Table 1 Comparison of characteristics of Sousse BOLD study participants with or without a reduced FVCa using NHANES values
Characteristics | Overall participants (n = 661, 100%) | ||
|---|---|---|---|
FVC > LLN (n = 485, 73.4%) | FVC < LLN (n = 176, 26.6%) | p value | |
Age, years, median (IQR) | 52 (45–58) | 53 (48–60) | 0.017 |
Age group, years, n (%) | 0.057 | ||
 40–49 | 197 (40.6) | 52 (29.5) |  |
 50–59 | 192 (39.6) | 79 (44.9) |  |
 60–69 | 70 (14.4) | 35 (19.9) |  |
 ≥ 70 | 26 (5.4) | 10 (5.7) |  |
Male gender, n (%) | 229 (47.2) | 80 (45.5) | 0.725 |
Height, m, median (IQR) | 1.62 (1.55–1.70) | 1.66 (1.59–1.72) | < 0.001 |
Weight, Kg, median (IQR) | 77.1 (68.6–86.2) | 76.3 (67.1–85.5) | 0.600 |
BMI, Kg/m2, median (IQR) | 29.0 (25.6–33.1) | 27.4 (24.7–31.8) | 0.007 |
Waist circumference, cm, median (IQR) | 100.7 (91.0–109.0) | 97.2 (89.4–106.5) | 0.124 |
Hip circumference, cm, mean ± SD | 103.9 ± 13.7 | 103.4 ± 11.9 | 0.664 |
Waist-hip ratio, mean ± SD | 0.95 ± 0.09 | 0.94 ± 0.06 | 0.159 |
Abnormal waist circumferenceb, n (%) | |||
 Male | 99 (43.2) | 33 (41.3) | 0.758 |
 Female | 212 (82.8) | 73 (76.0) | 0.150 |
Abnormal waist-hip ratioc, n (%) | |||
 Male | 178 (77.7) | 61 (76.3) | 0.786 |
 Female | 243 (94.9) | 91 (94.8) | 1.000 |
History of hunger for lack of money at the age of five, n (%) | 205 (42.3) | 63 (35.8) | 0.152 |
Education, yr of schooling, n (%) | 0.011 | ||
 7 + | 275 (56.7) | 80 (45.5) |  |
 0–6 | 210 (43.3) | 96 (54.5) |  |
Smoking status, n (%) | 0.184 | ||
 Current smoker | 136 (28.0) | 40 (22.7) |  |
 Ex-smoker | 58 (12.0) | 29 (16.5) |  |
 Never-smoker | 291 (60.0) | 107 (60.8) |  |
PB spirometric parameters, median (IQR) | |||
 FEV1, L | 2.84 (2.36–3.49) | 2.07 (1.75–2.55) | < 0.001 |
 FEV1, % predicted | 97.16 (89.38–105.46) | 76.53 (68.80–82.20) | < 0.001 |
 FVC, L | 3.53 (2.89–4.33) | 2.61 (2.27–3.20) | < 0.001 |
 FVC, % predicted | 93.10 (86.80–100.64) | 74.64 (69.85–78.67) | < 0.001 |
 FEV1/FVC ratio, % | 81.47 (77.31–85.20) | 80.53 (75.88–84.27) | 0.023 |
Respiratory symptoms, n (%) | |||
 Chronic cough | 44 (9.0) | 31 (17.6) | 0.007 |
 Chronic wheeze | 108 (22.2) | 57 (32.4) | 0.008 |
 Chronic phlegm | 72 (14.8) | 30 (17.0) | 0.488 |
 Dyspnea | 258 (53.1) | 108 (61.7) | 0.049 |
Reported diagnosis, n (%) | |||
 Chronic bronchitis, emphysema or COPD | 4 (0.8) | 6 (3.4) | 0.026 |
 Hypertension | 86 (17.7) | 52 (29.5) | 0.001 |
 Diabetes | 49 (10.1) | 23 (13.1) | 0.279 |
 Heart disease | 20 (4.1) | 17 (9.7) | 0.006 |
 Stroke | 1 (0.2) | 0 (0.0) | 1.000 |
 Hospitalised as a child for breathing problems prior age 10 | 11 (2.3) | 7 (4.0) | 0.404 |
Exposure history, n (%) | |||
 Exposure to passive smoking during childhood | 306 (63.1) | 99 (56.3) | 0.110 |
Exposure to biomass smoke for heating£ | 0.034 | ||
 Exposed | 21 (4.3) | 17 (9.7) |  |
 Not exposed | 221 (45.6) | 75 (42.6) |  |
 Never heat the home | 243 (50.1) | 84 (47.7) |  |
Exposure to biomass smoke for heating duration, years, median (IQR) | 15.5 (10–30) | 20 (10–30) | 0.383 |
Exposure to biomass for cooking* | 205 (42.3) | 71 (40.3) | 0.721 |
Exposure to biomass smoke for cooking duration, years, median (IQR) | 10 (5.75–20.0) | 15 (8.0–22.5) | 0.092 |
Poor indoor ventilation | 417 (86.0) | 153 (86.9) | 0.432 |
Dusty job§ | 108 (22.3) | 36 (20.5) | 0.618 |