Clinical interpretation of reticulocyte hemoglobin content, RET-Y, in chronic hemodialysis patients.

BACKGROUND: Iron deficiency is the most common factor associated with erythropoietin (EPO) hyporesponsiveness. Current iron indices are inadequate to demonstrate the status or utility of iron in erythropoiesis. The aims of this study are to investigate the value of the reticulocyte hemoglobin content, RET-Y, in hemodialysis (HD) patients and compare the levels with conventional iron indices. METHODS: HD patients (n = 289) were divided into 4 groups according to serum ferritin (cutoff value 100 ng/ml) and transferrin saturation (TSAT, cutoff value 20%). The RET-Y value, hemogram and biochemical data were determined and compared between groups. Factors associated with RET-Y were examined. RESULTS: The mean RET-Y value was 1,716 +/- 125 AU. Patients with absolute iron deficiency had lower RET-Y levels and mean corpuscular volume (MCV). Patients with functional iron deficiency had a lower reticulocyte production index and serum albumin levels. MCV, mean corpuscular hemoglobin concentration (MCHC) and albumin were independently correlated with the RET-Y level (all p < 0.001). EPO-independent patients had low iron indices and low RET-Y levels, but a higher reticulocyte production index and albumin levels were noted. CONCLUSION: RET-Y levels in HD patients were close to that of the normal population. Low RET-Y levels were observed in patients with absolute iron deficiency and also in EPO-independent patients with low ferritin and low TSAT. There was a strong association between the serum albumin and RET-Y levels in chronic HD patients.

Factors determining cardiovascular and renal outcomes after adrenalectomy in patients with aldosterone-producing adrenal adenoma.

Primary aldosteronism is an important cause of secondary hypertension, because it is potentially curable, especially in case of unilateral aldosterone-producing adrenal adenoma (APA). However, the information is limited concerning the cardiovascular and renal outcomes in this patient population. We studied 52 patients with APA in order to determine the pre-operative and post-operative factors predicting cardiovascular and renal outcomes. All 52 patients were hypertensive before the operation. Among 35 patients who underwent pre-operative electrocardiogram, 23 patients had left ventricular hypertrophy (LVH). Patients with LVH had lower estimated glomerular filtration rate (eGFR). Adrenalectomy successfully normalized or improved hypertension, hypokalemia, and aldosterone excess. One month after the adrenalectomy, 32 patients (62%) became normotensive, but 20 patients (38%) remained hypertensive. However, after an average follow-up period of 51 months, only 18 patients remained normotensive, while 34 patients were hypertensive. Thus, the rate of recurrent hypertension after adrenalectomy was high (14/32, 43%). Pre-operative systolic blood pressure (BP), diastolic BP, and post-operative plasma aldosterone concentrations were the only variables significantly different between the hypertensive and normotensive patients. Using pre-operative BP 165/110 mmHg as a cutoff has good positive predictive values (73-92%) for post-operative long-term hypertension. Patients whose renal function worsened after adrenalectomy had significantly higher pre-operative plasma active renin levels. Thus, in patients with APA, the presence of LVH is correlated with impaired renal function (lower eGFR). In conclusion, pre-operative BP and post-operative plasma aldosterone are important in predicting post-adrenalectomy hypertension, and a lower pre-operative plasma renin predicts the improvement in renal function after adrenalectomy.

Inflammatory marker but not adipokine predicts mortality among long-term hemodialysis patients.

AIMS: chronic inflammation contributes significantly to the morbidity and mortality of chronic hemodialysis patients. A recent research has shown that adipokines were associated with inflammation in these patients. We aim to investigate whether biomarkers of inflammation, adipokines, and clinical features can predict the outcome of hemodialysis patients. MATERIALS AND METHODS: we enrolled 181 hemodialysis patients (men: 97, mean age: 56.3+/-13.6) and analyzed predictors of long-term outcomes. RESULTS: during the 3-year followup period, 41 patients died; the main causes of death were infection and cardiovascular disease. Elevated serum levels of hsCRP and albumin and advanced age were highly associated with death (all P<.001). Leptin and adiponectin levels were not significantly different between deceased patients and survivors. Cox-regression analysis indicated that age, diabetes, albumin level, and hsCRP were independent factors predicting mortality. CONCLUSION: the presence of underlying disease, advanced age, and markers of chronic inflammation is strongly related to survival rate in long-term hemodialysis patients.

Sex differences in kidney size and clinical features of patients with uremia.

BACKGROUND: Ultrasonographic evaluation of the kidney size is a useful method for assessment of the progression and, in some cases, the type of nephropathy. Ultrasonography (USG) also plays an important role in the evaluation of both acute and chronic renal failure. OBJECTIVE: To investigate the ultrasonographic appearance of the kidneys in patients with uremia, underlying renal diseases and clinical characteristics, including biological sex, were studied. METHODS: This was a retrospective study of data from consecutive adult patients with uremia starting a dialysis program between January 2005 and December 2006 at the nephrology department of a university hospital in Taiwan. Kidney size was determined by USG; demographic and clinical data were obtained prior to initiation of dialysis. RESULTS: Of the patients (167 men, 151 women) included in the analysis, diabetes mellitus (DM) was the leading cause of uremia (127/318; 39.9%). The distribution of DM was similar between male and female patients. In addition to levels of blood urea nitrogen and hemoglobin, body mass index was similar between male and female patients (mean [SD], 22.9 [3.1] vs 22.1 [3.4] kg/m(2), respectively). Female patients had significantly lower serum creatinine levels (P < 0.05) and higher estimated glomerular filtration rates (P < 0.01) than did male patients when they initiated chronic dialysis therapy. Among those with DM, male patients were younger and had larger kidney size on initiation of dialysis therapy than did female patients (age, 59.9 [9.4] vs 64.6 [11.9] years; right renal length, 10.3 [1.4] vs 9.5 [1.5] cm; left renal length, 10.4 [1.5] vs 9.5 [1.4] cm; all, P < 0.05). These sex differences in age and kidney size at the start of dialysis were not observed in patients who did not have DM. Patients with DM had significantly larger kidney size than those without DM (P < 0.05). CONCLUSIONS: The kidney size of these uremic patients varied considerably, depending on sex and the underlying disease. Male patients with DM at the terminal stage of renal failure had larger kidney size and were younger at the start of dialysis therapy than female patients with DM. In uremic patients without DM, no such discrepancy was observed, and both male and female patients started dialysis therapy at a comparable age and kidney size.