Practical measurement of body composition using bioelectrical impedance, air displacement plethysmography and ultrasound in stable outpatients with short bowel syndrome receiving home parenteral nutrition: comparison of agreement between the methods

Abstract

Background People diagnosed with intestinal failure ( IF ) as a result of short bowel syndrome are dependent on home parenteral nutrition ( HPN ). Measuring nutritional status is essential for monitoring treatment. The present study aimed to determine the agreement and feasibility of three methods bioelectrical impedance analysis ( BIA ), ultrasound and air displacement plethysmography ( ADP ) for measuring body composition in people receiving HPN . Methods Body composition data were collected from patients attending an IF clinic. Results There were 50 participants recruited and data were collected for BIA ( n = 46), ultrasound ( n = 49) and ADP ( n = 9). Numbers for ADP were much lower because of a lack of participant uptake. Fat‐free mass ( FFM ) measured by BIA and ultrasound in comparison to ADP was found to have good intraclass correlation ( ICC ) 0.791 (95% confidence interval (CI) CI −0.21 to 0.96) and a moderate ICC 0.659 [95% ( CI) −0.27 to 0.92], respectively. Fat mass ( FM ) measured by both BIA and ultrasound in comparison to ADP was found to have moderate ICC 0.660 (95% CI −0.28 to 0.92) and poor ICC −0.005 (95% CI −0.73 to 0.65), respectively. Conclusions Compared to ADP , BIA indicated moderate to good agreement for measuring body composition, whereas ultrasound indicated far less agreement, particularly when measuring FM . The lack of uptake of ADP suggests that participants found the Bodpod (COSMED Srl, Shepperton, UK) unfavourable. Considering that ultrasound has limited agreement and ADP was not the preferred option for participants, BIA shows some potential. However, the difference between ADP and BIA was larger for FM compared to FFM , which needs to be considered in the clinical setting.

Body composition in patients with type 2 intestinal failure

“…However, it is important to note the limitations of the kappa analysis which is affected by the prevalence of the finding under observation and that the analysis relies on diagnostic cut‐off points for body composition measurements. Nonetheless, these results complement the findings of similar studies in this area 14,34,35 . In a study of critically ill patients, BIA and CT were shown to be moderately associated, 34 whereas in esophageal cancer patients BIA underestimated fat and lean mass percentages compared with CT scans 35 .…”

“…Only those patients who had undergone a CT scan as part of a routine investigation within 40 days of BIA measurement were included. Forty days was chosen as a clinically pragmatic timeframe to allow comparison between modalities and is reflective of other studies evaluating body composition techniques in other disease cohorts 14,17 …”

“…CT data are presented as cross‐sectional areas (in centimeters squared). The muscle area was also standardized by dividing muscle area by height squared to provide a skeletal muscle index (SMI) and expressed as cm 2 /m 2 14 . All CT scans were anonymized to ensure the researcher was anonymized to the patient characteristics.…”

“…Obtaining reliable body composition measurements is especially challenging in the patient population with type 2 IF characterized by unstable fluid balance, which could result in a high variability in skeletal muscle mass measurements 11 . BIA is an alternative method for the measurement of muscle mass; however, so far no recommendations could be made regarding the validity of BIA in IF patients because of the limited number of studies to date 12–14 . Nevertheless, body composition measured by CT is not always available in clinical practice and is associated with a risk of radiation.…”

Priority setting for adult malnutrition and nutritional screening in healthcare: a James Lind Alliance

“…This highlights the need to reach vulnerable groups in the community and to be able to identify issues before they develop. This would include: practical ways of measuring nutritional status and body composition validated against criterion measurements ; improvements in communication after discharge ; and adaptation of the current screening methods according to the circumstances . Improvements in this area have already been made with novel developments in self‐screening tools that are more suitable for community use in the voluntary sector domiciliary care and with social care partners.…”