Table 4.

Features of study participants categorized by frequency of exacerbations^‡ in SARP

		Exacerbations
Characteristics	0	1 – 2	≥ 3	P Value*	P Value**
	(n =281)	(n = 126)	(n = 61)
Severe asthmatics — %	46.6	72.2	90.2	<0.0001	<0.0001
Age — yr	47 ± 14	49 ± 14	50 ± 12	0.18	0.11
Female — % Ancestry — %	63	74	70	0.03	0.2
European ancestry	63	66	75	0.6	0.05
African ancestry	26	24	15	0.6	0.06
Body mass index — kg/m2	31.6 ± 7.8	33.3 ± 8.2	33.2 ± 9.2	0.05	0.2
Blood pressure — mm Hg
Systolic	124 ± 14	125 ± 15	126 ± 17	0.5	0.3
Diastolic	78 ± 10	76 ± 10	76 ± 10	0.2	0.4
Lung functions
Forced expiratory volume in 1 second — % predicted	75 ± 19	70 ± 21	63 ± 22	0.01	0.0001
Forced vital capacity —% predicted	87 ± 16	80 ± 18	77 ± 18	0.0005	0.0002
FEV1/FVC	0.69 ± 0.10	0.69 ± 0.12	0.64 ± 0.14	0.7	0.005
Asthma control test†	18.3 ± 4.2	15.8 ± 4.8	13.9 ± 5.4	<0.0001	<0.0001
White blood cells — x109/liter	7.0 ± 2.2	7.7 ± 2.5	8.8 ± 3.9	0.006	0.0007
Neutrophils	4.1 ± 1.7	4.7 ± 2.1	5.5 ± 3.3	0.008	0.001
Eosinophils	0.26 ± 0.23	0.28 ± 0.26	0.38 ± 0.34	0.4	0.01
IgE — IU/ml	358 ± 576	295 ± 443	255 ± 485	0.2	0.15
Superoxide dismutase — U/ml	22.2 ± 9.7	21.9 ± 8.2	21.4 ± 7.3	0.7	0.4
Fractional exhaled nitric oxide — ppb	28 ± 22	31 ± 27	40 ± 46	0.2	0.06
Adjusted mtDNA-CN residuals	0.029 ± 0.880	0.051 ± 0.846	-0.183 ± 0.381	0.8	0.003

Mean ± SD;

^*P value for asthmatics having zero exacerbations vs. 1–2 exacerbations,

^**P value for asthmatics having zero exacerbations vs. three or more exacerbations.

^‡Number of exacerbations in one-year longitudinal follow-up.