Background

Studies that examined dietary energy requirements (DERs) of patients undergoing maintenance hemodialysis (MHD) have shown mixed results. Many studies reported normal DERs, but some described increased energy needs. DERs in MHD patients have been estimated primarily from indirect calorimetry and from nitrogen balance studies. The present study measured DERs in MHD patients on the basis of their dietary energy intake and changes in body composition.

Objective

This study assessed DERs in MHD patients who received a constant energy intake while changes in their body composition were measured.

Design

Seven male and 6 female sedentary, clinically stable MHD patients received a constant mean (±SD) energy intake for 92.2 ± 7.9 d while residing in a metabolic research ward. Changes in fat and fat-free mass, measured by dual-energy X-ray absorptiometry, were converted to calorie equivalents and added to energy intake to calculate energy requirements.

Results

The average DER was 31 ± 3 kcal · kg(-1) · d(-1) calculated from energy intake and change in fat and fat-free calories, which was 28 ± 197 kcal/d over the 92 d of the study. DERs of MHD patients correlated strongly with their body weight (r = 0.81, P = 0.002) and less closely with their measured resting energy expenditure expressed as kcal/d (r = 0.69, P = 0.01). Although the average observed DER in MHD patients was similar to published estimated values for normal sedentary individuals of similar age and sex, there was wide variability in DER among individual patients (range: 26-36 kcal · kg(-1) · d(-1)).

Conclusions

Average DERs of sedentary, clinically stable patients receiving MHD are similar to those of sedentary normal individuals. Our data do not support the theory that MHD patients have increased DERs. Due to the high variability in DERs, careful monitoring of the nutritional status of individual MHD patients is essential. This trial was registered at clinicaltrials.gov as NCT02194114.

Objectives: Studies suggest that maintenance hemodialysis (MHD) patients report dietary energy intakes (EIs) that are lower than what is actually ingested. Data supporting this conclusion have several important limitations. The present study introduces a novel approach of assessing underreporting of EI in MHD patients. Design: Comparisons of EI of free-living MHD patients determined from food records to their measured energy needs. Setting: Metabolic research ward. Subjects: Thirteen clinically stable MHD patients with unchanging weights whose EI was assessed by dietitian interview-assisted 3-day food records. Intervention: EI was compared with (1) patients' resting energy expenditure (REE), measured by indirect calorimetry, and estimated total energy expenditure (TEE) and (2) patients' dietary energy requirements (DER) measured while patients underwent nitrogen balance studies and consumed a constant energy diet in a research ward for a mean duration of 89.5days. DER was calculated as the actual EI during the research study corrected for changes in body fat and lean body mass measured by Dual X-Ray Absorptiometry. Main Outcome Measure: Underreporting of EI was determined by an EI:REE ratio <1.27 and an EI:TEE ratio or EI:DEE ratio <1.0. Results: Seven of the 13 MHD patients studied were male. Patient's ages were 47.7±standard deviation 9.7years; body mass index averaged 25.4±2.8kg/m2, and dialysis vintage was 53.3±37.1months. The EI:REE ratio (1.03±0.23) was significantly less than the cutoff value for underreporting of 1.27 (P=.001); 12 of 13 patients had EI:REE ratios <1.27. The mean EI:TEE ratio was significantly less than the cutoff value of 1.0 (0.73±0.17, P<.0001), and 12 MHD patients had EI:TEE ratios <1.0. The EI:DER ratio was also <1.0 (0.83±0.25, P=.012), and 10 MHD had EI:DER ratios <1.0. Conclusions: Dietitian interview-assisted diet records by MHD patients substantially underestimate the patient's dietary EI.

Objectives

Studies suggest that maintenance hemodialysis (MHD) patients report dietary energy intakes (EIs) that are lower than what is actually ingested. Data supporting this conclusion have several important limitations. The present study introduces a novel approach of assessing underreporting of EI in MHD patients.

Design

Comparisons of EI of free-living MHD patients determined from food records to their measured energy needs.

Setting

Metabolic research ward.

Subjects

Thirteen clinically stable MHD patients with unchanging weights whose EI was assessed by dietitian interview-assisted 3-day food records.

Intervention

EI was compared with (1) patients' resting energy expenditure (REE), measured by indirect calorimetry, and estimated total energy expenditure (TEE) and (2) patients' dietary energy requirements (DER) measured while patients underwent nitrogen balance studies and consumed a constant energy diet in a research ward for a mean duration of 89.5 days. DER was calculated as the actual EI during the research study corrected for changes in body fat and lean body mass measured by Dual X-Ray Absorptiometry.

Main outcome measure

Underreporting of EI was determined by an EI:REE ratio <1.27 and an EI:TEE ratio or EI:DEE ratio <1.0.

Results

Seven of the 13 MHD patients studied were male. Patient's ages were 47.7 ± standard deviation 9.7 years; body mass index averaged 25.4 ± 2.8 kg/m2, and dialysis vintage was 53.3 ± 37.1 months. The EI:REE ratio (1.03 ± 0.23) was significantly less than the cutoff value for underreporting of 1.27 (P = .001); 12 of 13 patients had EI:REE ratios <1.27. The mean EI:TEE ratio was significantly less than the cutoff value of 1.0 (0.73 ± 0.17, P < .0001), and 12 MHD patients had EI:TEE ratios <1.0. The EI:DER ratio was also <1.0 (0.83 ± 0.25, P = .012), and 10 MHD had EI:DER ratios <1.0.

Conclusions

Dietitian interview-assisted diet records by MHD patients substantially underestimate the patient's dietary EI.