Interleukin-7 Plasma Levels in Human Differentiate Anorexia Nervosa, Constitutional Thinness and Healthy Obesity.
BACKGROUND
Interleukin-7 (IL-7) is a cytokine involved in energy homeostasis as demonstrated in rodents. Anorexia nervosa is characterized by restrained eating behavior despite adaptive orexigenic regulation profile including high ghrelin plasma levels. Constitutional thinness is a physiological condition of resistance to weight gain with physiological anorexigenic profile including high Peptide YY plasma level. Healthy obesity can be considered as a physiological state of resistance to weight loss with opposite appetite regulating profile to constitutional thinness including low Peptide YY plasma level. No studies in IL-7 are yet available in those populations. Therefore we evaluated circadian plasma levels of IL-7 in anorexia nervosa compared to constitutional thinness, healthy obese and control females.


METHODS
10 restrictive-type anorexia nervosa women, 5 bingeing/purging anorexia nervosa woman, 5 recovered restrictive anorexia nervosa women, 4 bulimic females, 10 constitutional thinness women, 7 healthy obese females, and 10 normal weight women controls were enrolled in this cross-sectional study, performed in endocrinology unit and academic laboratory. Twelve-point circadian profiles of plasma IL-7 levels were measured in each subject.


RESULTS
24h mean IL-7 plasma levels (pg/ml, mean±SEM) were decreased in restrictive-type anorexia nervosa (123.4±14.4, p<0.0037), bingeing/purging anorexia nervosa (24.2±5.6, p<0.001), recovered restrictive anorexia nervosa (64.2±16.1, p = 0.01) and healthy obese patients (51±3.2, p<0.001) compared to controls (187.7±28.6). Bulimic patients (197.4±42.7) and constitutional thinness patients (264.3±35.8) were similar to controls.


CONCLUSIONS
Low IL-7 is part of the adaptive profile in restrictive-type anorexia nervosa, confirming its difference with constitutional thinness. Healthy obesity, with low IL-7, is once again in mirror image of constitutional thinness with normal high IL-7.
Division of Endocrinology, Diabetes, Metabolism and Eating Disorders, CHU Saint-Etienne, Saint-Etienne, France.|TAPE (Eating Disorders, Addictions & Extreme Bodyweight) Research Group EA 7423, Saint-Etienne, France.
Natacha
N
Germain
Univ. Lille, INSERM, CHU Lille, UMR-S 1172 - JPArc - Jean-Pierre AUBERT Research Center, Neurosciences and Cancer, F-59000, Lille, France.
Odile
O
Viltart
Univ. Lille, INSERM, CHU Lille, UMR-S 1172 - JPArc - Jean-Pierre AUBERT Research Center, Neurosciences and Cancer, F-59000, Lille, France.
Anne
A
Loyens
Division of Endocrinology, Diabetes, Metabolism and Eating Disorders, CHU Saint-Etienne, Saint-Etienne, France.|TAPE (Eating Disorders, Addictions & Extreme Bodyweight) Research Group EA 7423, Saint-Etienne, France.
Céline
C
Bruchet
Division of Endocrinology, Diabetes, Metabolism and Eating Disorders, CHU Saint-Etienne, Saint-Etienne, France.|TAPE (Eating Disorders, Addictions & Extreme Bodyweight) Research Group EA 7423, Saint-Etienne, France.
Katia
K
Nadin
Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019 - UMR8204 - CIIL - Center for Infection and Immunity of Lille, F-59000, Lille, France.
Isabelle
I
Wolowczuk
Division of Endocrinology, Diabetes, Metabolism and Eating Disorders, CHU Saint-Etienne, Saint-Etienne, France.|TAPE (Eating Disorders, Addictions & Extreme Bodyweight) Research Group EA 7423, Saint-Etienne, France.
Bruno
B
Estour
Division of Endocrinology, Diabetes, Metabolism and Eating Disorders, CHU Saint-Etienne, Saint-Etienne, France.|TAPE (Eating Disorders, Addictions & Extreme Bodyweight) Research Group EA 7423, Saint-Etienne, France.
Bogdan
B
Galusca
D000328:Adult; D000856:Anorexia Nervosa / Q000097:blood*; D001823:Body Composition / Q000502:physiology; D003430:Cross-Sectional Studies; D005260:Female; D054439:Ghrelin / Q000097:blood; D006801:Humans; D015851:Interleukin-7 / Q000097:blood*; D009765:Obesity / Q000097:blood*; D019894:Peptide YY / Q000097:blood; D013851:Thinness / Q000097:blood*; D055815:Young Adult
D054439:Ghrelin; D015851:Interleukin-7; D019894:Peptide YY