Effect of high bicarbonate hemodialysis solution on biochemical parameters and anthropometric indices

Association Between the Dialysate Bicarbonate and the Pre-dialysis Serum Bicarbonate Concentration in Maintenance Hemodialysis: A Retrospective Cohort Study

Background

It is unclear whether the use of higher dialysate bicarbonate concentrations is associated with clinically relevant changes in the pre-dialysis serum bicarbonate concentration.

Objective

The objective is to examine the association between the dialysate bicarbonate prescription and the pre-dialysis serum bicarbonate concentration.

Design

This is a retrospective cohort study.

Setting

The study was performed using linked administrative health care databases in Ontario, Canada.

Patients

Prevalent adults receiving maintenance in-center hemodialysis as of April 1, 2020 (n = 5414) were included.

Measurements

Patients were grouped into the following dialysate bicarbonate categories at the dialysis center-level: individualized (adjustment based on pre-dialysis serum bicarbonate concentration) or standardized (>90% of patients received the same dialysate bicarbonate concentration). The standardized category was stratified by concentration: 35, 36 to 37, and ≥38 mmol/L. The primary outcome was the mean outpatient pre-dialysis serum bicarbonate concentration at the patient level.

Methods

We examined the association between dialysate bicarbonate category and pre-dialysis serum bicarbonate using an adjusted linear mixed model.

Results

All dialysate bicarbonate categories had a mean pre-dialysis serum bicarbonate concentration within the normal range. In the individualized category, 91% achieved a pre-dialysis serum bicarbonate ≥22 mmol/L, compared to 87% in the standardized category. Patients in the standardized category tended to have a serum bicarbonate that was 0.25 (95% confidence interval [CI] = -0.93, 0.43) mmol/L lower than patients in the individualized category. Relative to patients in the 35 mmol/L category, patients in the 36 to 37 and ≥38 mmol/L categories tended to have a serum bicarbonate that was 0.70 (95% CI = -0.30, 1.70) mmol/L and 0.87 (95% CI = 0.14, 1.60) mmol/L higher, respectively. There was no effect modification by age, sex, or history of chronic lung disease.

Limitations

We could not directly confirm that all laboratory measurements were pre-dialysis. Data on prescribed dialysate bicarbonate concentrations for individual dialysis sessions were not available, which may have led to some misclassification, and adherence to a practice of individualization could not be measured. Residual confounding is possible.

Conclusions

We found no significant difference in the pre-dialysis serum bicarbonate concentration irrespective of whether an individualized or standardized dialysate bicarbonate was used. Dialysate bicarbonate concentrations ≥38 mmol/L (vs 35 mmol/L) may increase the pre-dialysis serum bicarbonate concentration by 0.9 mmol/L.

The effect of changing dialysate bicarbonate concentration on serum bicarbonate, body weight and normalized nitrogen appearance rate

INTRODUCTION

Most hemodialysis machines deliver a fixed bicarbonate concentration. Higher concentrations may improve acidosis, but risk post-hemodialysis alkalosis, whereas lower concentrations potentially increase acidosis but reduce alkalosis. We reviewed the effects of lowering dialysate bicarbonate.

METHODS

We reviewed peri-dialysis chemistries in patients switching to a lower bicarbonate dialysate at 4 time points over 19 months.

RESULTS

We studied 126 patients, mean age 63.7 ± 16.3 years, 57.9% males. Post-hemodialysis alkalosis fell from 1.6 to 0.3% sessions, but pre-hemodialysis acidosis increased from 11.9 to 23.8% sessions (p = 0.005) reducing dialysate bicarbonate from 32 to 28 mmol/L. After 3 months, pre-hemodialysis serum bicarbonate fell (21.1 ± 2.3 to 19.8 ± 2.2 mmol/L), and post-hemodialysis (24.9 ± 2.1 to 22.5 ± 2.0 mmol/L, p < 0.001) with a fall in pre-hemodialysis weight from 74.6 ± 20.7 to 71.7 ± 18.2 kg, normalized protein nitrogen accumulation rate 0.8 ± 0.28 to 0.77 ± 0.2 g/kg/day, p < 0.05, and serum albumin 39.7 ± 4.2 to 37.7 ± 4.9 g/L, p < 0.001. Thereafter, apart from pre- and post-hemodialysis serum bicarbonate, weight and normalized protein nitrogen accumulation stabilized, although albumin remained lower (37.6 ± 4.0 g/L, p < 0.001). On multivariate logistic analysis, serum bicarbonate increased more with lower pre-hemodialysis bicarbonate standardized coefficient β 0.5 (95% confidence interval -0.6 to -0.42), increased normalized protein nitrogen accumulation β 0.2 (0.96 to 2.38), p < 0.001, and session time β 0.09, (0.47 to 5.98), p < 0.022, and less with lower dialysate bicarbonate 0.0-0.23 (-1.54 to -0.74), p < 0.001.

CONCLUSION

Increases in SE-Bic with hemodialysis, depend on the bicarbonate gradient, session time and nPNA. Lower D-Bic reduces post-hemodialysis alkalosis but increases pre-hemodialysis acidosis and may initially have adverse effects on weight and normalized protein nitrogen accumulation.

Serum irisin level is higher in peritoneal dialysis than in hemodialysis

BACKGROUND

Previous studies have proved that irisin is related to the development of chronic kidney disease. In this study, we aimed to compare serum irisin level in patients treated with peritoneal dialysis (PD) and hemodialysis (HD).

METHODS

Two hundred and fifty-two dialysis patients (146 PD patients and 106 HD patients) were included in the study. Levels of serum irisin and other parameters were compared between the two groups' patients.

RESULTS

There were higher serum irisin levels in PD patients than those in HD patients [113.10 (106.15 ~ 119.15) ng/ml vs. 45.72(21.67 ~ 79.71) ng/ml, P < 0.001]. Moreover, body fat mass, percent body fat, serum calcium, high-density lipoprotein, low-density lipoprotein, carbon dioxide combining power (CO₂CP) and residual renal function were higher in patients on PD than that in those on HD, whereas levels of lean body mass, systolic blood pressure, albumin, serum uric acid, potassium, and phosphorus（It should be "were" replace are) are higher in HD patients in comparison to PD patients. Dialysis modality (PD/HD), serum CO₂CP level, lean body mass, and percent body fat independently positively correlated with natural logarithm of irisin (lnirisin) by multivariate linear regression analysis.

CONCLUSIONS

In this study, we prove that serum irisin level is significantly higher in patients treated with peritoneal dialysis than that with hemodialysis. As well as, increasing skeletal muscle mass and fat body percent, and correcting metabolic acidosis may increase serum irisin levels.

Dietary assessment and effect of Pilates exercises on quality of life, body composition, and physical fitness in Iranian postmenopausal women

Menopause is an important period of life for women, all of whom experience this natural state. However, awareness of the bodily changes during this period is of great significance. Hence, not paying attention to the dietary, physical, and psychological criteria can reduce the quality of women’s lives. This study aimed to evaluate health-related quality of life (HRQoL), body composition, and physical fitness in postmenopausal women after Pilates exercises. Thirty postmenopausal Iranian women were randomly divided into Pilates (performed for 8 weeks) and control groups. The HRQoL Questionnaire (SF-12) was filled out, and a three-day record of food intake was also kept for dietary assessment. The diet of the women consisted of mean values of 1,923 Kcal daily energy, 16% protein, 72% carbohydrate, 12% fat, and 11.32 mg iron. Calcium, zinc, vitamin D, and vitamin E intake were respectively 73, 87.5, 81.7 and 83.53% of the recommended daily allowance. Pilates exercises had a significant effect on flexibility (P=0.002), endurance (P=0.001), muscle strength (P=0.001), body mass index (P=0.001), lean mass (P=0.003), body fat percentage (P=0.001), and quality of life (P=0.001). Therefore, Pilates is an appropriate training to increase body fitness and improve body composition, lean mass, and quality of life in postmenopausal women.