Clinical Research Directory

Functional Capacity, Sleep Quality, and Cognitive Function in Obesity Hypoventilation Syndrome

Introduction: Obesity Hypoventilation Syndrome (OHS) is defined as the coexistence of obesity (BMI ≥ 30 kg/m²), daytime hypercapnia (PaCO₂ \> 45 mmHg) in the absence of other causes of hypoventilation, and sleep-disordered breathing. OHS represents the most severe form of obesity-related respiratory failure and leads to serious consequences such as increased mortality rates, chronic heart failure, pulmonary hypertension, and hospitalisations due to acute or chronic hypercapnic respiratory failure. Aim: The aim of this study is to evaluate cognitive functions in individuals with OHS and to investigate the relationship between cognitive functions, sleep quality, and functional capacity. A review of the literature indicates that cognitive functions in OHS have not been sufficiently examined, and existing studies mainly focus on cognitive impairment in individuals with obstructive sleep apnea syndrome (OSAS). However, OHS may also cause cognitive deficits, and therefore, patients should be assessed from this perspective. Cognitive impairment may negatively affect participation in pulmonary rehabilitation programs and reduce the benefits gained from such programs. Moreover, psychological conditions such as depression and anxiety may also influence the success of pulmonary rehabilitation. Thus, identifying cognitive impairment and its association with parameters such as functional capacity and sleep quality is of great importance. Early detection of cognitive deficits may provide positive outcomes for both patients and the healthcare system. Methods: The study will include 18 individuals with OHS diagnosed by a pulmonologist through polysomnographic evaluation at the Department of Pulmonology, Istanbul University, Istanbul Faculty of Medicine, along with 18 age- and sex-matched individuals with simple obesity (BMI \>30 kg/m²). All participants will be evaluated at the Department of Pulmonology, Istanbul University, Istanbul Faculty of Medicine. Body composition will be assessed using bioelectrical impedance analysis with the "Tanita BC-545N Body Composition Monitor." Functional exercise capacity will be evaluated with the Incremental Shuttle Walk Test (ISWT) and the Six-Minute Walk Test (6MWT). Cognitive functions and attention will be assessed using the Montreal Cognitive Assessment (MoCA) and the Visual Reaction Time Test. Daytime sleepiness will be measured with the Epworth Sleepiness Scale (ESS), while sleep quality will be evaluated with the Pittsburgh Sleep Quality Index (PSQI). Psychological status will be assessed using the Depression Anxiety Stress Scale (DASS-21). Statistical analyses will be conducted using the Statistical Package for Social Sciences (SPSS, version 21.0). Arithmetic mean, standard deviation (SD), and confidence intervals (CI) will be presented in tables and figures. The Shapiro-Wilk test will be applied to assess the normality of data distribution. For comparisons between the OHS and simple obesity groups, the Independent Samples T-Test will be used for normally distributed data, while the Mann-Whitney U test will be used for non-normally distributed data. Pearson or Spearman correlation analyses will be performed to investigate the relationship between functional capacity, sleep quality, and cognitive functions.

The Use of Entropy to Assess Sleep Disordered Breathing in Chronic Respiratory Disease

Research is being conducted into chronic respiratory diseases, including chronic obstructive pulmonary disease (COPD), asthma, interstitial lung disease, and bronchiectasis. The investigation specifically focuses on sleep-disordered breathing (SDB) in individuals with chronic respiratory disease. SDB encompasses a range of conditions, the most common of which is obstructive sleep apnoea. In obstructive sleep apnoea, periodic pauses in breathing (apnoea) lead to reduced blood oxygen levels. To detect these events, patients typically undergo sleep studies that involve monitoring oxygen saturation, heart rate, and respiratory patterns during sleep. When chronic respiratory disease and SDB coexist, breathing disturbances during sleep may be exacerbated. To identify SDB, sleep studies are commonly used to assess oxygen levels, heart rate, and breathing patterns. The objective of this research is to identify differences between patients with chronic respiratory diseases who have SDB and those who do not. This will be achieved by analysing sleep study data using a novel analytical approach. The aim is to determine whether this method can yield more detailed insights into the underlying pathophysiology of these conditions.

The Effect of Mask Design on Ventilation Parameters in COPD and OHS Patients on Long-term Home Non-invasive Ventilation. An Experimental Study.

Chronic obstructive pulmonary disease (COPD) and obesity hypoventilation syndrome (OHS) are respiratory conditions that disrupt normal breathing. Positive airway pressure, specifically Non-Invasive Ventilation (NIV) delivers positive pressures via an interface such as a face mask and has been shown to improve breathing and reduce symptoms in patients with these conditions. Regular use of NIV can lead to better symptom management, improved quality of life, and reduced use of healthcare resources. However, poor performance of the NIV mask and poor comfort can make NIV therapy harder to tolerate. This study will assess if a new mask helps to improve the breathing of people on NIV and normalize blood gases.

Assessment of Breathing Pattern During NIV

COPD and OHS are respiratory conditions that disrupt normal breathing. Positive airway pressure, specifically Non-Invasive Ventilation (NIV), has been shown to improve breathing and reduce symptoms in patients with these conditions. Regular use of NIV can lead to better symptom management, improved quality of life, and reduced use of healthcare resources. The type of mask used for breathing support can greatly affect a patient's comfort and willingness to use it. For conditions like Obstructive Sleep Apnea (OSA), which is a physical blockage of the airway caused by the relaxation of the muscles of the throat, nasal masks are often used because they are comfortable and work well. But for breathing support in the hospital, full face masks are typically used because patients are having significant trouble breathing and tend to breathe through their mouth. However, it's important to note that we don't yet fully understand the best way to provide breathing support for long-term NIV users, like COPD and OHS patients. The understanding of breathing route is currently only established for OSA. However, conditions like COPD affect the lungs and the overall system used for breathing, which is different from the throat blockage seen in OSA. So, the assumptions we make based on conditions like OSA may not apply to these other conditions. More research is needed to understand this better.

Detecting Systemic Carbon Dioxide Levels With a Novel Biosensor

The study is an open, prospective, single center clinical observational pilot investigation. The aim is to compare the carbon dioxide values measured by the IscAlert sensor, which is inserted in proximity to the nasal mucosa. The study wants to investigate if the nasal mucosa application and measurements are feasible, what kind of possible complications such a measurement can cause, and if the measurements can be a surrogate marker for systemic carbon dioxide values.

Evaluation of Upper Extremity Functions in Obesity Hypoventilation Syndrome Patients

Obesity Hypoventilation Syndrome (OHS) is a disease characterized by daytime hypercapnia and sleep-related respiratory disturbances in individuals with a body mass index (BMI) greater than 30 kg/m², without any other condition that could lead to hypoventilation. Although various mechanisms play a role in the pathogenesis of OHS, the most significant one is the altered respiratory system mechanics due to obesity. Obesity also leads to a decrease in peripheral muscle strength and exercise capacity. It has been reported that in obese individuals, not only general body movements and lower extremities but also upper extremity movements are negatively affected. Specifically, it has been observed that during activities against gravity, movement speed is low while the duration of movement is high. In OHS patients, daily living activities, physical activity, and exercise capacity are also negatively impacted. Supported or unsupported arm movements are of great importance in performing daily living activities. The muscles activated during both simple arm lifting and combined movements also function as accessory respiratory muscles. In individuals with cardiopulmonary diseases, an increase in the respiratory workload, especially during unsupported arm movements, has been observed. It is thought that in OHS patients, both the effects of obesity and the respiratory system may limit upper extremity functions. However, no studies have evaluated upper extremity functions in these individuals. Therefore, the aim of investigators study is to evaluate upper extremity functions in OHS patients.

The Effect of Sarcopenic Obesity on Sleep in Individuals With Obesity Hypoventilation Syndrome

Obesity Hypoventilation Syndrome(OHS) is characterized by daytime hypercapnia and sleep-disordered breathing without other causes of hypoventilation in individuals with a body mass index above 30 kg/m2. It is stated that obesity is at the basis of the metabolic changes seen in individuals diagnosed with OHS. Also sedentary lifestyle habits, which are common in obese individuals, cause the risk of sarcopenia due to loss of muscle strength and mass, accumulation of adipose tissue in the body, and decreased exercise capacity. Reduced exercise capacity due to obesity has been shown in the literature to strongly interact with mortality risk. As a result of obesity and all this negative picture, impaired emotional state and decreased quality of life are observed in individuals. Simultaneously, sleep parameters are also negatively affected. In particular, increased adipose tissue leads to loss of muscle mass and strength, increased risk of sarcopenia and sleep-related problems. The association of obesity and sarcopenia is referred to as 'sarcopenic obesity'. Sarcopenic obesity is defined as the coexistence of sarcopenia and obesity. The concept of sarcopenic obesity has recently taken its place in the literature. In particular, there are very few studies on its relationship with sleep parameters. However, while obesity is the basis of OHS, there are no studies on the presence and effects of sarcopenic obesity in this patient group. Based on this point, we aim to investigate the effects of sarcopenic obesity on sleep parameters, exercise capacity and quality of life in individuals with OHS.