Lack of clinical predictors for low mineral density in children with celiac disease

Anti-tissue transglutaminase antibodies (TG2A) positivity and the risk of vitamin D deficiency among children - a cross-sectional study in the generation R cohort

BACKGROUND

Suboptimal vitamin D status is common in people with celiac disease (CeD), a disease that can be characterized by the presence of serum anti-tissue transglutaminase antibodies (TG2A) (i.e., TG2A positivity). To date, it remains unclear whether childhood TG2A positivity is associated with vitamin D status and how this potential association can be explained by other factors than malabsorption only, since vitamin D is mainly derived from exposure to sunlight. The aim of our study was therefore to assess whether childhood TG2A positivity is associated with vitamin D concentrations, and if so, to what extent this association can be explained by sociodemographic and lifestyle factors.

METHODS

This cross-sectional study was embedded in the Generation R Study, a population-based prospective cohort. We measured serum anti-tissue transglutaminase antibodies (TG2A) concentrations and serum 25-hydroxyvitamin D (25(OH)D) concentrations of 3994 children (median age of 5.9 years). Children with serum TG2A concentrations ≥ 7 U/mL were considered TG2A positive. To examine associations between TG2A positivity and 25(OH)D concentrations, we performed multivariable linear regression, adjusted for sociodemographic and lifestyle factors.

RESULTS

Vitamin D deficiency (serum 25(OH)D < 50 nmol/L) was found in 17 out of 54 TG2A positive children (31.5%), as compared to 1182 out of 3940 TG2A negative children (30.0%). Furthermore, TG2A positivity was not associated with 25(OH)D concentrations (β -2.20; 95% CI -9.72;5.33 for TG2A positive vs. TG2A negative children), and this did not change after adjustment for confounders (β -1.73, 95% CI -8.31;4.85).

CONCLUSIONS

Our findings suggest there is no association between TG2A positivity and suboptimal vitamin D status in the general pediatric population. However, the overall prevalence of vitamin D deficiency in both populations was high, suggesting that screening for vitamin D deficiency among children, regardless of TG2A positivity, would be beneficial to ensure early dietary intervention if needed.

Serum and salivary tissue transglutaminase IGA (tTG-IGA) level in celiac patients

BACKGROUND

Celiac disease (CD) is a genetically determined autoimmune disease triggered by gluten consumption. Patients with these conditions have intraepithelial lymphocytosis, crypt hyperplasia, and severe intestinal atrophy. Gluten elimination is the only way to reduce this chronic inflammation. The diagnosis of CD is usually made by analyzing anti-tTG, anti-DGP, or EMA serological tests, and it is confirmed by biopsy of the duodenum. In people with CD, xerostomia or dry mouth is a common complication. This condition causes the salivary glands to malfunction and, in turn, may result in oral plaque and periodontal disease. By comparing salivary and serum levels of tissue transglutaminase IgA (tTG-IgA), this study aims to suggest a non-invasive method for diagnosis of CD. Furthermore, the present study evaluates the severity of xerostomia symptoms in people with CD.

METHODS

In this case-control study, participants were patients referred to the internal ward of Sayyad Shirazi hospital. The control group was selected from healthy people who attended Gorgan Dental College. In this study, an analysis of serum was performed following consent from patients. This was followed by a salivary test, and the results of both tests were compared. The Xerostomia Inventory questionnaire was also used to determine the severity of xerostomia. As part of this study, examination of factors such as total protein concentration of saliva, albumin concentration, amylase level, pH, sodium, calcium, potassium, phosphorus, and interleukin (6, 18, and 21) were conducted.

RESULTS

A total of 78 people were studied (aged 15 to 68), 26 were male (33.3%) and 52 were female (66.7%). In comparisons of the serum and saliva of people with and without CD, the level of amylase was higher in the latter group. The average levels of IL-6، IL-18 ،IL-21, and salivary and serum tTG were higher in people with CD. Additionally, CD patients were more likely to develop xerostomia.

CONCLUSION

Study findings showed that CD can reduce certain salivary enzymes and elements, as well as increase inflammatory cytokines, salivary, and serum tTG. The management of dry mouth should also be recommended for celiac disease patients in order to prevent its complications.

Investigation of the Factors Affecting Bone Mineral Density in Children with Celiac Disease

PURPOSE

Children with celiac disease (CD) are at an increased risk of low bone mineral density (BMD) owing to malabsorption of fat-soluble vitamins, inflammation, and malnutrition. This study aimed to determine the prevalence and risk factors for low BMD in Iranian children with CD.

METHODS

This prospective cohort study examined 149 Iranian children with CD between 2011 and 2018 at Zabol University of Medical Sciences. BMD was measured using dual-energy X-ray absorptiometry. Demographic, clinical, and laboratory data were collected from patients' medical records. Logistic regression analysis was performed to identify the factors associated with low areal BMD (BMD-Z <-2) in the lumbar spine and femoral neck. Descriptive data were analyzed using the mean, standard deviation, and relative frequency. Data were analyzed using the chi-square test, t-test, and analysis of variance.

RESULTS

Of the 149 children with CD, 27.5% had osteoporosis. The mean body mass index (BMI) Z score was -1.28±1.2. Lower BMI was associated with a higher likelihood of BMD-Z (odds ratio 2.17; p≤0.05).

CONCLUSION

Overall, the findings of this study showed that there was no correlation among Marsh classification, presence of specific human leukocyte antigens, and low BMD in Iranian children with CD. BMI can be a predictor of bone density in children with CD and may be applied clinically in early screenings to evaluate the bone health status in these children.

Follow-up practices for children and adolescents with celiac disease: results of an international survey

Adequate follow-up in celiac disease is important to improve dietary compliance and treat disease-related symptoms and possible complications. However, data on the follow-up of celiac children is scarce. We aimed to assess current pediatric celiac follow-up practices across Europe. Pediatricians and pediatric gastroenterologists from 35 countries in Europe, Israel, Turkey, and Russia completed an anonymous survey which comprised a 52-item questionnaire developed by the ESPGHAN Special Interest Group on Celiac Disease. A total of 911 physicians, the majority of whom exclusively worked in pediatric care (83%) and academic institutions (60%), completed the questionnaire. Mean age and mean experience with celiac care were 48.7 years (± 10.6) and 15.7 years (± 9.9), respectively. The vast majority (≥ 92%) always assessed anthropometry, dietary adherence, and tissue-transglutaminase IgA-antibodies at every visit, with the first visit being between 3 and 6 months after diagnosis. Other parameters (% always tested) were as follows: complete blood count (60%), iron status (48%), liver enzymes (42%), thyroid function (38%), and vitamin D (26%). Quality of life was never assessed by 35% of the responding physicians. Transition to adult care was mostly completed via a written transition report (37%) or no formal transition at all (27%).Conclusions: Follow-up of celiac children and adolescents in Europe may be improved, especially regarding a more rational use of (laboratory) tests, dietary and QoL assessment, and transition to adult care. Evidence-based advice from international scientific societies is needed. What is Known: • Follow-up in celiac disease is important to treat disease-related symptoms, improve dietary compliance, and prevent possible complications. • There is a lack of consensus about the appropriate follow-up. What is New: • Almost all European physicians assess anthropometry, tissue-transglutaminase IgA-antibodies, and dietary adherence at every visit, but there are large variations in other follow-up aspects. • Follow-up could be improved by a more rational use of (laboratory) tests, increased intention to dietary compliance, and quality of life together with transition programs to adult care.

Vitamin D deficiency negatively affects both the intestinal epithelial integrity and bone metabolism in children with Celiac disease

BACKGROUND AND AIM

We aim to evaluate serum vitamin D levels, vitamin D receptor (VDR) expression in the intestinal epithelium, and their relation with epithelial barrier proteins and bone metabolism in children with Celiac disease (CD).

METHODS

Immunostaining for VDR, Claudin-2 and E-cadherin was performed in duodenal samples of the patients with CD and controls. H-score [∑Pi(I+1)] where I is the intensity score and Pi is the corresponding percentage of stained cells was calculated for each samples. The clinic, laboratory and histopathological findings were compared between patients and controls.

RESULTS

Thirty-six patients with CD and age and sex matched 36 controls were enrolled. 25-OH vitamin D levels were significantly lower in the patient group compared to the control group. The mean bone mineral density (BMD) value was significantly lower in patients with vitamin D deficiency compared to patients with normal vitamin D level. H-scores for both VDR and Claudin-2 were significantly lower in patient group when compared to the control group. H-scores for VDR, Claudin-2 and E-cadherin were significantly lower in patients with vitamin D deficiency compared to patients with normal vitamin D level. There were positive correlations between 25-OH vitamin D level and H-scores for VDR, E-cadherin and Claudin-2 in patient group.

CONCLUSIONS

Our findings showed that vitamin D deficiency is common among children with CD. Expression of VDR and epithelial barrier proteins Claudin-2 and E-cadherin which have important roles in paracellular pathway, was decreased in children with CD in correlation with histological findings of disease severity. Furthermore, deficiency of vitamin D was related to decreased expression of VDR and epithelial barrier proteins E-cadherin and Claudin-2. These findings indicate that paracellular pathway structures responsible for calcium absorption are disturbed in CD which is aggravated by vitamin D deficiency.

S2k guidelines (consensus statement) for diagnosis and therapy of dermatitis herpetiformis initiated by the European Academy of Dermatology and Venereology (EADV)

INTRODUCTION

Dermatitis herpetiformis (DH) is a chronic, pruritic, gluten-induced skin disorder characterized by subepidermal granular IgA deposition and a variable degree of enteropathy identical to that seen in coeliac disease. So far, there has been no European consensus about the management of DH.

METHODS

The guidelines were created by small subgroups of a guideline committee consisting of 26 specialists from various medical fields and one patients' representative. The members of the committee then discussed the guidelines and voted for the final version at two consensus meetings. The guidelines were developed under the support of the European Academy of Dermatology and Venereology (EADV) and in collaboration with the European Dermatology Forum (EDF).

RESULTS

The guidelines summarize evidence-based and expert-based recommendations (S2 level) for the management of DH (see Appendix).

CONCLUSION

These guidelines will improve the quality of management of DH and support dermatologists in their diagnostic and therapeutic decisions.

Significant improvement in bone mineral density in pediatric celiac disease: even at six months with gluten-free diet

OBJECTIVES

Patients with celiac disease had significantly decreased bone mineral density even in patients with no gastrointestinal symptoms. Only few bone studies are available on pediatric patients with celiac disease.

METHODS

Forty-six patients underwent measurement of areal bone mineral density (aBMD) by dual-energy X-ray absorptiometry (DXA) before the initiation of gluten-free diet. Anthropometric, laboratory and DXA measurements at baseline and at sixth month of the treatment were compared.

RESULTS

The frequency of low aBMD Z-score (≤-1 SDS) in both or any site was found to be 78.2% in this study. Of 16 patients with an aBMD Z-score of <-2 SDS five gained more than 1 SDS, and one gained more than 2 SDS. Nine of 20 patients with an aBMD Z-score of <-1 SDS completely normalized.

CONCLUSIONS

The results of the study showed that low BMD is common in children with celiac disease at the time of diagnosis and could improve in a short period of six months with a strict gluten-free diet and adequate supplementation of calcium and vitamin D.

The Prevalence of Anti-Zein Antibodies: A Comparative Study between Celiac Disease and Irritable Bowel Syndrome

Celiac disease (CD) is a chronic immune-mediated enteropathy triggered by exposure to dietary gluten in genetically predisposed individuals. In contrast, irritable bowel syndrome (IBS) is a common functional gastrointestinal disorder affecting the large intestine, without an autoimmune component. Here, we evaluated the prevalence of IgA and IgG antibodies to maize zeins (AZA) in patients with CD and IBS. Using an in-house ELISA assay, the IgA and IgG anti-zein antibodies in the serum of 37 newly diagnosed CD (16 biopsy proved and 21 serological diagnosis) and 375 IBS patients or 302 healthy control (HC) subjects were measured. Elevated levels of IgA AZA were found in CD patients compared with IBS patients (p < 0.01) and HC (p < 0.05). CD patients had the highest prevalence (35.1%), followed by IBS (4.3%) and HCs (2.3%) (p < 0.0001). IgG AZA antibodies were not found in any CD patients, IBS patients, or HC subjects. A significant positive correlation was found between IgA AZA with IgA anti-gliadin (AGA, r = 0.34, p < 0.01) and IgA anti-deaminated gliadin peptides (DGP, r = 0.42, p < 0.001) in the celiac disease group. Taken together, our results show for the first time a higher prevalence of AZA IgA antibodies in newly diagnosed CD patients than in IBS patients, confirming a biased immune response to other gliadin-related prolamins such as maize zeins in genetically susceptible individuals.

Association between Elevated TGA-IgA Titers and Older Age at Diagnosis with Absence of HBV Seroconversion in Celiac Children

Patients with celiac disease can have a low rate of protective hepatitis B (HBV) antibody titers after vaccination. We aimed to evaluate the HBV seroconversion in celiac disease (CD) children at the time of diagnosis as well as to identify the presence of possible predictive factors. Celiac disease children were prospectively enrolled and tested for antibodies against the S protein of HBV (HBsAg) at time of diagnosis between January 2009 and February 2020. Based on the serologic response to the vaccine, “responders” and “non-responders” were identified. Statistical analysis has been performed through R statistical software (3.5.1 version, R core Team) Of 96 CD children evaluated, 41.7% (n = 40) showed non-protective or absent antibody titers against HBV. Elevated IgA-antibodies against transglutaminase 2 (TGA-IgA) values and older age at diagnosis were associated with an absent seroconversion to HBV vaccine, while presenting symptoms were not significant. An elevated prevalence of absent seroconversion to HBV vaccine exists in this cohort of CD patients at the time of disease diagnosis. Elevated TGA-IgA titers and older age at diagnosis seem to negatively predict seroconversion. Further studies are needed to identify the real profile of “non-responders”, aiming to organize surveillance and eventual revaccination strategy.

Seroprevalence of Antitransglutaminase and Antiendomysium Antibodies in Adult Colombian Blood Bank Donors

Celiac disease (CD) is an autoimmune enteropathy induced by the ingestion of gluten from wheat, barley, and rye in genetically susceptible individuals. The global prevalence of CD is 1.4%. However, most of the prevalence studies have been conducted in Caucasian populations; few studies have been performed in Latin America. The aim of this study is to determine the seroprevalence of auto-antibodies used as markers for CD in a Colombian cohort. In this cross-sectional study, the serum samples from Colombian donors of the National Red Cross Blood Bank were collected between June and September 2017 in Bogotá, Colombia. All sera were tested for IgA antitissue transglutaminase (TTG) by enzyme-linked immunosorbent assay. Seropositive sera were tested for IgA antiendomysium (EMA) using indirect immunofluorescence assay. The ancestral genetic composition was determined in donor samples with antibody assay reactivity. Those with two seroreactive assays were typed for HLA class II DQ2 and DQ8. In total, 228 blood donors participated in the study. Among them, 113 were females (49.56%) with an average age of 31.63 years (SD ± 12.99); males had an average of 34.71 years (SD ± 13.01). Only 3 (1.31%) donors reported chronic diarrhea and nonintentional weight loss; 11 (4.82%) had a family history of CD. For the serological assays, 11 donors (4.82%) were seroreactive to IgA anti-TTG: 3 had high reactivity and 8 had low reactivity. Of those seroreactive to IgA anti-TTG, 3 (1.32%) were also seroreactive to anti-EMA, and they were typed as HLA-DQ8 or HLA-DQ2. The baseline ancestral percentage of the seroreactive donors was higher for European and Native American than for African genes. The seroprevalence for anti-TTG and anti-EMA with the presence of HLA-DQ8 and HLA-DQ2 was 1.32%. Additionally, 4.82% donor participants were reactive only for anti-TTG. Compared with other studies, our findings suggest that Colombia has a high prevalence of CD markers.

Causes of low peak bone mass in women

Peak bone mass is the maximum bone mass that accrues during growth and development. Consolidation of peak bone mass normally occurs during early adulthood. Low peak bone mass results from failure to achieve peak bone mass genetic potential, primarily due to bone loss caused by a variety of conditions or processes occurring at younger ages than usual. Recognized causes of low peak bone mass include genetic causes, endocrine disorders, nutritional disorders, chronic diseases of childhood or adolescence, medications, and idiopathic factors.

Reduced Bone Mineral Density in Children With Screening-detected Celiac Disease

OBJECTIVES

The aim of the study was to assess whether bone mass and metabolism are impaired in genetically at-risk children with screening-detected celiac disease.

METHODS

Included were 71 children with screening-detected celiac disease diagnosed at 10.0 ± 0.7 (mean ± standard deviation) years and 142 matched controls and 30 children with screening-detected celiac disease diagnosed at 3.3 ± 0.4 years of age presently on a gluten-free diet for 6.9 ± 1.1 years and 60 matched controls. All participants were assessed for bone mineral density (BMD) of total body and spine by dual x-ray absorptiometry, serum 25(OH) vitamin D3, parathyroid hormone (PTH), interleukin (IL)-1β, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12p70, IL-13, IL-15, interferon gamma, and tumor necrosis factor alpha.

RESULTS

At diagnosis, screening-detected celiac disease children as compared to controls had a mean -0.03 g/cm reduced BMD of both total body and spine (P = 0.009 and P = 0.005, respectively), a mean -11.4 nmol/L lower level of 25(OH) vitamin D3 (P < 0.001), and a mean +1.0 pmol/L higher PTH level (P < 0.001). Systemic levels of the cytokines IL-1β, IL-6, IL-8, IL-10, IL-12p70, IL-13, and tumor necrosis factor alpha were all increased in screening-detected celiac disease as compared to controls (P < 0.001). No difference in BMD, 25(OH) vitamin D3, PTH, and cytokine levels were detected in children on a gluten-free diet compared with controls.

CONCLUSIONS

Children with screening-detected celiac disease have reduced BMD, lower levels of vitamin D3, higher levels of PTH, and signs of systemic inflammation compared with controls. These differences were not found in celiac disease children on a gluten-free diet, indicating that children with screening-detected celiac disease benefit from an early diagnosis and treatment.

Pediatric Celiac Disease: Follow-Up in the Spotlight

The follow-up of celiac disease (CD) is challenging due to the scarcity of published data and the lack of standardized evidence-based protocols. The worldwide frequency and methods of CD follow-up appear to be heavily influenced by expert opinions of the individual physicians who assess children with CD. The aim of this review was to summarize the available studies on CD follow-up in children. We conducted a literature search with the use of PubMed, Medline, and Embase (from 1900 to 15 December 2016) for terms relevant to this review, including CD, follow-up, dietary adherence or dietary compliance, nutrition, comorbidities, complications, and quality of life. The aims of follow-up are as follows: to ensure strict adherence to a gluten-free diet, to ensure nutritional adequacy, to improve quality of life, and to prevent disease complications. For the correct evaluation of children with CD at follow-up, a clinical and biochemical evaluation is necessary on a regular basis. It is advisable to assess compliance, nutrition, comorbidities, or possible complications once a year at the referral center. Laboratory tests might be useful for a thorough evaluation of any patient with CD to rule out a micronutrient deficiency (full blood count, ferritin, folic acid, vitamin B-6, and vitamin B-12) and possible cardiovascular risk factors (glucose, LDL cholesterol, triglycerides). Biochemical evaluation is essential when there are clinical problems and should be customized on the basis of the specific clinical suspicion. Associated autoimmune thyroiditis should also be screened for yearly by measuring thyroid-stimulating hormone and thyroid autoantibody concentrations, regardless of symptoms, because hypothyroidism is often subtle and methods for early treatment are available and desirable. Although evidence-based recommendations for follow-up of pediatric patients with CD have not yet been established, we advise a yearly follow-up visit as the safest approach.

Update on Bone Health in Pediatric Chronic Disease

Children and adolescents with chronic disease are predisposed to impaired bone health. Pediatric illness, including type 1 diabetes mellitus, celiac disease, and cystic fibrosis, have significant risk of low bone mineralization and fracture due to underlying inflammation, malabsorption, lack of physical activity, and delayed puberty. Dual-energy x-ray absorptiometry is the primary imaging method to assess bone health in this population. The purpose of this review is to update readers about the assessment and management of bone health in children with common pediatric chronic illnesses and review recent advances in the prevention and treatment of impaired bone health.

Repeated Screening Can Be Restricted to At-Genetic-Risk Birth Cohorts

OBJECTIVES

Celiac disease (CD) is associated with tissue transglutaminase autoantibodies (tTGAs) in individuals carrying the human leukocyte antigen (HLA) risk haplotypes DQA1*05:01-DQB1*02:01 (DQ2) and/or DQA1*03:01-DQB1*03:02 (DQ8). The aim of the study was to identify CD in an HLA-genotyped birth cohort prospectively screened for CD.

METHODS

In the initial screening, 13,860 HLA-DQ-genotyped children were invited, of whom 3435/13,860 (25%) accepted participation. Of the 3435, 1620 (47%) carried DQ2 and/or DQ8, of whom 73 (4.5%) were tTGA positive assessed in radioligand-binding assays and 56 (3.5%) developed CD. At age 9 years, 13,024 children from the original cohort were re-invited to follow-up screening using the same study protocol and tTGA assays as in the first screening. Diagnosis of CD was confirmed by intestinal biopsy in children with persistent tTGA.

RESULTS

In the follow-up screening, 1910/4077 (46.8%) carried DQ2 and/or DQ8, of whom 79/1910 (4.1%) were persistently tTGA positive and 72/1907 (3.8%) developed CD. Only 1/2167 (0.05%) child without HLA risk was IgG-tTGA positive, but did not have CD. Of the 980/1910 (51%) children carrying DQ2 and/or DQ8 who were already screened at 3 years of age, 30/979 (3.1%) were diagnosed as new patients at 9 years of age, compared with 42/928 (4.5%) children who did not participate in the initial screening (P = 0.094).

CONCLUSIONS

Screening for CD can be restricted to children carrying HLA-DQ2 and/or DQ8. Repeated screening using tTGA is necessary to identify new patients by 9 years of age. These findings may be relevant when considering implementing screening of the general population.

Reduced Bone Mineral Density Is Associated with Celiac Disease Autoimmunity in Children with Type 1 Diabetes

OBJECTIVE

To evaluate the association between bone mineral density (BMD), glycemic control (hemoglobin A1c [HbA1c]), and celiac autoimmunity in children with type 1 diabetes mellitus (T1D) and in an appropriate control population.

STUDY DESIGN

BMD was assessed cross-sectionally in 252 children with T1D (123 positive for anti-tissue transglutaminase antibody [tTGA] and 129 matched children who were negative for tTGA). In addition, BMD was assessed in 141 children without diabetes who carried T1D-associated HLD-DR, DQ genotypes (71 positive for tTGA and 70 negative).

RESULTS

Children with T1D who were positive for tTGA had significantly worse BMD L1-L4 z-score compared with children with T1D who were negative for tTGA (-0.45 ± 1.22 vs 0.09 ± 1.10, P = .0003). No differences in growth measures, urine N-telopeptides, 25-hydroxyvitamin D, ferritin, thyroid stimulating hormone, or HbA1c were found. However, both higher HbA1c (β = -1.25 ± 0.85, P = .0016) and tTGA (β = -0.13 ± 0.05, P = .0056) were significant and independent predictors of lower BMD in multivariate analyses. No differences in BMD or other variables measured were found between children without diabetes who were positive vs negative for tTGA.

CONCLUSIONS

The results suggest a synergistic effect of hyperglycemia and celiac autoimmunity on low BMD.

Lower Limb Metaphyseal Bone Is Lost in Men with Coeliac Disease and Does Not Relate to Parathyroid Status

Aims. To investigate regional lower limb bone density and associations with weight, PTH, and bone breakdown in coeliac men. Methods. From whole body DXA scans bone mineral density (BMD) was measured in 28 coeliac men, in the lower limb (subdivided into 6 regions, 3 being metaphyseal (mainly trabecular) and 2 diaphyseal (mainly cortical)). BMD at femoral neck (FN) and lumbar spine L2-4, body weight, height, serum calcium, alkaline phosphatase, parathyroid hormone (PTH), and urinary calcium and NTx/Cr, a measure of bone breakdown, were also measured. Age matched healthy men provided values for BMD calculation of z and T scores and for biochemical measurements. Results. Low BMD z scores were found at metaphyseal regions in the leg (p < 0.001) and in the FN (p < 0.05). The distal metaphyseal region BMD in the leg was lower than spine or FN (p < 0.05). PTH, urinary calcium/creatinine, and urinary NTx/Cr were similar to controls. Both metaphyseal and diaphyseal BMD z scores were associated with body weight (p < 0.02), but not with either PTH or urinary NTx/Cr. Conclusions. Low BMD lower limb regions comprising mostly trabecular bone occur early in CD and in the absence of elevated PTH or increased bone resorption. Low BMD is associated with low body weight.