Impact of dialysis duration and glucose absorption on nutritional indices in stable continuous ambulatory peritoneal dialysis patients

Hypertriglyceridemia is a risk factor for treatment failure in patients with peritoneal dialysis-related peritonitis

OBJECTIVE

Disorders of triglycerides (TG) are common in patients with peritoneal dialysis (PD). Hypertriglyceridemia has been demonstrated in various infections. The association between triglycerides and the outcomes of peritoneal dialysis-related peritonitis (PDRP) was investigated in this study.

METHODS

We retrospectively investigated patients with PDRP from January 1, 2013 to October 31, 2020. Hypertriglyceridemia was defined as triglycerides ≥ 1.7 mmol/L. PDRP episodes were divided into two groups: hypertriglyceridemia and normal levels of triglycerides. The clinical and laboratory baseline data of the two groups were collected and compared. The association between triglycerides and treatment failure was analyzed by logistic regression analysis.

RESULTS

Ninety episodes in 66 patients were recorded in our center. Hypertriglyceridemia occurred in 38% (34/90) of episodes. Twenty-five episodes were not cured in 90 episodes (27.8%, 25/90). The levels of thrombocytes, high-sensitivity C-reactive protein (hs-CRP), low-density lipoprotein cholesterol (LDL-C) and glycated hemoglobin, were higher in hypertriglyceridemia episodes of PDRP at baseline. The bacterial classification was different between elevated triglyceride group and normal triglyceride group. Adjusted for age, duration of dialysis, residual renal function, diabetes, thrombocytes, hs-CRP, serum albumin, cholesterol, HDL-C, LDL-C, intact parathyroid hormone (iPTH), glycated hemoglobin and spectrum of bacteria, hypertriglyceridemia were associated significantly with treatment failure of PDRP in our study (OR 3.416, 95% CI 1.223-9.540 p < 0.05).

CONCLUSION

Hypertriglyceridemia at baseline was an independent risk factor for treatment failure of PDRP.

Change in appendicular lean mass in patients established on peritoneal dialysis as measured by dual x-ray absorptiometry (DXA) scanning

BACKGROUND/OBJECTIVES

Peritoneal dialysis (PD) patients are at increased risk of malnutrition and cachexia, definitions of which include weight loss. However, PD patients can absorb glucose from the dialysate and loss of muscle mass may be overlooked by fat weight gain. As such, we wished to review changes in body composition in prevalent PD patients.

SUBJECTS/METHODS

We compared changes in body composition measured by dual x-ray absorptiometry (DXA) in adult PD patients, and calculated glucose absorption based on 24-h collections of PD dialysate.

RESULTS

Overall, 73 prevalent PD patients, 60.3% male, mean age 62.5 ± 16.4 years, had DXA scans a median of 24 (15-27) months apart. Weight did not change (70.7 ± 16.8 vs. 70.9 ± 16.8 kg), with a median 198 (88-295) mmol glucose absorbed/day. Appendicular lean mass (ALM) decreased in most of the male (59%) and female (52%) patients, and the change in ALM was negatively associated with the change in percentage body fat mass (%BFM) r = -0.54, p < 0.001. Overall, 56 patients (76.7%) were admitted to hospital with intercurrent illnesses. Women who lost ALM and gained %BFM had more hospital admissions and those with an increase in %BFM had more admissions due to PD peritonitis while, in males, these outcomes were not seen.

CONCLUSION

Although overall weight did not change, the majority of PD patients lost ALM, and this loss of muscle mass was masked by a gain in fat mass. Definitions of malnutrition and cachexia, which include unintentional weight loss criteria will underestimate the prevalence of PD patients with loss of muscle mass.

Glucose absorption from peritoneal dialysate is associated with a gain in fat mass and a reduction in lean body mass in prevalent peritoneal dialysis patients

The majority of peritoneal dialysates use glucose to generate an osmotic gradient for the convective removal of water and Na. Although glucose can potentially be absorbed, previous studies have failed to establish whether this leads to increased fat weight gain. We measured body composition using bioimpedance in peritoneal dialysis (PD) patients, electively starting PD, attending for their first assessment of peritoneal membrane function after 2-3 months, and then after 12 months. We studied 143 patients: eighty-nine (62·2 %) males, fifty-three (37·1 %) diabetics, mean age 61·3 (SD 14·9) years, with ninety (62·1 %) patients treated by automated PD cyclers with a daytime icodextrin exchange and thirty-seven (25·9 %) by continuous ambulatory PD. Median fat mass increased by 1·8 (-0·5 to 4·1) kg, whereas fat-free mass fell -1·3 (-2·9 to 1·0) kg, and the increase in fat mass was negatively associated with the fall in soft lean mass (r -0·41, P < 0·001). Increased fat mass was associated with measured peritoneal glucose absorption (r 0·69, P < 0·001), and glucose absorption was associated with the amount of 22·7 g/l glucose dialysate (OR 2·0, 95 % CI 1·5, 2·5, P < 0·001), peritoneal urea clearance (OR 9·5, 95 % CI 2·4, 37·1, P = 0·001) and male sex (OR 4·8, 95 % CI 1·5, 14·9, P = 0·008). We report an observational study in prevalent PD patients following body composition from their first assessment of PD membrane function for approximately 12 months, and despite the majority of patients prescribed icodextrin, we have demonstrated not only an association between intra-peritoneal glucose absorption and fat weight gain but also loss of fat-free mass.

The impact of peritoneal dialysis-related peritonitis on mortality in peritoneal dialysis patients

BACKGROUND

Results concerning the association between peritoneal dialysis-related peritonitis and mortality in peritoneal dialysis patients are inconclusive, with one potential reason being that the time-dependent effect of peritonitis has rarely been considered in previous studies. This study aimed to evaluate whether peritonitis has a negative impact on mortality in a large cohort of peritoneal dialysis patients. We also assessed the changing impact of peritonitis on patient mortality with respect to duration of follow-up.

METHODS

This retrospective cohort study included incident patients who started peritoneal dialysis from 1 January 2006 to 31 December 2011. Episodes of peritonitis were recorded at the time of onset, and peritonitis was parameterized as a time-dependent variable for analysis. We used the Cox regression model to assess whether peritonitis has a negative impact on mortality.

RESULTS

A total of 1321 patients were included. The mean age was 48.1 ± 15.3 years, 41.3% were female, and 23.5% with diabetes mellitus. The median (interquartile) follow-up time was 34 (21-48) months. After adjusting for confounders, peritonitis was independently associated with 95% increased risk of all-cause mortality (hazard ratio, 1.95; 95% confidence interval: 1.46-2.60), 90% increased risk of cardiovascular mortality (hazard ratio, 1.90; 95% confidence interval: 1.28-2.81) and near 4-fold increased risk of infection-related mortality (hazard ratio, 4.94; 95% confidence interval: 2.47-9.86). Further analyses showed that peritonitis was not significantly associated with mortality within 2 years of peritoneal dialysis initiation, but strongly influenced mortality in patients dialysed longer than 2 years.

CONCLUSIONS

Peritonitis was independently associated with higher risk of all-cause, cardiovascular and infection-related mortality in peritoneal dialysis patients, and its impact on mortality was more significant in patients with longer peritoneal dialysis duration.

APPETITE PREDICTS INTAKE AND NUTRITIONAL STATUS IN PATIENTS RECEIVING PERITONEAL DIALYSIS

BACKGROUND

Sub-optimal nutrition status is common amongst patients receiving peritoneal dialysis (PD) and leads to poor clinical outcome. This population experiences multi-factorial challenges to achieving optimal nutritional status, particularly driven by inadequate intake.

OBJECTIVES

The aim of this investigation was to identify factors associated with inadequate protein intake and sub-optimal nutritional status in patients undergoing PD.

DESIGN/PARTICIPANTS

This was a cross-sectional study of 67 adult patients receiving PD (mean age 59 ± 14 years; 57% male) within a single centre. Participants were consecutively recruited and interviewed by renal dietitians, collecting: Subjective Global Assessment (SGA); quality of life (using EQ-5D); dietary intake (via dietary interview); and appetite (using Appetite and Diet Assessment Tool). Participant demographics were obtained via survey or medical charts. Main outcome measures were inadequate dietary protein intake (<1.1 g/kg adjusted body weight/day) and malnutrition (as defined by SGA rating B or C).

RESULTS

Overall, 15 (22%) patients were malnourished and 29 (43%) had inadequate protein intake. Poor appetite (anorexia) was reported in 62% (18/29) of participants with inadequate protein malnourished patients reported anorexia versus 12 (23%) of the well-nourished patients (p = 0.0001).

CONCLUSION

Anorexia was a key risk factor for inadequate protein intake and malnutrition in patients undergoing PD. These findings highlight a need to closely monitor patients with appetite disturbances.