Clinical consequences of intermittent elevation of C-reactive protein levels in hemodialysis patients

Additional Effect of Hyperparathyroidism on Inflammatory Status and rHuEPO Requirements in Hemodialysis Patients

BACKGROUND

The aim of this study was to analyze the effects of elevated parathyroid hormone (iPTH) and C-reactive protein (CRP) on rHuEPO requirements and associated clinical and biochemical parameters of hemodialysis patients.

METHODS

A total of 127 hemodialysis patients were included. Laboratory values from the previous 3 months (monthly measured CRP, iPTH, albumin, prealbumin, calcium, phosphorus, and hemoglobin) and clinical findings (rHuEPO requirements, iron supplements, Kt/V) were recorded retrospectively. Patients were subgrouped according to presence of hyperparathyroidism (mean iPTH > 350 pg/mL) and chronic inflammation (mean CRP > 8.5 mg/L) as group I (low iPTH, low CRP, n = 32), group II (high iPTH, low CRP, n = 32), group III (low iPTH, high CRP, n = 32), and group IV (high iPTH, high CRP, n = 31).

RESULTS

We found that group IV had lowest hemoglobin (P < .0001, .0001, .01, respectively), albumin (P < .0001), prealbumin (P < .0001, .0001, .02, respectively), and highest rHuEPO requirements (P < .0001, .0001, .01, respectively) compared to other groups despite of similar iron indices. Group III also had lower albumin (P < .002, .0001, respectively), prealbumin (P < .001, .01, respectively), hemoglobin (P < .001, .005, respectively), but higher rHuEPO requirements (P < .01) compared to group I and group II.

CONCLUSIONS

We propose that hyperparathyroidism increases rHuEPO requirements and aggravates the negative effects of chronic inflammation in hemodialysis patients.

Use of EPO in Critically Ill Patients With Acute Renal Failure Requiring Renal Replacement Therapy

BACKGROUND

Recombinant human erythropoietin (EPO) is used widely to treat anemia in patients with chronic kidney disease, but the benefits of EPO use in patients with acute renal failure (ARF) are unclear. In vitro and animal studies suggest that EPO may promote renal recovery and decrease mortality in ARF.

METHODS

We conducted a retrospective cohort study at a tertiary-care center to evaluate the use of EPO in 187 critically ill patients with ARF requiring renal replacement therapy.

RESULTS

Compared with patients not administered EPO (n = 116), patients administered EPO (n = 71) were significantly more likely to have baseline chronic kidney disease, have undergone vascular surgery, and have received intermittent hemodialysis, rather than continuous renal replacement therapy. In a propensity-adjusted analysis that controlled for differences between the 2 cohorts and baseline hemoglobin level, EPO use did not decrease the transfusion of packed red blood cells. Renal recovery was not more common in patients administered EPO: the odds ratio for renal recovery in the propensity-adjusted analysis was 0.63 (95% confidence interval, 0.30 to 1.3) with EPO use. In-hospital survival was more common in the EPO-treated group, but this potential benefit was not significant in propensity-adjusted analyses.

CONCLUSION

Although EPO use was not associated with a decrease in transfusion requirements or with renal recovery in our retrospective study, 37% of critically ill patients with ARF were treated with EPO at varying doses. A randomized controlled trial is needed to evaluate the potential benefits of EPO use in patients with ARF.

A Preliminary Study of PDA-Based Dietary Self-Monitoring in Hemodialysis Patients

OBJECTIVE

The purpose of this study was to pilot test an intervention to enhance the adherence of study participants to the hemodialysis dietary regimen.

DESIGN

A single case study design was used to examine the potential effectiveness of the intervention over a 4-month period of time.

SETTING

A dialysis center in southwestern Pennsylvania.

PATIENTS

Of the five individuals entered into the study, one was male and four were female, four were black, and one was white. Participants were 63 to 70 years of age, and had been receiving dialysis for a median of 36 months (range, 18 to 84 months).

INTERVENTION

The intervention included counseling to enhance self-efficacy, by a renal dietitian, paired with personal digital assistant-based dietary self-monitoring. Participants met twice per week with interventionists during the first 6 weeks, weekly during the second 6-week period, and biweekly in the final 4-week period.

MAIN OUTCOME MEASURES

Monthly laboratory data regarding serum albumin, potassium, and phosphorus levels; Kt/V; and data on average monthly interdialytic weight gain were abstracted from the participants' medical records. C-reactive protein level was determined at baseline and at 4 months.

RESULTS

Four of five study participants had an increase in serum albumin level from baseline to their final measurement, and one participant maintained a stable albumin level. Four of five participants also experienced a small increase in serum phosphorus level. Mixed results were obtained with regard to serum potassium and average monthly interdialytic weight gain.

CONCLUSIONS

Because of the small sample and single case study design, caution must be used in drawing firm conclusions from this study. Data suggest that the intervention may result in improved dietary intake and improved serum albumin levels. With increased dietary intake, serum phosphorus levels may increase. Additional research is needed to determine the potential efficacy and cost-effectiveness of this intervention for improving dietary adherence.

C-reactive protein and end-stage renal disease

The significance of CRP and inflammation has increased over time, especially in the end-stage renal disease (ESRD) population. From a simple marker it now appears that CRP is an active participant in pro-atherosclerotic phenomenon including local pro-inflammatory and thrombotic events. Studies in the general population indicate the usefulness of CRP in prognostication and in monitoring response to therapy. The clinical usefulness of CRP monitoring in chronic kidney disease (CKD) and especially in ESRD deserves closer study. In the meantime, the utility of CRP measurements for monitoring and treatment is on a case-by-case basis. Management of traditional cardiovascular risk factors should be considered. In the interest of optimizing therapy it is prudent to use biocompatible membranes and ultrapure water. A careful search for infectious processes in dialysis patients is recommended, with special attention to vascular access sites, periodontitis, gastritis, and other potentially chronic or covert infections. ACE-inhibitor use should be maximized in all eligible CKD patients. The data on the use of statins in ESRD have been generally positive but await further validation. Individualized use for selected patients is probably beneficial.