Table 2.

I¹²⁵ iothalamate glomerular filtration rate (iGFR) slopes (mL/min/1.73m²/year) by quartiles of estimated net endogenous acid production (NEAP), dietary protein intake, and dietary potassium intake.

iGFR slope (mL/min/1.73 m2/year)
	Unadjusted			Adjusted*		Bicarbonate Adjusted†
Quartiles	Absolute slope (95% CI)	Difference from Q1 (95% CI)	P-value	Difference from Q1 (95% CI)	P-value	Difference from Q1 (95% CI)	P-value
Estimated NEAP
1	−1.45 (−2.02, −0.88)	Ref	--	Ref	--	Ref	--
2	−2.11 (−2.75, −1.46)	−0.59 (−1.44, 0.26)	0.17	−0.69 (−1.46, 0.09)	0.08	−0.69 (−1.45, 0.08)	0.08
3	−2.25 (−2.85, −1.65)	−0.76 (−1.61, 0.10)	0.08	−0.85 (−1.63, −0.08)	0.03	−0.82 (−1.59, −0.04)	0.04
4	−2.34 (−2.93, −1.76)	−0.86 (−1.72, −0.01)	0.05	−1.01 (−1.79, −0.23)	0.01	−0.94 (−1.72, −0.16)	0.02
p-trend		0.05		0.01		0.02
Estimated Protein Intake
1	−1.99 (−2.58, −1.39)	Ref	--	Ref	--	Ref	--
2	−1.24 (−1.82, −0.66)	0.66 (−0.21, 1.54)	0.14	0.60 (−0.23, 1.42)	0.16	0.54 (−0.28, 1.36)	0.20
3	−2.58 (−3.17, −1.98)	−0.57 (−1.43, 0.29)	0.19	−0.42 (−1.25, 0.42)	0.33	−0.45 (−1.28, 0.38)	0.29
4	−2.26 (−2.88, −1.64)	−0.28 (−1.13, 0.57)	0.52	−0.05 (−0.90, 0.80)	0.91	−0.04 (−0.89, 0.80)	0.92
p-trend		0.13		0.37		0.39
Estimated Potassium Intake
1	−2.26 (−2.85, −1.66)	Ref	--	Ref	--	Ref	--
2	−2.00 (−2.53, −1.47)	0.15 (−0.73, 1.02)	0.74	0.27 (−0.55, 1.08)	0.52	0.26 (−0.55, 1.07)	0.53
3	−1.88 (−2.51, −1.25)	0.38 (−0.50, 1.26)	0.40	0.62 (−0.20, 1.45)	0.14	0.57 (−0.25, 1.39)	0.17
4	−2.05 (−2.70, −1.40)	0.24 (−0.63, 1.11)	0.59	0.71 (−0.13, 1.54)	0.10	0.65 (−0.18, 1.49)	0.13
p-trend		0.51		0.07		0.09

^*Slopes adjusted for randomized blood pressure and drug groups and categories of age, proteinuria, baseline GFR and body mass index.

^†Adjusted for above plus quartiles of serum bicarbonate

CI: confidence interval; Q1: quartile 1