral blood samples. Unit of measure: mg/dL |
| Glycated haemoglobin (HbA1c) | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Glycated haemoglobin measured from peripheral blood samples. Unit of measure: % |
| Creatine kinase (CK) | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Serum creatine kinase activity measured from peripheral blood samples. Unit of measure: U/L |
| Red blood cell count | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Red blood cell count measured from peripheral blood samples. Unit of measure: 10\^6/µL |
| Haemoglobin | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Haemoglobin concentration measured from peripheral blood samples. Unit of measure: g/dL |
| Haematocrit | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Haematocrit measured from peripheral blood samples. Unit of measure: % |
| White blood cell count | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | White blood cell count measured from peripheral blood samples. Unit of measure: 10\^3/µL |
| Platelet count | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Platelet count measured from peripheral blood samples. Unit of measure: 10\^3/µL |
| Natural killer (NK) cell count | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Natural killer cell count measured by spectral flow cytometry from peripheral blood samples. Unit of measure: cells/µL and % |
| CD3+ T cell count | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | CD3+ T lymphocyte count measured by spectral flow cytometry from peripheral blood samples. Unit of measure: cells/µL |
| CD4+ T cell count | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | CD4+ T lymphocyte count measured by spectral flow cytometry from peripheral blood samples. Unit of measure: cells/µL |
| CD8+ T cell count | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | CD8+ T lymphocyte count measured by spectral flow cytometry from peripheral blood samples. Unit of measure: cells/µL |
| B cell count | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | B lymphocyte count measured by spectral flow cytometry from peripheral blood samples. Unit of measure: cells/µL |
| Interleukin-6 (IL-6) | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Plasma IL-6 concentration measured using multiplex technology from peripheral blood samples. Unit of measure: pg/mL |
| Tumour necrosis factor-alpha (TNF-α) | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Plasma TNF-α concentration measured using multiplex technology from peripheral blood samples. Unit of measure: pg/mL |
| Interleukin-10 (IL-10) | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Plasma IL-10 concentration measured using multiplex technology from peripheral blood samples. Unit of measure: pg/mL |
| Interleukin-1 beta (IL-1β) | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Plasma IL-1β concentration measured using multiplex technology from peripheral blood samples. Unit of measure: pg/mL |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Height | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Height measured using a portable stadiometer. Unit of measure: m |
| Weight | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Body weight measured using a portable scale. Unit of measure: kg |
| Body mass index (BMI) | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Body mass index calculated from height and body weight. Unit of measure: kg/m² |
| Visceral fat | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Visceral fat measured using a portable scale. Unit of measure: score |
| Body fat percentage | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Body fat percentage measured using a portable scale. Unit of measure: % |
| Muscle mass percentage | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Muscle mass percentage measured using a portable scale. Unit of measure: % |
| Waist circumference | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Waist circumference measured using a retractable fiberglass tape measure. Unit of measure: cm |
| Arm circumference | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Arm circumference measured using a retractable fiberglass tape measure. Unit of measure: cm |
| Leg circumference | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Leg circumference measured using a retractable fiberglass tape measure. Unit of measure: cm |
| 30-Second Chair Stand Test | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Number of full stands completed in 30 seconds from a seated position, used to assess lower body strength. Unit of measure: repetitions |
| 30-Second Arm Curl Test | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Number of arm curls completed in 30 seconds, used to assess upper body strength. Unit of measure: repetitions |
| 6-Minute Walk Test | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Distance covered in 6 minutes while walking, used to assess cardiorespiratory endurance. Unit of measure: meters |
| Chair Sit-and-Reach Test | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Distance between the extended fingers and the tip of the toe in the seated sit-and-reach position, used to assess lower body flexibility. Unit of measure: cm |
| Back Scratch Test | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Distance between the middle fingers when reaching one hand over the shoulder and the other up the middle of the back, used to assess upper body flexibility. Unit of measure: cm |
| 8-Foot Up-and-Go Test | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Time taken to rise from a chair, walk 8 feet, turn, and return to the seated position, used to assess agility and dynamic balance. Unit of measure: seconds |
| Heart rate (HR) | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Resting heart rate measured using an automatic digital sphygmomanometer. The average of three measurements will be recorded. Unit of measure: beats per minute (bpm) |
| Systolic blood pressure (SBP) | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Resting systolic blood pressure measured using an automatic digital sphygmomanometer. The average of three measurements will be recorded. Unit of measure: mmHg |
| Diastolic blood pressure (DBP) | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Resting diastolic blood pressure measured using an automatic digital sphygmomanometer. The average of three measurements will be recorded. Unit of measure: mmHg |
| Heart rate variability (HRV) | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Heart rate variability assessed during a 10-minute resting test using a heart rate monitor in a calm, quiet, and dimly lit environment. Data will be transferred from the Polar Flow Web Service for analysis. Unit of measure: ms |
| Perceived stress | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Perceived stress assessed using the Perceived Stress Scale (PSS). Unit of measure: score |
| General health status | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Health-related quality of life assessed using the EuroQol (EQ-5D). Unit of measure: score |
| Life satisfaction | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Satisfaction with life assessed using the Satisfaction With Life Scale (SWLS). Unit of measure: score |
| Positive affect | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Positive affect assessed using the Positive and Negative Affect Schedule (PANAS). Unit of measure: score |
| Negative affect | Baseline (T0); After 6 weeks of intervention (T6); After 12 weeks of intervention (T12); After 4 week detraining (T16); After 4 weeks re-intervention (T20) | Negative affect assessed using the Positive and Negative Affect Schedule (PANAS). Unit of measure: score |
Contacts
CONTACTCarlos M Farinha, Carlos Farinha, Dr.
Outcome results
None listed