Anorexia nervosa and osteoporosis

Abstract

Anorexia nervosa (AN), a condition of severe undernutrition, is associated with low bone mineral density (BMD) in adults and adolescents. Whereas adult women with AN have an uncoupling of bone turnover markers with increased bone resorption and decreased bone formation markers, adolescents with AN have decreased bone turnover overall. Possible contributors to low BMD in AN include hypoestrogenism and hypoandrogenism, undernutrition with decreased lean body mass, and hypercortisolemia. IGF-I, a known bone trophic factor, is reduced despite elevated growth hormone (GH) levels, leading to an acquired GH resistant state. Elevated ghrelin and peptide YY levels may also contribute to impaired bone metabolism. Weight recovery is associated with recovery of BMD but this is often partial, and long-term and sustained weight recovery may be necessary before significant improvements are observed. Anti-resorptive therapies have been studied in AN with conflicting results. Oral estrogen does not increase BMD or prevent bone loss in AN. The combination of bone anabolic and anti-resorptive therapy (rhIGF-I with oral estrogen), however, did result in a significant increase in BMD in a study of adult women with AN. A better understanding of the pathophysiology of low BMD in AN, and development of effective therapeutic strategies is critical. This is particularly so for adolescents, who are in the process of accruing peak bone mass, and in whom a failure to attain peak bone mass may occur in AN in addition to loss of established bone.

TGF-β1, metabolizm kostny, osteoprotegeryna i rozpuszczalny ligand receptora aktywatora czynnika jądrowego-B u dziewcząt z jadłowstrętem psychicznym

“…High levels of TGF-β1 upregulated the expression of osteoprotegerin (OPG) and downregulated the expression of RANKL by osteoblasts [2,3,7,11]. Osteopaenia, or low bone mass, and osteoporosis are among the most severe and common complications of anorexia nervosa (AN) [12][13][14][15][16]. Several studies have reported a positive relationship between body mass, body mass index (BMI), and/or bone mineral density (BMD) in adolescents with AN [15,[17][18][19][20][21][22].…”

“…Osteopaenia, or low bone mass, and osteoporosis are among the most severe and common complications of anorexia nervosa (AN) [12][13][14][15][16]. Several studies have reported a positive relationship between body mass, body mass index (BMI), and/or bone mineral density (BMD) in adolescents with AN [15,[17][18][19][20][21][22]. Adolescents with AN also have lower levels of biochemical markers of bone formation and resorption than normal-weight controls, indicating a decrease in bone turnover [15,[23][24][25][26][27][28][29][30][31].…”

Metabolizm kostny, osteoprotegeryna i ligand receptora aktywatora czynnika jądrowego-kB a wybrane hormony tkanki tłuszczowej u dziewcząt z jadłowstrętem psychicznym

“…Girls with AN exhibit considerable suppression of bone metabolism markers, i.e. bone-specific alkaline phosphatase, OC, C-terminal cross-linked telopeptide of type I collagen a chain (CTx), N-terminal cross-linked telopeptide of type-I collagen type I collagen a chain (NTx) and/or deoxypyridinoline [9, 10, 21-23, 60, 61] correlating with a decrease in BMD and LP levels [9,10,23]. Several authors have determined OPG concentrations in girls with AN and found that, similar to young females with AN, the girls had elevated serum levels of this cytokine [4,8,21,22,61].…”

“…Disturbances in the production, release and action of osteotropic agents, mainly hormones (including adipose tissue hormones, i.e. LP and maybe also ADIPO, RES, VISF and APE), might lead to bone mineral density (BMD) decrease or, alternatively, absence of the BMD increase expected in adolescence [9,10,23] resulting from excessive bone resorption and inadequate formation of new bone. The system of receptor activator of nuclear factor-kB ligand/receptor activator of nuclear factor-kB/osteoprotegerin (RANKL/RANK/OPG) might play an important role in this process [24,25].…”

Avaliação da densidade mineral óssea em adolescentes do sexo feminino com transtorno alimentar

“…Duas característi-cas clínicas da AN -deficiência estrogênica e perda de peso -são fatores de risco importantes para redução da massa óssea. É incerto se ocorre declínio progressivo e permanente na massa óssea dessas pacientes (13,14).…”