Review article: Osteoporosis and inflammatory bowel disease

Inflammatory bowel disease and osteoporosis: Common genetic effects, pleiotropy, and causality

INTRODUCTION

Previous studies have shown that inflammatory bowel disease (IBD) is associated with osteoporosis (OP) and bone mineral density (BMD), but the underlying genetic mechanisms are unclear. Our study wanted to explore the genetic and causal relationship between IBD and OP.

MATERIALS AND METHODS

Based on large-scale genome-wide association summary statistics and individual-level datasets (i.e., the UK Biobank), this study performed linkage disequilibrium score regression (LDSC), pleiotropic analysis under the composite null hypothesis (PLACO), and Mendelian randomization (MR) analyses to explore the genetic association, the pleiotropic genes and the causal relationship between IBD and BMD.

RESULTS

LDSC revealed significant genetic correlations between IBD and BMD (e.g., forearm BMD (rg = -0.3479, P = 0.019) and femoral neck BMD (rg = -0.1335, P = 0.0307). PLACO identified 14 overlapping pleiotropic loci, 1 shared risk gene (CDYL), and multiple shared pathways, revealing possible mechanisms for IBD and OP. MR analysis demonstrated a causal association between IBD and BMD.

CONCLUSIONS

Our study indicates that IBD may increase the risk of OP and reveals a complex genetic mechanism linking IBD and the risk of osteoporosis, which has important implications for diagnosing and treating IBD and OP.

The Role of Vitamin D in Patients with Inflammatory Bowel Disease Treated with Vedolizumab

BACKGROUND

Many clinical factors can contribute to the efficacy of medical therapy in Inflammatory Bowel Disease (IBD). We assessed their effects on the efficacy of vedolizumab therapy in a cohort of patients with IBD.

METHODS

We conducted a retrospective study on patients between 18 and 80 years of age with ulcerative colitis (UC) or Crohn's disease (CD) who were seen in the IBD program at Houston Methodist in Houston, TX and treated with vedolizumab for at least 6 months from 2018 to 2022. We investigated factors prior to the initiation of therapy that best predicted treatment response, with an emphasis on vitamin D levels and examined several variables including patients' demographics and clinical information on disease location and severity and nutritional status before and after the initiation of vedolizumab. Post-treatment data were gathered after a minimum of 6 months of vedolizumab therapy. The clinical parameters used for the study were the Harvey-Bradshaw Index for CD and the Activity Index for UC.

RESULTS

There were 88 patients included in our study of whom 44 had CD and 44 had UC.; median age was 39.5 (31.0, 53.25) years; 34% patients were male; and 80.7% were Caucasian. All patients received an induction dosing of 300 mg vedolizumab at 0, 2, and 6 weeks then maintenance dosing as standard of care every 8 weeks. Among UC patients with vitamin D ≥ 30 ng/mL at the initiation of vedolizumab therapy, UC Endoscopic Index of Severity (UCEIS) scores after 6 months of therapy were significantly lower than in those who had low pre-treatment vitamin D levels (1.5 vs. 3.87, p = 0.037). After treatment, vitamin D levels improved more significantly in the higher pre-treatment vitamin D group, with a median level of 56 ng/mL, than in the lower pre-treatment vitamin D group, with a median level of only 31 ng/mL (p = 0.007). In patients with CD with vitamin D ≥ 30 ng/mL at the initiation of vedolizumab therapy, we found higher iron saturation (12 vs. 25%, p = 0.008) and higher vitamin B12 levels (433.5 vs. 885 pg/mL, p = 0.003) than in those with vitamin D < 30 ng/mL. After treatment, CD patients with high pre-treatment vitamin D levels had significantly higher vedolizumab levels (27.35 vs. 14.35 μg/mL, p = 0.045) than those with low pre-treatment vitamin D. Post-treatment scores and inflammatory markers in CD patients (HBI, CRP, ESR, and SES-CD) were lower in those who had lower baseline vitamin D.

CONCLUSIONS

Our results show higher pre-treatment vitamin D levels predicted significant endoscopic improvement in patients with ulcerative colitis (UC). Improving vitamin D levels lowered C-reactive protein levels significantly in CD patients. Higher vitamin D levels were seen after treatment in both UC and CD patients. Vitamin D can play a role in clinical and endoscopic outcomes and should be assessed routinely and optimized in patients with IBD.

Two-sample Mendelian randomization analysis evaluates causal associations between inflammatory bowel disease and osteoporosis

Introduction

Over the past few years, multiple observational studies have speculated a potential association between inflammatory bowel disease (IBD), which includes ulcerative colitis (UC) and Crohn's disease (CD), and osteoporosis. However, no consensus has been reached regarding their interdependence and pathogenesis. Herein, we sought to further explore the causal associations between them.

Methods

We validated the association between IBD and reduced bone mineral density in humans based on genome-wide association studies (GWAS) data. To investigate the causal relationship between IBD and osteoporosis, we performed a two-sample Mendelian randomization study using training and validation sets. Genetic variation data for IBD, CD, UC, and osteoporosis were derived from published genome-wide association studies in individuals of European ancestry. After a series of robust quality control steps, we included eligible instrumental variables (SNPs) significantly associated with exposure (IBD/CD/UC). We adopted five algorithms, including MR Egger, Weighted median, Inverse variance weighted, Simple mode, and Weighted mode, to infer the causal association between IBD and osteoporosis. In addition, we evaluated the robustness of Mendelian randomization analysis by heterogeneity test, pleiotropy test, leave-one-out sensitivity test, and multivariate Mendelian randomization.

Results

Genetically predicted CD was positively associated with osteoporosis risk, with ORs of 1.060 (95% CIs 1.016, 1.106; p = 0.007) and 1.044 (95% CIs 1.002, 1.088; p = 0.039) for CD in the training and validation sets, respectively. However, Mendelian randomization analysis did not reveal a significant causal relationship between UC and osteoporosis (p > 0.05). Furthermore, we found that overall IBD was associated with osteoporosis prediction, with ORs of 1.050 (95% CIs 0.999, 1.103; p = 0.055) and 1.063 (95% CIs 1.019, 1.109; p = 0.005) in the training and validation sets, respectively.

Conclusion

We demonstrated the causal association between CD and osteoporosis, complementing the framework for genetic variants that predispose to autoimmune disease.

Skeletal status assessed by quantitative ultrasound and dual-energy X-ray absorptiometry in children with inflammatory bowel disease: A 2-year prospective study

PURPOSE

To assess the bone status in children with inflammatory bowel diseases (IBD) using quantitative ultrasound (QUS) measurement and dual-energy X-ray absorptiometry (DXA) at baseline and after two years of adequate treatment of the IBD and bone protection medication.

METHODS

Sixteen children (six boys) with IBD, aged 13.4±2.4 years, were examined at baseline and two years later. DXA was used to asses bone mineral density (BMD) and reference data were provided by the device's manufacturer (Hologic Explorer). QUS measurements were performed in patients and controls - 48 healthy children.

RESULTS

Mean Z-scores for TB- and s-BMD were significantly below zero for both, baseline and follow-up (-2.61±0.99 and -2.48±0.88 for TB, and -1.83±1.33 and -1.61±1.19 for s-BMD, respectively), and did not differ significantly, as well as mean Ad-SoS Z-score. The changes in time of TB Z-score and body weight Z-score correlated positively (r=0.63; P<0.01). The QUS results did not differ between patients and controls. There was a negative correlation between the baseline nutritional status and the activity of the disease, as well as of the number of flares before the enrolment and Ad-SoS Z-score.

CONCLUSIONS

BMD was found to be lowered both at baseline and follow-up. No further deterioration was observed during 2-year follow-up. Proper treatment, defined as treatment following ECCO Guidelines, may allow to keep a similar trend in the development of bone tissue as in healthy children. The bone properties assessed by QUS method did not differ between patients and controls. QUS at hand phalanges appears not to be proper diagnostic tool in IBD children.

Comorbidities in adolescents with inflammatory bowel disease: findings from a population-based cohort study

BACKGROUND

Inflammatory bowel diseases are associated with various immune- and non-immune-mediated conditions. We aimed to assess the association of inflammatory bowel diseases with comorbidities at late adolescence.

METHODS

Jewish Israeli adolescents who underwent a general health evaluation prior to enlistment to the Israeli Defense Forces from 2002 to 2016 were included.

RESULTS

Overall, 891 subjects (595 Crohn's disease, 296 ulcerative colitis, median age 17.1 years) and 1,141,841 controls were analyzed. Crohn's disease was associated with arthritis (odds ratio (OR) 4.7, 95% confidence interval (CI) 2.4-9.1), thyroid disease (OR 2.6, 95% CI 1.2-5.5), atopic dermatitis (OR 2, 95% CI 1.1-3.6), autoimmune hepatitis (OR 4.4, 95% CI 2.3-8.6), nephrolithiasis (OR 3.6, 95% CI 1.2-11.4), and pancreatitis (OR 41.8, 95% CI 17.2-101.9). Ulcerative colitis was associated with arthritis (OR 3.6, 95% CI 1.0-9.8), thyroid disease (OR 4.8, 95% CI 1.2-19.4), autoimmune hepatitis (OR 8, 95% CI 4-16.2), and pancreatitis (OR 51, 95% CI 16.1-158.9). Primary sclerosing cholangitis was associated with both diseases. Asthma, celiac, type 1 diabetes, psoriasis, and bone fractures were not more common in both diseases. Male predominance was noted for most associations.

CONCLUSIONS

At adolescence, both Crohn's disease and ulcerative colitis are associated with multiple comorbidities, not limited to autoimmune disorders.

Bone status assessed by quantitative ultrasound in children with inflammatory bowel disease: a comparison with DXA

BACKGROUND

To determine the bone status in children with inflammatory bowel diseases (IBD) using quantitative ultrasound (QUS) measurement at hand phalanges and compare the obtained results with dual-energy X-ray absorptiometry (DXA).

METHODS

Fifty-one children with IBD underwent DXA and QUS measurements at hand phalanges in the year 2013. The control group for the QUS consisted of 460 children. Reference data for DXA comes from Hologic Explorer.

RESULTS

QUS measurements did not differ significantly between IBD patients and healthy controls. There was no difference between UC and CD subjects. DXA measurements in patients with IBD were lower than in the healthy population. Tanner stage and nutritional status correlated with bone status contrary to steroids therapy.

CONCLUSION

Low bone mineral density often complicates IBD in children. QUS is not an appropriate method for the assessment of bone status in children. Nutritional status seems to have a greater impact on bone status than corticosteroids therapy.

Clinical Course of Bone Metabolism Disorders in Patients with Inflammatory Bowel Disease: A 5-Year Prospective Study

BACKGROUND

The clinical course of bone mineral density (BMD) disorders and the efficacy of treatment of osteopenia and osteoporosis have been poorly studied in patients with inflammatory bowel disease (IBD). The objective was to study the course of BMD disorders in patients with IBD, analyze the factors influencing their development, and assess the effect of treatment with calcium, vitamin D, and bisphosphonates.

METHODS

Consecutive patients with IBD were included and followed up for 5 years. After a baseline densitometry, calcium (1000 mg/d) and vitamin D (800 IU/d) were administered to patients with osteopenia; bisphosphonates to patients with osteoporosis; and patients with normal BMD were only followed-up. After completing the follow-up period, a second densitometry was performed.

RESULTS

One hundred patients were initially included, 60% having a low BMD (44% osteopenia and 16% osteoporosis). Fifty-eight patients completed the follow-up period. At baseline, osteopenia was more frequently found in Crohn's disease than in ulcerative colitis (63% versus 21%, P < 0.05). In patients with normal BMD at baseline, age, smoking habit, and the presence of flares during follow-up were associated with the development of osteopenia. Treatment with calcium and vitamin D improved the hip T-score in patients with osteopenia (-1.03 versus -0.58, P < 0.001) and bisphosphonates provided the same improvement (-1.482 versus -1.072, P < 0.05) in patients with osteoporosis.

CONCLUSIONS

Age, smoking habit, and IBD activity negatively influence the clinical course of BMD. Treatment with calcium and vitamin D improves hip T-score in patients with osteopenia whereas bisphosphonates improve hip T-score in patients with osteoporosis.

Body composition analysis using abdominal scans from routine clinical care in patients with Crohn's Disease

OBJECTIVE

Crohn's Disease is associated with body composition changes, which have important treatment and prognostic implications. Measurement of body composition usually requires dedicated scanning or measurement, with retrospective analysis of existing datasets impossible. We sought to determine whether single slice analysis of abdominal scans, obtained during routine clinical care, in patients with Crohn's Disease accurately predicts body composition compartments.

MATERIALS AND METHODS

Abdominal CT images of patients with Crohn's disease were analyzed and comparison was made with total body fat-free mass, total body fat mass, femoral neck t-score, and other parameters reported from DXA, the reference method.

RESULTS

Thirty-seven subjects were identified, 15 male and 22 female, with a mean age of 43.8 years. There was significant correlation (Pearson r = 0.923, p < 0.001) between skeletal muscle area from CT and total fat-free mass measured by DXA. Similarly, total body fat mass correlated strongly (r = 0.928, p < 0.0001) with subcutaneous fat area. In this cohort of ambulatory Crohn's Disease patients, low muscle mass/sarcopenia was prevalent and predictive of lower bone mineral density.

CONCLUSIONS

Fat mass, fat-free mass, and appendicular skeletal muscle index can be predicted by analysis of a single CT slice in patients with Crohn's Disease. Similar to published data from healthy subjects, the L3 vertebral body level provided the most robust correlation with most parameters. This study represents the first published use of routinely obtained abdominal imaging to demonstrate this relationship - and to predict body composition components - in patients with inflammatory bowel disease.

Infliximab reverses inflammatory muscle wasting (sarcopenia) in Crohn's disease

BACKGROUND

Muscle wasting or sarcopenia arising from chronic inflammation is found in 60% of patients with Crohn's disease. Transcriptional protein NF-κB reduces muscle formation through MyoD transcription and increases muscle breakdown by proteolysis.

AIM

As TNF is a potent activator of NF-κB, and anti-TNF agent infliximab (IFX) prevents NF-κB activation, to determine whether or not Crohn's patients treated with IFX gain muscle volume and strength.

METHODS

We performed a prospective, repeated-measures cohort study in adult Crohn's disease patients with an acute disease flare. Patients were instructed not to vary diet or activity. Concomitant medications were kept stable. At week 1 (pre-treatment), week 16 (post-IFX induction) and week 25 (post-first IFX maintenance dose), we assessed (i) MRI volume of quadriceps femoris at anatomical mid-thigh; (ii) maximal concentric quadriceps contractions strength at three specific speeds of contraction; (iii) physical activity by validated instrument (IPAQ); (iv) Three-day food record of intake and composition (food-weighing method); (v) Serum levels of IL6.

RESULTS

Nineteen patients (58% female; mean age 33.2 ± 10.7 years) were recruited. IFX increased muscle volume in both legs from baseline (right, 1505 cm(3) ) to week 25 (right, 1569 cm(3) ; P = 0.010). IFX also increased muscle strength in both legs from baseline (right 30°/s, 184.8 Nm) to week 25 (right 30°/s, 213.6 Nm; P = 0.002). Muscle volume gain correlated with male gender (P = 0.003). Significant gains in muscle volume and strength were unrelated to prednisolone use. Serum IL6 levels decreased by week 25 (P = 0.037).

CONCLUSION

The anti-TNF agent infliximab reverses inflammatory sarcopenia in patients with Crohn's disease.

Vitamin D as a novel therapy in inflammatory bowel disease: new hope or false dawn?

There is increasing scientific interest in the field of vitamin D research, moving the focus beyond bone health to other disease processes. Low circulating vitamin D levels have been reported as a risk factor for several pathophysiologically divergent diseases, including cancers, diabetes, CVD, multiple sclerosis and inflammatory diseases, including rheumatoid arthritis and inflammatory bowel disease (IBD). But, therein, remains the challenge: can any single nutrient contribute to multiple complex disease mechanisms and, ultimately, have therapeutic potential? The aim of this review is to critically evaluate several strands of scientific evidence surrounding vitamin D and inflammation, primarily focusing on IBD. Epidemiological studies suggest an increased incidence of IBD and rheumatoid arthritis in countries of more northern latitudes, mirroring sunlight patterns. A considerable body of evidence supports the anti-inflammatory effects of vitamin D, at least in animal models of IBD. Although it is accepted that suboptimal vitamin D status is common in IBD, some studies suggest that this associates with more severe disease. With regard to treatment, the data are only beginning to emerge from randomised controlled trials to suggest that people with IBD may remain in remission longer when treated with oral vitamin D. In conclusion, several strands of evidence suggest that vitamin D may modify the immune response in IBD. There is a continued need for large well-designed clinical trials and mechanistic studies to determine if, and how, this emerging promise translates into tangible clinical benefits for people with chronic debilitating diseases such as IBD.

The role of vitamin D in gastrointestinal inflammation

The emerging role of vitamin D as a regulator of both innate and adaptive immune responses has encouraged the investigation of its role in the pathogenesis of a variety of autoimmune conditions including the inflammatory bowel diseases (IBD), Crohn's disease and ulcerative colitis. Animal models consistently demonstrate that vitamin D significantly impacts on the modulation of astrointestinal inflammation, while epidemiological and observational data show an inverse relationship between vitamin D status and the onset/progression of Crohn's disease as well as the development of colorectal cancer. As vitamin D supplementation is readily available, at low cost, it is a very attractive potential therapeutic option. The biological plausibility for a role for vitamin D in inflammation modulation, the potential genetic links associated with vitamin D metabolism and the clinical aspects for it in IBD will be discussed.

Effect of phylloquinone (vitamin K1) supplementation for 12 months on the indices of vitamin K status and bone health in adult patients with Crohn's disease

Although epidemiological findings support a role for vitamin K status in the improvement of bone indices in adult patients with Crohn's disease (CD), this needs to be confirmed in double-blind, randomised controlled trials (RCT) with phylloquinone (vitamin K1). By conducting two RCT, the present study aimed to first establish whether supplementation with 1000 μg of phylloquinone daily near-maximally suppresses the percentage of undercarboxylated osteocalcin in serum (%ucOC; marker of vitamin K status) in adult patients with CD currently in remission as it does in healthy adults and second determine the effect of supplementation with phylloquinone at this dose for 12 months on the indices of bone turnover and bone mass. The initial dose-ranging RCT was conducted in adult patients with CD (n 10 per group) using 0 (placebo), 1000 or 2000 μg of phylloquinone daily for 2 weeks. In the main RCT, the effect of placebo v. 1000 μg vitamin K/d (both co-administered with Ca (500 mg/d) and vitamin D3 (10 μg/d)) for 12 months (n 43 per group) on the biochemical indices of bone turnover (determined by enzyme immunoassay) and bone mass (determined by dual-energy X-ray absorptiometry) were investigated. At baseline, the mean %ucOC was 47 %, and this was suppressed upon supplementation with 1000 μg of phylloquinone daily ( - 81 %; P< 0·01) and not suppressed further by 2000 μg of phylloquinone daily. Compared with the placebo, supplementation with 1000 μg of phylloquinone daily for 12 months had no significant effect (P>0·1) on bone turnover markers or on the bone mass of the lumbar spine or femur, but modestly increased (P< 0·05) the bone mass of the total radius. Despite near maximal suppression of serum %ucOC, supplementation with 1000 μg of phylloquinone daily (with Ca and vitamin D3) had no effect on the indices of bone health in adult CD patients with likely vitamin K insufficiency.

Risk factors and management of osteoporosis in inflammatory bowel disease

PURPOSE OF REVIEW

To provide a synopsis on established and new research evaluating bone disease in patients with inflammatory bowel disease (IBD).

RECENT FINDINGS

Persons with IBD, including Crohn's disease and ulcerative colitis are believed to be at high risk for osteoporosis and fracture. As osteoporosis is clinically silent and persons with IBD are not universally screened, the burden of bone disease in IBD has been difficult to accurately assess. It is also unclear whether bone disease is due to inflammatory activity, medication use, poor nutrient intake/absorption, or body habitus characteristics. Recent studies using population-wide databases of bone mineral density (BMD) analyses suggest that Crohn's disease is responsible for a small effect on BMD after adjusting for other risk factors for low BMD, whereas ulcerative colitis does not appear to confer an independent risk. Furthermore, IBD does not appear to be a risk for overall fracture once controlling for factors which are associated with both IBD and fracture risk. The ability to assess BMD on incidentally performed computed tomography scans may allow detection of low BMD in IBD patients.

SUMMARY

Although reduced BMD and fracture are more common in persons with IBD, the precise burden is not well characterized. Also, the relative impact of IBD-associated factors and IBD-specific inflammation on bone health is still uncertain.

The P2X7 receptor: a key player in immune-mediated bone loss?

Inflammatory diseases are often multiorganic diseases with manifestations not related directly to the primary affected organ. They are often complicated by a generalized bone loss that subsequently leads to osteoporosis and bone fractures. The exact mechanism for the accompanying bone loss is not understood in full detail, but factors such as glucocorticoid treatment, immobilization, malnutrition, and insufficient intake of vitamin D play a role. However, it has become evident that the inflammatory process itself is involved and the resulting bone loss is termed immune-mediated bone loss. It stems from an increase in bone resorption and the pro-inflammatory cytokines tumor necrosis factor alpha and interleukin 1 beta and has been shown to not only mediate the inflammatory response but also to strongly stimulate bone degradation. The purinergic P2X7 receptor is central in the processing of these two cytokines and in the initiation of the inflammatory response, and it is a key molecule in the regulation of both bone formation and bone resorption. The aim of this review is therefore to provide evidence-based novel hypotheses of the role of ATP-mediated purinergic signalling via the P2X7 receptor in immune-mediated bone loss and -osteoporosis.

Review article: vitamin D and inflammatory bowel diseases

BACKGROUND

Vitamin D is traditionally associated with bone metabolism. The immunological effects of vitamin D have increasingly come into focus.

AIM

To review the evidence supporting a role of vitamin D in inflammatory bowel diseases.

METHODS

A comprehensive search was performed on PubMed using the terms 'crohn's disease' 'ulcerative colitis' and 'vitamin D'.

RESULTS

Vitamin D deficiency is common in patients with inflammatory bowel diseases (IBD) (16-95%) including those with recently diagnosed disease. Evidence supports immunological role of vitamin D in IBD. In animal models, deficiency of vitamin D increases susceptibility to dextran sodium sulphate colitis, while 1,25(OH)2 D3 ameliorates such colitis. One prospective cohort study found low predicted vitamin D levels to be associated with an increased risk of Crohn's disease (CD). Limited data also suggest an association between low vitamin D levels and increased disease activity, particularly in CD. In a large cohort, vitamin D deficiency (<20 ng/mL) was associated with increased risk of surgery (OR 1.8, 95% CI 1.2-2.5) in CD and hospitalisations in both CD (OR 2.1, 95% CI 1.6-2.7) and UC (OR 2.3, 95% CI 1.7-3.1). A single randomised controlled trial demonstrated that vitamin D supplementation may be associated with reduced frequency of relapses in patients with CD compared with placebo (13% vs. 29%, P = 0.06).

CONCLUSIONS

There is growing epidemiological evidence to suggest a role for vitamin D deficiency in the development of IBD and also its influence on disease severity. The possible therapeutic role of vitamin D in patients with IBD merits continued investigation.

Health care for osteoporosis in inflammatory bowel disease: unmet needs in care of male patients?

BACKGROUND AND AIMS

Osteoporosis is a frequent complication of inflammatory bowel disease (IBD). It may be related to IBD itself or to its therapy. In this study, the quality of care regarding diagnosis and treatment of osteoporosis was examined.

METHODS

In this retrospective, monocentric study 293 consecutive patients with IBD (98 ulcerative colitis, 195 Crohn's disease) were included. Information on age, gender, weight, nicotine abuse, course, disease pattern and medication was assessed, results of dual X-ray absorptiometry (DEXA-scan) were evaluated.

RESULTS

DEXA-scan was performed in 174 patients (59 male, 115 female). Bone mineral density (BMD) was impaired in 38.5% of these patients. Male patients were diagnosed more often with osteopenia or osteoporosis than females (55.9% vs. 29.6%, p=0.03) and had a risk of bone disease comparable to postmenopausal women. Additionally, duration of corticosteroid treatment and IBD were identified as risk factors for osteoporosis. Follow up DEXA-scan demonstrated an overall deterioration of BMD in patients with normal baseline results.

CONCLUSIONS

While in general, women are considered at higher risk for osteoporosis, male patients had a higher risk of impaired BMD, especially when under treatment with corticosteroids. The high incidence of reduced BMD supports the recommendation to screen patients with IBD at an early stage of disease, although a possible bias has to be considered for patients at a tertial referral centre for IBD. Patients with normal baseline DEXA-scan were still at risk to develop bone disease and it seems advisable to monitor patients with IBD for reduced BMD continually.

Inflammatory bowel disease and the risk of osteoporosis and fracture

Inflammatory bowel disease (IBD) is commonly believed to increase the risk of bone mineral loss, leading to osteoporosis and an increased risk of disabling fractures. In this narrative review, we will presenting a summary of the published medical literature in regards to the relationship between IBD and the development of osteoporosis, bone mineral loss, and fractures. We will explore the epidemiology of metabolic bone disease in IBD, focusing on the prevalence and both the general and IBD-specific risk factors for the development of osteoporosis and of fracture in persons with IBD. We will also examine the role of the inflammatory process in IBD promoting excessive bone mineral loss, as well as the role that low body mass, corticosteroid use, diet, and nutrient malabsorption play in contributing to bone disease. Last, we will discuss our recommendation for: screening for osteoporosis in IBD patients, the use of preventative strategies, and therapeutic interventions for treating osteoporosis in persons with IBD.

C-reactive protein, bone strength, and nine-year fracture risk: data from the Study of Women's Health Across the Nation (SWAN)

Higher levels of C-reactive protein (CRP), an inflammatory marker, are associated with increased fracture risk, although previous studies on CRP and bone mineral density (BMD) have yielded conflicting results. We aimed to test the hypotheses that composite indices of femoral neck strength relative to load, which are inversely associated with fracture risk, would also be inversely associated with CRP, and would explain part of the association between CRP and fracture risk. We analyzed data from a multisite, multiethnic prospective cohort of 1872 community-dwelling women, premenopausal or early perimenopausal at baseline. Femoral neck composite strength indices in three failure modes were calculated using dual-energy X-ray absorptiometry (DXA)-derived femoral neck width (FNW), femoral neck axis length (FNAL), femoral neck BMD and body size at baseline, as BMD*FNW/weight for compression strength, BMD*(FNW)(2) /(FNAL*weight) for bending strength, and BMD*FNW*FNAL/(height*weight) for impact strength. Incident nondigital, noncraniofacial fractures were ascertained annually over a median follow-up of 9 years. In analyses adjusted for age, race/ethnicity, diabetes, menopause transition stage, body mass index, smoking, alcohol use, physical activity, medications, prior fracture, and study site, CRP was associated inversely with each composite strength index (0.035-0.041 SD decrement per doubling of CRP, all p < 0.001), but not associated with femoral neck or lumbar spine BMD. During the follow-up, 194 women (10.4%) had fractures. In Cox proportional hazards analyses, fracture hazard increased linearly with loge (CRP), only for CRP levels ≥ 3 mg/L. Addition of femoral neck or lumbar spine BMD to the model did not attenuate the CRP-fracture association. However, addition of any of the composite strength indices attenuated the CRP-fracture association and made it statistically nonsignificant. We conclude that fracture risk increases with increasing CRP, only above the threshold of 3 mg/L. Unlike BMD, composite strength indices are inversely related to CRP levels, and partially explain the increased fracture risk associated with inflammation.

Increase in bone mineral density in strictly treated Crohn's disease patients with concomitant calcium and vitamin D supplementation

BACKGROUND AND AIMS

Decreased bone mineral density (BMD) is common in Crohn's disease (CD) patients. This paper reports on the prevalence of decreased BMD in a referral cohort study of CD-patients next to the change of BMD over time in relation with CD-associated clinical characteristics.

METHODS

205 CD patients of a referral hospital were enrolled between January1998-January 2010 when measurement of BMD by dual X-ray absorptiometry (DXA) was available. Follow-up DXA scan was performed in subjects with known risk factors besides Crohn indicative for low BMD. Treatment of CD patients was according to a protocol which is comparable to the current (inter)national guidelines. In osteopenic patients, supplemental vitamin D (800 IU) and Calcium (500-1000 mg) were prescribed.

RESULTS

Mean BMD at baseline was 0.97 ± 0.16 gram/cm(2) in lumbar spine and 0.87 ± 0.12 gram/cm(2) in the total hip. At baseline, higher age and low Body Mass Index (BMI), were negatively correlated with BMD. Eighty-four patients underwent a second BMD assessment with a median interval period of 4 years (IQR 3-6). A mean annual increase of +0.76% (95%CI: -2.63%; +3.87%) in lumbar spine and +0.43% (95%CI: -2.65% ; +1.11%) in total hip was observed.

CONCLUSIONS

Higher age, male sex, low BMI, and a higher age at diagnosis of CD were associated with low BMD. Follow-up of BMD in CD patients showed a contraintuitive small increase of BMD at lumbar spine and total hip in CD patients only using supplemental vitamin D and calcium next to strict treatment of CD.

Is the quality of drinking water a risk factor for self-reported forearm fractures? Cohort of Norway

SUMMARY

Compared to pH ≥7.0 in Norwegian municipal drinking water, pH <7.0 increased the risk of forearm fractures in the population-based Cohort of Norway (CONOR; n = 127,272). The association was attenuated (p > 0.05) after adjustments for indicators of bacteria and organic matter, which may signify an association between poor drinking water and bone health.

INTRODUCTION

The Norwegian population has the highest rate of fractures ever reported. A large variation in fracture rate both between and within countries indicates that an environmental factor, such as the quality of drinking water, could be one of the causes of the disparities. Our aim was to investigate a possible association between pH (an important parameter for water quality) and self-reported forearm fracture and to examine whether other water quality factors could account for this association.

METHODS

Using Geographic Information Systems, information on the quality of drinking water was linked to CONOR (n = 127,272; mean age, 50.2 ± 15.8 years), a database comprising ten regional epidemiological health surveys from across the country in the time period 1994-2003.

RESULTS

The highest risk of forearm fracture was found at a pH of around 6.75, with a decreasing risk toward both higher and lower pH values. The increased adjusted odds of forearm fracture in men consuming municipal drinking water with pH <7.0 compared to water with pH ≥7.0 was odds ratio (OR) = 1.19 (95 % CI, 1.14, 1.25), and the corresponding increased odds in women was OR = 1.14 (95 % CI, 1.08, 1.19). This association was attenuated (p > 0.05) after further adjustments for other water quality factors (color grade, intestinal enterococci, and Clostridium perfringens).

CONCLUSIONS

Our findings indicate a higher risk of fracture when consuming water of an acidic pH; however, the risk does not only seem to be due to the acidity level per se, but also to other aspects of water quality associated with pH.

The early onset of disease may be a risk factor for decreased bone mineral density in patients with inflammatory bowel disease

Background/Aims

The pathogenesis of bone loss in patients with inflammatory bowel disease (IBD) is complex, multifactorial, and only partly understood. We aimed to examine the extent and risk factors of bone mass reduction and to analyze the impact of early onset of a disease before attaining peak bone mass in IBD patients.

Methods

We compared the risk factors for osteoporosis and BMD at the lumbar spine and the hip bone in IBD patients.

Results

A total of 44 patients with IBD were enrolled. Twenty-one and 23 patients were diagnosed as IBD before and after the age of 30 and designated as group A and group B, respectively. Group A had significant bone mass reduction at the lumbar spine than group B (BMD, 1.01±0.10 vs. 1.14±0.17, p<0.01; T-score, -1.22±0.84 vs. -0.08±1.39, p<0.01; Z-score, -1.11±0.81 vs. -0.03±1.32, p<0.01, respectively). Multivariate analysis showed that patients diagnosed as IBD before the age of 30 had possible risk factor of bone mass reduction (hazard ratio, 3.96; p=0.06).

Conclusions

Bone mass reduction was more severe in patients who were diagnosed with IBD before the age of 30 than in those diagnosed after the age of 30.

Review article: non-alcoholic fatty liver disease and osteoporosis--clinical and molecular crosstalk

BACKGROUND

Low bone mineral density (BMD) has been reported in both paediatric and adult patients with non-alcoholic fatty liver disease (NAFLD). The mechanisms behind the reduced BMD in NAFLD are still not completely understood.

AIM

To provide a critical overview of the pathophysiological pathways linking NAFLD, reduced BMD and osteoporosis, with a special focus on the alterations of soluble mediators which could link fat accumulation in the liver with bone health. The MEDLINE database was searched by a combination of keywords: non-alcoholic fatty liver disease OR hepatic steatosis OR metabolic syndrome OR insulin resistance AND bone mineral density OR osteoporosis OR bone AND biomarkers OR serum marker.

RESULTS

Several factors that may influence bone mineralisation and the increased risk of osteoporosis in NAFLD can be discussed. These include the release of cytokines from the inflamed liver which may influence the bone microenvironment, vitamin D deficiency, and limited physical activity. Circulating markers of bone metabolism, including osteopontin, osteoprotegerin, osteocalcin and fetuin-A, have been found to be altered in patients with NAFLD.

CONCLUSION

A better understanding of the mechanisms that link bone metabolism and the liver may open a new frontier to fight two highly prevalent conditions like NAFLD and osteoporosis.

Seasonal variation of serum 25-hydroxyvitamin D levels in adult patients with inflammatory bowel disease

Patients with inflammatory bowel disease (IBD) are at risk of osteoporosis. Vitamin D (vitD) deficiency is known as a risk factor of osteoporosis. We observed low vitD blood levels in adult IBD patients both at the end of summer and winter. Furthermore, effects of oral vitD supplementation in (generally low) daily dosages were poor.

INTRODUCTION

Patients with IBD are at risk of osteoporosis. This study evaluates seasonal vitD status, determinants of vitD deficiency and effects of vitD supplementation in adult IBD patients.

METHODS

Patients were screened for vitD deficiency at the end of summer and winter using serum 25OHD(3) (cut-off point, <50 nmol/L) combined with routine laboratory tests. A standardized questionnaire was used for demographic/lifestyle data i.e. IBD activity, health behaviour and vitD intake through diet and ultraviolet light.

RESULTS

Late-summer, 39% of the included 316 patients were vitD deficient. Late-winter, 57% of the follow-up patients (n=281) were deficient. Independent protective determinants of vitD deficiency were oral vitD supplementation (summer/winter: odds ratio [OR], 0.52 [95% confidence interval [CI], 0.29-0.94]/OR, 0.44 [95% CI, 0.26-0.75]), recent sun holiday (summer: OR, 0.42 [95% CI, 0.24-0.74]) and regular solarium visits (summer/winter: OR, 0.28 [95% CI, 0.13-0.63]/OR, 0.17 [0.06-0.50]). IBD activity (p=0.031), red blood cell distribution width (RDW; p=0.04) and erythrocyte sedimentation rate (p=0.03) were associated with low vitD levels using univariate analyses of the extreme 25OHD quartiles. In a subgroup with vitD supplementation, still 30% (late-summer) and 44% (late-winter) were vitD deficient.

CONCLUSION

VitD deficiency is common in IBD patients, but prevalence might be comparable with the general population. Ultraviolet light is essential for adequate vitD levels. Effects of oral vitD supplementation in (generally low) daily dosages are poor. Determinants for low vitD levels were IBD activity and elevated inflammatory markers, suggesting that increased risk of osteoporosis in IBD might be more related to the inflammation than to vitD deficiency.

Influence of ileal pouch anal anastomosis on bone loss in ulcerative colitis patients

BACKGROUND AND AIM

Patients with ulcerative colitis (UC) are at an increased risk for low bone mineral density (BMD). It is unclear whether proctocolectomy with ileal pouch-anal anastomosis (IPAA) for UC alters the risk of bone loss. The aim of this study was to compare BMD in UC patients with and without IPAA.

METHODS

A total of 267 patients with UC and IPAA (study group) were compared to 119 UC patients without IPAA (control group) in this cross-sectional study. The demographic and clinical variables including dual-energy X-ray absorptiometry scan results were compared. Patients were classified as having normal or low BMD, based on the criteria by the International Society for Clinical Densitometry. Univariate and multivariate analyses were performed to assess risk factors associated with low BMD. Age, gender, race, smoking status, steroid use, alcohol use, body mass index, years of absent estrogen protection, use of calcium, vitamin D supplements and disease duration were selected as covariates.

RESULTS

83 (31.1%) had low BMD in the study group vs. 18 (15.1%) in the control group (p=0.001). 2/13 (15.4%) had low BMD before surgery. The mean age of patients in the study and control groups were 44.7 ± 14.1 vs. 52.4 ± 17.7 years, respectively (p<0.001). The hip BMD was lower in the study group (0.93 ± 0.17 g/cm2) than that in the control group (0.98 ± 0.17 g/cm2) (p=0.038). Fragility fracture was documented in 23 (8.6%) patients in the study group vs. 3 (2.5%) in the control group (p=0.038) Sixty-four (24.0%) of the study group patients were using corticosteroids after surgery in contrast to 93 (78.2%) in the control group (p<0.001). On multivariable analyses, covariate adjusted factors associated with a low BMD in UC patients were advanced age [odds ratio (OR) 1.51 per 5 years; 95% confidence interval [CI], 1.34-1.71], low body mass index (OR=2.37 per 5 kg/m(2) decrease; 95% CI, 1.68-3.36), and the presence of IPAA (OR=6.02; 95% CI, 2.46-14.70). For the 13 IPAA patients who had information available, BMD before IPAA was low. After a median of 46 (Range 7-84) months after IPAA, BMD improved in 7/13 patients (53.8%), while it continued to be low in 6/13 (46.2%) patients.

CONCLUSIONS

Low BMD is common in patients with UC. The risk appears to persist even after colectomy and IPAA surgery suggesting that these patients need to be monitored for bone loss.

A multicenter study of the efficacy and safety of leukocytapheresis therapy without concomitant systemic steroid treatment in patients with active ulcerative colitis

We conducted a multicenter study to investigate the efficacy of leukocytapheresis (LCAP) without concomitant steroid therapy in active ulcerative colitis (UC) patients. Twenty patients were enrolled. LCAP was performed twice a week for 3 weeks. The results revealed a significant decrease of the Lichtiger's clinical activity index (CAI) from 11.7±2.6 at baseline to 6.6±4.1 after the therapy. The endoscopic index and serum C-reactive protein levels also decreased significantly after the therapy. Of the 20 patients, 15 (75%) were assessed as responders (CAI≤4 or ΔCAI≥3), and 7 (35%) achieved complete remission (CAI≤4). No serious adverse reactions were encountered. The results suggest that LCAP is an effective and safe option for patients with active UC who had not received systemic steroid treatment.

Histomorphometric analysis reveals reduced bone mass and bone formation in patients with quiescent Crohn's disease

BACKGROUND & AIMS

Crohn's disease (CD) is associated with an increased prevalence of osteoporosis, but the pathogenesis of this bone loss is only partly understood. We assessed bone structure and remodeling at the tissue level in patients with quiescent CD. We also investigated the roles of osteocyte density and apoptosis in CD-associated bone loss.

METHODS

The study included 23 patients with quiescent CD; this was a subgroup of patients from a large randomized, double-blind, placebo-controlled, multicenter trial. We obtained transiliac bone biopsy samples and performed histomorphometric analysis. Results were compared with data from age- and sex-matched healthy individuals (controls).

RESULTS

Trabecular bone volume was decreased among patients with CD compared with controls (18.90% vs 25.49%; P < .001). The low bone volume was characterized by decreased trabecular thickness (120.61 vs 151.42 μm; P < .01). Bone formation and resorption were reduced, as indicated by a decreased mineral apposition rate (0.671 vs 0.746 μm/day; P < .01) and a low osteoclast number and surface area compared with controls and published values, respectively. In trabecular bone of patients with CD, osteocyte density and apoptosis were normal. The percentage of empty lacunae among patients was higher than that of published values in controls.

CONCLUSIONS

In adult patients with quiescent CD, bone histomorphometric analysis revealed a reduction in bone mass that was characterized by trabecular thinning. The CD-associated bone loss was caused by reduced bone formation, possibly as a consequence of decreased osteocyte viability in the patients' past.

Fracture-associated hospitalizations in patients with inflammatory bowel disease

BACKGROUND

Maintenance of bone health is an important concern in patients with inflammatory bowel disease (IBD). They may frequently have impaired bone density resulting in greater incidence of fractures.

AIMS

To examine fracture-associated hospitalization costs in IBD patients from a nationwide representative sample, and to compare the risk factors for such fractures in IBD and non-IBD patients.

METHODS

We identified discharges with IBD and coexisting codes for hip, vertebral or wrist fractures (IBD-Fr) from the Nationwide Inpatient Sample and compared them with IBD hospitalizations without codes for these fractures. A second analysis was performed using 2008 inpatient data from the Wisconsin Hospital Association (WHA) comparing characteristics of patients with IBD-Fr and non-IBD controls hospitalized for similar fractures.

RESULTS

There were 1,653 discharges in the IBD-Fr group accounting for 10,461 days of hospital stay and US $46 million in total hospitalization charges. On multivariate analysis, age>65 years [odds ratio (OR) 28.8, 95% confidence interval (CI) 12.3-67.6] and female sex (OR 1.3, 95%CI 1.0-1.6) were associated with higher odds of hospitalization associated with fractures. We found no differences in age, gender, or race among IBD-Fr and non-IBD fracture controls. However, IBD-fractures were twice as likely to be associated with osteoporosis as non-IBD fractures (OR 2.19, 95%CI 1.10-4.33).

CONCLUSIONS

Older age, female sex, and osteoporosis were more commonly associated with hospitalization for fractures in IBD patients. Osteoporosis appears to be more common among IBD-Fr patients than non-IBD fracture controls.

Inflammatory bowel disease in young people: the case for transitional clinics

BACKGROUND

The incidence of inflammatory bowel disease (IBD) is increasing among adolescents. In all, 25% of patients are diagnosed before the age of 16, when they are traditionally transferred from the pediatric to the adult service.

METHODS

We conducted a retrospective case-controlled study to characterize patients treated in a novel transitional adolescent-young adult IBD clinic. This compared disease extent, radiation exposure, therapeutic strategy, and requirement for surgery in 100 adolescents with controls from our adult IBD clinic matched for disease duration.

RESULTS

The median (range) ages for the adolescent and adult population was 19 (16-28) and 43 (24-84), with a median age at diagnosis of 15 (3-26) and 39 (13-82) respectively (P < 0.001). Crohn's disease was significantly more common in the adolescents. Disease distribution was ileocolonic in 69% of adolescents and 28% of adults, restricted to the ileum in 20% of adolescents and 47% of adults, and colonic only in 11% and 22%, respectively. Upper gastrointestinal involvement occurred in 23% of adolescents, but was not seen in adults (P < 0.01). Total ulcerative colitis was seen in 67% of adolescents and 44% of adults (P < 0.01). Contrary to previous data adolescents did not receive more ionizing radiation than adults. Requirement for immunosuppressive therapy was higher in the adolescent group (53% versus 31%, respectively, P < 0.01). Likewise, 20% of adolescents had required biological therapy compared to only 8% in the adult cohort (P < 0.05).

CONCLUSIONS

Gastroenterologists should recognize that IBD is more complex when presenting in adolescence and our data support the creation of specific adolescent transitional clinics.

How activity of inflammatory bowel disease influences bone loss

Bone loss is a common problem for individuals with inflammatory bowel disease (IBD). The aim of our study was to assess bone mineral density (BMD) in patients with IBD and to investigate the role of corticosteroid (CS) use and duration and activity of disease on BMD. Ninety-two patients (56 men and 36 women) with IBD, of whom 32 had ulcerative colitis (UC) and 60 had Crohn's disease (CD), underwent clinical assessment. Lumbar and femoral neck BMDs were measured by dual-energy X-ray absorptiometry. Osteopenia was observed in 14 patients (43%) with UC and in 24 patients (40%) with CD (p=0.187). Four patients (12%) with UC and 7 patients (11%) with CD had osteoporosis (p=0.308). Femoral BMD decreased in patients with long duration of CS use and correlated inversely with disease activity. Multiple regression analysis of BMD showed that statistically significant risk factors were duration of active disease and body mass index as well. Based on our results, it is necessary to take into account the risk of decreased BMD in patients with IBD. It is most important to achieve disease remission as soon as possible in addition to nutritional support.

[Low levels of 25-hydroxyvitamin D (25OHD) in patients with inflammatory bowel disease and its correlation with bone mineral density]

Patients with inflammatory bowel disease (IBD) are at risk of having vitamin D deficiency (25-OHD) and low bone mineral density (BMD).

OBJECTIVES

To measure 25OHD in a young group of IBD patients submitted to a clinical evaluation, routine biochemistry and BMD measurement (lumbar spine and proximal femur).

RESULTS

39 Crohn disease (CD) and 37 ulcerative colitis (UC) patients had lower serum levels of 25OHD compared to the control group (CD p = 0.003; UC p < 0.001), and 48.5% of the UC patients were 25OHD deficient. Lumbar spine BMD was lower in patients than controls (CD p = 0.001; UC p = 0.008). In CD patients, serum levels of 25OHD were significantly correlated with total femur (r = 0.391; p = 0.027) and femoral neck (r = 0.384; p = 0.03) BMD.

CONCLUSION

It was found lower levels of 25OHD and BMD in young IBD patients compared to normal controls, suggesting an important role of 25OHD deficiency in the pathogenesis of the IBD bone disease.

Tumor necrosis factor-alpha impairs intestinal phosphate absorption in colitis

Phosphate homeostasis is critical for many physiological functions. Up to 85% of phosphate is stored in bone and teeth. The remaining 15% is distributed in cells. Phosphate absorption across the brush-border membrane (BBM) of enterocytes occurs mainly via a sodium-dependent pathway, which is mediated by type IIb sodium-phosphate cotransporters (NaPi-IIb). Patients of inflammatory bowel diseases (IBDs) suffer not only from diarrhea and nutrient malabsorption but also from bone loss. About 31-59% of patients with IBD develop bone disorders. Since the intestine is a primary location for dietary phosphate absorption, it is logical to postulate that there is an inverse relationship between gastrointestinal disorders and phosphate transport, which, in turn, contributes to bone disorders observed in patients with IBD. Phosphate absorption and NaPi-IIb expression was studied with BBM vesicles isolated from trinitrobenzene sulphonic acid (TNBS) animals as well as in Caco-2 cells. The mechanism of TNF-alpha downregulation of NaPi-IIb expression was investigated by luciferase assay, gel mobility shift assay (GMSA), and coimmunoprecipitation. Intestinal phosphate absorption mediated by NaPi-IIb was reduced both in TNBS colitis and in TNF-alpha-treated cells. Transient transfection indicated that TNF-alpha inhibits NaPi-IIb expression by reducing NaPi-IIb basal promoter activity. GMSAs identified NF1 protein as an important factor in TNF-alpha-mediated NaPi-IIb downregulation. Signaling transduction study and coimmunoprecipitation suggested that TNF-alpha interacts with EGF receptor to activate ERK1/2 pathway. Intestinal phosphate absorption mediated by NaPi-IIb protein is reduced in colitis. This inhibition is mediated by the proinflammatory cytokine TNF-alpha through a novel molecular mechanism involving TNF-alpha/EGF receptor interaction.

Risk factors for low bone mass in patients with ulcerative colitis following ileal pouch-anal anastomosis

OBJECTIVES

Bone mineral density (BMD) can be adversely affected by the chronic nature of inflammatory bowel disease. Ileal pouch-anal anastomosis (IPAA) is the surgical treatment of choice for patients with ulcerative colitis (UC) who require proctocolectomy. There are few data on BMD in UC patients with IPAA. The aim of the study was to assess the prevalence and risk factors associated with low BMD in UC patients after IPAA.

METHODS

A total of 327 eligible patients with UC and IPAA from the Pouchitis Clinic were enrolled. Dual-energy X-ray absorptiometry was performed. Patients were classified as having normal or low BMD, based on the criteria by the International Society for Clinical Densitometry. A total of 39 demographic and clinical variables were evaluated with logistic regression models.

RESULTS

Of 327 patients with a median of 4 years after IPAA, 105 (32.1%) had low BMD. Fragility fracture was documented in 11 patients (10.5%) in the low BMD group and in 13 of 222 patients (5.9%) in the normal BMD group (P=0.14). In the multivariable analysis, covariate-adjusted factors associated with a low BMD were advanced age (odds ratio (OR) =1.64 per 5 years; 95% CI, 1.44-1.87), low body mass index (OR=0.43 per 5 kg/m(2); 95% CI, 0.30-0.62), and non-use of daily calcium supplement (OR=0.53; 95% CI, 0.29-0.96). Pouch-associated factors were not found to be significantly associated with the bone loss.

CONCLUSIONS

Low BMD was common in patients with UC, even after colectomy and IPAA. Low BMD in this patient population was associated with certain risk factors, some of which may be modifiable.

Symposium on 'The challenge of translating nutrition research into public health nutrition'. Session 3: Joint Nutrition Society and Irish Nutrition and Dietetic Institute Symposium on 'Nutrition and autoimmune disease'. Nutrition in Crohn's disease

The exact aetiology of Crohn's disease remains unknown. The consensus is that the disease results from a complex interaction between genes, immunity and environmental factors. Diet is attractive, in theory, as an environmental risk factor in the aetiology of the disease. The epidemiological data, often impeded by methodological issues, have failed to confirm a direct link between pre-diet illness and the development of Crohn's disease. Once diagnosed, however, nutrition has an important role in disease management. Among the nutritional issues are malnutrition, weight loss and suboptimal nutritional status; these outcomes may be present at any stage of the disease but are likely to be overt during acute illness and hospitalisation. Malnutrition has been identified in approximately 40% of hospital admissions with Crohn's disease and is associated with higher mortality, longer hospital stays and higher healthcare costs. Patients in remission may indeed be overweight and appear to be influenced by the general population trends toward overweight and obesity. Irrespective of BMI, patients are at risk of micronutrient deficiencies. Vitamin D deficiency, for example, is common in Crohn's disease and has important implications for bone health. Moreover, newer evidence suggests that vitamin D has potential anti-inflammatory effects. Dietary approaches, in the form of enteral nutrition, have previously been shown to reduce inflammation and treat the active disease. Current guidelines now recommend that corticosteroids are more effective than enteral nutrition for treating adults. Enteral nutrition has important growth and developmental benefits and continues to be a recommended therapy for children with Crohn's disease.

High prevalence of low bone mineral density in patients with Inflammatory Bowel Disease in the setting of a peripheral Dutch hospital

BACKGROUND AND AIMS

Osteopenia and osteoporosis are frequently encountered in patients with Inflammatory Bowel Disease (IBD). Our aims were to evaluate the actual practice of screening for low bone mineral density (BMD) by dual energy X-ray absorptiometry (DEXA), to determine the prevalence of low BMD and to investigate the risk factors associated with a low BMD in the IBD population of a regional Dutch hospital.

METHODS

A retrospective chart review was performed in 474 patients (259 with ulcerative colitis, 210 with Crohn's disease and 5 with indeterminate colitis). DEXA results and potential predictive factors of low BMD were documented. Predictive factors of low BMD were assessed by logistic regression.

RESULTS

DEXA was performed in 168 IBD patients (35.4%). A low BMD (T-score<-1) was present in 64.3%. Osteoporosis (T-score<-2.5) was found in 23.8%. Low BMI, older age at the moment of diagnosis and male gender were found to be predictive factors of low BMD. For patients with osteoporosis, disease duration was an additional predictive factor. After subgroup analysis predictive factors were found to be the same in patients with Crohn's disease.

CONCLUSIONS

The prevalence of osteopenia and osteoporosis in IBD patients in a regional centre is as high as the prevalence rates reported from tertiary referral centres. A low BMI, an older age at the moment of diagnosis and male gender were predictive factors of low BMD. Prediction of osteoporosis and osteopenia using risk factors identified in this and previous studies is presently not feasible.

High prevalence of morphometric vertebral deformities in patients with inflammatory bowel disease

BACKGROUND

Earlier studies have documented that the prevalence of decreased bone mineral density (BMD) is elevated in patients with inflammatory bowel disease. The objective of this study was to investigate the prevalence of vertebral deformities in inflammatory bowel disease patients and their relation with BMD and bone turnover.

METHODS

One hundred and nine patients with Crohn's disease (CD) and 72 with ulcerative colitis (UC) (age 44.5+/-14.2 years) were studied. BMD of the hip (by dual X-ray absorptiometry) was measured and a lateral single energy densitometry of the spine for assessment of vertebral deformities was performed. Serum markers of bone resorption (carboxy-terminal cross-linked telopeptide of type I collagen) and formation (procollagen type I amino-terminal propeptide) were measured, and determinants of prevalent vertebral deformities were assessed using logistic regression analysis.

RESULTS

Vertebral deformities were found in 25% of both CD and UC patients. Comparing patients with and without vertebral deformities, no significant difference was found between Z-scores and T-scores of BMD, or levels of serum carboxy-terminal cross-linked telopeptide of type I collagen and serum procollagen type I amino-terminal propeptide. Using logistic regression analysis the only determinant of any morphometric vertebral deformity was sex. The presence of multiple vertebral deformities was associated with older age and glucocorticoid use.

CONCLUSION

The prevalence of morphometric vertebral deformities is high in CD and UC. Male sex, but neither disease activity, bone turnover markers, clinical risk factors, nor BMD predicted their presence. The determinants for having more than one vertebral deformity were age and glucocorticoid use. This implies that in addition to screening for low BMD, morphometric assessment of vertebral deformities is warranted in CD and UC.

Altered bone metabolism in inflammatory disease: role for nutrition

Osteoporosis is a major public health problem, and as life expectancy and the world's population continue to increase will become even more important. Thus, there is an urgent need to develop and implement nutritional approaches and policies for the prevention and treatment of osteoporosis. Patients with some chronic inflammatory diseases appear to be more likely to develop osteopenia, and in some cases earlier in life, which is of particular concern as the incidence of inflammatory diseases in the Western world is increasing. While the cause of bone loss in patients with inflammatory disease is multifactorial, nutrition may have a role. Many of these patients may have one or more nutritional deficiencies, which can lead to altered rates of bone metabolism. On the other hand, some nutritional factors may attenuate the inflammatory process itself, and thus may indirectly benefit bone metabolism and bone health in patients with inflammatory disease. The present review will consider these issues, particularly in the context of inflammatory bowel disease, coeliac diease and atherosclerosis.

A double-blind placebo-controlled study of intravenous clodronate for prevention of steroid-induced bone loss in inflammatory bowel disease

BACKGROUND & AIMS

Osteoporosis is common in patients with inflammatory bowel disease (IBD). Corticosteroids induce a rapid and important bone loss. Clinical trials have shown oral bisphosphonates to effectively prevent steroid-induced bone loss. However, patients with IBD have been excluded from most of these studies because of potential digestive adverse events. Clodronate is a non-amino-bisphosphonate available in intravenous form without expected digestive (as oral bisphosphonates) or proinflammatory (as amine bisphosphonates) side effects. Our aim was to assess the efficacy of intravenous clodronate in preventing steroid-induced bone loss.

METHODS

A 12-month, double-blind, randomized, placebo-controlled trial was conducted in IBD patients beginning a steroid therapy. Sixty-seven patients (median disease duration, 38 mo; range, 1-240 mo) were randomized to receive one infusion per 3 months of either intravenous clodronate (900 mg, n = 33) or placebo. All the patients received calcium (1 g/day) and vitamin D (800 IU/day). The main outcome was the change in lumbar bone mineral density (BMD) between baseline and 1 year. Secondary outcomes included change in femoral neck BMD and adverse events.

RESULTS

After 1 year, there was no change in BMD in the clodronate group, neither at the spine (-0.2%, not significant) nor at the femoral neck (2.3%, NS). In contrast, there was a significant decrease in lumbar spine (-2.0%, P = .0018) and femoral neck (-1.7%, P = .045) BMD in the placebo group. Tolerance to treatment was good.

CONCLUSIONS

Intravenous clodronate is effective in the prevention of bone loss induced by steroids in patients with IBD.

Tumor necrosis factor-alpha haplotype is strongly associated with bone mineral density in patients with Crohn's disease

BACKGROUND AND AIM

There is limited consensus on the major variables that determine bone integrity and bone loss in patients with Crohn's disease. Twin and family studies in the general population indicate that up to 85% of variance in bone mineral density is inherited. The aim was to determine the prevalence of bone loss and both molecular and clinical risk factors for bone loss in a large Crohn's disease population.

METHODS

This was a cross-sectional study of 304 patients with Crohn's disease attending the Inflammatory Bowel Disease unit at Royal Brisbane and Women's Hospital, Queensland. The results of bone density testing were ascertained directly and by a mailed questionnaire. Bone mineral density data were combined with clinical information and correlated with single nucleotide polymorphisms within the tumor necrosis factor-alpha (TNF-alpha), interleukin-10, and NOD2/CARD15 genes.

RESULTS

Of 304 Crohn's disease patients, 101 had undergone previous bone density testing. Forty-five patients (45%) had been diagnosed with osteopenia and 18 (18%) were osteoporotic. After multivariate analysis, both the TNF-alpha GT haplotype and the -857 CC genotype showed strong associations with bone mineral density overall (P = 0.003 and P = 0.002, respectively). Body mass index (P = 0.01) and previous bowel resection in female patients (P = 0.03) were predictive of a higher spine bone density, while body mass index (P = 0.003) and the effect of years since first bowel resection (P = 0.02) remained independent predictors of proximal femur bone mineral density. There were no other significant associations observed.

CONCLUSIONS

This study has identified a novel protective association between a TNF-alpha haplotype and bone mineral density in Crohn's disease. It confirms the important influence of body mass index and intestinal resection on bone loss in this population.

The role of tumor necrosis factor alpha in down-regulation of osteoblast Phex gene expression in experimental murine colitis

BACKGROUND & AIMS

Reduced bone mass is a common complication of inflammatory bowel disease (IBD), although the mechanisms that contribute to osteopenia are not completely understood. Tumor necrosis factor alpha (TNF-alpha) is up-regulated in patients with IBD and has detrimental effects on osteoblasts. Phex gene is expressed predominantly in osteoblasts, and its disruption results in defective bone mineralization. The aim of this study was to evaluate whether TNF-alpha regulates Phex gene expression thus contributing to the abnormal bone metabolism observed in IBD.

METHODS

Phex gene expression was evaluated in calvaria of 6-7-week-old mice administered with trinitrobenzene sulfonic acid (TNBS) with or without neutralizing anti-TNF-alpha antibody, dietary curcumin, or systemically with recombinant TNF-alpha. TNF-alpha-treated UMR-106 osteoblasts were also examined. Phex promoter activity was assayed in transiently transfected TNF-alpha-treated UMR-106 cells.

RESULTS

Compared with control animals, Phex messenger RNA (mRNA) expression decreased by 40%-50% in both TNBS colitis and TNF-alpha-injected mice. Dietary curcumin and anti-TNF-alpha antibody counteracted the detrimental effect of TNBS on Phex gene expression. TNF-alpha-treated UMR-106 cells showed a concentration-dependent and transcriptionally mediated decrease in Phex mRNA and gene promoter activity, with the -133 to -74 bp region of the Phex promoter likely involved in the mechanism of TNF-alpha action. Coinciding with decreased Phex protein level, TNF-alpha drastically reduced mineralization in UMR-106 osteoblasts.

CONCLUSIONS

Acute colitis and TNF-alpha decrease Phex mRNA and protein expression via a transcriptional mechanism. TNF-alpha-mediated reduction in Phex protein is at least in part responsible for inhibition of osteoblast mineralization, and the described mechanism may contribute to the abnormal bone metabolism associated with IBD.

Screening of tumor necrosis factor receptor-associated factor 6 as a candidate gene for inflammatory bowel disease

OBJECTIVE

The two forms of inflammatory bowel disease (IBD), Crohn's disease (CD) and ulcerative colitis (UC), are thought to arise because of an interplay of unfavorable genetic and exogenous factors. During a genome-wide linkage study of IBD, we observed a nominal linkage to chromosome 11p12-q13 that was further confirmed upon fine density mapping. This chromosomal region contains a functional IBD candidate gene coding for tumor necrosis factor receptor-associated factor 6 (TRAF6), a signal transducer regulating innate and adaptive immunity as well as bone homeostasis.

MATERIAL AND METHODS

Using denaturing high-performance liquid chromatography (dHPLC) and DNA sequencing, all exons and exon-intron boundaries of the TRAF6 gene in probands of 95 IBD families were initially screened; this material comprised 20 CD, 39 UC and 36 mixed families.

RESULTS

No nucleotide changes in the coding sequence of TRAF6 were detected, but a single-base insertion/deletion polymorphism in a polythymine stretch (containing 8 or 7 thymines, respectively) in intron 3 was identified. However, examination of an extended material of 290 unrelated CD patients, 416 UC patients and 320 healthy blood donors failed to show any association with this 7T/8T variation and IBD, nor was this polymorphism related to specific clinical features in IBD.

CONCLUSIONS

Our study tends to exclude a good positional and functional candidate gene, TRAF6, as an IBD predisposing gene and lends support to the idea that the function of TRAF6 is important enough not to permit structural alterations of this mediator.

Are activated T cells regulators of bone metabolism in children with Crohn disease?

OBJECTIVES

To test the hypothesis that circulating activated T cells may release cytokines that decrease bone turnover in children with Crohn disease.

STUDY DESIGN

Newly diagnosed Crohn disease and healthy controls of similar age were compared for bone age, bone mineral content and density, markers of bone remodeling, and serum concentration and in vitro T-cell production of receptor activator of nuclear factor kappaB ligand (RANKL), interferon (INF)-gamma, and osteoprotegerin (OPG).

RESULTS

Newly diagnosed children with Crohn disease (n=23) had similar bone mineral density (BMD) z-scores and body mass index as the controls (n=40). Biochemical markers of bone remodeling indicated a state of low bone turnover in the Crohn disease patients compared with controls. Serum OPG (pmol/L; mean+/-SD, median) was higher (4.24+/-1.74, 3.98 vs 3.38+/-0.83, 3.41; P<.05), and serum RANKL (pmol/L) was lower in the Crohn disease patients (0.50+/-0.86, 0.28 vs 1.02+/-1.63, 0.49; P<.01), consistent with decreased bone resorption. Activated T cells from Crohn disease patients produced a higher concentration of INF-gamma (ng/microg protein) than those from controls (20.03+/-26.39, 8.70 vs 9.76+/-14.10, 6.17; P<.05).

CONCLUSIONS

The newly diagnosed children with Crohn disease exhibited reduced bone remodeling, possibly due to T-cell INF-gamma and OPG.

Altered levels of biochemical indices of bone turnover and bone-related vitamins in patients with Crohn's disease and ulcerative colitis

BACKGROUND

The pathogenesis of inflammatory bowel disease-associated osteopenia may be related to pathological rates of bone turnover; however, the literature shows mixed results.

AIM

To compare bone biomarkers in inflammatory bowel disease patients (Crohn's disease: n = 68, and ulcerative colitis: n = 32, separately) with age- and sex-matched healthy controls.

SUBJECTS

Patients and controls were recruited from Cork University Hospital and Cork City area, respectively.

RESULTS

Relative to that in their respective controls, Crohn's disease (n = 47) and ulcerative colitis (n = 26) patients (i.e. excluding supplement users) had significantly (P < 0.05-0.001) higher serum undercarboxylated osteocalcin (by 27% and 63%, respectively) and bone-specific alkaline phosphatase (by 15% and 21%, respectively) and urinary Type I collagen cross-linked N-telopeptides concentrations (by 87% and 112%, respectively). Relative to that in their respective controls, Crohn's disease and ulcerative colitis patients had significantly (P < 0.01) lower serum total osteocalcin (by 20% and 42%, respectively) and 25-hydroxyvitamin D (by 37% and 42%, respectively), while serum parathyroid hormone levels were similar. In the combined patient group (n = 100), undercarboxylated osteocalcin was positively associated with bone markers.

CONCLUSIONS

Both Crohn's disease and ulcerative colitis patients have altered bone turnover relative to that in healthy controls.