Evaluation of the Effects of Systemic Vibration Therapy on Thermogenesis, Cardiovascular Parameters, Endocrine-inflammatory Markers, and Physical-functional Performance in Adults With Obesity.

Thermogenin (Uncoupling Protein 1 [UCP1]) was measured before and immediately after the WBV session. Blood samples were collected by a trained professional at the PPC/UERJ Clinical Analysis Laboratory (Capsule Unit), always during the same morning shift and no later than 8:00 a.m. For peripheral blood assays, serum and plasma collection tubes were centrifuged at 2,000 rpm at 25°C. Subsequently, 500 µL of serum was aliquoted into two microtubes and stored at -80°C until analysis. Serum UCP1 concentrations were determined using a specific enzyme-linked immunosorbent assay (ELISA) kit according to the manufacturer's instructions. Optical density (OD) was measured using a Thermo Scientific spectrophotometer.

The endocrine-inflammatory profile was assessed by measuring Interleukin-1 beta (IL-1β), Interleukin-1 Receptor Antagonist (IL-1RA), Interleukin-6 (IL-6), Interleukin-8 (IL-8), Interleukin-10 (IL-10), Tumor Necrosis Factor-alpha (TNF-α), Soluble TNF Receptor Type I (sTNF-RI), Soluble TNF Receptor Type II (sTNF-RII), adiponectin, resistin, leptin, and irisin. Blood samples were collected by a trained professional at the PPC/UERJ Clinical Analysis Laboratory (Capsule Unit), always during the same morning shift and no later than 8:00 a.m. For peripheral blood assays, serum and plasma collection tubes were centrifuged at 2,000 rpm at 25°C. Subsequently, 500 µL of serum was aliquoted into two microtubes and stored at -80°C until analysis. Biomarker concentrations were determined using specific enzyme-linked immunosorbent assay (ELISA) kits according to the manufacturer's instructions. Optical density (OD) was measured using a Thermo Scientific spectrophotometer.

Total Body Water (TBW) was assessed using a tetrapolar bioelectrical impedance analyzer (InBody 370, BIOSPACE, Republic of Korea). The analyzer measured impedance across five body segments (right arm, left arm, trunk, right leg, and left leg) at three frequencies (5, 50, and 500 kHz) and provided segmental body composition measurements, including total body water.

Unit of Measured: in liters (L).

The measures of body composition were analyzed using a Tetrapolar Bioelectrical Impedance Analyzer (InBody 370, BIOSPACE, Republic of Korea). The analyzer measured impedance across five body segments (right arm, left arm, trunk, right leg, and left leg) using three different frequencies (5, 50, and 500 kHz) and provided separate body mass readings for each segment. The following body composition components were measured:

Lean Body Mass: Measured in kilograms (kg).

Fat Mass: Measured in kilograms (kg).

Skeletal Muscle Mass: Measured in kilograms (kg).

The Body fat percentage of the body composition will be analyzed using a Tetrapolar Bioelectrical Impedance Analyzer (InBody 370, BIOSPACE, Republic of Korea). The analyzer performs impedance measurements across five body segments (right arm, left arm, trunk, right leg, and left leg) using three different frequencies (5, 50, and 500 kHz), and provides separate body mass readings for each segment.

Unit of measure: Expressed as a percentage (%).

Basal Metabolic Rate will be analyzed using a Tetrapolar Bioelectrical Impedance Analyzer (InBody 370, BIOSPACE, Republic of Korea). The analyzer performs impedance measurements across five body segments (right arm, left arm, trunk, right leg, and left leg) using three different frequencies (5, 50, and 500 kHz), and provides separate body mass readings for each segment. The device provides separate body mass readings for different body segments, being able to estimate the basal metabolic rate. The basal metabolic rate is directly proportional to the weight and amount of muscle. It was calculated from predictive formulas using the results of the body composition, and involves the data of age, sex and physical activity that is entered into the scale.

Unit of measure: kilocalories per day (kcal/day).

Body Mass Index (BMI) is a clinical index that is used in bioimpedance to assess a person's weight. BMI is calculated by dividing the weight (in kg) by the height (in meters) squared.

Unit of measure: kilograms per square meter (kg/m²).

The ratio of the circumference of the waist to the circumference of the hips, used as an indicator of cardiovascular risk. WHR was calculated by dividing the waist circumference in centimeters by the hip circumference. It is an element for the prognosis of cardiovascular events in adults. The cut-off index for cardiovascular risk is less than 0.85 for women and 0.90 for men. The unit of measurement is unitless.

Unit of measure: kilograms per square meter (kg/m²).

The ratio of the circumference of the waist to height, used as an indicator of metabolic and cardiovascular risk. Height was measured using a vertical stadiometer graduated in centimeters and millimeters. Waist circumference was assessed using a tape measure graduated in centimeters and millimeters. The tape measure was placed midway between the iliac crest and the last rib. This anatomical point has the strongest correlation with abdominal adiposity. The values obtained were stratified into three categories: between 0.40 and 0.44 (lowest % fat, below the risk threshold); between 0.45 and 0.50 (moderate risk); between 0.50 and 0.56 (above the risk threshold). The unit of measurement is unitless.

Conicity index is a measure of body fat distribution, particularly visceral fat, calculated using body circumference measurements. The C Index (CI) was determined based on the measurement of body mass, height and waist circumference, in meters, representing an indicator of abdominal obesity, and is based on the principle that some people accumulate fat around the abdomen, with the consequent change in body shape. This index is calculated using the formula:

C Index = waist circumference (m)/(0.109 x (√ body mass (kg)/height (m))).

For the classification of cardiovascular risk, values ≥ 1.18 for women and ≥ 1.25 for men are determined. The unit of measurement is unitless.

Anthropometric measurements, as circumferences were assessed to evaluate the distribution of fat and other physical characteristics. The circumference measurements will be taken at the following sites, measured in centimeters (cm): neck, waist, hip, arm, and calf.

The Timed Up and Go (TUG) test was used to assess functional mobility and dynamic balance. Participants were instructed to stand up from a standard chair, walk 3 m at their usual pace, turn around, walk back to the chair, and sit down. The time required to complete the test was recorded in seconds, with shorter completion times indicating better functional mobility and dynamic balance.

A Body Shape Index (ABSI) was used to assess body shape by considering waist circumference adjusted for body mass index (BMI) and height. Higher ABSI values indicate greater central adiposity and increased health risk. The cutoff values adopted were 0.0805 for women and 0.0828 for men.

Each participant completed the 36-Item Short Form Health Survey (SF-36) before the first and after the last intervention session. The SF-36 is a 36-item questionnaire that assesses health-related quality of life across eight domains: physical functioning, role limitations due to physical health, bodily pain, general health perceptions, vitality, social functioning, role limitations due to emotional problems, and mental health. Scores for each domain range from 0 to 100, with higher scores indicating better perceived health status and quality of life.

Handgrip strength was assessed using a Lafayette Hand Dynamometer (Model J00105). Participants were seated with their feet flat on the floor, the shoulder adducted, the elbow flexed at 90°, the forearm in a neutral position, and the wrist extended between 0° and 30°. Three maximal isometric grip contractions, each lasting 3 seconds, were performed with a 60-second rest interval between trials. The highest value recorded was used for analysis.

Isometric lower limb muscle strength was assessed using a Lafayette digital dynamometer (Model 01165A). Hip flexion, hip extension, hip external rotation, knee flexion, and knee extension were evaluated through maximal voluntary isometric contractions performed in standardized positions. Stabilization straps were used during testing to minimize compensatory movements and improve measurement reliability. Three trials were performed for each movement, and the mean value was used for analysis.