borderline significantP = 0.06
In a previous study 4 , a borderline significant relationship was found between mild COPD and CKD, while moderate COPD had a higher risk of CKD (mild COPD and CKD: OR: 1.23, 95% CI, 0.99-1.53, P = 0.06; moderate COPD and CKD: 1.33, 95% CI, 1.07-1.65, P = 0.01) and no significant association was found between severe COPD and CKD.