The Effect of Body Weight on Physical Activity Level, Functional Capacity, Balance, and Quality of Life in Individuals With Type 2 Diabetes Mellitus

Functional capacity will be evaluated using the 6-minute walk test (6MWT). At the beginning and end of the test, participants' oxygen saturation, heart rate, blood pressure, Borg dyspnea, and fatigue scores will be recorded. The test will be conducted in a 30-meter straight corridor, marked at 10-meter intervals, with chairs placed at both the starting and finishing points. Participants will be instructed to walk for 6 minutes at the fastest pace they can manage without running. To estimate the expected 6MWT distance, the reference equation by Enright et al. will be used in this study.

To evaluate patients' quality of life, the Nottingham Health Profile (NHP) will be used. The scale consists of six subdomains: pain, emotional reactions, sleep, social isolation, physical mobility, and energy. Within each subdomain, a score of 0 indicates the best quality of life, while a score of 100 indicates the worst quality of life.

For body composition analysis, the body mass index (BMI) of the participants (Body weight/height²) will be calculated. Using the Omron BF511 Body Composition Monitor (Omron Healthcare Co. Ltd; Japan), body fat percentage (%), skeletal m

Waist circumference will be measured in the standing position at the level of the umbilicus during the expiratory phase using a tape measure, and recorded in centimeters ("cm"). Hip circumference will be measured in the same position at the level of the greater trochanter and recorded in centimeters ("cm"). The waist-to-hip ratio will then be calculated.

Measurement of lower extremity muscle strength will be performed in a seated position, with the dominant leg in full knee extension, by applying maximum resistance using a handheld electronic dynamometer placed just above the ankle joint. The assessment will be conducted on the quadriceps muscle group using a handheld electronic dynamometer (Commander Muscle Tester; JTECH Medical, USA) and recorded in Newtons (N).

Handgrip strength will be measured on the dominant side using a Jamar hand dynamometer and recorded in pounds (lb). The test will be performed while the patients are seated comfortably on a chair, with the shoulder in adduction and neutral position, the elbow at 90° flexion, and the forearm and wrist in a neutral position.

Participants' physical activity levels will be evaluated using the International Physical Activity Questionnaire-Short Form (IPAQ-SF). The IPAQ short form consists of seven questions designed to determine, on a daily basis over the past seven days, the time spent in vigorous physical activity (VPA), moderate physical activity (MPA), walking (W), and sitting (sedentary time). To calculate the total physical activity score, the weekly duration (minutes) of each activity is multiplied by the Metabolic Equivalent of Task (MET) values established for the IPAQ, and the resulting scores are obtained. The Turkish validity and reliability study of the IPAQ-Short Form was conducted by Sağlam M. et al.

Patients' functional balance levels will be evaluated using the Turkish version of the Berg Balance Scale (BBS). This scale consists of tasks commonly used in daily life, such as static sitting, standing balance, transfers, turning, and picking up an object from the floor. Each item is scored on a scale from 0 (unable to perform the task) to 4 (normal performance).

Postural stability assessment will be performed using the Biodex Balance System (BBS) (Biodex Medical System, Inc; USA), including the Postural Stability Test for static postural stability and the Limits of Stability Test. The postural stability test evaluates the patient's ability to maintain their center of balance, and deviations from the center are recorded. The limits of stability test assesses the ability to move and control the center of gravity within the base of support. A higher score indicates a higher level of control.