Sex Modulates Cardiovascular Effects of Icodextrin-Based Peritoneal Dialysis Solutions.

Background/Aims: Some previous observations have noted that after six months of peritoneal dialysis (PD) treatment with icodextrin solutions, blood pressure (BP) and NT-proBNP tend to return to baseline values. This may be due to accumulation of icodextrin products that exert a colloid osmotic effect, which drives water into the bloodstream, causing the rise in blood pressure. Since icodextrin is metabolized by α-Amylase and its gene copies are lower in females than in males, we hypothesized icodextrin metabolites reach higher concentrations in females and that cardiovascular effects of icodextrin are influenced by sex. Methods: Secondary analysis of a RCT comparing factors influencing fluid balance control in diabetic PD patients with high or high average peritoneal transport receiving icodextrin (n = 30) or glucose (n = 29) PD solutions. Serum icodextrin metabolites, osmolality, body composition and Inferior Vena Cava (IVC) diameter were measured at baseline, and at 6 and 12 months of follow-up. Results: After six months of treatment, icodextrin metabolites showed higher levels in females than in males, particularly G5-7 and >G7, serum osmolality was lower in females. In spite of reduction in total and extracellular body water, ultrafiltration (UF) was lower and IVC diameter and BP increased in females, suggesting increment of blood volume. Conclusion: Females undergoing PD present with higher levels of icodextrin metabolites in serum that may exert an increased colloid-osmotic pressure followed by less UF volumes and increment in blood volume and blood pressure. Whether this could be due to the lesser number of α-Amylase gene copies described in diabetic females deserves further investigation.

Pulmonary Hypertension in Patients Starting Peritoneal Dialysis.

BACKGROUND: Cardiovascular complications are the major cause of morbidity and mortality in patients with chronic kidney disease (CKD). One such complication is pulmonary hypertension (PH). Its prevalence in patients in peritoneal dialysis (PD) varies from 12.6-41.7% and its related factors are not well known. The main objective of this multicenter study was to determine the prevalence of PH and its risk factors in patients starting in PD. METHODS: Patients incident in PD were studied. Clinical, biochemical, and PD parameters were evaluated. A transthoracic echocardiography was performed and the evaluated according to the American Society of Echocardiography. Systolic pulmonary artery pressure (sPAP) was calculated with tricuspid regurgitation gradient and PH considered if pulmonary artery pressure was ≥35 mmHg. RESULTS: There were 105 men and 72 women included in the study (aged 53.7 ± 12.8 vs. 52.9 ± 15.5 years). PH was found in 69 patients (38.98%), they had sPAP of 49.05 ± 13.80 vs. 18.81 ± 11.15 mmg, in patients without PH (p <0.001). Patients with PH tend to be more frequently men than women (42 vs. 35%, p = 0.33), and were younger (51.0 ± 14.9 vs. 55,1 ± 12.8 years; p = 0.05). Risk factor for PH were diastolic dysfunction of the left ventricle (LV) (OR = 1.46, 95% CI 1.094-1.973), left ventricular hypertrophy (LVF) (OR = 2.56, 95% CI 1.29-5.09); and residual renal function (RRF) was a protector factor (OR = 0.78, 95% CI 0.068-0.915). CONCLUSIONS: Prevalence of PH in patient's incident in PD was 38%. The factors associated with PH were diastolic dysfunction of the LV and LV hypertrophy. RRF was a protector factor.

[Peak expiratory flow vs. spirometry for the diagnosis of asthma in adults]. / Flujometría versus espirometría para el diagnóstico de asma en adultos.

BACKGROUND: The diagnosis of asthma is confirmed with a spirometry: FEV1 ratio (forced expiratory volume in one second)/FVC (forced vital capacity) <80% with reversibility (FEV1 >12% or 200 mL) after using salbutamol. The peak expiratory flow is cheap and easy to use; it measures the forced expiratory flow, of which reversibility > 20% suggests asthma. OBJECTIVE: To know the sensitivity, specificity, and the positive and negative predictive values of the flowmeter. METHODS: A cross-sectional, observational, comparative study. Individuals aged >18 years without contraindications for spirometry were included. They underwent spirometry and peak expiratory flow, and the ACT (Asthma Control Test) questionnaire was applied to them. Sensitivity, specificity, positive predictive value and negative predictive value of the flowmetry were calculated. ROC curve was carried out in order to know the cut-off point of greater sensitivity and specificity. RESULTS: Of 150 patients, 66% were male; the median age was 38 years. According to the guidelines of GINA 2018 (Global Initiative for Asthma); 58.7% were controlled. The sensitivity of the peak expiratory flow was 47%, and the specificity was 87%, with a positive predictive value of 54.8% and a negative predictive value of 84%. The peak expiratory flow showed higher specificity with FEV1 <59%. The cut-off point of greater sensitivity and specificity was a reversibility of 8%, with an area under the curve of 0.70. CONCLUSIONS: The flowmeter has got greater sensitivity in airway obstructions; it is useful when a spirometer is not available.

Antecedentes: El diagnóstico de asma se confirma con espirometría: VEF1 (volumen espiratorio forzado del primer segundo)/CVF (capacidad vital forzada) < 80 %, con reversibilidad (VEF1 >12 % o 200 mL) tras utilizar salbutamol. El flujómetro es barato y fácil de utilizar, mide el flujo espiratorio forzado, cuya reversibilidad > 20 % sugiere asma. Objetivo: Conocer sensibilidad, especificidad y valores predictivos positivos y negativo del flujómetro. Métodos: Estudio transversal, observacional, comparativo. Se incluyó a individuos > 18 años sin contraindicaciones para espirometría, quienes fueron sometidos a espirometría y flujometría y se les aplicó el Asthma Control Test. Se calculó sensibilidad, especificidad y valores predictivos positivo y negativo de la flujometría. Se realizó curva ROC para conocer el punto de corte de mayor sensibilidad y especificidad. Resultados: De 150 pacientes, 66 % fue del sexo masculino; la mediana de edad fue de 38 años. Conforme los criterios de Global Initiative for Asthma 2018, 58.7 % estaba controlado. La sensibilidad de la flujometría fue de 47 %, la especificidad de 87 %, valor predictivo positivo de 54.8 % y negativo de 84 %. La flujometría mostró mayor especificidad con VEF1 < 59 %. El punto de corte de mayor sensibilidad y especificidad fue una reversibilidad de 8 %, con área bajo la curva de 0.70. Conclusiones: El flujómetro tiene mayor sensibilidad en obstrucciones de vía aérea; es de utilidad cuando no se cuenta con un espirómetro.

High Prevalence of Diastolic Dysfunction in Incident Patients on Peritoneal Dialysis: Association with Low Thyroid Hormones.

BACKGROUND/AIMS: Diastolic dysfunction (DD) and low levels of thyroid hormones (TH) are frequent found in chronic kidney disease; both are associated with all-cause and cardiovascular mortality. However, a link between them has not yet been established. The aim of this study was to analyze DD as a surrogate marker of fibrosis and its association with TH in incident patients on peritoneal dialysis (PD). METHODS: A cross-sectional study with 183 incident patients on PD with preserved ejection fraction was performed. Clinical and demographic data were registered. Serum total and free (t/f) triiodothyronine (T3), thyroxin (T4), and thyroid stimulating hormone levels were determined by RIA kits, albumin and high-sensitivity C-reactive protein by conventional assays. Transthoracic 2D echocardiogram was performed for evaluation of left ventricular (LV) mass and ejection fraction. DD was evaluated using pulsed-wave tissue Doppler imaging. RESULTS: Patients were 43 ± 12, 42% with diabetes mellitus (DM). Some degree of DD was found in 62% of patients; 18% had grade I DD, 8% grade II DD and 36% grade III DD. Patients with grade III DD were more likely to have diabetes, older, high LV mass and low serum albumin, t/fT3 and tT4 levels. In logistic multivariate regression analysis, it was found that diabetes (B = -0.86, 95% CI 0.182-0.992, p < 0.05), hypertension (B = -0.95, 95% CI 0.184-0.817, p = 0.01) and tT3 (B = -1.94, 95% CI 0.023-0.876, p < 0.05) were associated with grade III DD. CONCLUSIONS: High prevalence of grade III DD was found in incident patients on PD. In addition to DM and hypertension, tT3 was found to be an independent risk factor for grade III DD and more studies are needed to understand the reasons as to why this association is present.

Effect of icodextrin on heart rate variability in diabetic patients on peritoneal dialysis.

INTRODUCTION: Spectral analysis of heart rate variability is a noninvasive method for evaluating autonomic cardiovascular dysfunction under various clinical conditions, such as in dialysis patients, in whom an imbalance between the sympathetic and parasympathetic nervous system appears to be an important risk factor for sudden cardiovascular death and arrhythmia. ♢ OBJECTIVE: We compared the effect of icodextrin-based dialysis solution, an option that allows for better metabolic and fluid overload control, with that of glucose-based dialysis fluid on sympathetic and parasympathetic activity in the heart, as assessed by heart rate variability, in diabetic patients on peritoneal dialysis (PD). ♢ METHODS: This secondary analysis uses data from a randomized controlled trial in diabetic PD patients with high or high-average peritoneal transport using icodextrin-based (ICO group, n = 30) or glucose-based (GLU group, n = 29) solutions for the long dwell. All patients underwent 24-hour electrocardiographic Holter monitoring at baseline, and at 6 and 12 months of follow-up. ♢ RESULTS: We observed no significant differences between the groups in most of the variables analyzed, although values were, in general, below reference values. In the ICO group, total power and both low- and high-frequency power in normalized units increased, but the percentage of RR intervals with variation of more than 50 ms declined over time; in the GLU group, all those values declined. Plasma catecholamine levels were higher at baseline and declined over time. ♢ CONCLUSIONS: These results indicate a partial recovery of sympathetic activity in the ICO group, probably because of better extracellular fluid control and lower exposure to glucose with the use of icodextrin-based dialysis solutions.

Icodextrin improves metabolic and fluid management in high and high-average transport diabetic patients.

BACKGROUND: Icodextrin-based solutions (ICO) have clinical and theoretical advantages over glucose-based solutions (GLU) in fluid and metabolic management of diabetic peritoneal dialysis (PD) patients; however, these advantages have not yet been tested in a randomized fashion. OBJECTIVE: To analyze the effects of ICO on metabolic and fluid control in high and high-average transport diabetic patients on continuous ambulatory PD (CAPD). PATIENTS AND METHODS: A 12-month, multicenter, open-label, randomized controlled trial was conducted to compare ICO (n = 30) versus GLU (n = 29) in diabetic CAPD patients with high-average and high peritoneal transport characteristics. The basic daily schedule was 3 x 2 L GLU (1.5%) and either 1 x 2 L ICO (7.5%) or 1 x 2 L GLU (2.5%) for the long-dwell exchange, with substitution of 2.5% or 4.25% for 1.5% GLU being allowed when clinically necessary. Variables related to metabolic and fluid control were measured each month. RESULTS: Groups were similar at baseline in all measured variables. More than 66% of the patients using GLU, but only 9% using ICO, needed prescriptions of higher glucose concentration solutions. Ultrafiltration (UF) was higher (198 +/- 101 mL/day, p < 0.05) in the ICO group than in the GLU group over time. Changes from baseline were more pronounced in the ICO group than in the GLU group for extracellular fluid volume (0.23 +/- 1.38 vs -1.0 +/- 1.48 L, p < 0.01) and blood pressure (systolic 1.5 +/- 24.0 vs -10.4 +/- 30.0 mmHg, p < 0.01; diastolic 1.5 +/- 13.5 vs -6.2 +/- 14.2 mmHg, p < 0.01). Compared to baseline, patients in the ICO group had better metabolic control than those in the GLU group: glucose absorption was more reduced (-17 +/- 44 vs -64 +/- 35 g/day) as were insulin needs (3.6 +/- 3.4 vs - 9.1 +/- 4.7 U/day, p < 0.01), fasting serum glucose (8.3 +/- 36.5 vs -37 +/- 25.8 mg/dL, p < 0.01), triglycerides (54.5 +/- 31.9 vs -54.7 +/- 39.9 mg/dL, p < 0.01), and glycated hemoglobin (0.79% +/- 0.79% vs -0.98% +/- 0.51%, p < 0.01). Patients in the ICO group had fewer adverse events related to fluid and glucose control than patients in the GLU group. CONCLUSION: Icodextrin represents a significant advantage in the management of high transport diabetic patients on PD, improving peritoneal UF and fluid control and reducing the burden of glucose overexposure, thereby facilitating metabolic control.