The phase angle and mass body cell as markers of nutritional status in hemodialysis patients

Nutrition and exercise in the management of liver cirrhosis

Liver cirrhosis (LC) patients often have protein-energy malnutrition (PEM) and decreased physical activity. These conditions often lead to sarcopenia, which is the loss of skeletal muscle volume and increased muscle weakness. Recent studies have demonstrated that PEM and sarcopenia are predictors for poor survival in LC patients. Nutrition and exercise management can improve PEM and sarcopenia in those patients. Nutrition management includes sufficient dietary intake and improved nutrient metabolism. With the current high prevalence of obesity, the number of obese LC patients has increased, and restriction of excessive caloric intake without the exacerbation of impaired nutrient metabolism is required for such patients. Branched chain amino acids are good candidates for supplemental nutrients for both obese and non-obese LC patients. Exercise management can increase skeletal muscle volume and strength and improve insulin resistance; however, nutritional status and LC complications should be assessed before an exercise management regimen is implemented in LC patients. The establishment of optimal exercise regimens for LC patients is currently required. In this review, we describe nutritional status and its clinical impact on the outcomes of LC patients and discuss general nutrition and exercise management in LC patients.

Protein-energy wasting, as well as overweight and obesity, is a long-term risk factor for mortality in chronic hemodialysis patients

INTRODUCTION

In patients with end-stage renal disease on chronic hemodialysis (HD), protein-energy wasting (PEW) is very common and is associated with increased morbidity and mortality. Evaluation of nutritional status should be performed regularly in all such patients, using multiple methods. In this study, we analyzed the influence of several nutritional markers on long-term (5 years) survival of HD patients in one center. This is the first study on the long-term influence of nutritional status on mortality in dialysis patients ever conducted in Romania.

MATERIALS AND METHODS

We included all prevalent HD patients in our center. Those with ongoing acute illnesses and with inflammation (C-reactive protein ≥ 6.0 mg/l) were excluded. In the remaining subjects (N = 149, 82 males, mean age 55 years old), we performed the following measurements of nutritional status: estimation of dietary protein intake by normalized protein equivalent of nitrogen appearance (nPNA), subjective global assessment (SGA), body mass index (BMI), tricipital skinfold thickness, mid-arm circumference, assessment of body composition by bioelectrical impedance analysis (BIA), and pre-dialysis serum creatinine, albumin, and total cholesterol. We used receiver operating characteristic curves to determine the cutoff points for most of the variables, and we applied the Kaplan-Meier estimator and the Cox's proportional hazards model (stepwise method) to analyze the influence of these variables on survival.

RESULTS

In univariate analysis, general factors including age ≥ 65 years, male gender, dialysis vintage ≥ 2 years, and the presence of diabetes and heart failure were all significant predictors of mortality. Among nutritional parameters, BMI ≥ 25 kg/m(2), SGA-B (mild PEW), nPNA < 1.15 g/kg per day, and the BIA-derived phase angle (PhA) <5.58° were also significantly associated with reduced survival. All of these factors maintained statistical significance in multivariate analysis, except for male gender and heart failure.

CONCLUSION

We showed that low values of SGA, nPNA, and PhA independently predict mortality in HD patients. In conjunction with an earlier study, we demonstrated that the relative risk of death associated with these markers is highest during the first year of monitoring and it decreases in the following 4 years, although it still remains significantly increased. On the other hand, overweight and obesity were also associated with lower survival after 5 years, whereas this association was not apparent after 1 year.

Association between phase angle, anthropometric measurements, and lipid profile in HCV-infected patients

OBJECTIVE

The objective of this study was to investigate the associations between phase angle, anthropometric measurements, and lipid profile in patients chronically infected with the hepatitis C virus.

METHODS

A total of 160 consecutive patients chronically infected with the hepatitis C virus and who received treatment at the hepatitis C outpatient unit of our hospital from April 2010 to May 2011 were prospectively evaluated. Bioelectrical impedance analysis, anthropometric measurements, and serum lipid profile analysis were performed.

RESULTS

Twenty-five patients were excluded. A total of 135 patients with a mean age of 49.8±11.4 years were studied. Among these patients, 60% were male. The phase angle and BMI means were 6.5±0.8° and 26.5±4.8 kg/m2, respectively. Regarding anthropometric variables, mid-arm circumference, mid-arm muscle circumference, and arm muscle area had a positive correlation with phase angle. In contrast, when analyzing the lipid profile, only HDL was inversely correlated with phase angle. However, in multiple regression models adjusted for age and gender, only mid-arm circumference (p = 0.005), mid-arm muscle circumference (p = 0.003), and arm muscle circumference (p = 0.001) were associated with phase angle in hepatitis C virus-infected patients.

CONCLUSIONS

In conclusion, phase angle is positively correlated with anthropometric measures in our study. However, there is no association between phase angle and lipid profile in these patients. Our results suggest that phase angle is related to lean body mass in patients chronically infected with hepatitis C virus.

Associations between bioelectrical impedance parameters and cardiovascular events in chronic dialysis patients

PURPOSE

Malnutrition and fluid overload contribute to the poor cardiovascular prognosis of dialysis patients. Since bioelectrical impedance analysis is an option for the evaluation of body composition and for the monitoring of hydration state, it may assist in the identification of subjects at high cardiovascular risk. The objective of this study was to evaluate the association between bioelectrical impedance parameters and cardiovascular events.

METHODS

The association between bioelectrical impedance parameters and fatal and non-fatal cardiovascular outcome was evaluated in 145 dialysis patients.

RESULTS

The mean age of the population studied was 54.9 ± 15.4 years, 49.7 % were males, and 35.9 % had diabetes. Forty (27.6 %) patients developed cardiovascular events during the 16 months (8; 32) of follow-up. Comparison of patients with and without cardiovascular events revealed higher extracellular mass/body cell mass (ECM/BCM) and extracellular water/total body water ratios and higher C-reactive protein levels in the former. Survival analysis showed that an ECM/BCM ratio >1.2 and a phase angle <6° were associated with poor cardiovascular prognosis. Among nondiabetic patients, these parameters and capacitance were independently associated with cardiovascular events, suggesting that poor nutritional status and fluid overload are associated with the occurrence of these events.

CONCLUSIONS

Phase angle, capacitance and ECM/BCM ratio are valuable parameters for the evaluation of cardiovascular prognosis, supporting the use of bioelectrical impedance for the clinical assessment of dialysis patients.

Altered taste perception and nutritional status among hemodialysis patients

OBJECTIVE

The objective of this study was to examine the association between altered taste perception and nutritional status among hemodialysis patients.

DESIGN

We performed a post hoc analysis of data from the Hemodialysis study (n = 1,745). Taste perception was assessed at baseline and then updated annually using an item from a quality of life survey that asked "During the past 4 weeks, to what extent were you bothered by loss of taste?" Responses were categorized as normal taste perception if subjects answered "not at all" or altered taste perception if they reported any degree of bother. Time-updated logistic regression models were used to evaluate predictors of altered taste perception. Time-updated linear regression models were used to examine the association between altered taste perception and indices of nutritional status. Multivariable proportional hazards and Poisson models were used to assess association between altered taste perception and mortality and hospitalization, respectively.

RESULTS

At baseline, 34.6% reported altered taste perception, which was associated with poorer baseline nutritional status. On time-updated analysis, altered taste perception was associated with a persistently higher proportion of subjects requiring enteral nutritional supplements and lower serum albumin, serum creatinine, normalized protein catabolic rate, protein intake, sodium intake, and mid-arm muscle circumference. Altered taste perception at baseline was independently associated with increased all-cause mortality: adjusted hazard ratio (95% confidence interval) of 1.17 (1.01-1.37), although not with increased rate of hospitalization.

CONCLUSION

Altered taste perception was common among prevalent hemodialysis patients and was independently associated with poorer indices of nutritional status and increased all-cause mortality.

Body composition variables and leptin levels in functional hypothalamic amenorrhea and amenorrhea related to eating disorders

The purpose of the study was to identify diagnostic criteria that can distinguish between subjects with functional hypothalamic amenorrhea largely related to minimal energy deficiency and those in whom failure of adaptive response to stress prevails. We studied 59 young women with secondary amenorrhea related to modest eating disorders and 58 who complained of stressful events in their history. We assessed anthropometric measurements, body composition using dual energy X-ray absorptiometry (DEXA) and bioelectrical impedance analysis (BIA), and basal endocrine profile. Subjects with disordered eating had lower body mass index (BMI), fat mass (FM) measured with both techniques, lumbar mineral density and direct and indirect measures of lean mass. Leptin and free tri-iodothyronine(FT(3)) concentrations also proved lower in the group of subjects with eating disorders, although there was no significant difference in cortisol between the two groups. Leptin levels were positively associated not only with fat mass, but also with body cell mass indexed to height and phase angle, parameters studied with BIA as expression of active lean compartment. A multivariate model confirmed the utility of integrating endocrine data with the study of body composition. The use of bioelectrical impedance analysis proved to be, in clinical use, a valid diagnostic alternative to DEXA, especially considering body cell mass and phase angle.

Determinants of bioelectrical phase angle in disease

Phase angle (PhA), a parameter of bioelectrical impedance analysis, is a well-known predictor of morbidity and mortality in various diseases. The causes of decreased PhA are, however, not yet completely understood. We therefore investigated determinants of PhA in 777 hospitalised patients in a retrospective analysis. PhA was assessed by bioelectrical impedance analysis at 50 KHz. Subjective global assessment (SGA) was used to evaluate nutritional status. Age, sex, BMI as well as nutritional status (SGA), benign or malignant disease and C-reactive protein (CRP) were investigated as potential determinants of PhA and standardised PhA (SPhA) = (observed PhA - mean PhA of reference values)/standard deviation of reference values in a general linear model regression analysis. Next to age (estimated effect size, 46·6%; P<0·0001), malnutrition (39·1%; P<0·0001) emerged as a major PhA determinant in our study population. Moreover, sex (6·4%; P<0·0001), CRP (4·4%; P<0·0001) and BMI (3·5%; P < 0·0001) exhibited a significant influence on PhA, whereas malignant disease showed no significant effect in this model. The only significant determinants of SPhA were malnutrition (85·4%; P<0·0001) and inflammation (9·6 %; P<0·0001). In conclusion, next to the established predictors, malnutrition and inflammation have a strong impact on PhA in sick individuals, which partly explains its prognostic power. When investigating the SPhA, only malnutrition and inflammation were found to be significant predictors, as a result of which the SPhA is considered a more suitable indicator of nutritional and health status.