Medical Policy: 06.01.31 

Original Effective Date: September 2013 

Reviewed: April 2018 

Revised: April 2016 

 

Benefit Application:

Benefit determinations are based on the applicable contract language in effect at the time the services were rendered. Exclusions, limitations or exceptions may apply. Benefits may vary based on contract, and individual member benefits must be verified. Wellmark determines medical necessity only if the benefit exists and no contract exclusions are applicable. This medical policy may not apply to FEP. Benefits are determined by the Federal Employee Program.

 

This Medical Policy document describes the status of medical technology at the time the document was developed. Since that time, new technology may have emerged or new medical literature may have been published. This Medical Policy will be reviewed regularly and be updated as scientific and medical literature becomes available.

 

Description:

Measurements of body composition have been used to study how lean body mass and body fat change during health and disease and have provided a research tool to study the metabolic effects of aging, obesity, and various wasting conditions such as occurs with AIDS or post bariatric surgery. A variety of measurement methods have been researched, including most commonly, anthropomorphic measures, bioelectrical impedance, dual x-ray absorptiometry (DXA), and underwater weighing and imaging. All of these methods are based in part on assumptions regarding the distribution of different body compartments and their density, and all rely on formulas to convert the measured parameter into an estimate of body composition. Therefore, all techniques will introduce variation based on how the underlying assumptions and formulas apply to different populations of subjects (ie, different age groups, ethnicities, or underlying conditions). There has been an interest in using whole body dual x-ray absorptiometry (DXA) and bioelectrical impedance analysis (BIA) in the clinical care setting rather than a research setting.

 

Body Composition Measurement Methods

Clinical Practice

Anthropomorphic Techniques

Routinely, anthropomorphic measures are sufficient to estimate adiposity in a clinical setting. Anthropometric measurements include the following:

  • Height and Weight: Height and weight are the most commonly measured and can be determined with great accuracy. They are important in making clinical decisions regarding treatment of obesity. Weight can be related to height by several methods, but the most widely used is the BMI (body mass index), which is weight in kilograms divided by the height in meters squared. Height and weight should be measured by a provider in the office. BMI is used routinely in the clinical setting to diagnose obesity. Although it correlates with body fat, it does not directly measure body fat.
  • Waist Circumference: Waist circumference is another essential anthropometric measurement. It is measured with flexible tape placed on horizontal plane at the level of iliac crest. Increasing central adiposity, as measured by waist circumference, is associated with an increased risk of morbidity and mortality.
  • Multisite Testing of Skinfold Thickness: Multisite testing of skinfold thickness is one of the oldest and still most common methods of determining a person’s body composition and body fat percentage. This test estimates the percentage of body fat by measuring skinfold thickness at specific locations on the body. The thickness of these folds is a measure of fat under the skin, also called subcutaneous adipose tissue. Skinfold thickness results rely on formulas that convert these numbers into an estimate of a person’s percentage of body fat according to a person’s age and gender. Skinfold measurements are generally taken at specific sites on the right side of the body. The tester pinches the skin at the location site and pulls the fold of skin away from the underlying muscle so only the skin and fat tissue are held. Special skinfold calipers are then used to measure the skinfold thickness in millimeters.

 

The measurement sites vary depending on the specific skinfold testing protocol being used, but typically include the following seven locations on the body:

  • Triceps – the back of the upper arm
  • Pectoral – the mid-chest just forward of the armpit
  • Subscapular – beneath the edge of the shoulder blade
  • Midaxilla – midline of the side of the torso
  • Abdomen – next to the belly button
  • Suprailiac – just above the iliac crest of the hip bone
  • Quadriceps – middle of the upper thigh

 

According to the American College of Sports Medicine, when performed by a trained, skilled tester, skinfold measurements of body fat are up to 98% accurate. However, due to new technologies available such as electrical impedance methods and scales that measure body composition instead of directly measuring skinfolds, skinfold testing may not be utilized like it once was in clinical practice setting.

 

Research Methods

Underwater Weighing

Underwater weighing requires the use of a specially constructed tank in which the subject is seated on a suspended chair. The subject is then submerged in the water while exhaling. While valued as a research tool, weighing people underwater is obviously not suitable for routine clinical use. This technique is based on the assumption that the body can be divided into 2 compartments with constant densities: adipose tissue, with a density of 0.9 g/cm3, and lean body mass (ie, muscle and bone), with a density of 1.1 g/cm3. One limitation of the underlying assumption is the variability in density between muscle and bone; for example, bone has a higher density than muscle, and bone mineral density varies with age and other conditions. In addition, the density of body fat may vary, depending on the relative components of its constituents (eg, glycerides, sterols, glycolipids).

 

Imaging

Magnetic resonance imaging (MRI) or computed tomography (CT) can be used to measure visceral adipose tissue. The technique usually quantifies adipose tissue in a single slice cross section at the level of the L4/L5 lumbar disc. The subcutaneous fat (outside the abdominal musculature) may be measured in the same image. These measures of visceral adiposity correlate with insulin resistance, triglycerides, hepatic steatosis, and other components of the metabolic syndrome. This technique is used for research in obesity and metabolic disease, and does not contribute to clinical care.

 

Bioelectrical Impedance

Bioelectrical impedance is based on the relationship between the volume of the conductor (i.e. human body), the conductor’s length (i.e. height), the components of the conductor (i.e. fat and fat-free mass), and its impedance. Estimates of body composition are based on the assumption that the overall conductivity of the human body is closely related to lean tissue. The impedance value is then combined with anthropomorphic data to give body compartment measures. The technique involves attaching surface electrodes to various locations on the arm and foot. Alternatively, the patient can stand on pad electrodes.

 

Whole Body Dual X-Ray Absorptiometry (DXA)

Using low dose x-rays different energy levels, whole body dual x-ray absorptiometry (DXA) measure lean tissue mass, total and regional body fat, as well as bone density. DXA scans have become a tool for research body composition, but there has been an interest in using DXA in the clinical care setting rather than a research setting.

 

While the cited techniques above assume 2 body compartments, DXA can estimate 3 body compartments consisting of fat mass, lean body mass, and bone mass. DXA systems use a source that generates x-rays at 2 energies. The differential attenuation of the 2 energies is used to estimate bone mineral content and the soft tissue composition. When 2 x-ray energies are used, only 2 tissue compartments can be measured; therefore, soft tissue measurements (i.e. fat and lean body mass) can only be measured in areas in which no bone is present. DXA also has the ability to determine body composition in defined regions (i.e. the arms, legs, and trunk). DXA measurements are based in part on the assumption that the hydration of fat-free mass remains constant at 73%. Hydration, however, can vary from 67% to 85% and can be variable in certain disease states. Other assumptions used to derive body composition estimates are considered proprietary by DXA manufacturers.

 

Dual X-RAY Absorptiometry as a Diagnostic Test to Detect Abnormal Body Composition

Most of the literature on dual x-ray absorptiometry (DXA) as a diagnostic test to detect abnormal body composition involves the use of the technology in the research setting, often as a reference test; studies have been conducted in different populations of patients and underlying disorders. In some cases studies have compared other techniques with DXA to identify simpler methods of determining body composition. In general, these studies have shown that DXA is highly correlated to various methods of body composition assessment. For example, a 2014 study Alves et. al. compared 2 bioelectrical impedance devices with DXA for the evaluation of body composition in heart failure. Another 2014 study Ziai et. al. compared bioelectrical impedance analysis with DXA for evaluating body composition in adults with cystic fibrosis. Whether or not DXA scan is considered the reference standard, the key consideration regarding its routine clinical use is whether the results of the scan can be used in the management of the patient and improve health outcomes.

 

As a single diagnostic measure, it is important to establish diagnostic cutoff points for normal versus abnormal values. This is problematic because normal values will require the development of normative databases for the different components of body composition (i.e. bone, fat, lean mass) for different populations of patients at different ages. Regarding measuring bone mineral density (BMD), normative databases have largely focused on postmenopausal white women, and these values cannot necessarily be extrapolated to men or to different races. DXA determinations of BMD are primarily used for fracture risk assessment in postmenopausal women and to select candidates for various pharmacologic therapies to reduce fracture risk. In addition to the uncertainties of establishing normal values for other components of body composition, it also is unclear how a single measure of body composition would be used in patient management.

 

Dual X-RAY Absorptiometry to Monitor Changes in Body Composition

The ability to detect a change in body composition over time is related in part to the precision of the technique, defined as the degree to which repeated measurements of the same variable give the same value. For example, DXA measurements of bone mass are thought to have a precision error of 1% to 3% and, given the slow rate of change in bone mineral density (BMD) in postmenopausal women treated for osteoporosis, it is likely that DXA scans would only be able to detect a significant change in BMD in the typical patient after 2 years of therapy. Of course, changes in body composition are anticipated to be larger and more rapid than changes in BMD in postmenopausal women; therefore, precision errors in DXA scans become less critical in interpreting results.

 

Several studies have reported on DXA measurement of body composition changes over time in clinical populations; none of these studies used DXA findings to make patient management decisions or addressed how serial body composition assessment might improve health outcomes.

 

Summary

For individuals who have a clinical condition associated with abnormal body composition who receive DXA body composition studies, the evidence includes several cross-sectional studies comparing DXA with other techniques. The available studies were primarily conducted in research settings and often used DXA body composition studies as a reference standard; these studies do not permit conclusions about the accuracy of DXA for measuring body composition. More importantly, no studies were identified in which DXA body composition measurements were actively used in patient management. The evidence is insufficient to determine the effects of the technology on net health outcomes.

 

For individuals who have a clinical condition managed by monitoring changes in body composition over time who receive DXA body composition studies, the evidence includes several prospective studies monitoring patients over time. The studies used DXA as a tool to measure body composition and were not designed to assess the accuracy of DXA. None of the studies used DXA findings to make patient management decisions or addressed how serial body composition assessment might improve health outcomes. The evidence is insufficient to determine the effects of the technology on net health outcomes.

 

Bioelectrical Impedance Analysis (BIA) to Detect Whole Body Composition

Bioelectrical impedance analysis (BIA) measurement is simple and widely used but has limitations. Impedance is measured by applying electrodes to one arm and one leg or by standing on foot plates of a special scale. Impedance is proportional to the length of the conductor and inversely related to the cross-sectional area of the conductor. Accuracy in placement of electrodes is essential because variations can cause relatively large errors in the measurement of impedance and corresponding errors in the estimate of body water.

 

A variety of formulas have been developed to convert impedance, which measures body water into an estimate of fat. Most formulas for estimating fat from bioelectric impedance analysis underestimate body fat. BIA is influenced by sex, age, disease state, and level of fatness (because total body water and relative extracellular water are greater in obese individuals). The data suggest that BIA results are not as accurate no matter which formula is used to do the calculation and remains problematic in its ability to assess percent body fat, fat mass or fat-free mass.

 

Based on review of the peer reviewed medical literature, there is currently no established role for whole body bioelectrical impedance analysis (BIA) for individuals who have a clinical condition associated with abnormal body composition or who have a clinical condition managed by monitoring changes in body composition over time. Currently no studies have been identified in the literature in which BIAmeasurements were actively used in patient management, and studies have not reported data demonstrating the impact of body composition assessment on net health outcomes. Further studies are needed to assess the clinical value of this testing.

 

Practice Guideline and Position Statements

International Society for Clinical Densitometry (ISCD)

In 2013, The International Society for Clinical Densitometry (ISCD) issued a statement on use of DXA body composition. The statement included the following ISCD official positions regarding the use of DXA total body composition with regional analysis:

  • To assess fat distribution in patients with HIV who are using antiretroviral agents known to increase the risk of lipoatrophy. The statement noted that, although most patients who were taking medications known to be associated with lipoatrophy switched to other medications, some remain on these medications and DXA may be useful in this population to detect changes in peripheral fat before they become clinically evident.
  • To assess fat and lean mass changes in obese patients undergoing bariatric surgery when weight loss exceeds approximately 10%. The statement noted that the impact of DXA studies on clinical outcomes in these patients is uncertain.
  • To assess fat and lean mass in patients with risk factors associated with sarcopenia, ie, with muscle weakness or poor physical functioning.

 

U.S. Preventative Services Task Force Recommendations (USPSTF)

Obesity in Adults: Screening and Management

In 2012, the USPSTF recommends screening all adults for obesity. Clinicians should offer or refer all patients with body mass index (BMI) of 30 kg/m2 or higher to intensive, multicomponent behavioral interventions.

 

Body mass index is calculated from the measured weight and height for an individual. Recent evidence suggests that waist circumference may be an acceptable alternative to BMI measurement in some patient subpopulations. In 2003, The USPSTF found adequate evidence that BMI is an acceptable measure for identifying adults with excess weight.

 

Obesity in Children and Adolescents: Screening

In 2017, the USPSTF recommends that clinicians screen for obesity in children and adolescents 6 years and older and offer or refer them to comprehensive, intensive behavioral interventions to promote improvements in weight status.

 

In 2005, the USPSTF found that age and sex adjusted BMI (calculated as weight in kilograms divided by the square of height in meters) percentile is the accepted measure for detecting overweight or obesity in children and adolescents because it is feasible for use in primary care, a reliable measure, and associated with adult obesity.

 

American College of Cardiology (ACC)/American Heart Association (AHA)/The Obesity Society (TOS)

In 2013, the ACC/AHA/TOS issued a guideline for the management of overweight and obesity in adults and the summary of recommendations for obesity state, “identifying patients who need to lose weight (BMI and waist circumference), measure height and weight and calculate BMI at annual visits or more frequently. Measure weight circumference at annual visits or more frequently in overweight and obese adults.” (E-Expert Opinion)

 

This guideline mentions no role of whole body dual x-ray absorptiometry (DXA) or bioelectrical impedance analysis (BIA) in the assessment and management of overweight and obese adults.

 

National Institute for Health and Clinical Excellence (NICE)

In 2014, NICE issued a guideline on obesity: identification, assessment and management. The guideline included the following:

  • Use BMI as a practical estimate of adiposity in adults. Think about using waist circumference in addition to BMI in people with a BMI less than 35 kg/m2.
  • Use BMI (adjusted for age and gender) as a practical estimate of adiposity in children and young people. Waist circumference is not recommended as a routine measure.
  • "Do not use bioimpedance as a substitute for BMI as a measure of general adiposity.”

 

Prior Approval:

Not applicable.

 

Policy:

Dual x-ray absorptiometry (DXA) and whole body bioelectrical impedance analysis (BIA) for body composition studies is considered investigational for all indications.

 

Based on review of the peer reviewed medical literature there is insufficient evidence to support the use of whole body dual x-ray absorptiometry (DXA) and whole body bioelectrical impedance analysis (BIA) for the purpose of determining body composition. It is unclear how information regarding body composition could be used in the active medical management of the patient to alter treatment decisions or improve health outcomes. Well-designed studies evaluating the diagnostic accuracy and clinical utility of this testing are lacking. Further studies are needed to assess the clinical value of this testing. The evidence is insufficient to determine the effects of the technology on net health outcomes.

 

Procedure Codes and Billing Guidelines:

To report provider services, use appropriate CPT* codes, Alpha Numeric (HCPCS level 2) codes, Revenue codes, and/or diagnosis codes.

  • 76499 Unlisted diagnostic radiographic procedure
  • 0358T Bioelectrical impedance analysis whole body composition assessment, with interpretation and report

 

Selected References:

  • Methods for Body Composition Analysis in Adults, The Open Obesity Journal, 2011, Volume 3, 62-69
  • Centers for Disease Control and Prevention: Healthy Weight: Assessing Your Weight: BMI: About BMI for Adults.
  • U.S. Preventative Services Task Force: Screening for and Management of Obesity in Adults.
  • U.S. Preventative Services Task Force: Screening for Obesity in Children and Adolescents. 
  • American Heart Society Body Composition Tests
  • Kendler DL, Borges JL, Fielding RA, et. al. International Society for Clinical Densitometry: The Official Positions of ISCD: Indications of Use and Reporting of DXA for Adults.
  • International Society for Clinical Densitometry: 2007 Pediatric Official Positions.
  • Agency for Healthcare Research and Quality: Screening and Intervention for Childhood Overweight: Evidence Synthesis. July 2005. Investigators: Evelyn P. Whitlock, M.D., MPH; Selvi B. Williams, M.D.; Rachel Gold, PhD, MPH; Paula Smith, R.N., BSN; Scott Shipman, M.D., MPH
  • Evaluation of Lunar Prodigy dual energy x-ray absorptiometry for assessing body composition in healthy persons and patients by comparison with the criterion 4-component model. American Journal of Clinical Nutrition 2006. Jane E. Williams, Jonathan CK Wells, Catherine M. Wilson, Dalia Haroun, Alan Lucas and Mary S. Fewtrell.
  • American College of Radiology (ACR) and the Society of Skeletal Radiology (SSR) Practice Guideline for the Performance of Dual Energy X-Ray Absorptiometry (DXA). Revised 2008
  • Pediatrics Official Journal of the American Academy of Pediatrics: Prevention of Pediatric Overweight and Obesity Committee on Nutrition, 2003, 112;424
  • ACR SPR-SSR Practice Parameter for the Performance of Dual-Energy X-Ray Asbsorptiometry (DXA), Amended 2014.
  • UpToDate Measurement of Body Composition in Children, Sarah M. Phillips, MS, RD, LD, Robert J. Shulman, M.D., Topic last updated April 18, 2017.
  • UpToDate Determining Body Composition in Adults, Leigh Perrault, M.D., Topic last updated July 10, 2017.
  • Jensen MD, Ryan DH, Apovian CM, et al.; American College of Cardiology/American Heart Association Task Force on Practice Guidelines; Obesity Society. 2013 AHA/ACC/TOS guideline for the management of overweight and obesity in adults: A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and The Obesity Society. Circulation. 2014;129(25 Suppl 2):S102-S138
  • National Institute for Health and Clinical Excellence (NICE), NICE Guidelines (CG 189), Obesity: Identification, Assessment and Management. Published November 2014.
  • Ritz P, Salle A, Audran M, et. al. Comparison of different methods to assess body composition of weight loss in obese and diabetic patients. Diabetes Res Clin Pract 2007 Sep:77(3):405-11. PMID 17306903
  • Alves FD, Souza GC, Biolo A, et. al. Comparison of two bioelectrical impedance devices and dual-energy x-ray absorptiometry to evaluate body composition in heart failure, J Hum Nutr Diet 2014 Dec: 27(6):632-8. PMID 24684316
  • Ziai S, Coriati A, Chabot K, et. al. Agreement of bioelectric impedance analysis and dual-energy x-ray absorptiometry for body composition evaluation in adults with cystic fibrosis. J Cyst Fibros 2014 Sep:13(5):585-8. PMID 24522087
  • Elkan AC, Engvall IL, Tengstrand B, et. al. Malnutrition in women with rheumatoid arthritis is not revealed by clinical anthropometrical measurements or nutritional evaluation tools. Eur J Clin Nutr 2008 Oct:62(10):1239-47. PMID 17637600
  • Jensky-Squires NE, Dieli-Conwright CM, Rossuello A, et. al. Validity and reliability of body composition analysers in children and adults. BR J Nutr 2008 Oct:100 (4):859-65. PMID 18346304
  • Liem ET, De Lucia Rolfe E, L’Abee C, et. al. Measuring abdominal adiposity in 6 to 7 year old children. Eur J Clin Nutr 2009 Jul:63(7):835-41. PMID 19127281
  • Bedogni G, Agosti F, De Col A, et. al. Comparison of dual energy x-ray absorptiometry, air displacement pleythysmography and bioelectrical impedance analysis for the assessment of body composition in morbidly obese women. Eur J Clin Nutr 2013 Nov:67(11):1129-32. PMID 24022260
  • Tompuri TT, Lakka TA, Hakulinen M, et. al. Assessment of body composition by dual energy x-ray absorptiometry, bioimpedance analysis and anthropometrics in children: the physical activity and nutrition in children study. Clin Physiol Funct Imaging 2015 Jan:35(1):21-33. PMID 24325400
  • Kullberg J, Brandberg J, Angelhed JE, et. al. Whole body adipose tissue analysis: comparison of MRI, CT and dual energy x-ray absorptiometry. BR J Radiol. Feb 2009;85(974): 123-130. PMID 19168691
  • Monteiro PA, Antunes Bde M, Silveira LS, et. al. Body composition variables as predictors of NAFLD by ultrasound in obese children and adolescents. BMC Pediatr 2014;14:25. PMID 24476029
  • Bazzocchi A, Ponti F, Cariani S, et. al. Visceral fat and body composition changes in a female population after RYGBP: A Two year follow up by DXA. Obes Surg. Sep 14 2014. PMID 25218013 
  • International Society for Clinical Densitometry: 2015 ISCD Official Positions-Adult.
  • UpToDate. Nutritional assessment in chronic liver disease. Puneeta Tandon M.D., FRCP, Leah Gramlich M.D., FRCP. Topic last updated August 17, 2015.
  • UpToDate. Growth failure and poor weight gain in children with inflammatory bowel disease. Jonathan E. Teitelbaum M.D., Topic last updated October 6, 2015.
  • UpToDate. Indications for nutritional assessment in childhood. Sarah M. Phillips MS RD LD, Craig Jensen M.D. Topic last updated November 29, 2017.
  • Franzoni E, Ciccarese F,  Di Piertro E, et. al. Follow-up of bone mineral density and body composition in adolescents with restrictive anorexia nervosa: role of dual-energy X-ray absorptiometry. European Journal of Clinical Nutrition February 2014;68(2):247-252. PMID 24346474

 

Policy History:

  • April 2018- Annual Review, Policy Renewed
  • April 2017- Annual Review, Policy Renewed
  • April 2016 - Annual Review, Policy Revised
  • July 2015 - Annual Review, Policy Revised
  • August 2014 - Annual Review, Policy Renewed
  • September 2013 - New policy

Wellmark medical policies address the complex issue of technology assessment of new and emerging treatments, devices, drugs, etc.   They are developed to assist in administering plan benefits and constitute neither offers of coverage nor medical advice. Wellmark medical policies contain only a partial, general description of plan or program benefits and do not constitute a contract. Wellmark does not provide health care services and, therefore, cannot guarantee any results or outcomes. Participating providers are independent contractors in private practice and are neither employees nor agents of Wellmark or its affiliates. Treating providers are solely responsible for medical advice and treatment of members. Our medical policies may be updated and therefore are subject to change without notice.

 

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