Changes in cytokine production and impaired hematopoiesis in patients with anorexia nervosa: the effect of refeeding

Energy expenditure during nutritional rehabilitation: a scoping review to investigate hypermetabolism in individuals with anorexia nervosa

BACKGROUND

Weight gain and nutritional rehabilitation are essential first steps to achieve medical stabilization in anorexia nervosa, and frequent resistance to weight gain requires patients to consume high kilocalorie loads. Adaptive hypometabolism is common when patients begin treatment, and rebound hypermetabolism is suspected to be a significant barrier to weight gain. The aim of this review was to summarize existing data describing metabolic changes in anorexia nervosa during weight restoration. The reported findings challenge current hypotheses of weight gain resistance and highlight key areas for future research.

METHODS

Using scoping review guidelines, three databases were searched for studies investigating metabolic changes in anorexia nervosa before and after renourishment. Two reviewers systematically screened the titles and abstracts of 447 articles, and full-text versions of 106 studies were assessed for eligibility. A total of 36 studies were included for review. Data regarding the study description, sample population (including age, weight, BMI, duration of treatment, and caloric intake), and metabolic variable descriptions were extracted.

RESULTS

Female patients with anorexia nervosa from studies across 13 countries were included. Across the studies, average BMI increased from 13.7 kg/m2 at admission to 17.57 kg/m2. Patients presented to treatment with clinically reduced energy expenditure levels. After varying levels of nutritional rehabilitation and weight restoration, measured energy expenditure increased significantly in 76% of the studies. Energy expenditure values at the second timepoint increased to the standard range for normal weight female teenagers and adults. Despite these increases, the studies do not indicate the presence of a hypermetabolic state during renourishment. Additionally, all studies including both measured and predicted energy expenditure reported that predicted energy expenditure overestimated measured values.

CONCLUSION

This study provides a detailed evaluation of the literature investigating energy expenditure and metabolic rate in patients with anorexia nervosa before and following a period of renourishment. The findings from this review identify important gaps in the current beliefs of energy expenditure in anorexia nervosa and highlight a need for further exploration of metabolic alterations during weight restoration.

Anorexia Nervosa in vivo cytokine production: a systematic review

INTRODUCTION

The underlying psychobiology that contributes to Anorexia Nervosa (AN) onset and disease progression remains unclear. New research is emerging suggesting a possible link between inflammation and a variety of mental illnesses. Alterations of cytokines may play a role in the pathogenesis of AN. Some studies have found differences in the cytokine profile of those with AN compared to healthy controls, but results are heterogeneous. The aim of this work was to systematically review existing studies investigating in-vivo cytokine production in those with AN before and after weight restoration compared to controls.

METHODS

A comprehensive literature search of four electronic databases (PubMed, PsychInfo, EMBASE and CINAH) was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines to identify human in-vivo studies investigating the relationship between AN and cytokine production. Data extracted from included studies related to population characteristics (e.g. age, gender, mean mBMI/%IBW), cytokine measurement and relevant findings. Confounding factors (e.g. smoking status, co-morbid mental illness, menstruation status) were also collected.

RESULTS

36 studies were eligible for this systematic review of which the majority were conducted in Europe (77.8%) and involved female subjects (97.2%). Those with AN ranged in age from 13 to 47 years and had an illness duration of 3 months to 24 years. 15 candidate cytokines and 3 receptors were identified (TNF-alpha, IL-6, IL-1B, CRP, IL-2, IL-7, IL-10, IFN-γ, TNF-R2, IL-1 α, IL-15, TNF-R1, IL-17, IL-18, TGF-B1, IL-12, IL-6R and TGF-B2) exploring in-vivo levels in patients with AN and comparing to controls. TNF-alpha and IL-6 were the most extensively studied with IL-6 being significantly elevated in 4 out of 8 (50%) of longitudinal studies when comparing AN patients at baseline compared to post weight restoration. Following weight restoration, there was no difference in IL-6 levels when comparing to HC in 7 of 8 (87.5%) longitudinal studies examined.

CONCLUSIONS

The most promising cytokine potentially involved in the pathogenesis of AN appears to be IL-6, and possibly TNF-alpha pathways. The heterogeneity of clinical and methodology factors impedes the generalizability of results. Future studies may wish to address these methodological shortcomings as alterations in cytokine levels in AN could act as therapeutic targets assisting with weight restoration and psychopathology and may offer diagnostic potential.

Growth factors in anorexia nervosa: a systematic review and meta-analysis of cross-sectional and longitudinal data

OBJECTIVES

Growth factors are signalling molecules that play roles in the survival, proliferation, migration, and differentiation of cells. Studies have found alterations in specific growth factors in anorexia nervosa (AN).

METHODS

This systematic review and meta-analysis examined articles from three databases, measuring growth factors in AN cross-sectionally and longitudinally, and in recovered AN (rec-AN) cross-sectionally. Random-effects meta-analyses were conducted for brain-derived neurotrophic factor (BDNF) and insulin growth factor-I (IGF-1) for cross-sectional and longitudinal studies.

RESULTS

A total of 82 studies were included: 56 cross-sectional (BDNF: n = 15; IGF-1: n = 41) and 24 longitudinal (BDNF: n = 5; IGF-1: n = 19) were meta-analysed and 20 studies were narratively synthesised. In cross-sectional analyses, BDNF and IGF-1 were lower in AN compared to controls, and BDNF was marginally greater in rec-AN compared to controls. In longitudinal meta-analyses, BDNF and IGF-1 increased from baseline to follow-up. Cross-sectional subgroup analyses revealed no differences in BDNF between controls and AN binge-eating/purging subtypes.

CONCLUSIONS

It is likely that the low BDNF and IGF-1 levels found in AN are consequences of starvation, which are reversible with weight restoration. The increase in BDNF and IGF-1 during therapeutic weight restoration might improve neuroplasticity, which is the basis of learning, and thus psychotherapeutic success.

Persistent nonregenerative anemia in a 4-year-old cat

A 4-year-old male neutered domestic shorthair cat was presented to The Ohio State University College of Veterinary Medicine for a 2-month history of severe weight loss, lethargy, anemia, and bilaterally hyperechoic kidneys with loss of corticomedullary distinction as reported by the referring veterinarian. Relevant initial laboratory results included severe non-regenerative normocytic hypochromic anemia, increased blood urea nitrogen, minimally concentrated urine, proteinuria, and an increased urine protein:creatinine ratio. Cytologic evaluation of a bone marrow aspirate revealed a markedly hypocellular marrow with abundant mucinous material. Gelatinous marrow transformation (GMT) was confirmed histologically by the presence of mucinous material in the bone marrow that stained positive for Alcian blue but negative for periodic acid-Schiff. The cat died despite repeated blood transfusions and supportive care. Gelatinous marrow transformation, immune complex-mediated membranoproliferative glomerulonephritis, and gastrointestinal hemorrhage were observed on autopsy and histology. It is likely that the development of GMT was secondary to chronic kidney disease (CKD) and that CKD, GMT, and gastrointestinal hemorrhage contributed to the cat's non-regenerative anemia.

Can improvement in hormonal and energy balance reverse cardiovascular risk factors in athletes with amenorrhea?

Female athletes display a high prevalence of hypothalamic amenorrhea as a result of energy imbalance. In these athletes with amenorrhea, decreased luteinizing hormone/follicule-stimulating hormone secretion leads to deficiency in endogenous estrogen. The severe estrogen deficiency in these athletes may increase cardiovascular risk similar to that in postmenopausal women. This review discusses the potential cardiovascular risk factors in athletes with amenorrhea as a result of hypoestrogenism, which include endothelial dysfunction and unfavorable lipid profiles. We also consider the potential to reverse the cardiovascular risk by restoring energy or hormonal imbalance along the reproductive axis in athletes with amenorrhea.

A meta-analysis of cytokine concentrations in eating disorders

Cytokines are signalling molecules, which play an important role in both immune system function and brain development and function, and subsequently mental states and behaviour. Cytokines have been implicated in eating disorders (EDs) due to their role in psychological health, body weight and appetite regulation. This meta-analysis examined cross-sectional and longitudinal studies measuring concentrations of cytokines in individuals with EDs. Using PRISMA guidelines, we systematically reviewed relevant articles in PubMed, Web of Science, and MEDLINE. Random-effects meta-analyses were conducted for interleukin (IL)-1β, IL-6, transforming growth factor (TGF)-β, and tumor necrosis factor (TNF)-α, independently, firstly with all EDs combined and then stratified by ED diagnosis. Twenty-five studies were included: serum/plasma cytokine concentrations were measured in people with anorexia nervosa (AN) in 23 studies and bulimia nervosa (BN) in 4 studies. TNF-α and IL-6 were elevated in ED participants compared to healthy controls (HCs). Specifically, this pattern was seen only when comparing AN participants to HCs. Concentrations of these cytokines did not differ between people with BN and HCs. IL-1β and TGF-β did not differ between HCs and any ED group. Therefore, AN seems to be associated with elevated concentrations of TNF-α and IL-6. Considering the role of cytokines in appetite, mood regulation, and anxiety, these pro-inflammatory cytokines could be a potential future drug target to help people with AN, not only with weight gain, but also with various coexisting psychological problems. Future studies should consider confounding factors that affect cytokine concentrations and report ED-relevant clinical characteristics.

[Gelatinous transformation of the bone marrow: A retrospective monocentric case series of 12 patients]

PURPOSE

Gelatinous bone marrow transformation is a rare complication of unknown pathogenesis related to several underlying diseases. It is described as a focal loss of hematopoietic cells and a deposition of eosinophilic gelatinous substance rich in hyaluronic acid. We report a retrospective monocentric study followed by a literature review.

METHODS

We have identified 12 patients with gelatinous transformation from 1999 to 2014. Clinical, biological and cytological data were collected.

RESULTS

A bone marrow aspirate was performed for mild to severe pancytopenia (50%), less frequently for monocytopenia. Mean haemoglobin was 10.4g/dL, platelets 126.9G/L and leucocytes 3.82G/L. Gelatinous transformation was found in all patients. We have identified three hematologic malignancies, three cancers, three severe infections, two anorexia nervosa and one kidney injury. Ten patients had undernutrition, 9 out of the 12 patients died within a year due to advanced underlying disease and comorbidities.

CONCLUSION

Gelatinous bone marrow transformation is found in various situations of severe undernutrition including anorexia nervosa, advanced cancers or severe sepsis, especially in HIV infection. The deposition of hyaluronic acid probably reduces haematopoiesis. Due to a complex inflammatory process, it alters the hematopoietic microenvironment and the bone marrow stroma. Severe undernutrition and other mechanisms are reviewed in this study. Gelatinous degeneration is still a rare disorder, indicative of an advanced underlying disease; its recognition could help guide investigations.

[Blunted erythropoietic response in the anemia of anorexia nervosa]

BACKGROUND AND OBJECTIVE

The cause of the anemia in anorexia nervosa (AN) has not been fully ascertained. Ferritin, folate and cobalamin values are usually within normal ranges. Anemia does not have a relationship with bone marrow changes and erythropoietin (EPO) levels have not been investigated. The objective of this study was to evaluate the EPO response in a small group of AN patients.

PATIENTS AND METHODS

EPO levels were measured in serum samples of 41 female AN patients (11 with anemia, and 30 with normal blood cell count). The adequacy of EPO response was assessed by comparing the increase observed in a group of normal weight patients with anemia.

RESULTS

EPO concentrations in anemic AN patients were higher than in non-anemic: 20.63mU/mL (4.04-28.46) vs 8.7mU/mL (3.9-20.93), P=.0088, but the increase in EPO was lower than expected (27.85mU/mL [17.7-118.9]), P=.014. BMI and the difference between actual and expected EPO were inversely correlated.

CONCLUSIONS

Inadequate EPO response may partly explain anemia in AN, but further studies are necessary.

Inflammatory cytokines and anorexia nervosa: A meta-analysis of cross-sectional and longitudinal studies

OBJECTIVE

Although inflammation is increasingly implicated in psychiatric disorders, less is known about its role in anorexia nervosa (AN), an illness with low body mass index (BMI).

METHODS

We performed a systematic PubMed literature search until 12/31/2013 and meta-analyzed cross-sectional and longitudinal studies comparing circulating pro- and anti-inflammatory cytokines between patients with anorexia nervosa (AN) and healthy controls (HCs) (1) before and (2) after weight gain, and (3) within AN patients before and after weight gain. Standardized mean differences (SMDs)± 95% confidence intervals (CIs) for results from ≥ 2 studies were calculated.

RESULTS

Of 999 initial hits, 22 studies with 924 participants (AN=512, HCs=412) were eligible. Compared to HCs, tumor necrosis factor (TNF)-alpha (SMD=0.35, 95%CI=0.09-0.61, p=0.008), interleukin (IL)1-beta (SMD=0.51, 95%CI=0.18-0.84, p=0.003), IL-6 (SMD=0.43, 95%CI=0.11-0.76, p=0.009), and TNF-receptor-II (SMD=0.42, 95%CI:0.07-0.78, p=0.02) were significantly elevated in AN, while C-reactive protein (SMD=-0.53, 95%CI=-.77, -0.28, p<0.0001) and IL-6 receptor (SMD=-0.85, 95%CI=-1.33, -0.36, p=0.0006) were significantly decreased. No differences were found for TNF-receptor I and TGF-β. Across a subset of eight longitudinal studies (AN=152, HCs=129), significant weight gain (baseline BMI=15.4 ± 1.5, endpoint BMI=18.2 ± 1.6, p<0.0001) was not associated with significant changes in TNF-α, IL-6 and IL1-β. However, after weight gain, IL-6 was not different anymore compared to HCs (SMD=0.06, 95%CI=-0.32, 0.45, p=0.75). In meta-regression, shorter illness duration (p=0.0008), but not younger age (p=0.71) significantly moderated greater IL-6 levels.

CONCLUSION

Despite abnormally low BMI, AN seems to be associated with increased inflammatory cytokines. Whether specific elevated cytokines represent trait or state markers of AN, and whether they could be treatment targets requires further study.

[Hematological changes in adolescent anorexia nervosa]

OBJECTIVE

Hematological changes often occur in patients with acute anorexia nervosa (AN). However, the relationship between these disturbances and other clinical parameters remains unclear.

METHOD

Leucocyte, erythrocyte, and thrombocyte counts as well as hematocrit, hemoglobin, and differential blood counts were collected at admission and after weight restoration in 88 female adolescent patients with the diagnosis of AN according to DSM-IV. These were then compared to clinical parameters.

RESULTS

At admission, there were mild changes in the blood count, most of which, however, were reversible after weight gain. Patients with a greater weight loss, a lower age-adjusted BMI, and a history of taking psychotropic drugs were more likely to develop hematological abnormalities.

CONCLUSIONS

Although most of the hematological changes in adolescent patients with AN were mild, patients with high weight loss and/or low age-adjusted BMI as well as those on psychotropic medication should be monitored carefully in order to avoid severe medical complications. An altered immune function in adult patients with chronic AN might contribute to a higher rate of infections and thus to an increased mortality.

Tumour necrosis factor alpha and oxidative stress as maintaining factors in the evolution of anorexia nervosa

OBJECTIVE

Aim of the study was to evaluate tumour necrosis factor α (TNF-α) axis and oxidative status in patients with anorexia nervosa (AN) seeking a possible correlation with both nutritional status and evolution of the disease.

SUBJECTS AND METHODS

Thirty-nine consecutive women with AN and an age-matched healthy control group were studied. Patients were 26±9 yr, with a body mass index (BMI) of 13.9±2 kg/m(2). TNF-α, its receptors TNF-R55 and TNF-R75, and oxidative status markers (selenium, ascorbic/ dehydroascorbic acid, retinol, α-tocopherol, selenium-dependent gluthatione peroxidase, reduced/oxidated gluthatione) were measured. A correlation with both nutritional indexes (body weight, BMI, albumin, prealbumin, transferrin, lymphocyte count) and disease duration was investigated. Pearson's correlation and unpaired Student's t-test were used to compare patients and controls.

RESULTS

TNF-α and oxidative status markers were significantly higher in patients than controls and TNF-α was directly related to dehydroascorbic acid (p<0.05). Both TNF-R55 and TNF-R75 were higher in patients with duration of disease longer than one year as compared to controls and patients with shorter duration. Receptors inversely correlated with BMI (p<0.05 and p<0.01) and directly with disease duration (p<0.05). Inverse correlation between disease duration and BMI was present (p<0.01).

CONCLUSIONS

The study showed activation of TNF-α axis and oxidative stress in AN patients, as well as correlation between the two systems. Due to the correlation between TNF receptors and both BMI and disease duration, a possible role of pro-inflammatory cytokines in the evolution of the eating disorder is suggested.

[Gelatinous transformation of the bone marrow and acute hepatitis in a woman suffering from anorexia nervosa]

Anorexia nervosa can be a life-threatening eating disorder when complicated with electrolyte disturbance, gelatinous transformation of the bone marrow or starvation induced acute hepatitis. We report a 43-year-old woman suffering from anorexia nervosa for more than 25 years, who was admitted in intensive care unit for a fluctuating level of consciousness related to starvation-induced acute hepatitis. Gelatinous transformation of the bone marrow was also diagnosed. Those two entities are rare and, to our knowledge, have not been previously reported jointly in anorexia nervosa.

The hematology of anorexia nervosa

OBJECTIVE

Changes of the peripheral blood cell count in patients with anorexia nervosa (AN) are frequent. Anemia and leukopenia are observed in one-third of these patients. Examination of the bone marrow reveals in almost 50% of the patients with AN signs of bone marrow atrophy and can additionally suffer from a gelatinous bone marrow transformation.

METHOD

Published studies and investigations concerning hematological changes in patients with AN were reviewed.

RESULTS

Anemia and mild neutropenia are detectable in almost one-third of these patients, whereas thrombocytopenia is rather uncommon. The exact mechanism for these findings is still unclear, but 50% of AN-patients with hematological changes display morphological signs of partial bone marrow atrophy.

DISCUSSION

Changes of the peripheral blood cell count in patients with AN is a frequent observation but the peripheral blood cell count cannot predict the severity of bone marrow atrophy. All hematological and morphological alterations disappear completely and rapidly after sufficient refeeding.

Leptin-mediated neuroendocrine alterations in anorexia nervosa: somatic and behavioral implications

Hypoleptinemia is a key endocrinological feature of anorexia nervosa (AN). Several symptoms in acute AN are related to the low circulating leptin levels including amenorrhea and semi-starvation-induced hyperactivity. The drop in leptin levels results from the loss of fat mass; once leptin levels fall below specific thresholds the hypothalamic-pituitary-gonadal and -thyroid axes are down-regulated; in contrast, the hypothalamic-pituitary-adrenal axis is up-regulated. Hypoleptinemia is the major signal underlying both somatic and behavioral adaptations to starvation. Because the mechanisms involved in this adaptation are similar in rodents and humans, rodent models can be used to investigate the relevant central pathways which underly the respective starvation-induced symptoms. During therapeutically induced weight gain, leptin levels can intermittently increase above normal concentrations. This hyperleptinemia could predispose to renewed weight loss.

Immunological disturbance and infectious disease in anorexia nervosa: a review

OBJECTIVE

Severely malnourished patients with anorexia nervosa (AN) are reported to show fewer symptomatic viral infections and a poorer response to bacterial infection than controls. They are also reported to show mild immune system changes, although the relevance of these to altered infection disease presentation in AN and AN pathophysiology is unknown. Thus, in this paper, we suggest a range of immune system changes that might underpin these altered responses to common pathogens, and review a number of recent infectious disease findings for their utility in explaining the pathophysiology of AN.

METHODS

A systematic review of the literature pertaining to immunity and infectious disease in AN was performed.

RESULTS

AN is associated with leucopenia, and the increased spontaneous and stimulated levels of proinflammatory cytokines [i.e. interleukin (IL)-1β, IL-6 and tumour necrosis factor α). A range of less consistent findings are also reviewed. Most of these data were not controlled for length of illness, degree of malnutrition, micronutrient or vitamin deficiencies or recent refeeding and starvation.

CONCLUSION

Cytokine disturbances have been suggested to be causally related to AN symptomatology and pathophysiology of AN, although the evidence supporting this assertion is lacking. Immune and cytokine changes in AN do, however, occur in association with a decreased incidence of symptomatic viral infection, decreased clinical response to bacterial infection leading to delayed diagnosis and increased morbidity and mortality associated with the infections.

Low insulin-like growth factor I and leukopenia in anorexia nervosa

OBJECTIVE

Considering that leukopenia and anemia are commonly observed in anorexia nervosa (AN) and that growth hormone (GH) and insulin-like growth factor-I (IGF-I) markedly influence the activation, growth and survival of hemopoietic cells, we sought for possible relationships between hematologic parameters and the GH-IGF-I axis in a group of patients with AN.

METHOD

Twenty patients were studied. Leukocyte and erythrocyte counts, as well as baseline serum GH levels and IGF-I standard deviation score (SDS) values, were determined in each participant and correlations between parameters were searched.

RESULTS

Leukocyte and erythrocyte counts, as well as IGF-I SDS values, were significantly lower, conversely GH was significantly higher in AN patients than in normal weight participants. In patients, IGF-I SDS values were positively correlated with leukocyte count and BMI, whereas no correlation was found between IGF-I SDS and hemoglobin or erythrocytes.

CONCLUSION

The demonstration of a positive correlation between leukocyte number and circulating IGF-I in AN suggests a likely pathogenetic role of IGF-I deficiency in this hematologic abnormality.

Uncoupling of cardiovascular risk markers in adolescent girls with anorexia nervosa

OBJECTIVE

Cardiovascular (CV) risk begins in childhood, and low body weight should result in a favorable risk profile. However, adolescents with anorexia nervosa (AN) have alterations in many hormonal factors that mediate CV risk. We hypothesized that in AN, growth hormone (GH) resistance and hypercortisolemia would increase CV risk through effects on pro-inflammatory cytokines and lipid status despite low weight.

STUDY DESIGN

We examined CV risk markers (high sensitivity C-reactive protein [hsCRP], interleukin-6 [IL-6], apolipoprotein-B [Apo-B], and lipid profile) in 23 subjects with AN and in 20 control subjects 12 to 18 years of age, in whom GH, cortisol, leptin, and triiodothyronine (T3) had been previously determined.

RESULTS

Subjects with AN had higher Apo-B (P < .0001), IL-6 (P = .03), Apo-B/high-density lipoprotien (HDL) (P = .01), and Apo-B/low-density lipoprotein (LDL) (P < .0001) and lower hsCRP (P = .01) than controls. Triglycerides were lower and HDL higher in subjects with AN. IGF-I predicted hsCRP in controls but not in AN. Log hsCRP correlated positively with GH and inversely with leptin. On regression modeling, the most significant predictor of log hsCRP was leptin; T3 predicted log IL-6, log Apo-B, log Apo-B/HDL, and Apo-B/LDL; and cortisol independently predicted log Apo-B. IL-6 decreased with weight gain.

CONCLUSION

CV risk markers are uncoupled in AN, with increased Apo-B and IL-6 and decreased hsCRP, related to hormonal alterations. IL-6 normalizes with weight gain.

Anorexia nervosa and osteoporosis

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.

Body fat mass and serum leptin levels influence epoetin sensitivity in patients with ESRD

BACKGROUND

Dose requirements of epoetin vary considerably among patients with end-stage renal disease (ESRD), whereas determinants of epoetin sensitivity are poorly understood. Fat mass is an important source of adipokines, including interleukin 6 (IL-6), which is associated with decreased epoetin sensitivity. Furthermore, the adipokine leptin stimulates human erythroid development in vitro. In the present study, we investigate the impact of fat mass and leptin level on epoetin sensitivity in patients with ESRD.

METHODS

One hundred sixty-six patients with ESRD (107 men; 64%) with a mean age of 56.9 +/- 0.9 years were studied in a post hoc cross-sectional analysis. Body composition was analyzed by dual-energy X-ray absorptiometry and correlated with serum markers of inflammation and leptin (analyzed by enzyme-linked immunosorbent assays), as well as with epoetin dose, in international units administered per week (IU/wk). To correct for differences in body mass and hemoglobin (Hb) levels, epoetin sensitivity was approximated as epoetin/Hb ratio, ie, epoetin dose per unit of Hb (IU/wk/g/dL) and epoetin/Hb/kg ratio, ie, epoetin dose per unit of Hb and kilogram of patient body weight (IU/wk/Hb/kg).

RESULTS

Patients were divided into 3 groups according to epoetin/Hb/kg ratio (no-epoetin group, low-epoetin group, and high-epoetin group). The 3 groups had significantly different serum levels of high-sensitivity C-reactive protein (hsCRP; median, 8.6 versus 3.1 and 8.0 mg/L, respectively; P < 0.05), neopterin (median, 112.4 versus 94.3 and 96.1 ng/L, respectively; P < 0.05), and IL-6 (median, 6.8 versus 4.1 and 6.5 ng/mL, respectively; P < 0.05). Significant between-group differences also were found in fat mass and leptin levels (median, 14.8 versus 10.5 and 7.9 ng/mL, respectively; P = 0.02). In univariate analyses, significant relationships between epoetin sensitivity indices, leptin levels, and levels of the inflammatory markers hsCRP and IL-6 were found. In a multivariate stepwise regression model, log ferritin, parathyroid hormone, log leptin, log IL-6, and polycystic kidney disease were significantly associated with the epoetin/Hb ratio.

CONCLUSION

The present study shows that leptin level may be a predictor of epoetin sensitivity. The effect could be either direct stimulation of erythropoiesis or indirect stimulation by associated adipokines. Although truncal fat is associated with secretion of proinflammatory cytokines, this secretion appears not to have inhibitory effects on epoetin sensitivity in the presence of high leptin levels.

TNF-α and intPLA2 genes' polymorphism in anorexia nervosa

OBJECTIVE

The aim of this study was the assessment of -308G/A tumor necrosis factor (TNF)-α gene polymorphism and intPLA2 gene polymorphism in patients with anorexia nervosa (AN) and healthy controls.

SUBJECTS

We studied 91 non-related patients with AN and 144 healthy women (blood donors and students). The mean age of women from study group was 18.22 years (SD ± 3.13 years) and from control group was 31.71 years (SD ± 8.22).

METHODS

Gene polymorphisms were studied with the use of polymerase chain reaction-restriction fragment length polymorphism method. TNF-α gene polymorphism consists of G/A substitution in -308 promoter region. IntPLA2 gene polymorphism is related to intron 1, in which restrictive region is found and recognized by BanI enzyme.

RESULTS

We did not obtain statistically significant differences in the frequency of genotypes and alleles of -308G/A TNF-α polymorphism between the study and control groups (genotypes: P = 0.106, alleles: P = 0.076). We did analogous analysis in the restrictive and bulimic subgroups. We did not observe statistically relevant differences in the frequency of genotypes (P = 0.700) and alleles (P = 0.305). We did not obtain statistically relevant difference in the frequency of genotypes and alleles of intPLA2 gene between the study group and controls (genotypes: P = 0.300, alleles: P = 0.331). We did analogous analysis in both subgroups of AN. We did not observe statistically relevant differences in the frequency of genotypes (P = 0.344) and alleles (P = 0.230).

CONCLUSIONS

There was no statistically relevant trend for the association between TNF-α polymorphism and AN. We did not find association between studied polymorphism of intPLA2 gene and risk of AN.