Nutrient Intake During Peritoneal Dialysis at the Prince of Wales Hospital in Hong Kong

Background: Individuals undergoing peritoneal dialysis are at increased risk of developing cardiac disease and malnutrition. Study Design: A cross-sectional survey. Settings and Participants: 249 Chinese continuous ambulatory peritoneal dialysis (CAPD) patients were recruited from the Prince of Wales Hospital in Hong Kong. Another 249 age- and sex-matched controls were recruited from an archive of 1,010 individuals with known food frequency questionnaire (FFQ) data. Objective: To compare the dietary intake pattern of CAPD patients with controls and evaluate its association with background cardiac disease. Outcomes and Measurements: Intake of different nutrients was estimated by using a 7-day FFQ. Results: Intake of all nutrients was lower in CAPD patients than controls, with resulting lower overall energy intake. Nutrient intake was decreased further in CAPD patients with background cardiac disease, which corresponded to worse nutritional status. Controlling for age, male sex, body weight, diabetes mellitus, dialysis therapy duration, residual renal function, peritoneal dialysis urea clearance, and Charlson Comorbidity Index score, background cardiac disease was associated independently with less intake of energy and most macronutrients and micronutrients. However, the association between background cardiac disease and energy and most nutrient intake was decreased or even lost when additional adjustment was made for C-reactive protein and serum albumin levels. Limitations: An FFQ is limited in that nutrient quantitation is not exact and may be underestimated as a result of underreporting by patients. CAPD patients were compared with a control group without cardiovascular disease ascertainment that did not include subjects with diabetes. Conclusions: Chinese CAPD patients had significantly lower nutrient intake than age- and sex-matched controls. The association between cardiac disease and lower dietary macronutrient and micronutrient intake in CAPD patients was mediated in part through systemic inflammation, which also was associated with more malnutrition. More attention should be focused on improving the intake pattern of Chinese CAPD patients. © 2007 National Kidney Foundation, Inc.Link_to_subscribed_fulltex

Independent effects of residual renal function and dialysis adequacy on dietary micronutrient intakes in patients receiving continuous ambulatory peritoneal dialysis

Background: Dialysis patients are at risk of vitamin and mineral deficiencies, not only because of losses during chronic hemodialysis or peritoneal dialysis but also because of low intakes. Objective: The objective was to determine the importance of urea clearance (calculated as K t/V) and residual renal function (RRF) in predicting micronutrient intakes in a large cohort of patients receiving continuous ambulatory peritoneal dialysis (CAPD). Design: We conducted a survey of dietary intakes in 242 CAPD patients and divided them into 3 groups according to their weekly urea clearance and RRF: WD group (n = 84), a urea clearance ≥ 1.7 and a glomerular filtration rate (GFR) ≥ 1 mL · min -1 · 1.73 m -2; DD group (n = 71), a urea clearance ≥ 1.7 and a GFR < 1 mL · min -1 · 1.73 m -2; and ID group (n = 87), a urea clearance < 1.7. Results: Most of the patients had intakes of water-soluble vitamins and minerals that were lower than the recommended dietary allowance; most intakes were significantly higher in the WD group than in the DD and ID groups, except those of niacin and calcium. After age, sex, body weight, and the presence of diabetes were controlled for, total weekly urea clearance and the GFR (but not peritoneal dialysis urea clearance) were significantly associated with intakes of vitamins A and C, the B vitamins, and minerals (calcium, phosphate, iron, and zinc). Low intakes of vitamins and minerals with low RRF and urea clearance were the result of reduced overall food intakes, except for thiamine, vitamin B-6, and folic acid, which were deficient in the diet. Conclusions: Supplementation with most water-soluble vitamins and minerals, including iron and zinc, should be considered in CAPD patients, especially those with low RRF and low urea clearance. The optimal dose needs to be determined.Link_to_subscribed_fulltex

Resting energy expenditure and subsequent mortality risk in peritoneal dialysis patients

Cardiovascular disease is the leading cause of death in ESRD patients and is strongly associated with malnutrition. The mechanism of malnutrition is not clear, but hypermetabolism is suggested to contribute to cardiac cachexia. This study examined resting energy expenditure (REE) in relation to the clinical outcomes of ESRD patients who receive continuous ambulatory peritoneal dialysis (CAPD) treatment. A prospective observational cohort study was performed in 251 CAPD patients. REE was measured at study baseline using indirect calorimetry together with other clinical, nutritional, and dialysis parameters. Patients were followed up for a mean ± SD duration of 28.7 ± 14.3 mo. REE was 39.1 ± 9.6 and 40.1 ± 9.0 kcal/kg fat-free edema-free body mass per day for men and women, respectively (P = 0.391). Using multiple regression analysis, fat-free edema-free body mass-adjusted REE was negatively associated with residual GFR (P < 0.001) and serum albumin (P = 0.046) and positively associated with diabetes (P = 0.002), cardiovascular disease (P = 0.009), and C-reactive protein (P = 0.009). At 2 yr, the overall survival was 63.3, 73.6, and 95.9% (P < 0.0001), and cardiovascular event-free survival was 72.3, 84.6, and 97.2% (P = 0.0003), respectively, for patients in the upper, middle, and lower tertiles of REE. Adjusting for age, gender, diabetes, and cardiovascular disease, patients in the upper and middle tertiles showed a 4.19-fold (95% confidence interval, 2.15 to 8.16; P < 0.001) and a 2.90-fold (95% confidence interval, 1.49, 5.63; P = 0.002) respective increase in the risk of all-cause mortality compared with those in the lower tertile. However, the significance of REE in predicting mortality was gradually reduced when additional adjustment was made for C-reactive protein, serum albumin, and residual GFR in a stepwise manner. In conclusion, a higher REE is associated with increased mortality and cardiovascular death in CAPD patients and is partly related to its close correlations with residual kidney function, cardiovascular disease, inflammation, and malnutrition in these patients.Link_to_subscribed_fulltex

Energy intake and expenditure profile in chronic peritoneal dialysis patients complicated with circulatory congestion

Background: Circulatory congestion is an adverse predictor of mortality in peritoneal dialysis (PD) patients. Objective: This study evaluated the nutritional status, energy intake, and expenditure profile of PD patients with and without previous circulatory congestion. Design: We conducted a cross-sectional study in 244 PD patients, of whom 92 had previous circulatory congestion. We estimated dietary energy intake by using a locally validated 7-d food-frequency questionnaire and by assessing resting energy expenditure (REE) and total energy expenditure (TEE) with indirect calorimetry and a locally validated physical activity questionnaire, respectively. Results: In comparison with those without circulatory congestion, patients with previous circulatory congestion were more malnourished by subjective global assessment (59% compared with 36%; P < 0.001), had lower handgrip strength, had lower midarm muscle circumference, had lower dietary protein (0.98 ± 0.45 compared with 1.19 ± 0.44 g · kg-1 · d-1; P < 0.001), and had lower energy intake (92.5 ± 37.0 compared with 110.9 ± 35.7 kJ · kg-1 · d-1; P < 0.001) but had higher C-reactive protein (P = 0.025) and higher REE (P < 0.001). However, no difference in TEE was noted between the 2 groups, which indicated lower activity energy expenditure among patients with previous circulatory congestion. The resulting energy balance was significantly more negative for patients with previous circulatory congestion than for those without previous circulatory congestion (P = 0.050). Furthermore, the prevalence of malnutrition increased with increasing episodes of circulatory congestion (P = 0.017). Conclusions: Patients with previous circulatory congestion had significantly more inflammation, more muscle wasting, and higher REE but lower activity energy expenditure and energy and protein intakes in keeping with an anorexia-cachexia syndrome. The mechanisms of increased REE and reduced energy intake among patients with previous circulatory congestion warrant further investigation. © 2009 American Society for Nutrition.Link_to_subscribed_fulltex

Reply to C Fourtounas and JG Vlachojannis

link_to_subscribed_fulltex

Higher Estimated Net Endogenous Acid Production May Be Associated with Increased Prevalence of Nonalcoholic Fatty Liver Disease in Chinese Adults in Hong Kong

<div><p>Nonalcoholic fatty liver disease (NAFLD) has been associated with reduced growth hormone levels and signaling. Such hormonal changes also occur in metabolic acidosis. Since mild metabolic acidosis can be diet induced, diet-induced acid load may constitute a nutritional factor with possible influence on NAFLD development. This study explored whether a higher diet-induced acid load is associated with an increased likelihood of NAFLD. Apparently healthy Chinese adults (330 male, 463 female) aged 19-72 years were recruited through population screening between 2008 and 2010 in a cross-sectional population-based study in Hong Kong. Estimated net endogenous acid production (NEAP) was calculated using Frassetto’s method and potential renal acid load (PRAL) was calculated using Remer’s method based on dietary data from a food frequency questionnaire. NAFLD was defined as intrahepatic triglyceride content at >5% by proton-magnetic resonance spectroscopy. Possible advanced fibrosis was defined as liver stiffness at >7.9 kPa by transient elastography. Multivariate logistic regression models were used to examine the association between each measure of dietary acid load and prevalent NAFLD or possible advanced fibrosis with adjustment for potential anthropometric and lifestyle factors. 220 subjects (27.7%) were diagnosed with NAFLD. Estimated NEAP was positively associated with the likelihood of having NAFLD after adjustment for age, sex, body mass index, current drinker status and the presence of metabolic syndrome [OR (95% CI) = 1.25 (1.02-1.52), <i>p</i> = 0.022]. The association was slightly attenuated but remained significant when the model was further adjusted for other dietary variables. No association between PRAL and NAFLD prevalence was observed. Both estimated NEAP and PRAL were not associated with the presence of possible advance fibrosis. Our findings suggest that there may be a modest association between diet-induced acid load and NAFLD. More studies are needed to ascertain the link between diet-induced acid load and NAFLD and to investigate the underlying mechanisms.</p></div

Diet-Quality Scores and Prevalence of Nonalcoholic Fatty Liver Disease: A Population Study Using Proton-Magnetic Resonance Spectroscopy

<div><p>Dietary pattern analysis is an alternative approach to examine the association between diet and nonalcoholic fatty liver disease (NAFLD). This study examined the association of two diet-quality scores, namely Diet Quality Index-International (DQI-I) and Mediterranean Diet Score (MDS) with NAFLD prevalence. Apparently healthy Chinese adults (332 male, 465 female) aged 18 years or above were recruited through a population screening between 2008 and 2010 in a cross-sectional population-based study in Hong Kong. DQI-I and MDS, as well as major food group and nutrient intakes were calculated based on dietary data from a food frequency questionnaire. NAFLD was defined as intrahepatic triglyceride content at ≥5% by proton-magnetic resonance spectroscopy. Multivariate logistic regression models were used to examine the association between each diet-quality score or dietary component and prevalent NAFLD with adjustment for potential lifestyle, metabolic and genetic factors. A total of 220 subjects (27.6%) were diagnosed with NAFLD. DQI-I but not MDS was associated with the prevalence of NAFLD. A 10-unit decrease in DQI-I was associated with 24% increase in the likelihood of having NAFLD in the age and sex adjusted model (95% CI: 1.06–1.45, <i>p</i> = 0.009), and the association remained significant when the model was further adjusted for other lifestyle factors, metabolic and genetic factors [OR: 1.26 (95% CI: 1.03–1.54), <i>p</i> = 0.027]. Multivariate regression analyses showed an inverse association of the intake of vegetables and legumes, fruits and dried fruits, as well as vitamin C with the NAFLD prevalence (<i>p</i><0.05). In conclusion, a better diet quality as characterized by a higher DQI-I and a higher consumption of vegetables, legumes and fruits was associated with a reduced likelihood of having NAFLD in Hong Kong Chinese.</p></div

Correlation between each diet-quality score and selected food group and nutrient intakes (n = 797).

<p>¹ Spearman’s rank correlation was used for food group intake analysis and vitamin C intake analysis whereas Pearson’s correlation was used for other nutrient intakes analysis</p><p>² Included mainly sweetened beverages or juice, carbonated drinks and sports drinks</p><p>DQI-I, Diet Quality Index-International; MDS, Mediterranean Diet Score</p><p>Correlation between each diet-quality score and selected food group and nutrient intakes (n = 797).</p