A novel technique to demonstrate disturbed appetite profiles in haemodialysis patients

Disturbed Appetite Patterns and Nutrient Intake in Peritoneal Dialysis Patients

Objective

Malnutrition is common among peritoneal dialysis (PD) patients. Reduced nutrient intake contributes to this. It has long been assumed that this reflects disturbed appetite. We set out to define the appetite profiles of a group of PD patients using a novel technique.

Design

Prospective, cross-sectional comparison of PD patients versus controls.

Setting

Teaching hospital dialysis unit.

Patients

39 PD patients and 42 healthy controls.

Intervention

Visual analog ratings were recorded at hourly intervals to generate daily profiles for hunger and fullness. Summary statistics were generated to compare the groups. Food intake was measured using 3-day dietary records.

Main Outcome Measures

Hunger and fullness profiles. Derived hunger and fullness scores.

Results

Controls demonstrated peaks of hunger before mealtimes, with fullness scores peaking after meals. The PD profiles had much reduced premeal hunger peaks. A postmeal reduction in hunger was evident, but the rest of the trace was flat. The PD fullness profile was also flatter than in the controls. Mean scores were similar despite the marked discrepancy in the profiles. The PD group had lower peak hunger and less diurnal variability in their hunger scores. They also demonstrated much less change in fullness rating around mealtimes, while the mean and peak fullness scores were little different. The reported nutrient intake was significantly lower for PD.

Conclusion

The data suggest that PD patients normalize their mean appetite perception at a lower level of nutrient intake than controls, suggesting that patient-reported appetite may be misleading in clinical practice. There is a loss of the usual daily variation for the PD group, which may contribute to their reduced food intake. The technique described here could be used to assess the impact of interventions upon the abnormal PD appetite profile.

Age modifies the association between serum obestatin, appetite and nutritional status in maintenance hemodialysis patients

BACKGROUND/OBJECTIVES

Increased age is strongly associated with anorexia and protein-energy wasting (PEW) in maintenance hemodialysis (MHD) population. We hypothesized that the association of obestatin, a recently discovered anorexigenic gut hormone, with appetite and nutritional status differs by age groups.

SUBJECTS/METHODS

We performed a cross-sectional study on 261MHD patients. Obestatin, acyl-ghrelin, markers of inflammation (CRP, IL-6, TNF-α) and nutrition (self-reported appetite, dietary intake, biochemical nutritional parameters, and body composition) were measured.

RESULTS

Obestatin was associated with appetite in multivariate analyses even after controlling for such confounders as lean body mass (LBM), IL-6 and acyl-ghrelin in patients younger than 71 years. For each ng/ml increase in obestatin levels, the odds for diminished appetite was 0.75 (95% CI: 0.59-0.96). However, these associations were not observed in patients 71 years and older. Multivariable logistic regression models (including appetite) also showed increasing odds for PEW (defined by ESPEN consensus-based criteria for the diagnosis of malnutrition) across increasing serum obestatin levels (OR: 1.51, 95% CI: 1.05-2.18) in patients 71 years and older. However, after lean body mass (LBM) was added to this model, the association between obestatin and malnutrition was abolished (OR: 1.26, 95% CI: 0.83-1.91).

CONCLUSIONS

The association between serum obestatin, appetite and PEW differs depending on age in MHD patients. A positive link with appetite exists in patients younger than 71 years, whereas this relationship disappears by the age of 71. In older MHD patients, obestatin is associated with PEW through mechanisms related to LBM, but not to appetite.

Food intake assessment of elderly patients on hemodialysis

OBJECTIVE

To investigate whether the dietary intake of elderly patients on hemodialysis (HD) is lower than that of elderly individuals with normal renal function. In addition, we also assessed whether the dietary intake of elderly on HD is lower on the dialysis day (DD) than on nondialysis days (non-DD).

DESIGN

A cross-sectional and observational study including elderly on HD and non-chronic kidney disease (non-CKD) elderly.

SUBJECTS

We assessed 54 noninstitutionalized elderly patients on HD (study group) and 47 non-CKD elderly (control group) aged ≥60 years.

MAIN OUTCOME MEASURES

All participants had their dietary intake assessed by 3-day food diaries. As a sensitivity analysis, we also assessed the dietary intake in the adequate reporters, which were identified when the ratio-energy intake-to-estimated basal metabolic rate-was above 1.27 (Goldberg index).

RESULTS

When comparing dietary intake between the study and control groups, adjusted for sex and underreporting, it was noted that only the intake of protein (β: -9.9; P: .01) and phosphorus (β: -104; P: .04) were significantly lower in the study group. In addition, when furthering the analysis in the study group by comparing DD with non-DD, it was observed that energy (18 ± 7 vs. 21 ± 8 kcal/kg/day), protein (0.8 ± 0.4 vs. 1.0 ± 0.4 g/kg/day), lipids (41 ± 20 vs. 48 ± 23 g/day), potassium (1371 ± 587 vs. 1540 ± 484 mg/day), and phosphorous intake (647 ± 312 vs. 789 ± 287 mg/day), but not carbohydrate (155 ± 54 vs. 167 ± 55 g/day) and calcium (470 ± 345 vs. 518 ± 333 g/day) were significantly lower on DDs than on non-DDs, respectively.

CONCLUSIONS

Except for protein and phosphorous, energy and nutrient intake of elderly patients on HD are similar to that of non-CKD elderly. In addition, the dietary intake is lower on DDs, highlighting the importance of focusing efforts to improve nutritional intake mainly during the day of dialysis treatment.

Gastrointestinal symptoms and nutritional status in women and men on maintenance hemodialysis

OBJECTIVE

The main objective was to investigate whether the prevalences of nausea, vomiting, diarrhea, and reduced appetite varied by gender in maintenance hemodialysis (MHD) patients. We also evaluated whether these symptoms explain female-male difference in nutritional status.

DESIGN

Cross section of baseline data of the Prospective Study of the Prognosis in Chronic Hemodialysis Patients.

SETTING

Dialysis units in the city of Salvador, Brazil.

PATIENTS

Three hundred ninety-seven men and 287 women with more than three months on MHD.

PREDICTOR VARIABLE

Gender.

OUTCOME MEASURES

The patient's self-reported nausea, vomiting, diarrhea, and reduced appetite. The malnutrition-inflammation score (MIS) was used to assess nutritional status.

RESULTS

The prevalence of symptoms was 24.3% for reduced appetite, 19.7% for nausea, 12.3% for vomiting, and 3.5% for diarrhea. In a logistic regression model with adjustments for age, diabetes, congestive heart failure, hemoglobin, albumin, Kt/V, and years on dialysis, women were found to have significantly higher odds of reduced appetite (odds ratio [OR] = 1.97), nausea (OR = 1.90), and vomiting (OR = 2.21). MIS was 5.41 ± 3.18 for women and 4.66 ± 3.28 for men (P = .002) corresponding to a percentage difference of 13.86%. The female-male difference reduced by more than half after excluding the gastrointestinal symptoms component and by approximately 65% after excluding both the gastrointestinal symptoms and the dietary intake components from the MIS.

CONCLUSIONS

The results suggest that the prevalences of nausea, vomiting, and reduced appetite are higher in women than in men on MHD. These gastrointestinal symptoms and perhaps their detrimental effects on dietary intake may partially explain a poorer nutritional status in MHD women.

Assessment of subjective appetite sensations in hemodialysis patients. Agreement and feasibility between traditional paper and pen and a novel electronic appetite rating system

The aim of this study was to assess the agreement between a novel Electronic Appetite Rating System (EARS) and traditional paper and pen visual analog scales (VASs) in a clinical population. 28 hemodialysis patients (mean age 61+/-17 years, 50% male, median dialysis vintage 19.5(4-101) months) were asked to rate their subjective sensations of hunger, fullness and desire to eat on VAS using both methods. The mean (S.D.) bias ranged from 2.6(16.6)mm to 6.2(15.7)mm which indicated that the two methods did not agree. Patients preferred the paper and pen method compared with the EARS. Either method would be suitable to use in a clinical population; however, it would be inappropriate to use the methods interchangeably.

Polydipsia: a feature of peritoneal dialysis

BACKGROUND

Some dialysis patients fail to comply with their fluid restriction causing problems due to volume overload. These patients sometimes blame excessive thirst. There has been little work in this area and no work documenting polydipsia among peritoneal dialysis (PD) patients.

METHODS

We measured motivation to drink and fluid consumption in 46 haemodialysis patients (HD), 39 PD patients and 42 healthy controls (HC) using a modified palmtop computer to collect visual analogue scores at hourly intervals.

RESULTS

Mean thirst scores were markedly depressed on the dialysis day (day 1) for HD (P<0.0001). The profile for day 2 was similar to that of HC. PD generated consistently higher scores than HD day 1 and HC (P = 0.01 vs. HC and P<0.0001 vs HD day 1). Reported mean daily water consumption was similar for HD and PD with both significantly less than HC (P<0.001 for both). However, measured fluid losses were similar for PD and HC whilst HD were lower (P<0.001 for both) suggesting that the PD group may have underestimated their fluid intake.

CONCLUSION

Our results indicate that HD causes a protracted period of reduced thirst but that the population's thirst perception is similar to HC on the interdialytic day despite a reduced fluid intake. In contrast, the PD group recorded high thirst scores throughout the day and were apparently less compliant with their fluid restriction. This is potentially important because the volume status of PD patients influences their survival.

Eating Behavior Disorders in Uremia: A Question of Balance in Appetite Regulation

Eating and appetite disorders are frequent complications of the uremic syndrome which contribute to malnutrition in dialysis patients. The data suggest that uremic anorexia may occur with or without abdominal and visceral fat accumulation despite a lower food intake. This form of obesity (i.e., with low food intake and malnutrition) is more common in dialysis patients than obesity with high food intake. This article reviews the current knowledge regarding mechanisms responsible for appetite regulation in normal conditions and in uremic patients. Anorexia in dialysis patients has been historically considered as a sign of uremic toxicity due to "inadequate" dialysis as judged by uncertain means ("middle molecule" accumulation, Kt/V, "peak-concentration hypothesis," and others). We propose the tryptophan-serotonin hypothesis, based on a uremia-induced disorder in patients' amino acid profile--low concentrations of large neutral and branched-chain amino acids with high tryptophan levels. A high rate of tryptophan transport across the blood-brain barrier increases the synthesis of serotonin, a major appetite inhibitor. Inflammation may also play a role in the genesis of anorexia and malnutrition. For example, silent infection with Helicobacter pylori may be a source of cytokines with cachectic action; its eradication improves appetite and nutrition. The evaluation of appetite should take into account cultural and social aspects. Uremic patients showed a universal trend to carbohydrate preference and red meat refusal compared to healthy people. In contrast, white meat was less problematic. Uremic patients also have a remarkable attraction for citrics and strong flavors in general. Eating preferences or refusals have been related to the predominance of some appetite peptide modulators. High levels of cholecystokinin (CCK) (a powerful anorexigen) are associated with early satiety for carbohydrates and neuropeptide Y (NPY) (an orexigen) with repeated food intake. Obesity and elevated body mass index often falsely suggest a good nutritional status. In uremic patients (a hyperinsulinemia state), disorders in the regulation of fat distribution (insulin, leptin, insulin-like growth factor [IGF]-1, fatty acids, and disorders in receptors for insulin, lipoprotein lipase, mitochondrial uncoupling protein-2, and beta 3 adrenoreceptors) may cause abdominal fat accumulation without an increase in appetite. Finally, appetite regulation in uremia is highly complex. Disorders in adipose tissue, gastrointestinal and neuropeptides, retained or hyperproduced inflammatory end products, and central nervous system changes may all play a role. Uremic anorexia may be explained by a hypothalamic hyperserotoninergic state derived from a high concentration of tryptophan and low branched-chain amino acids.

Cholecystokinin and leptin: their influence upon the eating behaviour and nutrient intake of dialysis patients

BACKGROUND

We have used serial visual analogue scores to demonstrate disturbances of the appetite profile in dialysis patients. This is potentially important as dialysis patients are prone to malnutrition yet have a lower nutrient intake than controls. Appetite disturbance may be influenced by accumulation of appetite inhibitors such as leptin and cholecystokinin (CCK) in dialysis patients.

METHODS

Fasting blood samples were drawn from 43 controls, 50 haemodialysis (HD) and 39 peritoneal dialysis (PD) patients to measure leptin and CCK. Hunger and fullness scores were derived from profiles compiled using hourly visual analogue scores. Nutrient intake was derived from 3 day dietary records.

RESULTS

Fasting CCK was elevated for PD (6.73 +/- 4.42 ng/l vs control 4.99 +/- 2.23 ng/l, P < 0.05; vs HD 4.43 +/- 2.15 ng/l, P < 0.01). Fasting CCK correlated with the variability of the hunger (r = 0.426, P = 0.01) and fullness (r = 0.52, P = 0.002) scores for PD. There was a notable relationship with the increase in fullness after lunch for PD (r = 0.455, P = 0.006). When well nourished PD patients were compared with their malnourished counterparts, CCK was higher in the malnourished group (P = 0.004). Leptin levels were higher for the dialysis patients than controls (HD and PD, P < 0.001) with pronounced hyperleptinaemia evident in some PD patients. Control leptin levels demonstrated correlation with fullness scores (e.g. peak fullness, r = 0.45, P = 0.007) but the dialysis patients did not. PD nutrient intake (energy and protein intake, r = -0.56, P < 0.0001) demonstrated significant negative correlation with leptin.

CONCLUSION

Increased CCK levels appear to influence fullness and hunger perception in PD patients and thus may contribute to malnutrition. Leptin does not appear to affect perceived appetite in dialysis patients but it may influence nutrient intake in PD patients via central feeding centres.

Nutritional requirements in maintenance hemodialysis

There is a high prevalence of nutritional disorders in maintenance hemodialysis patients. This fact has been recently confirmed because larger routine assessments of MHD patients body composition are now performed. Food records and dietary interviews show spontaneous low intakes of protein and energy in many patients. An increasing dialysis dose above a Kt/V (single pool) of 1.5 may not improve patients nutritional intakes. Inflammation may further impair the balance between protein synthesis and catabolism and cause anorexia. In response to these abnormalities, the management of energy, protein, vitamins, and trace elements intake will be discussed with special emphasis on calcium, phosphorus, enteral support, and parenteral nutrition.

Effects of dietary intake, appetite, and eating habits on dialysis and non-dialysis treatment days in hemodialysis patients: cross-sectional results from the HEMO study

OBJECTIVE

To evaluate differences between dietary energy intake (DEI), dietary protein intake (DPI), appetite, dietary patterns, and eating habits during dialysis treatment days (DD) and non-dialysis treatment days (NDD) in 1,901 adults receiving maintenance hemodialysis who were enrolled in the baseline phase of the National Institutes of Health-sponsored Hemodialysis (HEMO) study.

DESIGN

A cross-sectional analysis of participants at baseline (before randomization).

SETTING

Fifteen clinical centers across the United States.

MEASUREMENTS

DEI, DPI, and self-reported assessment of appetite, dietary patterns, and eating habits.

RESULTS

For the entire study cohort, total mean (+/- SD) DEI (1,566 +/- 636 kcal/day) and weight-adjusted DEI (23.2 +/- 9.5 kcal/kg/day) were significantly higher (P <.0001) on NDD than on DD (1,488 +/- 620 kcal/day and 22.2 +/- 9.6 kcal/kg/day), respectively. Similarly, DPI was significantly higher (P <.0001) on NDD (65.0 +/- 29.0 g/day and 0.96 +/- 0.43 g/kg/day) than on DD (60.2 +/- 26.5 g/day and 0.90 +/- 0.41 g/kg/day). On DD and NDD, the mean weight-adjusted DEI for the entire cohort was less than the HEMO study standard of care (SOC) of > or =28 kcal/kg/day, whereas on NDD, several subgroups reported dietary protein intakes that were closer to the study's SOC. These included men, patients under 50 years of age, nonblack participants, those without diabetes, those with a normal or mild Index of Co-Existing Disease score, and those on dialysis for more than 5 years. Protein and energy intakes declined with worsening self-reported appetites in both DD and NDD after adjusting for other subgroup effects.

CONCLUSION

Dietary energy and protein intakes of HEMO study participants were lower on DD than on NDD, and also lower than the SOC on both days, particularly with regard to energy intake. People receiving maintenance hemodialysis should be counseled to consume adequate amounts of energy and protein daily, especially on DD. Practitioners should monitor closely those patients who report poor appetite and should intervene appropriately.