An objective means of diagnosing anorexia nervosa and bulimia nervosa using ¹⁵N/¹⁴N and ¹³C/¹²C ratios in hair

Abstract

An objective means based on the carbon and nitrogen stable isotope analysis of five hairs per individual is presented for distinguishing between individuals with anorexia nervosa and/or bulimia nervosa from non-clinical individuals (i.e. clinically normal controls). Using discriminant analysis, an algorithm has been developed that provides both sensitivity and specificity of 80% in making diagnoses of individuals with these eating disorders. With further refinements, the results suggest that it may be also possible to distinguish between individuals with anorexia or bulimia. Finally, the study shows the value of conducting blind tests and using larger sample sizes of both control and treatment groups. Both groups are needed to validate the diagnostic value of a method and to provide measures of sensitivity and specificity of any diagnostic test.

δ15N and δ13C in hair from newborn infants and their mothers: a cohort study

“…In mothers, an increase in nitrogen retention in the later stages of gestation, a decrease in urea excretion and synthesis (25,26), and a decrease of branched-chain amino-acid transamination (27) will all act to lower the δ 15 N in hair of mothers and increase the differential between a mother and her offspring. This is consistent with a study showing a decrease in δ 15 N of maternal hair throughout pregnancy (17) and with studies of eating disorders (28) and digestive malfunction (29), both of which lead to depletion in 15 N. Head circumference at birth was smaller in babies within the upper quartile of δ 15 N. This intriguing observation persists when data are adjusted to GA. The effect of maternal protein intake on brain development is poorly documented.…”

Laboratory and field methods for stable isotope analysis in human biology

“…Hair is the most commonly studied tissue for SIA in field studies among living humans (Bender et al, 2015;Bol et al, 2007;Bol and Pflieger, 2002;de Luca et al, 2012;Fuller et al, 2006;Hatch et al, 2006;Mekota et al, 2006;O'Connell and Hedges, 1999;Petzke et al, 2006;Petzke et al, 2010;Romek et al, 2013;Valenzuela et al, 2012;Valenzuela et al, 2011). One of the primary advantages of using hair in isotopic studies is the longitudinal record of isotopic data it contains.…”

“…Another example is starvation and wasting forcing an organism to recycle its own endogenous tissue reserves to meet maintenance and growth demands, which essentially increases the number of times nitrogen is subjected to fractionating steps in the body. Greater diet-tissue spaces and overall d 15 N ratios in nutritionally stressed organisms are the result of this (Deschner et al, 2012;Fuller et al, 2005;Hatch et al, 2006;Hobson et al, 1993;Mekota et al, 2006;Neuberger et al, 2013;Vogel et al, 2012).…”

“…Hatch et al (2006) and Mekota et al (2006) demonstrated that among individuals suffering from anorexia and bulimia, hair d 15 N ratios were elevated when patients were admitted to a treatment facility, and declined as treatment successfully progressed (and BMI increased). Neuberger et al (2013) (Longinelli, 1984;Luz et al, 1984).…”

Hagfish feeding habits along a depth gradient inferred from stable isotopes

“…In addition, when long periods of fasting occur, individuals will catabolise endogenous amino acids to meet the demands of protein synthesis (Deschner et al 2012), and consume their own body tissue. The result is 15 N enrichment in the remaining muscle tissue (Hatch et al 2006).…”