Low-Fiber Intake Is Associated With High Production of Intraperitoneal Inflammation Biomarkers.

OBJECTIVE: Fiber intake influences disturbances in the gastrointestinal tract and is associated with systemic inflammation in the general population. Systemic and intraperitoneal inflammation play an important role in defining outcomes in peritoneal dialysis (PD), but the relationship between dietary fiber intake and inflammatory biomarkers has not yet been reported in the population on PD. The objective of the present study is to analyze whether or not fiber intake in patients on PD is associated with serum and intraperitoneal levels of inflammatory biomarkers. DESIGN AND METHODS: Adult and clinically stable PD patients were included in this observational and cross-sectional study. Fiber intake was assessed by means of a dietary survey and calculated using the DietPro program 5.6i. The population was divided into two groups according to the median fiber intake. We investigated interleukin (IL)-1ß, IL-6, tumor necrosis factor-α, monocyte chemoattractant protein-1 (MCP-1), B-cell-activating factor, and plasminogen-activator inhibitor-1 in both serum and peritoneal fluid. The latter was determined after a dwell time of 4 hours. RESULTS: Fifty-two patients (42% men; aged 53 ± 14 years, 36% diabetics) were evaluated. Low intake of dietary fiber was found in 90% of patients, with a median of 12.2 g per day (3.4-33.3). The group with the highest fiber intake presented lower intraperitoneal levels of IL-6, IL-8, and MCP-1. In contrast, only MCP-1 was lower in the serum of those who consumed more fiber. All the associations remained significant after adjustment for confounders with plasminogen-activator inhibitor-1 included. CONCLUSIONS: Patients on PD frequently present inadequate dietary fiber intake, which appears to have an association with the inflammatory response, particularly in the intraperitoneal component. Further prospective studies, evaluating whether or not a dietetic intervention with a focus on fiber intake affects these biomarkers and clinical outcomes, are essential to determine causality and clinical relevance.

Predictive value of malnutrition markers for mortality in peritoneal dialysis patients.

INTRODUCTION: Alterations in nutritional status have been described as important predictors of mortality in patients with chronic kidney disease (CKD). However, the association between multiple markers for nutritional status and the mortality rates of patients with CKD on peritoneal dialysis (PD) has not yet been illustrated in previously published data, particularly by using the new definition of protein energy wasting (PEW). OBJECTIVE: To evaluate the predictive value of malnutrition markers for mortality rates, on the basis of the PEW definition, of PD patients. MATERIALS AND METHODS: At the start of PD treatment, the nutritional status of 199 patients (mean age, 56 ± 13.3 years; 53% females) was evaluated. Body mass index (BMI), arm circumference, mid-arm muscle circumference, protein and caloric intake (by using a 3-day food record), and serum albumin were all recorded, as well as a subjective global assessment (SGA) and presence of PEW. Cut-off points were defined on the basis of the consensus of the International Society for Renal Nutrition and Metabolism (albumin, <3.8 g/dL; BMI, <23 kg/m(2); mid-arm muscle circumference, >10% in comparison with the 50th percentile for the reference population; protein intake, <0.8 g/kg/daily; caloric intake, <25 kcal/kg/daily). The data were obtained retrospectively between the years 2001 and 2008 on the basis of routine nutritional evaluation. Patients were monitored for fatal events from all possible causes. RESULT: The mean BMI for the population was 26.6 ± 5.0 kg/m(2). A median protein intake of 0.94 (0.18 to 4.57) g/kg/daily was reported and 60.3% of the patients reported a protein intake of <0.8 g/kg/daily. With respect to caloric intake, 38.7% of the patients consumed <25 kcal/kg/daily. A median of 3.5 (1.4 to 5.3) g/dL for serum albumin was observed and 29.3% of the patients presented values of <3.8 g/dL. PEW was diagnosed in 17.5% of patients. In the univariate model, being of age >65 years (P = .002), cardiovascular disease (P < .001), diabetes mellitus (P = .02), SGA (P = .02), and albumin (P = .002), were all significant markers for mortality. The presence of patients aged >65 years (P = .02), with diabetes mellitus (P = .057), cardiovascular disease (P = .005), and albumin were considered as independent factors for mortality in this study. CONCLUSION: SGA, albumin, and PEW were the only nutritional markers found to be associated with mortality in this cohort of PD patients. In the multivariate analysis, after adjusting for classic mortality risk factors, only patients with hypoalbuminemia were found to be at a high risk for mortality at follow-up. These results may be limited by the number of observations and a necessity for confirmation in larger prospective studies.

Association between body mass index and body fat in chronic kidney disease stages 3 to 5, hemodialysis, and peritoneal dialysis patients.

OBJECTIVE: Chronic kidney disease (CKD) patients may present with altered body composition. Body mass index (BMI) is a simple method for evaluating body fat mass (FM) in the general population. In CKD patients, there are few reports demonstrating the association between BMI and body composition. Our objective was to investigate the reliability of BMI as an indicator of FM in patients with CKD stages 3 to 5. METHODS: Seventy-eight nondiabetic CKD patients (aged 48, SD +/- 12 years; 45% male) and 30 healthy control subjects (aged 46, SD +/- 12 years; 40% male), matched for age and sex, were evaluated. Chronic kidney disease patients were divided, according to K/DOQI guidelines, into 27 subjects at stages 3 to 4 (mean glomerular filtration rate of 43 +/- 12 mL/minute; age, 52 +/- 10 years), and 51 at stage 5: 25 in hemodialysis (HD) (aged 45, SD +/- 12 years; 44% male), and 26 in peritoneal dialysis (PD) (aged 49, SD +/- 13 years; 42% male). Body mass index was calculated as weight/height(2), and body composition was evaluated through dual-energy x-ray absorptiometry. RESULTS: There was no difference in median BMI (kg/m(2)) among healthy control subjects (24.8; range, 19.2-34.1), CKD stages 3 to 4 (26.4; range, 20.4-37.6), HD patients (24.5; range, 19.4-35.7), and PD patients (24.5; range, 20.2-37.7; P > .05). Likewise, no significant difference was verified in median body FM (kg) among control subjects (18.8; range, 9.2-36.5), CKD stages 3 to 4 (21.2; range, 11.6-37.9), HD patients (17.1; range, 4.8-38.9), and PD patients (20.1; range, 6.5-41.5; P > .05). Moreover, a positive and significant correlation was found between BMI and FM (kg) in CKD stages 3 to 4 (Rho = 0.67, P = .0002), in HD patients (Rho = 0.67, P = .0002), in PD patients (Rho = 0.79, P < .0001), and in control subjects (Rho = 0.79, P < .0001). Although BMI and lean body mass (in kg) was significantly correlated in CKD stages 3 to 4 (Rho = 0.58, P = .001) and healthy control subjects (Rho = 0.30, P = .007), no significant correlation was found in HD patients (Rho = 0.19, P = .34) and in PD patients (Rho = 0.17, P = .38). CONCLUSIONS: Body composition did not differ in patients with CKD stages 3 to 5, and between dialysis modalities. Although BMI was strongly and significantly correlated with body FM in CKD patients at stages 3 to 5, lean body mass was not. These findings suggest that BMI is a reliable indicator of body FM in this CKD population.

Insulin resistance is associated with circulating fibrinogen levels in nondiabetic patients receiving peritoneal dialysis.

BACKGROUND: Insulin resistance (IR) and inflammation are associated with increased risk of cardiovascular disease in the general population. Continuous glucose absorption in peritoneal dialysis (PD) may induce hyperglycemia and hyperinsulinemia. METHODS: We evaluated IR in nondiabetic patients receiving PD, and analyzed the association between IR and systemic inflammation biomarkers by performing a cross-sectional study on ambulatory dialysis. A total of 25 nondiabetic patients receiving PD and 25 healthy individuals, matched for gender, age, and body mass index (BMI), were included. The PD group was composed of 11 men and 14 women, with a mean age of 47 +/- 14 years and mean BMI of 25.5 +/- 4.7 kg/m(2). The control group was composed of 10 men and 15 women, with a mean age of 45 +/- 12 years and BMI of 24.0 +/- 2.8 kg/m(2). RESULTS: IR was evaluated by the homeostasis model assessment method (HOMA-IR). Inflammation was assessed through high-sensitivity C-reactive protein (CRP) and fibrinogen. Body composition and truncal fat were evaluated by dual energy x-ray absorptiometry. HOMA-IR was significantly higher (P < .0001) in subjects receiving PD (4.9, range: 2.3-9.3 mmol/L x muU/mL) compared with healthy subjects (1.2, range: 0.4-4.8 mmol/L x muU/mL). As expected, compared with controls, patients receiving PD had significantly higher levels of insulin (26.5 +/- 7.5 muU/mL vs 6.3 +/- 3.4 muU/mL; P < .0001), CRP (6.3, range: 0.3-61.1 mg/L vs 2.4, range: 0.6-5.9 mg/L; P = .001), and fibrinogen (379 +/- 101 mg/dL vs 268 +/- 66 mg/dL; P < .0001). However, there were no significant differences in body and truncal fat mass between the groups. A significant correlation between HOMA-IR and fibrinogen (Rho = 0.48; P = .01) was observed. However, no correlation was found between HOMA-IR and CRP. Also, no significant correlations were found between HOMA-IR and body fat mass (Rho = 0.11), and between HOMA-IR and truncal fat mass (Rho = 0.19). CONCLUSIONS: Patients receiving PD demonstrate a state of IR that is associated with high circulating levels of fibrinogen. This suggests that hyperfibrinogenemia may be involved in the pathogenesis of IR in this setting.