Table 5. Interactions between dietary intakes, hypertension and use of diuretic medication and SLC9A3_rs4957061 for renal cell cancer risk in the Netherlands Cohort Study, 1986–2006.

	Person years	SLC9A3_rs4957061
		CC			CT + TT			P-interactionb	FDR-adjusted p-value
		Cases	HRa	95% CI	Cases	HRa	95% CI
Sodium intakec,d
T1	16,402	30	1.00	(ref)	85	1.19	(0.77–1.87)
T2	16,621	34	1.13	(0.66–1.91)	92	1.25	(0.80–1.95)
T3	15,903	45	1.69	(1.02–2.79)	120	1.67	(1.09–2.56)	0.808
Increment of 1 g/d	48,926	109	1.33	(0.91–1.93)	297	1.20	(0.99–1.45)	0.827	0.923
Potassium intakec,d
T1	15,969	36	1.00		87	1.07	(0.70–1.63)
T2	16,642	33	1.03		104	1.11	(0.73–1.68)
T3	16,316	40	1.06	(0.65–1.73)	106	1.20	(0.79–1.81)	0.978
Increment of 1 g/d	48,926	109	0.77	(0.54–1.12)	297	1.18	(0.94–1.49)	0.028	0.504
Fluid intake
Low	11,281	28	1.00	(ref)	59	0.82	(0.50–1.34)
Moderate	21,686	58	1.01	(0.61–1.67)	120	0.81	(0.51–1.28)
High	15,959	23	0.47	(0.26–0.86)	118	1.03	(0.64–1.65)	0.002
Increment of 1 L/d	48,926	109	0.60	(0.36–1.02)	297	1.10	(0.83–1.46)	0.031	0.504
Hypertension
No	36,292	68	1.00	(ref)	204	1.18	(0.88–1.59)
Yes	12,635	41	1.57	(1.01–2.42)	93	1.49	(1.03–2.15)	0.399	0.810
Use of diuretic medication
No	43,944	85	1.00	(ref)	267	1.25	(0.96–1.62)
yes	4,982	24	2.15	(1.23–3.75)	30	1.16	(0.71–1.87)	0.013	0.504

^aHRs are adjusted for age at baseline (years), sex (male/female), total energy intake (kcal per day), smoking status (non-current/current), smoking intensity (cigarettes per day), smoking duration (years), BMI (Kg per m²), alcohol intake (grams of ethanol per day), hypertension (yes/no) and use of diuretic medication (yes/no).

^bUsing Wald χ² test for interaction.

^cTertile distribution is sex-specific and based on subcohort members.

^dIntakes are energy-adjusted by using the residual mean method.