Table 6.

Environmental predictors of renal disease progression in ADPKD

Environmental Predictor	No. of Patients/ Experimental Platform	Patient Characteristics/Experimental Platform	Study Features	Highest P Value	Major Refs.	Additional Supporting Refs.
High water intake	8	ADPKD patients; normal renal function; patients eating typical diets	Phase 1: baseline measurements; phase 2: water administration to reduce urine osmolality<285 mosM/kg	0.02	106,107	99–105
Caffeine	Cysts epithelial cells	Mural epithelial cell from human ADPKD cysts	cAMP levels determined after caffeine or receptor-mediated agonist stimulation	<0.001	96	97
Low protein intake	200	ADPKD patients from MDRD; reduced renal function	2.2 yr follow-up	0.06	78	NA
Smoking	323	Consecutive ADPKD patients at Istanbul University	Prospective observational (n=198); mean (SD) follow-up=100±38 mo	0.01	48	NA
	582	Patients diagnosed with IgA nephropathy or ADPKD	Retrospective	0.002	98	NA
Low birth weight	284	Retrospective cohort of ADPKD patients with ESRD from Denmark	Retrospective	0.01	95	NA

NA, not applicable.