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 (FHN) Daily Trial.

INTRODUCTION

Serum bicarbonate (S) is a surrogate for acid-base. While higher and lower S concentrations are associated with mortality in patients receiving maintenance hemodialysis (HD), the association of S 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 with general well-being (feeling thermometer score), Beck's Depression Inventory 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 25-<28 mEq/L, S <22 mEq/L and S ≥28 mEq/L were associated with lower feeling thermometer scores (-3.4; 95%CI -10.3, +3.5 and -4.4; 95%CI -12.2, +3.4), respectively); S levels ≥28 mEq/L were associated with higher Beck's Depression Inventory scores (4.3; 95%CI +0.5, +8.1). Compared with S 25-<28 mEq/L in the adjusted repeated measures analysis, S <22 mEq/L and S ≥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 levels ≥28 mEq/L were associated with higher Beck's Depression Inventory scores (1.5; 95%CI -0.0, +3.1). There was no association of S with Physical Health Composite score.

CONCLUSION

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