The effect of posture on body circumferences in older adults

Standards for anthropometrical assessment define that measurements must be carried out with the subject in the standing position, although this is not always possible. The effect of body position on girth measurement has not been evaluated, even though this issue is clinically relevant because it may bias nutritional assessment results. The present study aimed to evaluate the effect of body position and symmetry on girth measurement.

A cross-sectional study was conducted on 102 older adults aged ≥65 years from care homes and tertiary hospitals. Right and left arm, waist, hip mid-thigh and calf girths were obtained with the subject standing or in the supine position. Mini-Nutritional Assessment Short-Form (MNA-SF) score and reference data percentiles (NHANES IV) misclassification according to girths assessed in the supine position was evaluated.

A high intraclass correlation coefficient (ICC > 0.97) and quartiles agreement (k > 0.89) were found between girth measurements conducted on participants in the standing and supine positions. According to MNA-SF, 23.5% of the participants were undernourished and 51% were at risk of undernutrition. A high agreement between MNA-SF score using calf circumference measured on standing or supine position was found (k = 0.96). A relevant agreement for NHANES IV girth percentiles by sex and age was also found (ICC > 0.89).

Agreement between girth measurements on standing and supine positions among older adults is high and differences do not have any clinically relevant impact on MNA-SF classification and reference data percentiles.