A randomized controlled trial of two dialysate sodium concentrations in hospitalized hemodialysis patients.

BACKGROUND: Several large dialysis organizations have lowered the dialysate sodium concentration (DNa) in an effort to ameliorate hypervolemia. The implications of lower DNa on intra-dialytic hypotension (IDH) during hospitalizations of hemodialysis (HD) patients is unclear. METHODS: In this double-blind, single center, randomized controlled trial (RCT), hospitalized maintenance HD patients were randomized to receive higher (142 mmol/L) or lower (138 mmol/L) DNa for up to six sessions. Blood pressure (BP) was measured in a standardized fashion pre-HD, post-HD and every 15 min during HD. The endpoints were: (i) the average decline in systolic BP (pre-HD minus lowest intra-HD, primary endpoint) and (ii) the proportion of total sessions complicated by IDH (drop of ≥20 mmHg from the pre-HD systolic BP, secondary endpoint). RESULTS: A total of 139 patients completed the trial, contributing 311 study visits. There were no significant differences in the average systolic blood pressure (SBP) decline between the higher and lower DNa groups (23 ± 16 versus 26 ± 16 mmHg; P = 0.57). The proportion of total sessions complicated by IDH was similar in the higher DNa group, compared with the lower DNa group [54% versus 59%; odds ratio 0.72; 95% confidence interval (95% CI) 0.36-1.44; P = 0.35]. In post hoc analyses adjusting for imbalances in baseline characteristics, higher DNa was associated with 8 mmHg (95% CI 2-13 mmHg) less decline in SBP, compared with lower DNa. Patient symptoms and adverse events were similar between the groups. CONCLUSIONS: In this RCT for hospitalized maintenance of HD patients, we found no difference in the absolute SBP decline between those who received higher versus lower DNa in intention-to-treat analyses. Post hoc adjusted analyses suggested a lower risk of IDH with higher DNa; thus, larger, multi-center studies to confirm these findings are warranted.

Marital status, dipping and nocturnal blood pressure: results from the Dietary Approaches to Stop Hypertension trial.

OBJECTIVE: Blood pressure normally declines during the night ('dipping'); a blunted nocturnal decline is an important cardiovascular risk factor. Marriage may be associated with lower ambulatory blood pressure, although this may be confounded by socio-economic and dietary factors. We examined the association of marital status with nocturnal dipping and night-time SBP amongst individuals on a controlled diet. METHODS: We analysed 325 individuals enrolled in the Dietary Approaches to Stop Hypertension trial who had available 24-h SBP data and who ingested a control diet. Logistic and linear regression models were fit to estimate the association of marital status with nocturnal dipping and mean night-time SBP. RESULTS: Of the 325 individuals, 52.9% were men, the average age was 45.1 years and 48.9% reported being married. Compared with nonmarried individuals, those who were married had greater adjusted odds of dipping [odds ratio (OR) 2.26; 95% confidence interval (CI) 1.26-4.03; P = 0.01]. In adjusted models, being married was associated with lower night-time SBP (-2.4  mmHg; 95% CI -3.8 to -0.9  mmHg; P = 0.002), with the suggestion of a greater association in married men compared with married women (-3.1 vs. -1.7  mmHg); there was less difference for married nonblacks compared with married blacks (-2.7 and -2.4  mmHg, respectively). CONCLUSION: Being married is independently associated with a greater likelihood of nocturnal dipping and with lower night-time SBP among individuals participating in a controlled dietary intervention; the association was particularly strong in married men. Marital status is a variable that may be considered in future analyses of ambulatory blood pressure.