The relation between hemoglobin variability and carotid intima-media thickness in chronic hemodialysis patients

Association between hemoglobin variability and incidence of hypertension over 40 years: a Korean national cohort study

Hemoglobin level determines blood viscosity and as hemoglobin level rises, blood pressure rises. However, hemoglobin level in individuals is not fixed and change in hemoglobin is affected by various clinical conditions. The purpose of this study is to investigate whether the hemoglobin variability affects the development of hypertension using Korean cohort database. This study was conducted with 94,798 adults (age ≥ 40 years) who visited the health screening in 2006 or 2007 (index year) and had at least 3 health screenings from 2002 to 2007. Hemoglobin variability was assessed by 3 indices of coefficient of variation (CV), standard deviation, and variability independent of the mean. Cox proportional hazard regression analysis was performed for each index of quartile groups (Q1–Q4). A total of 29,145 participants (30.7%) had the incidence of hypertension during a median follow-up of 7.4 ± 2.5 years. In the multivariable adjusted model, the hazard ratio and 95% confidence interval for incidence of hypertension of Q2, Q3, and Q4 compared with Q1 of hemoglobin variability CV were 1.014 [0.981–1.047], 1.064 [1.030–1.099] and 1.094 [1.059–1.131] respectively. The results were consistent in various sensitivity and subgroup analyses. This study showed that hemoglobin variability could be associated with hypertension development.

Sitagliptin on Carotid Intima-Media Thickness in Type 2 Diabetes Mellitus Patients and Anemia: A Subgroup Analysis of the PROLOGUE Study

Introduction

Randomized clinical trials have not shown an additional clinical benefit of sitagliptin treatment over conventional treatment alone. However, studies of sitagliptin treatment have not examined the relationship between anemia and treatment group outcomes.

Methods

The PROLOGUE study is a prospective clinical trial of 442 participants with type 2 diabetes mellitus (T2DM) randomized to sitagliptin treatment or conventional treatment which showed no treatment differences [Estimated mean (± standard error) common carotid intima-media thickness (CIMT) was 0.827 ± 0.007 mm and 0.837 ± 0.007 mm, respectively, with a mean difference of -0.009 mm (97.2% CI −0.028 to 0.011, p = 0.309) at 24 mo of follow-up]. This is a post hoc subanalysis using data obtained from the PROLOGUE study; the study population was divided into anemic groups (n = 94) and nonanemic group (n = 343) based on hemoglobin level. And we analyzed for the changes in each CIMT parameter from baseline to 24 months in subgroups.

Results

The treatment group difference in baseline-adjusted mean common carotid artery- (CCA-) IMT at 24 months was −0.003 mm (95% CI −0.022 to 0.015, p = 0.718) in the nonanemic subgroup and −0.007 mm (95% CI −0.043 to 0.030, p = 0.724) in the anemic subgroup. Although there were no significant differences in the other CIMT parameters between the treatment groups in the anemic subgroup, the changes in mean and max ICA-IMT at 24 months in the nonanemic subgroup were significantly lower in the sitagliptin group than the conventional group [−0.104 mm (95% CI −0.182 to −0.026), p = 0.009 and −0.142 mm (−0.252 to −0.033), p = 0.011, respectively].

Conclusion

These data suggest that nonanemia may indicate a potentially large subgroup of those with T2DM patients that sitagliptin therapy has a better antiatherosclerotic effect than conventional therapy. Further research is needed to confirm these preliminary observations.

Time-averaged hemoglobin values, not hemoglobin cycling, have an impact on outcomes in pediatric dialysis patients

BACKGROUND

During erythropoietin-stimulating agent (ESA) treatment, hemoglobin (Hb) levels usually fluctuate; this phenomenon is known as "Hb cycling (HC)." In this study, we aimed to evaluate the predictors of HC and its impact on left ventricular hypertrophy (LVH) as a patient-important outcome parameter in pediatric dialysis patients.

METHODS

Records of patients followed up in nine pediatric nephrology centers between 2008 and 2013 were reviewed. More than 1 g/dL decrease or increase in Hb level was considered as HC. Patients were divided into two groups according to 12-month Hb trajectory as rare cycling (RC) (≤ 3) and frequent cycling (FC) (> 3 fluctuation) as well as three groups based on T-A-Hb levels: < 10, 10-11, and > 11 g/dL.

RESULTS

Two hundred forty-five dialysis (160 peritoneal dialysis (PD) and 85 hemodialysis (HD)) patients aged 12.3 ± 5.1 (range 0.5-21) years were enrolled in this study. Fifty-two percent of the patients had RC, 45% had FC, and only 3% had no cycling. There were no differences between HC groups with respect to age, dialysis modality, having anemia, hospitalization rate, residual urine volume, and mortality. Although left ventricular mass index (LVMI) tended to be higher in RC than FC group (65 ± 37 vs 52 ± 23 g/m^2.7, p = 0.056), prevalence of LVH was not different between the groups (p = 0.920). In regression analysis, FC was not a risk factor for LVH, but low T-A Hb level (< 10 g/dL) was a significant risk for LVH (OR = 0.414, 95% CI 0.177-0.966, p = 0.04). The target Hb levels were more often achieved in PD patients, and the number of deaths was significantly lower in non-anemic patients (Hb level > 11 g/dL).

CONCLUSION

Hb cycling is common among dialysis patients. Severity of anemia rather than its cycling has more significant impact on the prevalence of LVH and on inflammatory state.

Hemodialysis-induced cardiovascular disease

More than half of all deaths among end stage renal disease (ESRD) patients are due to cardiovascular disease (CVD). Cardiovascular changes secondary to renal dysfunction, including fluid overload, uremic cardiomyopathy, secondary hyperparathyroidism, anemia, altered lipid metabolism, and accumulation of gut microbiota-derived uremic toxins like trimethylamine N-oxidase, contribute to the high risk for CVD in the ESRD population. In addition, conventional hemodialysis (HD) itself poses myocardial stress and injury on the already compromised cardiovascular system in uremic patients. This review will provide an overview of cardiovascular changes in chronic kidney disease and ESRD, a description of reported mechanisms for HD-induced myocardial injury, comparison of HD with other treatment modalities in the context of CVD, and possible management strategies.