The albumin-nutrition connection: separating myth from fact

Subjective and objective nutritional assessment methods: what do they really assess?

PURPOSE OF REVIEW

Objective and subjective methods are used to assess nutritional status. They are used as diagnostic, prognostic and response tools. It is still controversial which of them is more suitable for each situation and what they are really assessing. The most recent findings about these methods will be discussed in this review.

RECENT FINDINGS

Malnutrition still has a high prevalence all over the world. Anthropometric measurements are best useful to assess chronic malnutrition, and albumin and other visceral protein should no longer be considered as nutritional markers, but inflammatory response markers. Subjective global assessment enables comparison among different populations, and its scored version may be useful in other clinical situations besides cancer. Functional methods and bioelectrical impedance analysis may become possible to identify malnutrition in an early stage. Nitrogen balance seems to be the only way to assess the response to nutritional interventions.

SUMMARY

Malnutrition should be understood as a continuum. Nutritional assessment should not be an expensive and time-consuming process, and simple methods such as subjective global assessment may be enough to identify those patients who need nutritional intervention. Future studies may show which method is more suitable to evaluate the response to this treatment.

Nutrition assessment and hormonal influences on body composition in children with chronic kidney disease

Malnutrition is a serious complication of chronic kidney disease (CKD) in the pediatric population. Management of the nutritional status of children presents the challenge of ensuring sufficient energy to promote linear growth, development of brain and organs, and maintenance of appropriate fat and muscle stores, while preventing excess protein intake and controlling electrolytes. Aggressive nutrition intervention in the early stages of CKD may be critical in the prevention of more serious complications further in the disease process. Nutrition assessment involves analysis of dietary intake, anthropometric parameters, and laboratory data. Currently, no guidelines are available for nutritional management of pediatric patients with CKD before the onset of dialysis. The content and algorithms in this article are intended to serve as a guide in the management of the nutritional status of children with CKD. Although adequate calorie and protein intake is critical in prevention of malnutrition, it is only part of a complex mechanism in the development of cachexia in CKD. Research suggests that the effects of inflammatory cytokines and hormones such as leptin and ghrelin play a role in the development of malnutrition in CKD. As a more thorough understanding of this mechanism emerges, new treatments aimed at inhibiting cachexia can be developed.

A longitudinal study on the nutritional state of elderly women at a nursing home in Japan

OBJECTIVE

Elderly people at nursing homes often suffer from malnutrition, which is characterized by a loss of muscle mass and hypoalbuminemia. This malnourished state is closely associated with an impaired activity of daily living (ADL). We analyzed the nutritional state of such elderly individuals longitudinally over 3 years by anthropometry, serum albumin, and muscle and fat volume as estimated by MRI.

PATIENTS AND METHODS

The subjects consisted of 16 elderly women aged 83 +/- 7 (mean +/- SD) years who resided at a nursing home in an urban area of central Japan. We determined their ADL levels using the Barthel Index (BI) at entry. Seven women belonged to group A (BI; 65-100), thus implying either a mild or no decline in ADL, while the other 9 were in group B (BI; 0-60) and they demonstrated a severe decline in ADL. We measured the following parameters every year from 2000 to 2003; anthropometry including height, body weight, arm circumference (AC), and arm muscle circumference (AMC), thigh muscle and fat volume as estimated by MRI [thigh muscle volume (TMV) and thigh fat volume (TFV)], serum albumin, and plasma amino acid levels by blood biochemistry. The anthropometric values were converted into percentages of the age- and sex-matched reference values for Japanese.

RESULTS

In all subjects, the TMV, %AMC, and serum albumin level decreased significantly during the three-year period (p<0.05, respectively). The change in TMV correlated significantly with those in the %AC and %AMC (p<0.05, respectively). Group B showed significantly larger decreases in the %AMC and serum albumin level than group A.

CONCLUSION

Both the muscular and visceral protein levels were found to decrease with aging in the subjects at the nursing home. This decrease depends partly on the ADL level of each subject.

Albumin therapy in clinical practice

Albumin is the predominant product of hepatic protein synthesis and one of the more abundant plasma proteins. Among its multiple physiologic roles, it plays an essential part in the generation of colloid-oncotic pressure. In the United States, the indications for which albumin therapy are considered include hypovolemia or shock, burns, hypoalbuminemia, surgery or trauma, cardiopulmonary bypass, acute respiratory distress syndrome, hemodialysis, and sequestration of protein-rich fluids. The use of this relatively expensive therapy accounts for up to 30% of the total pharmacy budget in certain hospitals. The use of albumin therapy in different clinical situations and its influence in morbidity and mortality have been reviewed in multiple randomized controlled trials and meta-analyses. Despite frequent reviews, the use of albumin remains controversial in several clinical situations. At the same time, these valuable reviews seem to have documented the advantages of albumin therapy in the management of ascites and clarified the use of albumin in volume resuscitation. More studies have been recommended to investigate the use of albumin in different doses and its role in hypoalbuminemia. This article will provide an overview of albumin metabolism, use of albumin for volume expansion, the potential therapeutic role of albumin in liver disease, and the role of albumin therapy in nutrition.

Poor nutritional habits are predictors of poor outcome in very old hospitalized patients

BACKGROUND

Malnutrition is prevalent in elderly populations. Recommended methods of nutritional screening are often too complicated and time-consuming for routine application in frail, very old, hospitalized patients.

OBJECTIVE

Our aims were to identify risk factors for development of malnutrition in very old hospitalized patients and to evaluate the total Mini Nutritional Assessment (MNA) score and MNA subscores as predictors of in-hospital and long-term mortality.

DESIGN

A prospective cohort study of patients aged > or =75 y was conducted in a geriatric hospital. Assessment included demographic, clinical, and laboratory data and cognitive, functional, and nutritional status. Follow-up was conducted for < or =2.7 y.

RESULTS

Of the 414 patients studied, only 73 (17.6%) were well-nourished. Low serum albumin and phosphorus concentrations, dementia, and cerebrovascular accident (CVA) were significant risk factors for malnutrition. Survival was significantly lower in malnourished patients and patients at risk of malnutrition than in well-nourished patients (P < 0.0001). Low MNA-3 subscores (dietary habits) were significantly correlated with laboratory indexes of malnutrition and were significantly lower in patients with infections, malignancy, pressure ulcers, dementia, recent orthopedic surgery, and CVA. Multivariate analysis showed that a low MNA-3 score was an independent predictor of mortality; scores <7.5 increased the risk of death 2.05-fold.

CONCLUSIONS

The prevalence of malnutrition was high in elderly hospitalized patients. Dietary habits were significant predictors of poor hospitalization outcome. A questionnaire on dietary habits can serve as a useful tool in assessing nutritional status and prognosis in elderly patients.

The albumin controversy

There are relatively few studies of albumin use in neonates and children, with most showing no consistent benefit compared with the use of crystalloid solutions. Certainly, albumin treatment is not indicated for treatment of hypoalbuminemia alone. Studies also show that albumin is not indicated in neonates for the initial treatment of hypotension, respiratory distress, or partial exchange transfusions. In adults, albumin is not considered to be the initial therapy for hypovolemia, burn injury, or nutritional supplementation. Based on the evidence, albumin should be used rarely in the neonatal ICU. Albumin may be indicated in the treatment of hypovolemia only after crystalloid infusion has failed. In patients with acute hemorrhagic shock, albumin may be used with crystalloids when blood products are not available immediately. Inpatients with acute or continuing losses of albumin and normal capillary permeability and lymphatic function, such as during persistent thoracostomy tube or surgical site drainage, albumin supplementation will prevent the development of hypoalbuminemia, and possibly edema formation. This has not been studied systematically, however. In patients with hypoalbuminemia and increased capillary permeability, albumin supplementation often leads to greater albumin leakage across the capillary membrane, contributing to edema formation without improvement in outcome. As the disease process improves and capillary permeability normalizes, albumin supplementation may accelerate recovery, but long-term benefits of albumin treatment usually cannot be demonstrated. These patients will recover whether or not albumin is administered.

Hepatic proteins and nutrition assessment

Serum hepatic protein (albumin, transferrin, and prealbumin) levels have historically been linked in clinical practice to nutritional status. This paradigm can be traced to two conventional categories of malnutrition: kwashiorkor and marasmus. Explanations for both of these conditions evolved before knowledge of the inflammatory processes of acute and chronic illness were known. Substantial literature on the inflammatory process and its effects on hepatic protein metabolism has replaced previous reports suggesting that nutritional status and protein intake are the significant correlates with serum hepatic protein levels. Compelling evidence suggests that serum hepatic protein levels correlate with morbidity and mortality. Thus, serum hepatic protein levels are useful indicators of severity of illness. They help identify those who are the most likely to develop malnutrition, even if well nourished prior to trauma or the onset of illness. Furthermore, hepatic protein levels do not accurately measure nutritional repletion. Low serum levels indicate that a patient is very ill and probably requires aggressive and closely monitored medical nutrition therapy.

Malnutrition in critically ill children: from admission to 6 months after discharge

BACKGROUND & AIMS

Little is known about the nutritional status of critically ill children during hospitalisation in and after discharge from an intensive care unit. We set up a prospective, observational study to evaluate the nutritional status of children in an intensive care unit from admission up to 6 months after discharge. A secondary aim was identifying patient characteristics that influence the course of the various anthropometric parameters.

METHODS

The nutritional status of 293 children--104 preterm neonates, 96 term neonates and 93 older children--admitted to our multidisciplinary tertiary pediatric and neonatal intensive care unit was evaluated by anthropometry upon and during admission, at discharge and 6 weeks and 6 months following discharge.

RESULTS

Upon admission, 24% of all children appeared to be undernourished. Preterm and term neonates, but not older children, showed a decline in nutritional status during admission. At 6 months after discharge almost all children showed complete recovery of nutritional status. Length of stay and history of disease were the parameters that most adversely affected the nutritional status of preterm and term neonates at discharge and during follow-up.

CONCLUSION

While malnutrition is a major problem in pediatric intensive care units, most children have good long-term outcome in terms of nutritional status after discharge.