Investigation of the Effects of Different Levels of Obesity on the Respiratory System
Condition: Obesity, Adolescent; Obesity, Morbid; Obesity, Abdominal; Obesity, Visceral; Weight, Body
MeSH terms: Obesity; Obesity, Morbid; Obesity, Abdominal; Pediatric Obesity; Body Weight
Study type: Observational

Summary: 
      Obesity can be defined as' a disease that occurs as a result of the energy (calorie) taken
      with food being more than the energy consumed and the excess energy being stored as fat in
      the body, negatively affecting the quality and duration of life. BMI is calculated by
      dividing the weight (kg) by the square of the height (m2) (1,2). According to the World
      Health Organization (WHO) classification, BMI between 25-29.9 kg / m2 is overweight, 30-34.9
      kg / m2 is light, 35-39.9 kg / m2 is medium, 40 kg / m2 and above is considered as severe
      obesity. Obesity has important effects on respiratory function. These mechanical and
      biochemical effects are not easily measured by pulmonary function test and BMI
      measurement.Changes caused by mediators produced by adipose tissue likely cause changes in
      lung function, but this effect is not fully understood at the moment. The aim of our study is
      to make these effects more understandable and to compare them with different obesity classes
      and people with normal weight who are considered healthy.

      Hypothesis 0: The effects of obesity on respiratory functions and multidimensional
      health-related parameters do not show a statistically significant difference compared to
      individuals with different levels of the disease and normal weight individuals classified as
      healthy.

      Hypothesis 1: The effects of obesity on respiratory functions and multidimensional
      health-related parameters show a statistically significant difference compared to people with
      different levels of the disease and normal weight individuals classified as healthy.

      The study will be carried out by face-to-face evaluations in a clinical setting with obese
      patients between the ages of 18-65 who have applied to the clinic with a diagnosis of obesity
      and agree to participate in the study, and healthy volunteers who are considered to be
      healthy without a diagnosis of obesity. Looking at the evaluations to be made; Measurement of
      respiratory function parameters, measurement of respiratory muscle strength, anthropometric
      measurements, evaluation of body composition, quality of life, upper extremity muscle
      strength and grip strength, lower extremity muscle strength, fatigue evaluation, vital signs,
      evaluation of exercise perception, presence of dyspnea and its level will be evaluated. A
      detailed description of these evaluations and the parameters to be used will be explained in
      detail in the next step.
    

Detailed description: 
      Obesity can be defined as' a disease that occurs as a result of the energy (calorie) taken
      with food being more than the energy consumed and the excess energy being stored as fat in
      the body, negatively affecting the quality and duration of life. A body mass index (BMI) of
      30 or above in adults is classified as obese. BMI is calculated by dividing the weight (kg)
      by the square of the height (m2). According to the World Health Organization (WHO)
      classification, BMI between 25-29. 9 kg / m2 is overweight, 30-34. 9 kg / m2 is light, 35-39.
      9 kg / m2 is medium, 40 kg / m2 and above is considered as severe obesity. As the increases
      in BMI are related to the number of comorbidities, weight loss also affects many risk
      factors. It has been shown that voluntary weight loss in obese individuals over short periods
      (weeks or months) reduces risk factors and improves disease symptoms associated with obesity,
      including heart disease, Type II Diabetes mellitus, and osteoarthritis. Obesity; It is an
      important risk factor and disease factor for asthma, obstructive sleep apnea syndrome,
      obesity hypoventilation syndrome (OHS) and pulmonary hypertension diseases. The overall
      effect of obesity on lung function is multifactorial and is related to the mechanical and
      inflammatory aspects of obesity. Obesity has important effects on respiratory function. These
      mechanical and biochemical effects are not easily measured by pulmonary function test and BMI
      measurement. Changes caused by mediators produced by adipose tissue likely cause changes in
      lung function, but this effect is not fully understood at the moment.As a result of the
      literature review the investigators conducted, it was observed that the studies conducted in
      order to make more understandable the physiological and mechanical effects of obesity on
      different systems in the body, especially the respiratory system, were limited and inadequate
      in terms of numerical and targeted purposes. It was observed that lower extremity muscle
      strength, fatigue, sleep quality parameters were not included, and their relations with
      respiratory system functions and measurements were not measured. The aim of our study is to
      make these effects more understandable and to compare them with different obesity classes and
      people with normal weight who are considered healthy. Individuals who volunteered to
      participate in the study, who met the inclusion criteria and volunteered to participate will
      be evaluated by dividing them into five different groups according to the BMI parameter, in
      accordance with the intervals determined by WHO, and the data obtained will be compared
      between the groups.

      Outcome Measures:

        -  Measurement of Pulmonary Function Parameters: The respiratory function parameters of the
           participants will be measured with a respiratory function test using a spirometer. With
           these tests, the static and dynamic lung volumes and functional status of the person
           will be determined.

        -  Measurement of Respiratory Muscle Strength:

      It consists of respiratory muscles, diaphragm, intercostal (internal and external), scalene,
      sternocleidomastoid, triangularis sterni, abdominal, shoulder and neck muscles. Respiratory
      muscle strength can be measured in many different ways. Among the pulmonary function tests,
      maximum inspiratory and expiratory pressures are the measurements that are frequently used to
      evaluate the strength of the respiratory muscles. -Measurement of Respiratory Muscle
      Strength:It consists of respiratory muscles, diaphragm, intercostal (internal and external),
      scalene, sternocleidomastoid, triangularis sterni, abdominal, shoulder and neck muscles.
      Respiratory muscle strength can be measured in many different ways. Among the pulmonary
      function tests, maximum inspiratory and expiratory pressures are the measurements that are
      frequently used to evaluate the strength of the respiratory muscles. These measurements are
      directly related to respiratory muscle strength and help to determine the rehabilitation and
      exercise program by providing information about the patient's condition.

      -Anthropometric Measurements: Participants' waist circumference, hip circumference, neck
      circumference will be measured, and their ratios (waist / height ratio, waist / hip ratio)
      will be calculated. Body mass index (BMI), waist circumference, and waist-to-hip ratio (B /
      C) is the diagnostic methods commonly used to detect adiposity. Waist circumference and
      waist-hip ratio have been found to be useful measurements for measuring visceral fat
      accumulation. Measurement of neck circumference is used as an anthropometric marker to
      identify patients at risk for sleep apnea syndrome. At the same time, neck circumference is
      thought to be associated with other metabolic diseases. In addition to these measurements,
      the measurement called 'New BMI' used in the literature will also be made. In this
      measurement, BMI is calculated with the formula 1.3 × (kg / m2).

      In order to calculate the body fat ratio, it is aimed to estimate the amount of body fat with
      the measurement of Clinica Universidad de Navarra-Body Adiposity Estimator (CUN-BAE) in
      addition to the bioelectric impedance method.

      BMI measurement is insufficient to determine body fat and muscle ratio. Since it is difficult
      to determine the location of the fat tissue in the body, it will be evaluated with the ''
      Body Shape Index ''.

      -Assessment of Body Composition: Body composition will be measured using the method called
      bioelectrical impedance analysis (BIA). This measurement is based on the principles of
      electrical conductivity of body tissues. It is a fast, practical and relatively inexpensive
      method compared to other similar devices and applications used to examine the body
      composition of individuals. This method shows the percentage and mass of body fat, lean body
      weight and the amount of water in the body and their distribution percentage. The person
      climbs on the device and places his or her hands in the designated places. Electric current
      travels through the body and provides information about parameters determined by certain
      algorithms and calculations.

      -Quality of Life: Quality of life is accepted as a multidimensional structure with many
      different contents. Considering the decrease in physical capacity, pain, deterioration in
      interpersonal relationships, decreased self-esteem, loss of self-esteem, depression, social
      stigma, difficulty in finding a job, rejection by the school and business environment, it is
      understood how low the health-related quality of life of obese individuals is. In measuring
      the quality of life; Nottingham Health Profile questionnaire will be used. Nottingham Health
      Profile is a questionnaire consisting of 7 subtitles and 45 questions, including physical,
      social and psychological evaluations.

      -Upper Extremity Muscle Strength and Gripping Strength: It is an important parameter related
      to muscle strength, functional capacity, cardiovascular disease risk factors and mortality.
      Upper extremity muscle strength and grip strength will be measured by hand dynamometer and
      weight lifting tests (arm curls test).

      -Lower Extremity Muscle Strength: Abnormalities that usually occur in lower extremity muscles
      affect patients' physical performance and daily living activities, reduce exercise tolerance
      and impair health-related quality of life. 30-second sit-and-go test will be used to measure
      lower extremity muscle strength. The score is determined by the number of times the
      participant sits and stands up for 30 seconds from the moment the participant is commanded to
      place his hands on the crossed, shoulders in the chair he is sitting with his back supported
      and to start in the position where his feet are in full contact with the floor.

        -  Fatigue Assessment:

      Fatigue is a common complaint in overweight and obese people. It has been stated that this is
      caused by increased body mass, decreased physical activity level and sleep disorders. In the
      assessment of fatigue, the Fatigue Severity Scale (39) will be used. The fatigue severity
      scale consists of 9 questions that question social relationship, physical performance and
      symptomatically the severity of fatigue. The total score is created according to the answers
      given to the questions.

      -Vital Sign: Type 2 diabetes mellitus (T2DM), hypertension (HT), dyslipidemia (DLP),
      obstructive sleep apnea syndrome (OSAS) comorbidities have been associated with morbid
      obesity in obese individuals. Blood pressure, heart rate, oxygen saturation will be evaluated
      in order to observe the negative effects of these comorbidities.

      -Evaluation of Exercise Perception: Aerobic exercise capacity is an essential component of
      physical fitness. Perceived benefits and perceived barriers to participating in physical
      activity will be assessed by Exercise Benefits / Barriers Scale (EBBS). It is a questionnaire
      consisting of 43 questions used to evaluate people's perception of exercise. Evaluates the
      ideas of being useful and preventive that exercise creates on people. The test score is
      determined by the score collected according to the answers given to the questions.

      -Assessment of the Presence and Level of Dyspnea: According to the American Thoracic Society
      (ATS) report, the definition of dyspnea was defined as "unpleasant or uncomfortable breathing
      sensation and personal respiratory disturbance caused by various intensity senses" and it was
      stated to be a subjective feeling. "Modified Medical Research Council Scale (MMRC)" will be
      used to evaluate the presence of dyspnea. The MMRC is a five-item scale created on the basis
      of various activities that cause shortness of breath. The presence and effect of dyspnea
      occur according to the substance chosen by the person.

      -Statistical method (s) to use: '' Hatem AM, Ismail MS, El-Hinnawy YH. 'Effect of different
      classes of obesity on the pulmonary functions among adult Egyptians: a cross-sectional
      study', Egypt J Bronchol 2019; 13: 510-5 '', the total number of samples determined for 5
      groups in the sample size study, based on the FVC value and standard deviations in table 2,
      was calculated as 80 on the condition that it was 16 per group. Sample size calculation was
      made using the NCSS / PASS program. In the calculation, it was determined that the difference
      between the averages of the 5 groups should be 80% power and 95% confidence level to be
      significant. The statistical test method to be applied ANOVA will be used in conditions of
      normal distribution between groups, and Kruskal-Wallis test method will be used if the
      condition of normal distribution between groups cannot be achieved.
    

Observational model: Case-Control
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        According to the WHO classification, the five groups to be formed will be group I normal
        weight (healthy), group II overweight, group III, class 1 obese, group IV, class 2 obese,
        group V, class 3 (morbid) obese.
      
Keywords: Obesity; Respiratory System; Quality of Life; Anthropometric Measurements; Body Composition