TABLE IV.

Association Between Respiratory Symptoms and Biomarkers with Lung Function and Morbidity Among Adults with Sickle Cell Disease

	FEV1, % predicted		FVC, % predicted		FEV1/FVC		Rates of pain		Rates of ACS
	βa	P	βa	P	βa	P	RRb (95% CI)	P	RRc (95% CI)	P
Wheezing in presence of cold	−9.8	0.006	−10.2	0.003	−1.1	0.52	2.2 (1.4−3.5)	<0.001	1.5 (0.8−2.8)	0.27
Wheezing in absence of cold	−6.8	0.06	−6.3	0.08	−1.2	0.47	0.97 (0.6−1.6)	0.92	0.8 (0.4−1.6)	0.57
Wheezing with exercise	−7.1	0.05	−6.3	0.07	−0.95	0.56	0.8 (0.5−1.3)	0.40	0.7 (0.4−1.4)	0.32
Cough in presence of cold	−7.2	0.18	−6.2	0.24	0.12	0.96	1.4 (0.7−2.9)	0.41	1.0 (0.4−2.5)	0.93
Cough in absence of cold	−7.5	0.88	0.10	0.98	1.3	0.41	1.4 (0.9−2.2)	0.19	0.9 (0.4−1.7)	0.65
Total serum IgEd	1.5	0.28	2.0	0.14	−0.34	0.59	1.1 (0.96−1.3)	0.59	0.99 (0.8−1.3)	0.96
Eosinophilsd	−2.2	0.31	−3.6	0.08	0.34	0.74	0.98 (0.7−1.4)	0.90	1.04 (0.7−1.6)	0.84

ACS, acute chest syndrome; CI, confidence interval; FEV₁, forced expiratory volume in 1 sec; FVC, forced vital capacity; RR, relative risk.

^aLinear regression models of lung function were adjusted for age, gender, and height.

^bNegative binomial regression models for pain were adjusted for SCD phenotype, age, gender, hemoglobin, tobacco smoke exposure, hydroxyurea use.

^cNegative binomial regression models for ACS were adjusted for SCD phenotype, age, hemoglobin, white blood cell count, tobacco smoke exposure, hydroxyurea use.

^dBecause of non-normally distributed data, IgE, and eosinophils were natural log transformed for all analyses.