Topic 10.3. Assessing nutritional status in Friedreich ataxia

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This chapter of the Clinical Management Guidelines for Friedreich Ataxia and the recommendations and best practice statements contained herein were endorsed by the authors and the Friedreich Ataxia Guidelines Panel in 2022.

Topic Contents

10.3 Assessing nutritional status in Friedreich ataxia
10.3.1 Nutrition and Friedreich ataxia
10.3.2 Body mass index thresholds

Disclaimer / Intended Use / Funding

Disclaimer
The Clinical Management Guidelines for Friedreich ataxia (‘Guidelines’) are protected by copyright owned by the authors who contributed to their development or said authors’ assignees.

These Guidelines are systematically developed evidence statements incorporating data from a comprehensive literature review of the most recent studies available (up to the Guidelines submission date) and reviewed according to the Grading of Recommendations, Assessment Development and Evaluations (GRADE) framework © The Grade Working Group.

Guidelines users must seek out the most recent information that might supersede the diagnostic and treatment recommendations contained within these Guidelines and consider local variations in clinical settings, funding and resources that may impact on the implementation of the recommendations set out in these Guidelines.

The authors of these Guidelines disclaim all liability for the accuracy or completeness of the Guidelines, and disclaim all warranties, express or implied to their incorrect use.

Intended Use
These Guidelines are made available as general information only and do not constitute medical advice. These Guidelines are intended to assist qualified healthcare professionals make informed treatment decisions about the care of individuals with Friedreich ataxia. They are not intended as a sole source of guidance in managing issues related to Friedreich ataxia. Rather, they are designed to assist clinicians by providing an evidence-based framework for decision-making.

These Guidelines are not intended to replace clinical judgment and other approaches to diagnosing and managing problems associated with Friedreich ataxia which may be appropriate in specific circumstances. Ultimately, healthcare professionals must make their own treatment decisions on a case-by-case basis, after consultation with their patients, using their clinical judgment, knowledge and expertise.
Guidelines users must not edit or modify the Guidelines in any way – including removing any branding, acknowledgement, authorship or copyright notice.

Funding
The authors of this document gratefully acknowledge the support of the Friedreich Ataxia Research Alliance (FARA). The views and opinions expressed in the Guidelines are solely those of the authors and do not necessarily reflect the official policy or position of FARA.


10.3 Assessing nutritional status in Friedreich ataxia

Jaclyn ‎Tamaroff, Andreas Eigentler, David R. Weber, Miriam Cnop and Shana E. McCormack

10.3.1 Nutrition and Friedreich ataxia

While there are limited data specifically related to Friedreich ataxia (FRDA), ensuring optimal nutrition is critical for any individual with a chronic medical condition. Body mass index (BMI) is frequently used in clinical practice to screen for undernutrition or over-nutrition, with specific cut-off values defined by the WHO (67). However, BMI is often missing from visits recorded in the FA-COMS study (5) and individuals with higher modified FRDA Rating Scale (mFARS) scores and/or who are non-ambulatory are less likely to have measurements recorded at visits (68). The reason for neglecting to measure BMI routinely may be due to difficulties in measuring height in individuals with FRDA. In another study, a cross-sectional analysis including anthropometric measurements in FRDA (n=158, 109 adults, 49 children) found that 20% of children were underweight, with BMI at or below the fifth percentile (3). Similarly, baseline characteristics in the FACOMS reported that 17% of children (42/253) were underweight and 33% of adults (105/317) were overweight or obese (BMI ≥ 25 kg/m2) (68). A smaller study reported that 7/16 individuals with FRDA were overweight and 1/16 was severely obese (14).

10.3.2 Body mass index thresholds

BMI may not be the optimal reflection of body composition (7), particularly when compared to results from detailed assessments typically available in the research setting; however, measuring BMI is a practical way to perform an initial screen for nutritional status in a clinical setting. Standard BMI thresholds, as defined by the WHO or country specific, that are used in the general population are also used in individuals with other disorders impacting the mitochondria. For example, one report using BMI notes a high prevalence of undernutrition in children with genetic mitochondrial diseases, and also a substantial prevalence of overweight or obesity in adults with the same disorders (69, 70). Therefore, we recommend assessing BMI annually in individuals with FRDA. We also suggest beginning with reference BMI thresholds to screen for underweight and overweight/obesity, recognizing that neither the extent to which BMI reflects body composition nor the clinical relevance of BMI are well characterized in FRDA.

While data are limited in FRDA, higher BMI increases the risk of diabetes and other cardio-metabolic disorders in the general population (71, 72). As diabetes and cardiomyopathy are known co-morbidities in FRDA, it is important to counsel patients on healthful nutrition and how to undertake exercise safely. Beyond the associated risks for health problems, elevated BMI may also make mobility and transfers more difficult. With respect to nutritional interventions, individuals who are overweight and/or individuals with specific FRDA-related co-morbidities (e.g., diabetes, cardiomyopathy) for which nutrition is an established part of management, should receive appropriate counseling. As with any child identified to be underweight, children with FRDA who are underweight should be evaluated by a multidisciplinary team with clinical expertise in nutritional management. Currently, there is no specific evidence in support of management practices of underweight children with FRDA.

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Please note: Recommendations are systematically developed evidence statements incorporating data from a comprehensive literature review of the most recent studies available (up to the Guidelines submission date) and reviewed according to the Grading of Recommendations, Assessment Development and Evaluations (GRADE) framework © The Grade Working Group. Best Practice Statements are commonly accepted practices, as such formal rating of the quality of evidence by the GRADE process is not indicated. In addition if recommendations from the 2014 guidelines were deemed still relevant, although unable to undergo the scrutiny from a GRADE framework, they were also included as best practice statements.
Standard BMI thresholds

QUESTION: Should standard BMI thresholds versus Friedreich ataxia-specific evaluation be used for defining undernutrition and over-nutrition in adults (18 years +) and children (under 18 years) with Friedreich ataxia?
[sg_popup id=”587″ event=”click”][/sg_popup]STRENGTH OF RECOMMENDATION:
[sg_popup id=”658″ event=”click”][/sg_popup]LEVEL OF EVIDENCE: ⨁◯◯◯

RECOMMENDATION: We suggest using standard BMI thresholds to define underweight and overweight in children and adults with Friedreich ataxia.

JUSTIFICATION: There is no current evidence to suggest that Friedreich ataxia-specific BMI thresholds are needed.

SUBGROUP CONSIDERATION: In children, studies have shown that there is an increased prevalence of being underweight (3) and therefore height and weight should be measured at every clinical or research visit. Standard BMI measurements are used in studies of children with other mitochondrial disorders and low BMI is prevalent (70).
While there are limited data on adults with Friedreich ataxia, studies in adults with mitochondrial disease report a high prevalence of being overweight or obese (28% overweight, 20% obese) (69).

Evidence to Recommendation Table PDF
Please note: Recommendations are systematically developed evidence statements incorporating data from a comprehensive literature review of the most recent studies available (up to the Guidelines submission date) and reviewed according to the Grading of Recommendations, Assessment Development and Evaluations (GRADE) framework © The Grade Working Group. Best Practice Statements are commonly accepted practices, as such formal rating of the quality of evidence by the GRADE process is not indicated. In addition if recommendations from the 2014 guidelines were deemed still relevant, although unable to undergo the scrutiny from a GRADE framework, they were also included as best practice statements.
All individuals with Friedreich ataxia should have height, weight, and BMI measured at least annually. In the minority of individuals who cannot safely stand with assistance, an alternate measurement could be used (e.g., ulnar length, supine length, seated height, or arm span).


The United States Preventive Services Task Force (USPSTF) and other organizations recommend routine screening for nutritional status with BMI (in children, adolescents, and adults).

Lay summary of clinical recommendation for assessing nutritional status in Friedreich ataxia


Why this recommendation?

Body mass index (BMI) is a screening tool used to evaluate an individual’s nutritional status using height and weight measurements. BMI is often used to indicate whether a person is underweight, normal weight or overweight although it does not always reflect body composition (that is, how much muscle, fat, and bone are present). Despite these limitations, both children and adults should have their height and weight measured annually.

What does this mean for you as a person living with Friedreich ataxia or caring for someone living with Friedreich ataxia?

Your healthcare professional may measure your height and weight at all visits. It might be important to speak to your healthcare professional about your BMI and what this means for you in terms of your nutritional status.

If you have an elevated BMI, your healthcare provider may discuss with you how this could increase your risk for diabetes and heart disease and how this might make mobility and transfers more difficult.

For all individuals with Friedreich ataxia, particularly those with BMI outside the typical range, your healthcare provider may discuss ensuring a balanced and nutritious diet.

Based on your individual comorbidities, such as diabetes or heart failure, your healthcare provider may provide specific nutritional recommendations.

Who is this recommendation specifically for? 

This recommendation is for all individuals with Friedreich ataxia.

Miriam Cnop, MD, PhD
Professor, Universite Libre de Bruxelles, Brussels, Belgium
Email: miriam.cnop@ulb.be

Andreas Eigentler, MD, PhD
Resident of Neurology, Department of Neurology, Medical University Innsbruck, Innsbruck, Austria
Email: andreas.eigentler@i-med.ac.at

Shana E. McCormack, MD, MTR
Assistant Professor of Pediatrics, Attending Physician, Perelman School of Medicine at the University of Pennsylvania, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
Email: mccormacks1@chop.edu

Jaclyn Tamaroff, MD
Instructor in Pediatrics, Division of Pediatric Endocrinology and Diabetes, Vanderbilt University Medical Center, Nasvhille, Tennessee, USA
Email: jaclyn.tamaroff@vumc.org

David R. Weber, MD, MSCE
Assistant Professor of Pediatrics – Endocrinology, The Children’s Hospital of Philadelphia and The Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
Email: weberd@chop.edu

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These Guidelines are systematically developed evidence statements incorporating data from a comprehensive literature review of the most recent studies available (up to the Guidelines submission date) and reviewed according to the Grading of Recommendations, Assessment Development and Evaluations (GRADE) framework © The Grade Working Group.

This chapter of the Clinical Management Guidelines for Friedreich Ataxia and the recommendations and best practice statements contained herein were endorsed by the authors and the Friedreich Ataxia Guidelines Panel in 2022.

It is our expectation that going forward individual topics can be updated in real-time in response to new evidence versus a re-evaluation and update of all topics simultaneously.