Elsevier

Nutrition

Volume 16, Issue 2, February 2000, Pages 131-140
Nutrition

Review Papers
Assessment of protein energy malnutrition in older persons, part II: laboratory evaluation

https://doi.org/10.1016/S0899-9007(99)00251-8Get rights and content

Abstract

A large proportion of chronic diseases affecting older persons can be either prevented or significantly improved by improving nutrition. This places an increased burden on health care professionals caring for older persons. Screening for malnutrition at an early stage allows the intervention to be most successful. History, physical examination, and anthropometric measurements are essential parts of any nutritional evaluation. However, these tools can be highly subjective and rely heavily on the knowledge and experience of the evaluator. Incorporating biochemical measurements in the routine nutritional assessment provides an often-needed objective dimension. Interpreting these measurements must take into consideration the normal biological changes seen with aging. In this article, we review many of the biochemical parameters used in nutritional assessment and their relation to morbidity and mortality, with a special focus on normal changes seen with aging.

Introduction

The objectives of biochemical nutritional assessment are 1) to identify individuals who will benefit from nutritional therapies, 2) to detect and treat micronutrient deficiencies, and 3) to establish baseline values against which to measure the effectiveness of nutritional intervention. Biochemical methods are more sensitive than other methods in showing recent changes in nutritional status. However, there are no clear criteria for the interpretation in the elderly group.1 Laboratory tests that may reflect protein-energy malnutrition are serum proteins, urine creatinine and 3-methylhistydine, immune-function parameters, serum cholesterol, and hemoglobin. Leptin levels may reflect total fat stores. Table I summarizes the effects of age and non-nutritional factors on biochemical measurements of nutritional status.

Section snippets

Serum proteins

Serum protein levels are important markers of the body protein pool. Measurable proteins include albumin, transferrin, transhyterin (prealbumin), retinol-binding protein (RBP), fibronectin, C-reactive protein, interleukines, and others. Proteins with a long half-life are most useful in evaluating chronic nutritional changes in the outpatient setting. Proteins with a short half-life are most useful in the acute or subacute settings.

Urine creatinine

Estimations of nutritional status that rely on 24-h urine collections have been validated for use as assessment tools.141 Measurement of 24-h urine creatinine is the most used biochemical index of muscle mass. It was successfully validated against anthropometric measurements, basal oxygen consumption,142, 143 and 40-K total body counting.144, 145, 146 Creatinine is produced at a constant rate proportionate to muscle mass in the presence of normal renal function and fluid intake. A strong

Immune function

Immunologic changes occur early in the course of nutritional depletion,157 resulting in the recognition of malnutrition as the most common cause of secondary immune deficiency.158, 159, 160 Protein-energy malnutrition has long been known to be marked by increased frequency and severity of infection,161 accounting for much of the morbidity and mortality associated with malnutrition.163 Despite mounting evidence on the relation between malnutrition and immunologic dysfunction,163, 164 the exact

Serum cholesterol

Total cholesterol values increase with age in healthy individuals and reach a peak between the sixth and ninth decades only to decrease afterward.23 The increase is greater in men than in women, whereas the subsequent decrease is greater in men.23

Serum cholesterol levels lower than 160 mg/dL have been considered a reflection of low lipoprotein and thus of low visceral protein.209, 210, 211, 212 Low cholesterol was prevalent in about 20% of nursing-home residents, according to Rudman et al.213 A

Leptin

Leptin is a protein hormone produced by fat cells. In animals, leptin decreases food intake and increases metabolic rate. Leptin levels are highly correlated with fat mass in humans. In females serum leptin levels peak at middle age and then decline with the decline in total body fat as aging proceeds.218 Leptin levels in females are higher than those in males, even when corrected for body fat.219 With aging, leptin levels increase in males despite the decline in total body fat.220 This has

Conclusion

Malnutrition is a common problem of the elderly, with significant effects on health and the economy. Nevertheless, physicians appear to be “nutrition blind” in failing to recognize and treat malnutrition in the majority of older persons.224, 225, 226 Tackling this problem starts by identifying subjects at risk and working on preventing the occurrence of malnutrition. Screening for malnutrition should be attempted at all levels. Patient self-screening should be encouraged by making the simple

References (227)

  • Y. Ingenbleek et al.

    Albumin, transferrin and thyroxin-binding prealbumin/retinol-binding protein (TBPA-RBP) complex in assessment of malnutrition

    Clin Chim Acta

    (1975)
  • S. Irie et al.

    Transferrin-mediated cellular iron uptake

    Am J Med Sci

    (1987)
  • G. Mancini et al.

    Immunological quantitation of antigens by single immunodiffusion

    Int J Immunochem

    (1965)
  • C. Mitchell et al.

    The effect of age and sex on the routinely used measurements to assess the nutritional status of hospitalized patients

    Am J Clin Nutr

    (1982)
  • J. Rubin et al.

    Protein losses and tobramycin absorption in peritonitistreated by hourly peritoneal dialysis

    Am J Kidney

    (1986)
  • P.S. Shetty et al.

    Rapid turnover transport proteinsan index of subclinical protein-calorie malnutrition

    Lancet

    (1979)
  • D.R. Clemmons et al.

    Use of plasma somatomedin-C/insulin-like growth factor I measurements to monitor the response to nutritional repletion in malnourished patient

    Am J Clin Nutr

    (1985)
  • M.F. Winkler et al.

    Transitional feedingthe relationship between nutritional intake and plasma protein concentrations

    J Am Dietitic Assoc

    (1989)
  • Y. Kanda et al.

    The amino acid sequence of human plasma prealbumin

    J Biol Chem

    (1974)
  • F.R. Smith et al.

    Serum vitamin A, retinol-binding protein, and prealbumin concentrations in protein-calorie malnutrition. I. A functional defect in hepatic retinol release

    Am J Clin Nutr

    (1973)
  • J. Robbins et al.

    Thyroxin transport proteins of plasmaMolecular properties and biosynthesis

    Rec Prog Horm Res

    (1978)
  • J.P. Grant et al.

    Current techniques of nutritional assessment

    Surg Clin North Am

    (1981)
  • H.N. Munro et al.

    Protein nutriture of a group of free-living elderly

    Am J Clin Nutr

    (1987)
  • D.M. Goldberg et al.

    Advances in the application of biochemical tests to diseases of the liver and biliary tracttheir role in diagnosis, prognosis, and the elucidation of pathogenetic mechanisms

    Clin Biochem

    (1987)
  • F.R. Smith et al.

    Plasma vitamin A, retinol-binding protein and prealbumin concentrations in protein-caloric malnutrition. III. Response to varying dietary treatments

    Am J Clin Nutr

    (1975)
  • P.A. Peterson

    Studies on the interaction between prealbumin, retinol-binding protein and vitamin A

    J Biol Chem

    (1971)
  • Y. Ingenbleek et al.

    The role of retinol-binding protein in protein-calorie malnutrition

    Metabolism

    (1975)
  • E. Bosin et al.

    Quantitation of serum retinol-binding protein by an enzyme-linked immunosorbent assay

    Anal Biochem

    (1983)
  • T.H. Gerlach et al.

    Metabolism and secretion of retinol transport complex in acute renal failure

    J Lipid Res

    (1991)
  • S.D. Krasinski et al.

    Relationship of vitamin A and vitamin E intake to fasting plasma retinol, retinol-binding protein, retinyl esters, carotene, 2-tocopherol, and cholesterol among elderly people and young adults; increased plasma retinyl esters among vitamin A-supplement users

    Am J Clin Nutr

    (1989)
  • D.R. Clemmons et al.

    Use of plasma somatomedin-C/insulin-like growth factor I measurements to monitor the response to nutritional repletion in malnourished patients

    Am J Clin Nutr

    (1985)
  • T.G. Unterman et al.

    Nutrition and somatomedin. XIII. Usefulness of somatomedin-C in nutritional assessment

    Am J Med

    (1985)
  • E.J. Grimley

    Aging and nutritionquestions needing answers

    Age Aging

    (1989)

  • Combined conditions and correlation with mortality risk among 3399 incident hemodialysis patients

    Am J Kidney Dis

    (1992)
  • M.C. Corti et al.

    Serum albumin level and physical disability as predictors of mortality in older persons

    JAMA

    (1994)
  • M.R. Law et al.

    Serum albumin and mortality in the BUPA study

    Int J Epidemiol

    (1994)
  • L.H. Kuller et al.

    The relation between serum albumin and risk of coronary heart disease in the multiple risk factor intervention trial

    Am J Epidemiol

    (1991)
  • M.A. Rothschild et al.

    Albumin synthesis

    N Engl J Med

    (1972)
  • G.L. Brackeen

    Serum albumindifferences in assay specificity

    Nutr Clin Pract

    (1989)
  • J.E.G. Gustafsson

    Improved specificity of serum albumin determination and estimation of acute phase reactants by use of the bromcresol green reaction

    Clin Chem

    (1976)
  • G.E. Speicher et al.

    An evaluation of the overestimation of serum albumin by bromcresol green

    Am J Clin Path

    (1978)
  • G.C.M. Koomen et al.

    Comparison between dye binding methods and nephrotometry for the measurement of albumin in plasma of dialysis patients

    Peritoneal Dial Int

    (1992)
  • F.E. Wells et al.

    Albumin analysis in serum of haemodialysis patientsdiscrepancies between bromcresol purple, bromcresol green, and electroimmunoassay

    Ann Clin Biochem

    (1985)
  • A.E. Pinnel et al.

    New automated dye-binding method for serum albumin determination with bromcresol purple

    Clin Chem

    (1978)
  • L.C. Rall et al.

    Albumin as a marker of nutritional and health status

  • N. Tietz et al.

    Laboratory values in fit aging individuals—sexagenarians through centenarians

    Clin Chem

    (1992)
  • M.E. Courtney et al.

    Rapidly declining serum albumin values in newly hospitalized patientsprevalence, severity, and contributory factors

    JPEN

    (1982)
  • B.E. Statland et al.

    Factors contributing to intra-individual variation of serum constituents in healthy subject

    Clin Chem

    (1974)
  • P. Hyltoft Peterson et al.

    Effects of posture on concentration of serum proteins in healthy adults. Dependence on the molecular size of protein

    Scand J Clin Lab Invest

    (1980)
  • M. Dixon et al.

    Posture and the composition of plasma

    Clin Chem

    (1978)

    • Cited by (260)

    • Predictive Value of the Naples Prognostic Score on Long-Term Outcomes in Patients with Peripheral Artery Disease Revascularized via Percutaneous Intervention

      2024, Annals of Vascular Surgery

    • Parkinson's disease: Let food be thy medicine and medicine be thy food (Hippocrates)

      2022, Parkinsonism and Related Disorders

    • Prevalence and associated factors of malnutrition in patients with Parkinson's disease using CONUT and GNRI

      2022, Parkinsonism and Related Disorders

    • Prognostic value of metabolic syndrome in patients with heart failure and malnutrition

      2024, BMC Cardiovascular Disorders

    • Cortical thickness of the rostral anterior cingulate gyrus is associated with frailty in patients with end-stage renal disease undergoing hemodialysis in Korea: a cross-sectional study

      2023, Journal of Yeungnam Medical Science

    • Risk Factors for Post-Stroke Pneumonia in a Patient Population with Subacute Stroke: A Retrospective Cohort Study

      2023, Journal of Clinical Medicine
    View all citing articles on Scopus
    View full text
    Copyright © 2000 Elsevier Science Inc. All rights reserved.