Table 6.

Pooled adjusted mean values and 95% confidence intervals of 24-hour urine components by quintile of dietary potassium intake

VariableQuintile 1, n=1227Quintile 2, n=1226Quintile 3, n=1224Quintile 4, n=1226Quintile 5, n=1226P Value for Trend
Median, mg/d26413052335736914162
Creatinine, g1.3 (1.3 to 1.3)1.3 (1.3 to 1.4)1.3 (1.3 to 1.4)1.4 (1.3 to 1.4)1.3 (1.3 to 1.4)0.12
Potassium, mEq56.1 (54.7 to 57.5)61.5 (60.1 to 62.8)63.7 (62.4 to 65.0)67.6 (66.2 to 68.9)71.3 (69.9 to 72.7)<0.001
Calcium, mg189 (182 to 196)194 (188 to 201)195 (189 to 202)192 (185 to 198)189 (182 to 196)0.84
Oxalate, mg32.6 (31.8 to 33.4)33.1 (32.4 to 33.9)32.9 (32.1 to 33.6)32.9 (32.3 to 33.7)34.2 (33.4 to 35.0)<0.01
Citrate, mg675 (655 to 696)681 (661 to 700)703 (683 to 722)696 (677 to 716)714 (693 to 735)0.002
Uric acid, mg517 (507 to 526)522 (513 to 531)527 (518 to 536)529 (520 to 538)543 (533 to 552)<0.001
Sodium, mEq151 (147 to 155)149 (147 to 152)148 (144 to 152)150 (146 to 154)149 (145 to 153)0.51
Magnesium, mg104 (102 to 107)107 (105 to 110)109 (106 to 112)110 (108 to 113)112 (109 to 115)<0.001
Phosphate, mg846 (830 to 862)866 (851 to 881)850 (835 to 865)873 (858 to 888)867 (851 to 883)0.03
Sulfate, mmol18.2 (17.8 to 18.6)18.6 (18.2 to 19.0)18.7 (18.3 to 19.0)19.1 (18.8 to 19.5)19.4 (19.0 to 19.8)<0.001
Ammonium, mmol29.2 (28.2 to 30.3)30.4 (29.5 to 31.3)28.4 (27.6 to 29.3)29.4 (28.5 to 30.3)29.1 (28.1 to 30.0)0.39
pH, U5.95 (5.92 to 5.99)6.00 (5.97 to 6.03)6.04 (6.01 to 6.07)6.05 (6.02 to 6.09)6.10 (6.06 to 6.13)<0.001
Volume, ml1737 (1687 to 1788)1853 (1805 to 1902)1830 (1783 to 1877)1878 (1829 to 1926)1974 (1923 to 2025)<0.001
SS CaOx
 Pharmacal1.74 (1.58 to 1.91)1.60 (1.44 to 1.77)1.60 (1.43 to 1.76)1.50 (1.34 to 1.66)1.48 (1.32 to 1.65)<0.001
 Litholink5.80 (5.46 to 6.13)5.56 (5.26 to 5.86)5.54 (5.24 to 5.83)5.25 (4.95 to 5.54)5.07 (4.76 to 5.39)0.001
SS CaP
 Pharmacal1.33 (1.14 to 1.51)1.39 (1.21 to 1.57)1.38 (1.20 to 1.56)1.44 (1.26 to 1.62)1.37 (1.19 to 1.56)0.43
 Litholink1.09 (0.99 to 1.19)1.07 (0.98 to 1.16)1.14 (1.05 to 1.22)1.07 (0.98 to 1.16)1.06 (0.96 to 1.15)0.21
SS UA
 Pharmacal2.05 (1.80 to 2.30)1.78 (1.53 to 2.02)1.76 (1.51 to 2.00)1.61 (1.37 to 1.85)1.55 (1.30 to 1.80)<0.001
 Litholink0.79 (0.72 to 0.86)0.68 (0.62 to 0.75)0.66 (0.60 to 0.73)0.65 (0.59 to 0.72)0.62 (0.55 to 0.69)0.002
  • Models were adjusted for age, body mass index, history of kidney stones, history of diabetes, history of hypertension, total fluid intake, use of thiazides, supplemental calcium, intake of protein (dairy, nondairy animal, and vegetable), study cohort, urine creatinine, and sodium. Ammonium data were only available for the Nurses’ Health Study II Litholink collection. Pharmacal results are reported as relative supersaturations, whereas Litholink results as supersaturations. Medians refer to the first time period; however, dietary variables were updated over the course of the study. SS CaOx, supersaturation calcium oxalate; SS CaP, supersaturation calcium phosphate (brushite); SS UA, supersaturation uric acid.