The Association of Serum Bicarbonate With Psychological and Physical Health-Related Quality of Life in Patients Receiving Maintenance Hemodialysis: A Secondary Analysis of the Frequent Hemodialysis Network Daily Trial.

Abstract

Introduction: Serum bicarbonate (S_BIC) is a surrogate for acid-base. Although higher and lower S_BIC concentrations are associated with mortality in patients receiving maintenance hemodialysis (HD), the association of S_BIC with patient-reported outcomes is unclear.

Methods: Using data from the Frequent Hemodialysis Network Daily Trial, we performed linear and repeated measures random effects regression to assess the association of pre-HD S_BIC with general well-being (feeling thermometer score), Beck Depression Inventory (BDI) score, and Physical Health Composite score.

Results: Among the 244 subjects included in this study, mean age was 50 ± 14 years, 39% were women, and 42% were Black. Compared with S_BIC 25-<28 mEq/L, S_BIC <22 mEq/L and S_BIC ≥28 mEq/L were associated with lower feeling thermometer scores (-3.4; 95% confidence interval [CI] -10.3, +3.5 and -4.4; 95% CI -12.2, +3.4, respectively); S_BIC levels ≥28 mEq/L were associated with higher BDI scores (4.3; 95% CI + 0.5, +8.1). Compared with S_BIC 25-<28 mEq/L in the adjusted repeated measures analysis, S_BIC <22 mEq/L and S_BIC ≥28 mEq/L were associated with lower feeling thermometer scores (-5.1; 95% CI -9.1, -1.1 and -3.7; 95% CI -8.2, +0.7, respectively); S_BIC levels ≥28 mEq/L were associated with higher BDI scores (1.5; 95% CI -0.0, +3.1). There was no association of S_BIC with Physical Health Composite score.

Conclusion: Higher and lower pre-HD S_BIC were associated with a lower sense of general well-being and higher S_BIC was associated with more pronounced depressive symptoms. Whether normalization of S_BIC could enhance the well-being of patients receiving maintenance dialysis is unclear.