Table 1 Baseline characteristics of included participants by baseline metformin use (n = 3969)
From: Metformin use and respiratory outcomes in asthma-COPD overlap
| Characteristic [N (%) or Mean ± SD] | Metformin Non-Users (n = 3728) | Metformin Users (n = 241) | p-value |
|---|---|---|---|
| Age | 63.4 ± 8.5 | 65.7 ± 7.5 | < 0.01 |
| Female gender | 1703 (46) | 82 (34) | < 0.01 |
| Black race | 747 (20) | 43 (18) | 0.4 |
| GOLD stage | |||
| GOLD 1 | 650 (17) | 34 (14) | |
| GOLD 2 | 1602 (43) | 107 (44) | 0.2 |
| GOLD 3 | 980 (26) | 75 (31) | |
| GOLD 4 | 496 (13) | 25 (10) | |
| Post-bronchodilator FEV1pp | 57.3 ± 22.7 | 56.5 ± 20.7 | 0.6 |
| Current smoker | 1513 (41) | 72 (30) | < 0.01 |
| Body mass index | |||
| Underweight | 103 (3) | 1 (1) | |
| Normal/overweight | 2508 (67) | 94 (39) | < 0.01 |
| Obese | 1117 (30) | 146 (61) | |
| Exacerbation in prior year | 1266 (34) | 97 (40) | 0.05 |
| Physician-diagnosed asthma | 818 (22) | 59 (25) | 0.4 |
| Before age 40 | 471 (13) | 39 (16) | 0.1 |
| Medications | |||
| Inhaled corticosteroids | 390 (11) | 27 (12) | 0.7 |
| Oral corticosteroids | 165 (5) | 10 (4) | 0.9 |
| Insulin | 18 (1) | 5 (2) | 0.01 |
| Other diabetes medication | 83 (2) | 103 (43) | < 0.01 |
| Comorbidities | |||
| Comorbidity count | 2.3 ± 1.7 | 4.1 ± 1.7 | < 0.01 |
| Coronary artery disease | 327 (9) | 48 (20) | < 0.01 |
| Congestive heart failure | 153 (4) | 18 (8) | 0.01 |
| Stroke | 125 (3) | 10 (4) | 0.5 |
| Hypertension | 1735 (47) | 179 (74) | < 0.01 |
| High cholesterol | 1522 (41) | 171 (71) | < 0.01 |