title: Respiratory muscle force and lung volume changes in a population of children with sickle cell disease.
abstract: Sickle cell disease (SCD) is a disorder known to impact the respiratory system. We sought to identify respiratory muscle force and lung volume relationships in a paediatric SCD population. Thirty-four SCD-SS subjects underwent pulmonary function testing. Height, weight, age, and gender-adjusted percent predicted maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) values were compared to spirometry and lung volumes. Statistical analyses were performed using Pearson's correlation coefficient and paired two-tailed t-test. The mean ± standard deviation (SD) MIP and MEP was 69·6 ± 31·6 cm H2 O and 66·9 ± 22·9 cm H2 O, respectively, and mean ± SD percent predicted MIP (101·3 ± 45·9) exceeded MEP (72·1 ± 26·0) (P = 0·002). MIP correlated with forced vital capacity (FVC; r = 0·51, P = 0·001) and TLC (r = 0·54, P < 0·0001). MEP also correlated with FVC (r = 0·43, P = 0·011) and total lung capacity (TLC; r = 0·42, P = 0·013). Pearson's correlation coefficient testing yielded relationships between MIP and MEP (r = 0·64, P < 0·0001). SCD-SS patients showed correlations between respiratory muscle force and lung volume, and reduced percent predicted expiratory muscle force compared to inspiratory muscle force. Respiratory muscle strength may affect lung volumes in these patients, and expiratory muscles may be more susceptible than the diaphragm to SCD-induced vaso-occlusive damage.
authors.affiliation: Division of Pediatric Pulmonology, Tripler Army Medical Center, Honolulu, HI, USA.
authors.forename: Bruce A
authors.initials: BA
authors.lastname: Ong
authors.forename: Jason
authors.initials: J
authors.lastname: Caboot
authors.forename: Abbas
authors.initials: A
authors.lastname: Jawad
authors.forename: Joseph
authors.initials: J
authors.lastname: McDonough
authors.forename: Tannoa
authors.initials: T
authors.lastname: Jackson
authors.forename: Raanan
authors.initials: R
authors.lastname: Arens
authors.forename: Carole L
authors.initials: CL
authors.lastname: Marcus
authors.forename: Kim
authors.initials: K
authors.lastname: Smith-Whitley
authors.forename: Thornton B A
authors.initials: TB
authors.lastname: Mason
authors.forename: Kwaku
authors.initials: K
authors.lastname: Ohene-Frempong
authors.forename: Julian L
authors.initials: JL
authors.lastname: Allen
mesh_terms: D000293:Adolescent; D000755:Anemia, Sickle Cell / Q000503:physiopathology*; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D053580:Muscle Strength; D011446:Prospective Studies; D012129:Respiratory Function Tests; D012132:Respiratory Muscles / Q000503:physiopathology*; D013147:Spirometry; D014109:Total Lung Capacity
keywords: muscle strength; paediatrics; pulmonary function; sickle cell anaemia