Browsing by Author "Stringer, William W."
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Item A new bronchodilator response grading strategy ıdentifies distinct patient populations(Amer Thoracic, 2019-12) Hansen, James E.; Porszasz, Janos; Stringer, William W.; Pak, Youngju; Rossiter, Harry B.; Casaburi, Richard; Dilektaşlı, Aslı G.; Bursa Uludağ Üniversitesi/Tıp Fakültesi/Dahili Tıp Bilimleri/Göğüs Hastalıkları Bölümü.; 0000-0001-7099-9647; 36466376600Rationale: A positive bronchodilator response (BDR) according to American Thoracic Society/European Respiratory Society (ATS/ERS) guidelines require both 200 ml and 12% increase in forced expiratory volume in 1 second (FEV1) or forced vital capacity (FVC) after bronchodilator inhalation. This dual criterion is insensitive in those with high or low FEV1. Objectives: To establish BDR criteria with volume or percentage FEV1 change. Methods: The largest FEV1 and FVC were identified fromthree pre- and three post-bronchodilator maneuvers in COPDGene (Genetic Epidemiology of COPD) participants. A total of 7,741 individuals with coefficient of variation less than 15% for both FEV1 and FVC formed bronchodilator categories of FEV1 response: negative (<= 0.00% or <= 0.00 L), minimal (>0.00% to <= 9.00% or >0.00 L to <= 0.09 L), mild (>9.00% to <= 16.00% or.0.09 L to <0.16 L), moderate (>16.00% to <= 26.00% or >0.16 L to <= 0.26 L), and marked (>26.00% or >0.26 L). These response size categories are based on empirical limits considering average FEV1 increase of approximately 160 ml and the clinically important difference for FEV1. To compare flow and volume response characteristics, BDR-FEV1 category assignments were applied for the BDR-FVC response. Results: Twenty percent met mild and 31% met moderate or marked BDR-FEV1 criteria, whereas 12% met mild and 33% met moderate or marked BDR-FVC criteria. In contrast, only 20.6% met ATS/ERS positive criteria. Compared with the negative BDR-FEV1 category, the minimal, mild, moderate, and marked BDR-FEV1 categories were associated with greater 6-minute-walk distance and lower St. George's Respiratory Questionnaire and modified Medical Research Council dyspnea scale scores. Compared with negative BDR, moderate and marked BDR-FEV1 categories were associated with fewer exacerbations, and minimal BDR was associated with lower computed tomography airway wall thickness. Compared with the negative category, all BDR-FVC categories were associated with increasing emphysema percentage and gas trapping percentage. Moderate and marked BDR-FVC categories were associated with higher St. George's Respiratory Questionnaire scores but fewer exacerbations and lower dyspnea scores. Conclusions: BDR grading by FEV1 volume or percentage response identified subjects otherwise missed by ATS/ERS criteria. BDR grades were associated with functional exercise performance, quality of life, exacerbation frequency, dyspnea, and radiological airway measures. BDR grades in FEV1 and FVC indicate different clinical and radiological characteristics.Item A novel spirometric measure identifies mild COPD unidentified by standard criteria(Elsevier, 2016-11) Porszasz, Janos; Casaburi, Richard; Stringer, William W.; Bhatt, Surya P.; Pak, Youngju; Rossiter, Harry B.; Washko, George; Castaldi, Peter J.; Estepar, Raul San Jose; Hansen, James E.; Dilektaşlı, Aslı Görek; Uludağ Üniversitesi/Tıp Fakültesi/Göğüs Hastalıkları Anabilim Dalı.; 36466376600BACKGROUND: In chronic obstructive pulmonary disease, both smaller and larger airways are affected. FEV1 mainly reflects large airways obstruction, while the later fraction of forced exhalation reflects reduction in terminal expiratory flow. In this study, the objective was to evaluate the relationship between spirometric ratios, including the ratio of forced expiratory volume in 3 and 6 seconds (FEV3/FEV6), and small airways measures and gas trapping at quantitative chest CT scanning, and clinical outcomes in the Genetic Epidemiology of COPD (COPDGene) cohort. METHODS: Seven thousand eight hundred fifty-three current and ex-smokers were evaluated for airflow obstruction by using recently defined linear iteratively derived equations of Hansen et al to determine lower limit of normal (LLN) equations for prebronchodilator FEV1/FVC, FEV1/FEV6, FEV3/FEV6, and FEV3/FVC. General linear and ordinal regression models were applied to the relationship between prebronchodilator spirometric and radiologic and clinical data. RESULTS: Of the 10,311 participants included in the COPDGene phase I study, participants with incomplete quantitative CT scanning or relevant spirometric data were excluded, resulting in 7,853 participants in the present study. Of 4,386 participants with FEV1/FVC greater than or equal to the LLN, 15.4% had abnormal FEV3/FEV6. Compared with normal FEV3/FEV6 and FEV1/FVC, abnormal FEV3/FEV6 was associated with significantly greater gas trapping; St. George's Respiratory Questionnaire score; modified Medical Research Council dyspnea score; and BMI, airflow obstruction, dyspnea, and exercise index and with shorter 6-min walking distance (all P < .0001) but not with CT scanning evidence of emphysema. CONCLUSIONS: Current and ex-smokers with prebronchodilator FEV3/FEV6 less than the LLN as the sole abnormality identifies a distinct population with evidence of small airways disease in quantitative CT scanning, impaired indexes of physical function and quality of life otherwise deemed normal by using the current spirometric definition.Publication Physiologic effects of oxygen supplementation during exercise in chronic obstructive pulmonary disease(W B Saunders Co-elsevier Inc, 2019-06-01) Porszasz, Janos; Stringer, William W.; Casaburi, Richard; Dilektaşlı, Aslı Görek; GÖREK DİLEKTAŞLI, ASLI; Bursa Uludağ Üniversitesi/Tıp Fakültesi; DTT-7416-2022Supplemental long-term oxygen therapy (LTOT) is a well-established therapy that improves mortality in patients with chronic obstructive pulmonary disease (COPD) with resting hypoxemia. In the large number of patients with COPD who do not have severe resting hypoxemia but who desaturate with exercise, the clinical benefits that can be obtained by supplemental O-2 therapy during exercise is an area of interest and active research. A summary of current evidence for benefits of supplemental O-2 therapy and a review of physiologic mechanisms underlying published observations are reviewed in this article.