By Kimberly Gottesman, DCN, RDN, LDN, CNSC
The discussion on global malnutrition started on January 19, 2016 with participants from 6 continents and 30 countries.1 Recognizing the challenges of identifying malnutrition based on screening criteria/tools that lacked full validation, the multiple definitions of malnutrition, and the limited appreciation of the role that inflammation plays in malnutrition, the GLIM directed its efforts towards exploring screening, assessment, diagnosis, and outcomes measures specific to malnutrition among diverse global settings.1-3 The group identified key focus areas including consistent nutrition screening, three consensus indicators of malnutrition which are unintentional weight loss, severe underweight, and decreased dietary intake, and other contributing factors to malnutrition such as disease injury and/or inflammation, body composition and functional status.1-3 Five domains for the diagnosis of malnutrition were established: 1) reduced food intake, anorexia; 2) nonvolitional weight loss; 3) reduced muscle mass, and related strength/weakness; 4) disease burden and inflammation and; 5) low body mass index (BMI) and underweight.2-3
GLIM proposed two steps for the identification of malnutrition. 2-3 Step 1 is the use of a validated tool to screen for malnutrition and step 2 is the assessment to diagnose and determine malnutrition and its severity.2-3 GLIM recommends using a combination of one phenotypic criterion and one etiologic criterion to diagnose malnutrition and several thresholds for identifying malnutrition were suggested using these criterions.2 For severity grading of malnutrition, only the phenotypic criterion of percent weight loss, low BMI or reduced muscle mass is needed; stage 1 is moderate malnutrition and stage 2 severe malnutrition.2 It is important to recognize the underlying cause of malnutrition, which could be related to chronic disease with inflammation, chronic disease with minimal or no perceived inflammation, acute disease/injury with severe inflammation, or starvation which includes hunger/food shortage related to socio-economic or environment influences.2
Dietitians need to recognize the barriers to nutrition assessment and diagnosis of malnutrition and work to implement standards of practice, which are reliable and support the timely and appropriate identification of patients at-risk of malnutrition.
In clinical practice, registered dietitians (RDs) must recognize that disease burden and resources available might impact the ability to assess the patient and diagnose malnutrition.4 For example, fluid retention affects weight trends and nutrition focused physical exam findings. Fluid resuscitation or medications, such as diuretics, can lead to fluctuations in weights.4 A hand dynamometer may not be available to measure handgrip strength or CT scan/MRI might not be an option to measure muscle mass.4 Surrogate markers such as C-reactive protein and prealbumin are used to identify an inflammatory response in addition to other signs of systemic inflammation such as fever.4 These laboratory tests are not meant to diagnose malnutrition given that they are poor markers of nutritional status but are helpful in detecting inflammation/injury.4 Information obtained through the patient interview may be limited based on level of consciousness or poor memory recall and nutrition and weight history might not be readily available.4 In North America, low BMI is infrequently used to diagnose malnutrition; however, other countries rely on this anthropometric measure.2 Given the proportion of Americans who are overweight or obese, BMI may not accurately identify malnutrition, as adults would need to lose significant amounts of weight before low BMI may occur.4 What RDs need to understand is that malnutrition can occur at any body mass size.4
Limited studies have been conducted to validate the use of GLIM for diagnosing malnutrition. Allard and colleagues recently had their work published.5 The aim of their research was to explore the sensitivity and specificity of GLIM criteria for diagnosing malnutrition, and its sensitivity grading, compared to subjective global assessment.5 The authors found that the overall prevalence of malnutrition per SGA was 45.2% compared to 33.3% per GLIM; the prevalence of severe malnutrition was 11.7% per SGA and 19.8% per GLIM.5 When using the GLIM-phenotypic criteria nonvolitional weight loss or low BMI and etiologic criteria low nutritional intake or high C-reactive protein compared to SGA, sensitivity was poor to fair and specificity was fair to good.5 Authors concluded that two-single GLIM combinations may not sufficiently diagnose malnutrition.5 It was suggested that using all criteria (weight loss, low BMI, low nutritional intake and high C-reactive protein) together might be more helpful for diagnosing malnutrition.5
So how do RDs continue the GLIM discussion? They familiarize themselves with the literature on GLIM and other malnutrition initiatives. RDs need to have a strong understanding of malnutrition, its underlying causes and its associated risks.4 They need to recognize the barriers to nutrition assessment and diagnosis of malnutrition and work to implement standards of practice, which are reliable and support the timely and appropriate identification of patients at-risk of malnutrition.4 This will allow RDs to better target and tailor nutritional interventions which will hopefully lead toward anticipated outcomes.4 More research is needed to support the use of GLIM; clinical trials, prospective and retrospective studies are necessary to validate GLIM for clinical practice.2,5
Kimberly Gottesman is a freelance registered dietitian with a strong background in clinical and food service management. Her clinical and research interests include neonatology, critical care, and weight management. Kimberly is an educator, a published author, and a volunteer ACEND Program Reviewer. In her spare time, Kimberly likes to run, take yoga classes, travel and spend time with her family and friends.
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Jensen GL. Global leadership conversation: addressing malnutrition. Journal of Parenteral and Enteral Nutrition. 2016;40(4): 455-457.
Cederholm T, Jensen GL, Correia MITD et al. GLIM criteria for the diagnosis of malnutrition- a consensus report from the global clinical nutrition community. Clinical Nutrition. 2019;38:1-9.
Jensen GL, Cederholm T. Global leadership initiative on malnutrition; progress report from ASPEN Clinical Nutrition Week 2017. Journal of Parenteral and Enteral Nutrition. 2018;42(2):266-267.
Kirsch R, Matthews K, Williams V. Using global criteria to detect malnutrition: application in disease states. Nutrition in Clinical Practice. 2020;35(1):85-97.
Allard JP, Keller H, Gramlich L, Jeejeebhoy KN, Laporte M, Duerksen DR. GLIM criteria has fair sensitivity and specificity for diagnosing malnutrition when using SGA as comparator. Clinical Nutrition. https://: 1016/j.clnu.2019.12.004