Table 1.
Participant characteristics grouped by alpha globin genotype
| HBA genotype | ||||||
| All participants | -a/-a | -a/aa | aa/aa | aa/aaa | P value† | |
| No. participants* | 643 | 30 (4.7%) | 197 (30.6%) | 408 (63%) | 8 (1.2%) | |
| Male sex, no. (%) | 222 (35) | 12 (40) | 66 (34) | 142 (35) | 4 (50) | 0.678 |
| Age, years | 20 (19, 22) | 20 (19, 22) | 20 (19, 22) | 20 (19, 22) | 19 (19, 24) | 0.833 |
| Mean FeNO‡,ppb | 20 (13, 31) | 25 (18, 39) | 20 (12, 27) | 20 (13, 32) | 37 (9, 52) | 0.107 |
| Total IgE, IU/mL | 58 (22, 160) | 28 (16, 96) | 66 (25, 176) | 57 (21, 158) | 36 (24, 46) | 0.125 |
| Body mass index, kg/m2 | 27 (24, 32) | 28 (26, 33) | 27 (23, 33) | 26 (23, 32) | 27 (25, 34) | 0.778 |
| Height, inches | 168 (162, 175) | 170 (161, 177) | 168 (163, 173) | 168 (162, 175) | 168 (163, 176) | 0.961 |
| Weight, kilograms | 77 (65, 92) | 81 (69, 93) | 77 (67, 93) | 76 (65, 91) | 85 (74, 101) | 0.716 |
| Systolic blood pressure, mm Hg | 117 (109, 124) | 117 (108, 130) | 117 (110, 123) | 117 (109, 125) | 127 (126, 133) | 0.242 |
| Diastolic blood pressure, mm Hg | 68 (63, 74) | 68 (63, 73) | 67 (62, 74) | 68 (63, 75) | 79 (70, 85) | 0.703 |
| Mean arterial pressure, mm Hg | 84 (79, 90) | 85 (80, 88) | 82 (79, 89) | 84 (80, 91) | 99 (91, 100) | 0.352 |
Values are median (25th, 75th percentile) except where otherwise indicated.
*P values calculated for differences between groups by Kruskal-Wallis non-parametric analysis of variance and for categorical variables p values were calculated as percentages within each category and differences were assessed by Fischer’s exact test.
†Total number of participants (n=643). Missing data are as follows: sex (n=2, <1%); age (n=13, 2%); mean FeNO (n=4, <1%); total IgE (n=25, 3.8%}; body mass index and weight (n=4, <1%); systolic blood pressure, diastolic blood pressure and mean arterial pressure (n=292, 45.4%).
‡Mean FeNO levels measured according to ATS recommendations (reported here as median (25th, 75th percentile) of the mean recorded FeNO).
FeNO, fractional exhaled nitric oxide; IgE, Immunoglobulin E; IU, international unit; MAP, mean arterial pressure; mL, millilitre; mm Hg, millimetres of mercury; No, number; ppb, parts per billion.