Intensive weight gain therapy in patients with anorexia nervosa results in improved serum tartrate-resistant acid phosphatase (TRAP) 5a and 5b isoform protein levels

Christina Patlaka,Per Magnusson,Bojan Tubic,Göran Andersson,Staffan Paulie,Pernilla Lång,Diana Swolin-Eide

doi:10.1007/s40519-019-00776-8

Abstract

AimTartrate-resistant acid phosphatase (TRAP) exists as isoforms 5a and 5b. TRAP 5a is a biomarker of chronic inflammation and influences adipose tissue and 5b associates with bone metabolism/pathologies. The aim was to investigate the association of serum TRAP 5a/5b isoforms with fat and bone markers and anthropometric parameters in patients with anorexia nervosa (AN) during weight gain therapy.MethodsTwenty-five Swedish female AN patients, age 16–24 years, were treated for 12 weeks with a high-energy diet with six meals daily. Serum TRAP 5a/5b, markers of fat/glucose metabolism, markers of bone resorption and formation were measured. Parameters of bone and body composition were assessed by dual-energy X-ray absorptiometry and peripheral quantitative computed tomography.ResultsBMI increased from median 15.4 kg/m2 to 19.0 kg/m2, p < 0.0001. TRAP 5a and 5a/5b ratio increased but TRAP 5b decreased during the study. TRAP Δ5a and Δ5b correlated with Δinsulin and Δadiponectin, respectively. TRAP 5b correlated with trabecular density at start but not at week 12. At 12 weeks, TRAP 5b correlated with CTX, and Δ decrease in TRAP 5b correlated to Δ increase in bone-specific alkaline phosphatase.ConclusionsThis clinical interventional study resulted in increased BMI in patients with AN. The decreased TRAP 5b protein levels confirm a role for TRAP 5b as a marker of bone resorption, whereas increased TRAP 5a seemed to derive from systemic changes in bone as well as metabolic changes. The combined detection of TRAP 5a and TRAP 5b in serum could be an indicator of improved bone metabolism.Level of evidenceLevel III, prospective interventional cohort study.

Highlights

Anorexia nervosa (AN) is a severe psychiatric disorder predominantly affecting female adolescents
Serum Tartrate-resistant acid phosphatase (TRAP) 5a and TRAP 5b are changed in opposite directions after weight gain therapy
TRAP 5b changes correlated positively to changes in bonespecific alkaline phosphatase (BALP) (ΔTRAP 5b versus ΔBALP, (Fig. 3d) R = 0.52, p = 0.01). In this prospective interventional study, we investigated changes in the circulating levels of TRAP 5a and TRAP 5b derived from patients with severe AN during rapid weight gain therapy for 12 weeks

Summary

Introduction

Anorexia nervosa (AN) is a severe psychiatric disorder predominantly affecting female adolescents. Teenagers will gradually recover from the illness, . Per Magnusson and Göran Andersson shared senior authorship. Extended author information available on the last page of the article. AN is known for its severe complications [1]. The prevalence of AN is approximately 1% among 17-year-old Swedish girls [2]. Many patients recover after treatment as outpatients, while some patients require hospitalization. A novel intensive nutrition therapy that initially starts with an extreme high caloric intake has recently and successfully been implemented for hospitalized AN patients resulting in significant increase in body mass index (BMI), weight and fat mass [3]

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