Israel Medical Association Journal

Background: Anemia management strategies among chronic hemodialysis patients with high ferritin levels remains challenging for nephrologists.

Objectives: To compare anemia management in stable hemodialysis patients with high (≥ 500 ng/ml) vs. low (< 500 ng/ml) ferritin levels

Methods: In a single center, record review, cohort study of stable hemodialysis patients who were followed for 24 months, an anemia management policy was amended to discontinue intravenous (IV) iron therapy for stable hemodialysis patients with hemoglobin > 10 g/dl and ferritin ≥ 500 ng/ml. Erythropoiesis-stimulating-agents (ESA), IV iron doses, and laboratory parameters were compared among patients with high vs. low baseline ferritin levels before and after IV iron cessation.

Results: Among 87 patients, 73.6% had baseline ferritin ≥ 500 ng/ml. Weekly ESA dose was greater among patients with high vs. low ferritin (6788.8 ± 4727.8 IU/week vs. 3305.0 ± 2953.9 IU/week, P = 0.001); whereas, cumulative and monthly IV iron doses were significantly lower (1628.2 ± 1491.1 mg vs. 2557.4 ± 1398.9 mg, P = 0.011, and 82.9 ± 85 vs. 140.7 ± 63.9 mg, P = 0.004). Among patients with high ferritin, IV iron was discontinued for more than 3 months in 41 patients (64%) and completely avoided in 6 (9.5%).ESA dose and hemoglobin levels did not change significantly during this period.

Conclusions: Iron cessation in chronic hemodialysis patients with high ferritin levels did not affect hemoglobin level or ESA dose and can be considered as a safe policy for attenuating the risk of chronic iron overload.

Background: Multiple factors are involved in the pathogenesis of hypertension in the obese individual.

Objective: To evaluate the role of a decrease in sympathetically mediated thermogenesis and the effect of the correlation between the plasma leptin and daily urinary nitric oxide levels on obesity-related hypertension.

Methods: We evaluated three groups: 25 obese hypertensive patients (age 45.7±1.37 years, body mass index 34.2±1.35 kg/m², systolic/diastolic blood pressure 155±2.9/105±1.3, mean arterial pressure 122±1.50 mmHg); 21 obese normotensive patients (age 39.6±1.72, BMI[1] 31.3±0.76, SBP/DBP[2] 124±2.1/85.4±1.8, MAP[3] 98.2±1.80); and 17 lean normotensive subjects (age 38.1±2.16, BMI 22.1±0.28, SBP/DBP 117±1.7/76.8±1.5, MAP 90.1±1.50). We determined basal resting metabolic rates, plasma insulin (radioimmunoassay), norepinephrine (high performance liquid chromatography) in all subjects. Thereafter, 14 obese hypertensives underwent a weight reduction diet. At weeks 6 (n=14) and 14 (n=10) of the diet the above determinations were repeated. Plasma leptin (enzyme-linked immunosorbent assay) and UNOx[4] (spectrophotometry) were assayed in 17 obese hypertensives and 17 obese normotensives, and in 19 obese hypertensives versus 11 obese normotensives, respectively.

Results: Obese hypertensive patients had significantly higher basal RMR[5] and plasma NE[6] levels. Insulin levels were lower in the lean group, with no difference between the hypertensive and normotensive obese groups. At weeks 6 and 14, BMI was significantly lower, as were insulin and NE levels. RMR decreased to values of normotensive subjects. MAP normalized but remained significantly higher than that of obese normotensives. Leptin blood levels and the leptin/UNOx ratio were significantly higher in the obese hypertensive compared to the obese normotensive patients. Both these parameters were strongly correlated to BMI, MAP⁵, RMR, and plasma NE and insulin .Obese hypertensive patients excreted less urinary NO metabolites. A strong correlation was found between MAP and the leptin/UNOx ratio.  

Conclusions: A reduction of sympathetically mediated thermogenesis, as reflected by RMR, results in normalization of obesity-related hypertension. In contrast, insulin does not seem to play a major role in the pathogenesis of hypertension associated with obesity. Increased leptin levels in conjunction with decreased NO production in the presence of enhanced sympathetic activity may contribute to blood pressure elevation in the obese.

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[1] BMI = body mass index

[2] SBP/DBP = systolic blood pressure/diastolic blood pressure

[3] MAP = mean arterial pressure

[4] UNOx = urinary nitric oxide

[5] RMR – resting metabolic rate

[6] NE = norepinephrine