Table 3.

Association of predialysis calculated osmolarity with intra-dialytic SBP decline and hypotension

	Intradialytic SBP decline per 10-mOsm/L greater predialysis calculated osmolarity	Odds of hypotension per 10-mOsm/L greater predialysis calculated osmolarity
Unadjusted model	2.22 (1.51 to 2.93) mm Hg; P<0.001	1.10 (1.05 to 1.15); P<0.001
Model 1	1.28 (0.68 to 1.88) mm Hg; P<0.001	1.08 (1.03 to 1.13); P=0.001
Model 2	1.48 (0.86 to 2.09) mm Hg; P<0.001	1.10 (1.05 to 1.15); P<0.001
Model 2A	0.98 (0.23 to 1.70) mm Hg; P=0.01	1.06 (1.00 to 1.12); P=0.06
Model 3	1.48 (0.87 to 2.10) mm Hg; P<0.001	1.10 (1.05 to 1.15); P<0.001
Lower dialysate sodium	1.71 (1.02 to 2.39) mm Hg; P<0.001	1.11 (1.06 to 1.18); P<0.001
Higher dialysate sodium	0.70 (−0.59 to 2.00) mm Hg; P=0.3	1.02 (0.93 to 1.13); P=0.6

Note: Values in parentheses are 95% confidence interval. Generalized linear models were fit to estimate the association of pre-dialysis calculated osmolality with intra-dialytic SBP decline or odds of intra-dialytic hypotension (decline in SBP >35 mmHg, or any intra-dialytic SBP <90 mmHg). Model 1 adjusted for age, sex, race (black versus non-black), diabetes, ischemic heart disease, congestive heart failure, access type (fistula, graft, catheter), pre-dialysis SBP and ultrafiltration rate. Model 2 adjusted for the same variables as Model 1 in addition to serum calcium, albumin, and bicarbonate. Model 2A excluded those with pre-dialysis serum glucose >132 mg/dL. Model 3 adjusted for the same variables as Model 2, in addition to dialysate sodium use (≤140 mmol/L vs. >140 mmol/L or modeling).

SBP, systolic blood pressure;