Description

Participant Selection This study will be conducted between November 15, 2024, and November 15, 2025, at the Yedikule Chest Diseases and Thoracic Surgery Training and Research Hospital Pulmonology Outpatient Clinic. Participants will include patients who will be diagnosed with COPD by a physician. The diagnosis of COPD will be based on spirometry, specifically when Forced Expiratory Volume in 1 second): FEV1 is below 80% of the predicted value.

COPD cases will be classified according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2020 Guidelines. Post-bronchodilator FEV1 values will categorize patients into mild (FEV1 ≥ 80% predicted), moderate (50% ≤ FEV1 < 80% predicted), severe (30% ≤ FEV1 < 50% predicted), or very severe (FEV1 < 30% predicted). Sample size calculations will assume a detectable change of 0.67 pg/mL in the primary outcome variable (Tumor Necrosis Factor-alpha, TNF-α) at a significance level of 0.05 and a power of 0.80. These calculations will be performed using the software available at http://hedwig.mgh.harvard.edu/sample_size/js/js_crossover_quant.html.

Acquisition and Preparation of Aronia Berries Aronia berries (Aronia melanocarpa) will be obtained in season from the Atatürk Horticultural Central Research Institute of the Turkish Ministry of Agriculture and Forestry. The berries will be freeze-dried using a TRS-2-4 lyophilizer at -55°C. A single fruit exchange (containing 15 g of carbohydrates) will correspond to 200 g of lyophilized aronia berries, which will be vacuum-packed for participant use.

Study Design This study will be designed as a randomized, placebo-controlled, double-blind trial. Patients diagnosed with COPD at the Yedikule Pulmonology Clinic and willing to volunteer will be included after providing informed consent. Fifty participants (25 male, 25 female) who meet the study criteria will be randomized into two groups using a sealed envelope method.

The placebo will consist of maltodextrin combined with oil-based berry flavoring, citric acid, powdered sugar, pink-black food coloring, and liquid oil as a solvent for the flavoring. Placebos will be provided in 30 g vacuum-sealed packets and will be indistinguishable from the aronia supplements in color and weight.

The intervention phase will last eight weeks. Physicians, researchers, and participants will remain blinded to the type of product consumed (aronia or placebo). Participants will record their dietary intake during the study, and a food diary will be collected for nutritional assessment. Clinical evaluations will occur twice: at baseline and at the end of the 8th week following randomization.

Data Collection and Assessment Data will be collected using a questionnaire developed by the researchers based on literature reviews, administered via face-to-face interviews. The questionnaire will include 20 questions covering demographics, health status, physical activity, dietary habits, weight changes, and appetite loss over the past six months. Participants will also complete a COPD Assessment Test (CAT) and record food intake. Anthropometric measurements, spirometry, and biochemical tests will be conducted, and blood samples will be collected for analysis.

To minimize daily variations, all assessments will be conducted between 8:00 and 10:00 AM, following an overnight fast (after 10:00 PM the previous night). At baseline, participants will complete a demographic survey during face-to-face interviews, and all participants will sign a written informed consent form.

Dietary Intake Records Participants' dietary intake will be evaluated before and after the intervention using a one-day food record. The food records will be obtained through face-to-face interviews and will include meal components, preparation methods, quantities, measurements, and, for processed or enteral products, brand names. Nutritional assessments will be performed using the BeBis 9.0 software, and results will be compared with the Turkey Dietary Guidelines (TÜBER) to calculate the percentage of daily nutrient requirements met. Intakes below 50% of daily recommendations will be considered insufficient.

Body Composition and Anthropometric Measurements Body composition will be assessed using bioelectrical impedance analysis (BIA) with an eight-electrode InBody 120 device (InBody Co., Ltd., Istanbul, Turkey). Measurements will be conducted after a minimum of 8 hours of fasting, with participants barefoot and standing in an upright position. Parameters measured will include body weight (kg), skeletal muscle mass (kg), body fat mass (kg), body fat percentage (%), total body water (L), and visceral fat level.

Anthropometric measurements will include height (m), waist circumference (cm), and mid arm circumference. Height will be measured with a portable InBody stadiometer in a standing position without shoes. Waist circumference will be measured at the midpoint between the lowest rib and the iliac crest, while mid arm circumference will be taken from the non-dominant arm at the midpoint between the acromion and olecranon.

Spirometry Lung function tests will be performed by trained spirometry technicians at the hospital. Patients will take three normal breaths, then perform a maximum inhalation followed by a forceful exhalation to measure Forced Expiratory Volume in 1 second (FEV1), Forced Vital Capacity (FVC), and the FEV1/FVC ratio.

The FEV1 refers to the volume of air exhaled in the first second of the forced breath. The FVC represents the total volume of air forcibly exhaled after a full inhalation. The FEV1/FVC ratio, expressed as a percentage, indicates the proportion of the FVC exhaled during the first second, serving as a key parameter for assessing airflow obstruction.

COPD Assessment Test (CAT) The CAT will evaluate the impact of COPD on patients' lives, including symptoms such as cough, sputum, breathlessness, fatigue, and confidence in leaving home. Validity and reliability for Turkish patients were established by Yorgancıoğlu et al. The CAT is an eight-item, self-administered questionnaire, each item is scored on a scale of 0 to 5, resulting in a total score ranging from 0 to 40, with higher scores indicating greater health impairment.

Biochemical Analyses Blood samples (5 mL) will be collected from fasting participants, centrifuged at 3000 g for 10 minutes, and stored in serum separator tubes. Serum samples will be preserved using a cold chain for biochemical analysis. Further details regarding the analyses will be available in the study protocol