Our finding of an apparent lack of association between smoking and progression of kidney disease in a population with CKD is in contrast to previous studies of smoking among people with CKD (Table S4)12, 13 and is surprising in view of the evidence that smoking increases urinary albumin excretion27 and blood pressure28 and has adverse effects on intrarenal hemodynamics, particularly among patients with CKD.29 Here, ALB is linked to kidney disorder.