Bone mineral density and dietary intake in patients with Crohn's disease

Risk of fracture and low bone mineral density in adults with inflammatory bowel diseases. A systematic literature review with meta-analysis

Inflammatory bowel diseases (IBDs) are associated with a decreased bone mineral density, but the impact on fractures is unknown. In our study, global risk of fracture is increased for patients with IBDs versus controls. This result will help to determine the appropriate assessment with early screening and management of osteoporosis. Inflammatory bowel diseases (IBDs), such as Crohn's disease (CD) and ulcerative colitis (UC), are associated with a decreased bone mineral density (BMD). However, the impact on fracture risk is unknown and data are contradictory across studies. In this systematic review and meta-analysis, we aimed to assess the risk of fracture and presence of low BMD in patients with IBDs compared to healthy controls. A systematic search of literature was conducted of MEDLINE, EMBASE, the Cochrane library and abstracts from appropriate scientific congresses. Studies were selected if they compared the incidence of fractures and/or BMD measurement by dual-energy X-ray absorptiometry in patients with IBDs and healthy sex- and age-matched controls. Data were extracted by two independent investigators. Meta-analysis was performed with the inverse variance approach to estimate pooled odds ratios (ORs) and risk ratios (RRs) with their 95% confidence intervals (CIs). Twenty-four studies met the inclusion criteria. On the basis of nine studies, global risk of fracture was increased for patients with IBDs versus controls (RR = 1.38, 95% CI 1.11-1.73; p = 0.005). Fracture risk with IBDs was significantly increased for vertebral fractures (OR = 2.26, 95% CI 1.04-4.90; p < 0.001), but not for any other site. The analysis of 16 studies evaluating BMD showed a significant decrease in mean BMD and Z-scores for IBD patients versus controls at all sites. In our meta-analysis, patients with IBDs have an increased risk of fractures, especially in the spine, and significant decreased BMD at all sites, which suggests the need for identifying high-risk individuals among this population.

What nutritional factors influence bone mineral density in Crohn's disease patients?

BACKGROUND/AIMS

Bone mineral density (BMD) is often low in patients with Crohn's disease (CD). This study aimed to evaluate the association between nutritional factors and BMD in a group of CD patients.

METHODS

CD patients 18 years of age or older were included. The body mass index (BMI), waist circumference (WC) and dietary intake were evaluated during two 24-hour recalls. Bone densitometry was performed by dual-energy X-ray absorptiometry of the full body to assess body composition and of the lumbar vertebrae and femoral neck to assess BMD.

RESULTS

In the 60 patients evaluated, there was no association between BMD and disease activity or between BMD and disease duration. We observed moderate correlations between BMD in at least one of the evaluated sites and BMI, lean mass, WC, and protein, calcium, phosphorus and magnesium dietary intakes (P<0.05). In the linear regression analysis for spinal BMD, only BMI and calcium dietary intake remained associated (P<0.05). In the linear regression analysis for femoral BMD, WC and phosphorus intake continued to be significant in the final model, although they had low explanatory power for BMD (P<0.05).

CONCLUSIONS

The prevalence of low BMD was high in CD patients. BMI, WC, calcium and phosphorus dietary intake were positively correlated with BMD.

Peripheral and central measurements of bone mineral density are equally strongly associated with clinical risk factors for osteoporosis

The aim of this study was to determine whether forearm bone mineral density (BMD) measurements are affected by clinical risk factors for osteoporosis to the same extent as spine and hip BMD. The study population consisted of 1,009 female patients and volunteers, of whom 238 were premenopausal. Women were placed into seven groups according to which clinical risk factor they had (women could be placed in more than one group): (1) atraumatic fracture since the age of 25 years, (2) report of X-ray osteopenia, (3) predisposing medical condition or use of therapy known to affect bone metabolism, (4) premature menopause before the age of 45 years or a history of amenorrhea of longer than 6 months' duration, (5) family history of osteoporosis, (6) body mass index (BMI) <20 kg/m(2), and (7) current smoking habit. Forearm BMD was measured using an Osteometer DTX-200 peripheral dual-energy X-ray absorptiometry scanner, and spine and hip BMD measurements were obtained on a Hologic QDR-4500 scanner. Manufacturers' reference ranges were used to calculate Z scores for the spine and forearm, and the NHANES III reference range was used to calculate Z scores for the hip. Multivariate regression analysis was used to estimate the mean decrease in Z score associated with each clinical risk factor. The Z-score reductions associated with the seven risk factors were similar for forearm and central BMD measurements. For forearm measurements, Z-score decreases associated with a history of atraumatic fracture (-0.25), a medical condition or therapy known to affect bone metabolism (-0.26), premature menopause or history of amenorrhea (-0.30), and BMI <20 kg/m(2) (-0.82) were all statistically significantly different from zero (P < 0.05). With an increasing number of risk factors in each individual, the mean Z score at each measurement site became progressively more negative. In conclusion, clinical risk factors for low BMD affect forearm BMD measurements to a similar extent as central BMD.

Seasonality of vitamin D status and bone turnover in patients with Crohn's disease

BACKGROUND

While winter-time vitamin D deficiency has been well-documented in Crohn's disease patients, less is known about vitamin D status during summertime and whether a seasonal variation exists in bone turnover.

AIMS

To compare vitamin D status and bone turnover markers in Crohn's disease patients with age- and sex-matched controls during late-summer and late-winter.

SUBJECTS

Crohn's disease patients (n = 44; mean age 36.9 years, currently in remission) and matched controls (n = 44) were recruited from Cork University Hospital and Cork City area, respectively.

METHODS

Bloods were analysed for 25-hydroxyvitamin D, parathyroid hormone, bone-specific alkaline phosphatase, osteocalcin and urine analysed for N-telopeptides of type 1 collagen.

RESULTS

Serum 25-hydroxyvitamin D concentrations were significantly (P < 0.003) lower in Crohn's disease patients than in control subjects during both seasons. In Crohn's disease patients, serum 25-hydroxyvitamin D concentrations were lower (P < 0.0001) whereas serum parathyroid hormone, osteocalcin and bone-specific alkaline phosphatase and urinary N-telopeptides of type 1 collagen levels were higher (P < 0.001) during late-winter than late-summer.

CONCLUSION

There were notable seasonal variations in vitamin D status and bone turnover markers in Crohn's disease patients. The impact of winter decline in vitamin D status and increase in bone turnover on long-term risk of osteopenia/osteoporosis in Crohn's disease patients is unclear.

Therapy Insight: osteoporosis in inflammatory bowel disease—advances and retreats

There is a discrepancy between the high rates of reduced bone mineral density (BMD) reported in patients with inflammatory bowel disease (IBD) and the relatively low fracture rates observed in population-based studies. When fractures occur, they are most common among the elderly IBD population. It has become clear that BMD is but one of several important factors to be considered when assessing fracture risk. Ideally, BMD should be assessed selectively, as opposed to assessing this measure in all IBD patients simply because they carry an IBD diagnosis. Preventing bone loss should begin with an attempt to limit corticosteroid-induced bone loss. This can be done by using the minimum effective prednisolone dose, substituting budesonide when appropriate, administering other steroid-sparing immunomodulators, or by prescribing additional agents that enhance bone health. The administration of calcium and vitamin D appears to maintain or enhance bone mass. Bisphosphonates are of unclear additional benefit to the majority of patients who are at low fracture risk. Although more data are required to understand the best strategy to prevent fractures, a greater appreciation of the role of selective BMD testing and the utility of simple therapeutic strategies (such as calcium and vitamin D supplements) is emerging.

Lack of relationship of calcium and vitamin D intake to bone mineral density in premenopausal women with inflammatory bowel disease

OBJECTIVES

Low bone mineral density has been widely reported in patients with inflammatory bowel disease (IBD). The exact etiology of this condition is not completely understood but is suggested to be multifactorial, possibly including low calcium and vitamin D intake. The objective of this study was to assess calcium and vitamin D intake and its relationship to bone mineral density (BMD) in premenopausal women with IBD.

METHODS

A total of 70 premenopausal women with IBD (mean age 33.3 yr, range 18-44 yr) drawn from the population-based University of Manitoba IBD Research Registry participated in the study. Calcium and vitamin D intake was determined using a semiquantitative food frequency questionnaire and compared to the Dietary Reference Intake values for adequacy. BMD of total body, lumbar spine, femoral neck, and hip was measured using dual-energy x-ray absorptiometry.

RESULTS

Of the 70 subjects, 66 successfully completed the study. Inadequate calcium intake (<1000 mg/day) was found in 69.7% of the subjects. This low intake group had a mean calcium intake of 508 mg/day. Inadequate vitamin D intake (<200 IU/day) was found in 53% of the subjects with a mean vitamin D intake of 76 IU/day in this group. Calcium and vitamin D intake correlated with each other with R2=0.57, p<0.00001. Daily calcium intake was not significantly different for subjects with T scores greater than -1 (901 mg) and for subjects with T scores less than -1 (875 mg, p=0.44). Daily vitamin D intake was not significantly different for subjects with T scores greater than -1 (297 IU) compared with subjects with T scores less than -1 was (267 IU, p=0.33). Comparing subjects with T scores greater than -1 to those with T score less than -1, there was no difference in the percentage of subjects ingesting >1 g/day calcium (14/43 vs 8/23, p=0.86) or in those with vitamin D intake >200 IU/day (21/43 vs 9/23, p=0.45).

CONCLUSIONS

The results show that, on average, premenopausal women with IBD have less than the recommended intake for calcium and vitamin D. However, this does not seem to influence BMD. Calcium and vitamin D intake is not a predictor of bone status in premenopausal women with IBD.

Corticosteroid-induced osteoporosis: does it occur in patients with Crohn's disease?

OBJECTIVE

In Crohn's disease, osteoporosis is frequently found. However, the etiology of osteoporosis remains unclear. The aim of this study was to determine disease-related variables predictive for impaired bone mineral density (BMD).

METHODS

A total of 91 patients with Crohn's disease who were admitted for BMD assessment were enrolled in the study. BMD was measured at the femoral neck and lumbar spine by dual energy x-ray absorptiometry (DXA). Results were expressed as T-score and as age- and sex-matched Z-score. Data were obtained by a questionnaire and from patients' medical records. Stepwise linear regression analysis was used to determine independent variables predictive for BMD.

RESULTS

Mean age at BMD assessment was 41 +/- 12 yr, duration of disease 11.6 +/- 8.5 yr, and body mass index (BMI) 23.0 +/- 4.1 kg/m2. The cumulative dose of steroids used was 18.7 +/- 19.2 g. Mean Z-scores were less than zero (spine, -1.1 +/- 1.3 SD; femur, -1.1 +/- 1.2 SD; p < 0.0001). A total of 27 patients (30%) fulfilled the World Health Organization criteria for osteoporosis and 46 patients (50%) for osteopenia. Osteoporotic patients used more corticosteroids and had longer duration of disease, lower BMI, and more bowel resections than patients with normal BMD. However, in the linear regression analysis, the only significant independent predictors for BMD of the lumbar spine and femoral neck were BMI and history of bowel resections. BMI and history of resections together accounted for 28% of BMD Z-scores.

CONCLUSIONS

BMI and a history of bowel resections were significant predictive variables for BMD. Despite the high dose of steroids used in this study, no detrimental effect could be demonstrated as independent predictor for osteoporosis.

Bones and Crohn's: problems and solutions

Inflammatory bowel disease may manifest in various extra intestinal manifestations. Osteopenia and various arthropathies may be debilitating. These may be related to the disease itself, patient genetics, lifestyle, or disease treatment. Calcium and vitamin D malabsorption, vitamin K deficiency, malnutrition, corticosteroid and other immunosuppressive medications, smoking, lack of exercise and postmenopausal state may all play important roles. Treatment may be undertaken to correct nutrient deficiencies, inhibit bone resorption and increase bone formation.