Table 2.
Characteristics of Participants by Oxyhemoglobin Saturation Categories
| n (%) or mean ± SD | SpO2 ≤ 85% | SpO2 86%–90% | SpO2 ≥91% | Total | p |
|---|---|---|---|---|---|
| Demographics | |||||
| Sample size | 103 (10.8) | 428 (44.9) | 423 (44.3) | 954 | |
| Age (years) | 63.5 ± 12.7 | 57.1 ± 12.1 | 52.9 ± 12.0 | 55.9 ± 12.5 | <0.001 |
| Male | 39 (44.8) | 185 (46.3) | 202 (51.7) | 426 (48.5) | 0.24 |
| Daily smoker | 2 (2.3) | 4 (1.0) | 5 (1.3) | 11 (1.3) | 0.62 |
| Daily biomass fuel use | 35 (40.2) | 161 (40.5) | 230 (59.9) | 426 (49.0) | <0.001 |
| Clinical parameters | |||||
| Height (cm) | 154.7 ± 9.2 | 155.4 ± 8.4 | 157.1 ± 8.4 | 156.1 ± 8.5 | <0.01 |
| Weight (kg) | 65.4 ± 15.7 | 65.7 ± 11.9 | 62.9 ± 10.9 | 64.4 ± 12.0 | <0.01 |
| BMI (kg/m2) | 27.2 ± 5.3 | 27.2 ± 4.3 | 25.5 ± 3.7 | 26.4 ± 4.2 | <0.001 |
| Systolic blood pressure (mmHg) | 115.4 ± 17.4 | 113.0 ± 17.2 | 114.2 ± 16.9 | 113.1 ± 16.5 | 0.27 |
| Diastolic blood pressure (mmHg) | 72.5 ± 10.2 | 72.8 ± 10.7 | 74.2 ± 10.2 | 73.4 ± 10.5 | 0.15 |
| Hypertension | 11 (10.7) | 44 (10.3) | 39 (9.2) | 94 (9.9) | 0.84 |
| Heart rate (bpm) | 72.2 ± 9.8 | 69.1 ± 10.3 | 66.4 ± 10.3 | 68.3 ± 10.4 | <0.001 |
| Oxygen saturation (%) | 83.1 ± 2.5 | 88.6 ± 1.3 | 92.7 ± 1.7 | 89.8 ± 3.4 | <0.001 |
| Hemoglobin (g/dL) | 17.8 ± 2.6 | 17.0 ± 1.9 | 16.4 ± 1.6 | 16.8 ± 1.9 | <0.001 |
| LDL-cholesterol (mg/dL) | 119.9 ± 37.9 | 125.2 ± 33.9 | 119.2 ± 36.4 | 122.1 ± 35.6 | <0.04 |
| HDL-cholesterol (mg/dL) | 41.7 ± 12.0 | 42.7 ± 11.5 | 43.2 ± 10.9 | 42.8 ± 11.3 | 0.26 |
| hs-CRP (log(mg/dL)) | 4.0 ± 6.0 | 3.4 ± 10.9 | 2.1 ± 5.1 | 2.9 ± 8.3 | <0.001 |
| Fasting insulin (mIU/L) | 8.9 ± 12.5 | 8.9 ± 9.8 | 6.7 ± 5.5 | 7.9 ± 8.6 | <0.001 |
| Fasting glucose (mg/dL) | 96.5 ± 30.3 | 93.5 ± 26.4 | 92.2 ± 26.8 | 93.3 ± 27.0 | <0.04 |
| HbA1c (%) | 6.3 ± 1.4 | 6.0 ± 0.7 | 5.8 ± 0.9 | 5.9 ± 0.9 | <0.001 |
| HOMA-IR (mass units) | 2.3 ± 3.5 | 2.2 ± 3.2 | 1.6 ± 1.5 | 1.9 ± 2.6 | <0.001 |
| Diabetic | 10 (9.7) | 20 (4.7) | 19 (4.5) | 49 (5.1) | 0.08 |
| Pulmonary function | |||||
| FEV1/height2 (L/m2) | 0.98 ± 0.29 | 1.13 ± 0.25 | 1.24 ± 0.25 | 1.17 ± 0.17 | <0.001 |
| FVC/height2 (L/m2) | 1.28 ± 0.37 | 1.45 ± 0.30 | 1.57 ± 0.30 | 1.49 ± 0.32 | <0.001 |
| Post FEV1/FVC ratio | 76.8 ± 7.1 | 78.3 ± 6.1 | 78.8 ± 6.1 | 78.4 ± 6.2 | <0.04 |
| Percent predicted FEV1 (%) NHANES III Mexican Americans | 103.1 ± 21.7 | 110.8 ± 17.0 | 115.2 ± 17.4 | 112.0 ± 18.0 | <0.001 |
| Percent predicted FVC (%) NHANES III, Mexican Americans | 103.1 ± 21.1 | 110.1 ± 15.2 | 115.0 ± 16.4 | 111.6 ± 16.8 | <0.001 |
Spo2, oxygen saturation as measured by pulse oximetry.