Browsing by Author "Agarwal, Dhiraj"
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- Bronchodilator responsiveness and future chronic airflow obstruction: a multinational longitudinal studyPublication . Knox-Brown, Ben; Algharbi, Fahad; Mulhern, Octavia; Potts, James; Harrabi, Imed; Janson, Christer; Nielsen, Rune; Agarwal, Dhiraj; Malinovschi, Andrei; Juvekar, Sanjay; Denguezli, Miriam; Gíslason, Thorarinn; Ahmed, Rana; Nafees, Asaad; Koul, Parvaiz A.; Obaseki, Daniel; Anand, Mahesh Padukudru; Loh, Li Cher; Hermínia Brites Dias; Rodrigues, Fátima; Mannino, David; Elbiaze, Mohammed; El Rhazi, Karima; Mejza, Filip; Devereux, Graham; Franssen, Frits; El Sony, Asma; Wouters, Emiel; Al Ghobain, Mohammed; Mortimer, Kevin; Rashid, Abdul; Osman, Rashid; Studnicka, Michael; Cardoso, João; Burney, Peter; Amaral, André; BOLD Collaborative Research GroupBackground: Bronchodilator responsiveness testing is mainly used for diagnosing asthma. We aimed to investigate whether it is associated with progression to chronic airflow obstruction over time. Methods: The multinational Burden of Obstructive Lung Disease cohort study surveyed adults, aged 40 years and above, at baseline and followed them up after a mean of 9.1 years. Recruitment took place between January 2, 2003, and December 26, 2016. Follow-up measurements were collected between January 29, 2019, and October 24, 2021. On both occasions, study participants provided information on respiratory symptoms, health status, and several environmental and lifestyle exposures. They also underwent pre- and post-bronchodilator spirometry. We defined bronchodilator responsiveness at baseline using the American Thoracic Society and European Respiratory Society (ATS/ERS) 2022 definition, and the presence of chronic airflow obstruction at follow-up as a post-bronchodilator forced expiratory volume in 1 s to forced vital capacity ratio (FEV1/FVC) less than the lower limit of normal. We used multi-level regression models to estimate the association between baseline bronchodilator responsiveness and incident chronic airflow obstruction. We stratified analyses by gender and performed a sensitivity analysis in never smokers. Findings: We analysed data from 3701 adults with 56% being women. Compared to those without bronchodilator responsiveness at baseline, those with bronchodilator responsiveness had a 36% increased risk of developing chronic airflow obstruction (RR: 1.36, 95%CI 1.04, 1.80). This effect was stronger in women (RR: 1.45, 95%CI 1.09, 1.91) than in men (RR: 1.07, 95%CI 0.51, 2.24). Never smokers with bronchodilator responsiveness also were at greater risk of incident chronic airflow obstruction (RR: 1.48, 95%CI 1.01, 2.20). Interpretation: Bronchodilator responsiveness appears to be a risk factor for incident chronic airflow obstruction. It is important that future studies in other large population-based cohorts replicate these findings.
- Geographical variation in lung function: results from the multicentric cross-sectional BOLD studyPublication . Burney, Peter G.; Potts, James; Knox-Brown, Ben; Erhabor, Gregory; Hacene Cherkaski, Hamid; Mortimer, Kevin; Anand, Mahesh Padukudru; Mannino, David M.; Cardoso, Joao; Ahmed, Rana; Elsony, Asma; Barbara, Cristina; Nielsen, Rune; Bateman, Eric; Paraguas, Stefanni Nonna; Cher Loh, Li; Rashid, Abdul; Wouters, Emiel F.; Franssen, Frits M.; Dias, Hermínia Brites; Gislason, Thorarinn; Ghobain, Mohammed A.; Biaze, Mohammed El; Agarwal, Dhiraj; Juvekar, Sanjay; Rodrigues, Fatima; Obaseki, Daniel O.; Koul, Parvaiz A.; Harrabi, Imed; Nafees, Asaad A; Seemungal, Terence; Janson, Christer; Vollmer, William M; Amaral, Andre F.; Buist, A SoniaSpirometry is used to determine what is "unusual" lung function compared with what is "usual" for healthy non-smokers. This study aimed to investigate regional variation in the forced vital capacity (FVC) and in the forced expiratory volume in one second to FVC ratio (FEV1/FVC) using cross-sectional data from all 41 sites of the multinational Burden of Obstructive Lung Disease study. Participants (5,368 men; 9,649 women), aged ≥40 years, had performed spirometry, had never smoked and reported no respiratory symptoms or diagnoses. To identify regions with similar FVC, we conducted a principal component analysis (PCA) on FVC with age, age2 and height2, separately for men and women. We regressed FVC against age, age2 and height2, and FEV1/FVC against age and height2, for each sex and site, stratified by region. Mean age was 54 years (both sexes), and mean height was 1.69 m (men) and 1.61 m (women). The PCA suggested four regions: 1) Europe and richer countries; 2) the Near East; 3) Africa; and 4) the Far East. For the FVC, there was little variation in the coefficients for age, or age2, but considerable variation in the constant (men: 2.97 L in the Far East to 4.08 L in Europe; women: 2.44 L in the Far East to 3.24 L in Europe) and the coefficient for height2. Regional differences in the constant and coefficients for FEV1/FVC were minimal (<1%). The relation of FVC with age, sex and height varies across and within regions. The same is not true for the FEV1/FVC ratio.