Bone density, ultrasound measurements and body composition in early ankylosing spondylitis

OBJECTIVES: In this cross-sectional study, we evaluated bone density using both dual-energy X-ray absorptiometry (DEXA) and quantitative ultrasound (QUS) techniques and examined the changes in body composition in patients with ankylosing spondylitis (AS). METHODS: Seventy-one patients were compared with seventy-one sex- and age-matched controls. Bone mineral density (BMD) was evaluated at the lumbar spine and femoral neck with a Lunar device. Total body measurements were also performed, giving BMD and bone mineral content (BMC) of the whole body, and fat and lean masses. Broadband ultrasound attenuation (BUA), speed of sound and stiffness were measured at the calcaneus using an Achilles ultrasound device. RESULTS: The patients had significantly lower lumbar spine, femoral neck and total body BMD as compared with controls (all P < 0.05). Total body BMC was also decreased in AS (P = 0.002). On the contrary, fat and lean masses did not differ between patients and controls as observed for QUS values. Mild to good correlations were found between BMD and QUS parameters (r ranging from 0.22 to 0.53; all P < or = 0.01). When applying the World Health Organization (WHO) definition for osteoporosis, we found that 46.5% of patients had lumbar spine osteopenia and/or osteoporosis, while 26.8% had femoral neck osteopenia and/or osteoporosis (controls: 23.9 and 10%; P = 0.001 and 0.08, respectively). No relationships between disease activity (as evaluated by erythrocyte sedimentation rate, serum C-reactive protein levels and BASDAI, a clinical index of disease activity) and BMD measurements were found and only femoral neck BMD correlated with disease duration (r = -0.25; P = 0.04). Finally, the presence of talalgia in AS did not influence the QUS values. CONCLUSION: These results confirm that AS patients have decreased BMD values at both the spine and femur, and also in total body measurements, reflecting a generalized bone loss. On the contrary, soft tissue composition does not seem to be influenced by the disease. QUS parameters were found to be similar between patients and controls, suggesting that the QUS method did not provide additive information to DEXA. As it is thought that QUS provides information about qualitative properties of bone, the normal results of QUS values in our patient series argue against modifications in AS bone micro-architecture.     

Osteopenia and osteoporosis in Crohn's disease: prevalence in a Dutch population-based cohort

Reduced bone mineral density (BMD) has been reported in 3-77% of patients with inflammatory bowel disease (IBD). The majority of these studies are cross-sectional and from tertiary referral centres. The aim of our study was to estimate the prevalence of metabolic bone disease and of symptomatic fractures in a population of patients with Crohn's disease (CD) living in a well-defined geographic area. Patients with CD living in three adjacent municipalities within the IBD South-Limburg study area were investigated. BMD was measured by dual X-ray absorptiometry (DXA) of the femoral neck, lumbar spine and total body. The population comprised of 181 CD patients, 23 of whom were excluded. One-hundred-and-nineteen (75%) of the 158 eligible patients (37 males, 82 females with a mean age of 42 years (17-78)) were investigated. Osteopenia of lumbar spine and/or femoral neck was found in 45% of patients. Osteoporosis was found in another 13% of patients. Mean BMD (T-score) of femoral neck was significantly lower than of lumbar spine (P < 0.001). Male CD patients and patients aged under 18 at diagnosis are more at risk of having a low bone mass at the lumbar spine (P < 0.001) and total body (P = 0.018). The prevalence of osteoporosis in postmenopausal CD patients (29%) was significantly higher than in premenopausal patients (3%) (odds ratio: 12). Twenty-nine of 119 (24%) patients had a history of symptomatic fractures. Osteopenia and osteoporosis are frequent in CD and should have the full attention of the treating physician.     

Poor correlations between measurements of bone quality by quantitative ultrasound sonography and dual energy X-ray absorptiometry in patients with beta-thalassaemia major

Objectives: Osteopenia/osteoporosis is a major component of morbidity even in young patients with β‐thalassaemia major. Dual energy X‐ray absorptiometry (DXA) is the reference method for determining bone mineral density (BMD). Quantitative ultrasound sonography (QUS) for bone measurement is a relatively new, inexpensive and radiation‐free method that could serve as an alternative to DXA. Our aim was to assess bone status in thalassaemic patients both with QUS and DXA and, consequently, to investigate the degree of correlation between the two methods. Methods: Thirty‐three patients (15 male and 18 female) with β‐thalassaemia major, regularly transfused and systematically iron‐chelated, participated in the study. Mean age was 22.0 ± 8.0 yr (range: 6.5–41.0 yr). All patients were evaluated with QUS at radius and tibia and had DXA scan at lumbar spine vertebrae (L2–L4), whereas 20 patients were additionally assessed with DXA at the left hip (femoral neck, trochanter region and Ward’s triangle). Results: Results were expressed as Z‐scores compared with sex‐ and age‐matched population. Lowest mean Z‐scores measured with DXA were recorded at lumbar spine and Ward’s triangle (?1.1 ± 1.13 and ?0.95 ± 1.07, respectively). Lowest mean QUS‐derived Z‐scores were measured at radius, statistically significant compared with Z‐scores measured at tibia (?0.6 ± 1.1 vs. 0.4 ± 1.1, P < 0.001). QUS measurements at radius were significantly correlated to QUS measurements at tibia (r = 0.51, P = 0.002). The latter were correlated to BMD measured at lumbar spine (r = 0.516, P = 0.002) and at trochanter region (r = 0.646, P = 0.003). All BMD measurements at hip were significantly correlated to each other. Lumbar spine BMD was correlated to BMD at femoral neck (r = 0.607, P = 0.003) and to BMD at Ward’s triangle (r = 0.438, P = 0.027). Finally, no agreement was recorded between the two methods in identifying thalassaemic patients at risk for osteoporosis (κ = 0.203, P = 0.04). Conclusion: Quantitative ultrasound sonography could not serve as an alternate to DXA.     

Discrepancy in bone mineral densities at different skeletal sites in hip osteoarthritis patients

Abstract

Objective. Increased femoral neck bone mineral density (BMD) in a hip with osteoarthritis (OA) has been previously reported, however, it is possible that increased BMD at sites other than the hip joint is influenced by the disease process of OA. Therefore, we measured BMD at locations different from the hip joint and determined whether higher BMD was also observed at these different skeletal sites in hip OA patients.

Methods. We measured BMD in 68 women (average age 61.0 years) scheduled to undergo total hip arthroplasty for end-stage OA and 100 healthy women (average age 60.9 years) as age-matched controls. BMD at the lumbar spine, radius, and calcaneus was measured by dual-energy X-ray absorptiometry (DXA). Moreover, we measured speed of sound (SOS), broadband ultrasound attenuation (BUA), and stiffness index of the calcaneus by quantitative ultrasonography (QUS).

Results. BMD obtained by DXA at the lumbar spine and radius was significantly higher in hip OA patients than in controls. However, at the calcaneus, no significant differences were observed between the groups in BMD obtained by DXA. SOS, BUA, and stiffness index obtained by QUS were significantly lower in the OA group than in controls.

Conclusion. Higher BMDs of the spine and radius suggest that the incidence of osteoporosis is inversely associated with the incidence of OA. However, it remains unclear whether lack of difference in BMD and lower SOS, BUA, and stiffness index of the calcaneus in the OA group was secondary to the effect walking disturbance resulting from hip pain. Our data suggest that hip OA patients have higher BMD than healthy women, and that inactivity or immobilization caused by hip OA may reduce BMD in the lower limb.     

Risk assessment for osteoporosis by quantitative ultrasound of the heel in ankylosing spondylitis

OBJECTIVE: The aim of this cross-sectional cohort study is to assess the potential of quantitative ultrasound (QUS) of the calcaneus in pre-screening for vertebral/non-vertebral fractures, and in discriminating osteoporotic from normal bone density in patients with ankylosing spondylitis (AS); a second objective is to determine the prevalence of osteoporosis using dual-energy X-ray absorptiometry (DEXA) in this patient group. RESULTS: Included are 50 consecutive AS patients with no history of osteoporosis: mean (SD) age 52 (12) yrs, range 26-75 yr; female/male ratio 15/35. The mean (SD) DEXA T score in the lumbar spine (AP view) was -0.82 (1.73), mean (SD) DEXA T score in femoral neck -1.46 (1.12). The mean (SD) calcaneal QUS T score was -0.73 (0.95). In our population of AS patients the prevalence of femoral neck osteoporosis according to the WHO definition (DEXA T < -2.5) was 20%. Osteoporosis criteria were met at the femoral neck in 10 (20%) patients, and 7 of them (70%) were correctly diagnosed using QUS, with T < -1.0 as cut-off value; normal bone density at the femoral neck was found in 15 AS patients (30%), yet in 2 of them the calcaneal QUS T was < -1.0. In AS the 20% pretest probability of having femoral neck osteoporosis increased using calcaneal QUS, with a cut-off level T < -1.0 (70% sensitivity, 68% specificity), and then rose to 35% as the predictive value of a positive test, yielding a net result of QUS testing of +15%. The predictive value of a negative QUS test result was 90%, which makes QUS applicable to exclude severe osteoporosis. Vertebral and/or non-vertebral fractures occurred in 12 out of 50 AS patients (24%); 5 of them (10%) were associated with osteoporosis as defined by WHO criteria measured via DEXA. CONCLUSION: The performance of QUS is similar to DEXA in finding patients with osteoporosis-associated fractures: the sensitivity of QUS T < -1.0 in finding the fracture is 80%, and the sensitivity of femoral neck DEXA T < -2.5 in finding fractured patients is 60%. We conclude that both osteoporosis and fractures are common sequelae in AS. Calcaneal QUS offers a promising approach to screen for osteoporosis, and may be applied to exclude osteoporosis-associated high fracture risk in AS.     

Lack of correlation between the vitamin D receptor Fokl start codon polymorphism and bone mineral density in patients with Crohn's disease.

INTRODUCTION: We have examined the association of bone mineral density of patients with inflammatory bowel disease with a polymorphism in the gene encoding the vitamin D receptor. The thymine/cytosine (T/C) polymorphism in the first of two start codons can be defined by a restriction fragment length polymorphism using the restriction endonuclease FokI. Vitamin D receptor alleles containing the polymorphism have been denoted by f and alleles lacking the site by F. METHODS: We report on an association analysis of a basic population of 244 caucasian patients with Crohn's disease. We have genotyped the FokI polymorphism of the VDR in these patients and associated the genotype with the bone mineral density of the lumbar spine and the femoral neck. RESULTS: In the cohort 42% of the patients were scored FF homozygous, 43.7% Ff heterozygous, and 14.3% ff homozygous. 14.4% of the FF patients, 18.8% of the Ff patients, and 9.7% of the ff patients had osteoporosis of the lumbar spine and 21.25% of the FF patients, 25.3% of the Ff patients, and 18.5% of the ff patients had osteoporosis of the femoral neck. In this cohort no association between the genotype and the bone mineral density in the group as a whole nor when separated according to sex or age was found. CONCLUSIONS: In summary in our cohort no association of the FokI polymorphism and the BMD of the lumbar spine and femoral neck in patients with inflammatory bowel disease was found.     

Diagnostic value of calcaneal quantitative ultrasound in the evaluation of osteoporosis in middle-aged and elderly patients

To study the correlation between calcaneal quantitative ultrasound (QUS) and dual-energy X-ray absorptiometry (DXA), and analyze the diagnostic value of calcaneal QUS in the evaluation of middle-aged and elderly osteoporosis.We assessed bone mineral density (BMD) at the femoral neck and intertrochanteric of left hip and lumbar spine (L1–L4) sites with DXA and QUS parameters of the right and left calcanei in a cohort of 82 patients over the age of 50 years. Using DXA parameters as the gold standard for the diagnosis of osteoporosis, the correlation coefficient between BMD and QUS parameters was calculated. Receiver operating characteristic curve was generated and areas under the curves were evaluated. Cut-off values for QUS were defined.In men, there was a moderate correlation between calcaneal QUS and proximal femoral BMD (P < .05), but no significant correlation between calcaneal QUS and lumbar BMD (P > .05). In women, calcaneal QUS were moderately correlated with lumbar spine and proximal femoral BMD (P < .05). Using DXA as the gold standard, the accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of calcaneal QUS in the diagnosis of osteoporosis were 90.2%, 89.2%, 100%, 100%, and 50.0%, respectively. According to the receiver operating characteristic curve, when the QUS T-score of calcaneum was –1.8, the area under the curve was 0.888, the sensitivity was 73.21%, and the specificity was 92.31% (P < .05). When the QUS T-score of calcaneum was –2.35, the sensitivity was 37.2% and the specificity was 100%.Calcaneal QUS can be used to predict proximal femoral BMD in middle-aged and elderly people, as well as lumbar BMD in women. As a screening method for osteoporosis, calcaneal QUS has good specificity, so it can be recommended to use it as a pre-screening tool to reduce the number of DXA screening. When the QUS T-score of calcaneum is –1.8, it has the greatest diagnostic efficiency for osteoporosis; when the QUS T-score of calcaneum is ≤–2.35, it can be diagnosed as osteoporosis.     

Bone mineral density and quantitative ultrasound in adults with cystic fibrosis

OBJECTIVE: With increasing life span osteoporosis becomes a more recognized problem in patients with cystic fibrosis (CF). The aim of this cross-sectional study in 75 adult patients with CF (mean age 25.3 years) was to assess the prevalence of low bone mineral density (BMD) by dual-energy x-ray absorptiometry (DEXA) and, for the first time, by quantitative ultrasound (QUS), and to identify predicting factors. DESIGN AND METHODS: Bone status was assessed at the lumbar spine (L2-L4) and the femoral neck by DEXA, and at the calcaneus by QUS (stiffness index). These data were correlated with a variety of clinical and anthropomorphic variables. Biochemical markers of bone turnover such as osteocalcin, bone-specific alkaline phosphatase, crosslinks in urine, 25-hydroxy vitamin D (25-OH vitamin D), parathyroid hormone, calcium and free testosterone were determined by standard assays. RESULTS: The mean BMD T score (+/-s.e.m.) was -1.4+/-0.17 at the lumbar spine, and -0.54+/-0.16 at the femoral neck. The mean T score of the calcaneal stiffness index was -0.83+/-0.19. Based on a lumbar spine T score <-2.5 by DEXA, 27% of the patients had osteoporosis. Multiple regression analysis showed that the forced expiratory volume in one second (FEV1) and the use of oral glucocorticoids were independent predictors of low lumbar spine BMD, whereas body mass index (BMI) and the use of oral glucocorticoids were independent predictors of low femoral neck BMD. The stiffness index correlated moderately with BMD (0.49-0.62, P<0.0001). QUS had a sensitivity and specificity of only 57% and 89% respectively for diagnosing 'osteoporosis' (based on a femoral neck T score <-2.5 by DEXA). Positive and negative predictive values were 36% and 95% respectively. CONCLUSIONS: Low BMD is frequent in adults with CF and is most strongly correlated with disease severity (BMI, FEV1) and the use of glucocorticoids. Calcaneal QUS might help to screen out patients with a normal BMD, but sensitivity and specificity were not sufficiently high to replace DEXA in these patients.     

Bone mineral density evolution in young premenopausal women with idiopathic osteoporosis

Idiopathic osteoporosis is a frequent cause of osteoporosis in young premenopausal women. However, there are no data about the treatment of these patients. The aim of this study was to analyse the evolution of bone mineral density (BMD) in premenopausal women with idiopathic osteoporosis treated with a conservative approach. Retrospective study of 16 premenopausal women with idiopathic osteoporosis (aged 35.7±7 years) with a mean follow-up period of 3 years (1–6 years). BMD measurements at the lumbar spine and femoral neck were obtained in all patients at baseline and yearly (patients had one or more fragility fractures and/or a Z score <−2 in the lumbar spine or femur). Secondary causes of osteoporosis were excluded in all patients. Patients were treated with calcium and vitamin D to achieve a calcium intake of up to 1,500 mg/day and were advised to increase physical activity. A significant increase in lumbar and femoral BMD was observed after 2 and 3 years of follow-up, respectively (1.9±1.9% mean increase in lumbar spine, p= 0.021, at 2 years) (5.6±4.5% mean increase in femur, p=0.04, at 3 years). The serum total alkaline phosphatase (TAP) values increased at 2 years (122±46 vs 140±36 U/l, p=0.054). In addition, a negative correlation between baseline TAP serum values and lumbar BMD evolution at 2 years was observed (r=−0.748, p=0.013). No patient developed new skeletal fractures during the follow-up period. In young premenopausal women with idiopathic osteoporosis the conservative treatment with supplements of calcium and vitamin D associated with an increase of physical activity is associated with an increase in BMD without evidence of further skeletal fractures after more than 3 years of follow-up.     

Bone mineral density and frequency of osteoporosis among Vietnamese women with early rheumatoid arthritis

Generalised bone mineral density (BMD) reduction often occurs in established rheumatoid arthritis (RA); however, in early RA, there is a disagreement with regard to BMD in the femoral neck and lumbar spine, and there is no available information for the whole body. Therefore, the aims of this study were to investigate the BMD, frequency of osteoporosis and the risk factors for BMD reduction in Vietnamese women with early RA. BMD in the femoral neck, lumbar spine L1–4 and whole body was measured in 105 women with early RA (disease duration ≤3 years) and 105 age-matched healthy women (26–73 years) using a dual energy X-ray absorptiometry. Femoral neck and whole body BMD in women with RA were lower (p < 0.05) than controls, while lumbar spine BMD was similar between two groups. The frequency of osteoporosis in the femoral neck, lumbar spine and whole body in women with RA aged ≥50 were higher (p < 0.05) than controls: 41.8% versus 29.5%, 42.2% versus 37.7% and 37.1% versus 28%, respectively. There were associations between the frequencies of osteoporosis at all sites with postmenopausal status, glucocorticoid use, rheumatoid factor positivity and disease activity with lumbar spine BMD and disease disability with femoral neck and whole body BMD. In conclusion, women with early RA had significantly lower femoral neck and whole body BMD, but had similar lumbar spine BMD compared with controls. The frequency of osteoporosis at all sites was significantly higher in women with RA than controls, suggesting that assessment of BMD should be considered in women with early RA.     

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.     

Effects of sex steroids on bone in women with subclinical or overt endogenous hypercortisolism

OBJECTIVE: Glucocorticoid-induced osteoporosis is the most frequent cause of secondary osteoporosis. Nevertheless, limited data are available on bone status in patients with endogenous cortisol excess. This study is aimed at investigating the role of sex steroids and severity of hypercortisolism on bone mineral density (BMD) and prevalence of vertebral fractures in female patients. DESIGN: Cross-sectional, case-control study. Patients: Seventy-one consecutive women were enrolled: 36 with overt hypercortisolism (26 with ACTH-secreting pituitary adenoma and 10 with cortisol-secreting adrenal tumor) and 35 with subclinical hypercortisolism due to adrenal incidentalomas. They were compared with 71 matched controls. METHODS: At diagnosis, we measured serum cortisol, FSH, LH, estradiol, testosterone, androstenedione and DHEAS, and urinary cortisol excretion. BMD was determined by dual energy X-ray absorptiometry at the lumbar spine and femoral neck. Vertebral fractures were investigated by a semiquantitative scoring method. RESULTS: Between women with overt and subclinical hypercortisolism BMD values and prevalence of any vertebral (69 vs 57%, P = 0.56), clinical (28 vs 11.4%, P = 0.22), and multiple vertebral fractures (36 vs 31%, P = 0.92) did not differ. Among patients with subclinical hypercortisolism, amenorrhoic women had a lower BMD (P = 0.035) and more frequent vertebral fractures (80 vs 40%; P = 0.043) when compared with the eumenorrhoic ones. Among women with overt hypercortisolism, there was no difference in lumbar BMD (P = 0.37) and prevalence of fractures (81 vs 60%; P = 0.26) between those amenorrhoic and eumenorrhoic. By logistic regression analysis, lumbar spine BMD values and cortisol-to-DHEAS ratio were the best predictors of vertebral fractures (P < 0.01). CONCLUSIONS: Vertebral fractures are very common in women with endogenous cortisol excess, regardless of its severity. The deleterious effects of hypercortisolism on the spine may be partly counterbalanced by DHEAS increase at any degree of cortisol excess, and by preserved menstrual cycles in women with subclinical but not in those with overt hypercortisolism.     

Rapid spinal trabecular bone loss in female patients with ileitis terminalis Crohn and additional sacroiliac joint inflammation

Patients with Crohn's disease are well known to have local and generalized osteopenia of varying degrees. The aim of this study was to investigate whether the additional involvement of the sacroiliac joint as an extra-intestinal manifestation has an influence on bone turnover in female patients with Crohn's disease. Osteocalcin and other parameters of bone metabolism were measured in 79 female patients with Crohn's disease. Bone mineral density (BMD) was measured using dual energy X-ray absorptiometry (DEXA). Z scores were obtained by comparison with age- and sex-matched normal values. As regards the sacroiliac involvement (n = 26; group 1), we found a significantly lower BMD in the lumbar spine (L4) and in Ward's triangle of the femoral neck compared to controls (P < 0.05) and those patients (n = 53; group 2) with pure ileitis terminalis Crohn. Furthermore, the duration of the disease process in patients with Crohn's disease and extra-intestinal involvement was markedly shorter than that of patients in group 2 (P < 0.05). In conclusion, osteoporosis in female patients with sacroiliac involvement manifested itself in a more severe way. Received: 19 October 1996 / Accepted: 22 January 1997     

Femoral neck osteopenia in patients with inflammatory bowel disease

Objective: The mechanism of bone loss in patients with inflammatory bowel disease (IBD) is not completely understood. The aim of this study was to assess indices of bone turnover and bone mineral density (BMD) in the lumbar spine and femoral neck in IBD patients.
Methods: Sixty-three patients with Crohn's disease and 41 with ulcerative colitis were studied. Serum bone-specific alkaline phosphatase (B-ALP), osteocalcin, parathyroid hormone (PTH), 25 hydroxyvitamin D, interleukin-6 (IL-6), and urinary N-telopeptide cross linked type 1 collagen (NTX) were determined. BMD of the lumbar spine and femoral neck was determined by dual x-ray absorptiometry in 59 patients.
Results: In the femoral neck 42% of the patients had osteopenia (−2.5 SD < BMD T score < −1 SD) and another 41% had osteoporosis (BMD T score < −2.5). In the spine 34% of the patients had osteopenia and additional 42% had osteoporosis. BMD T scores were lower in the femoral neck compared to the spine. Reduced BMD was unrelated to gender, disease type, lifetime corticosteroid dose, but inversely correlated with disease duration ( r =−0.36 , p < 0.05 ). Serum IL-6 was higher in IBD patients compared to controls. A reduced level of osteocalcin, a marker of bone formation, was present in 7% of patients and an increase in NTX, a marker of bone resorption, in 25% of them. Osteoporotic IBD patients (spine or hip BMD T score < −2.5) had increased serum IL-6, osteocalcin and PTH level compared to nonosteoporotic patients.
Conclusions: There is a high prevalence of reduced BMD at the spine and femoral neck in IBD patients, which is more severe in the hip. Bone turnover in osteoporotic IBD patients is associated with an increase in osteocalcin, PTH and IL-6. IL-6 may play a role in the pathogenesis of bone loss in IBD.     

Analysis of risk factors for low bone mineral density in inflammatory bowel disease

BACKGROUND/AIM: Several risk factors have been suggested for osteoporosis which frequently occurs in inflammatory bowel disease (IBD) patients. We studied prevalence and risk factors for reduced bone mineral density (BMD) in IBD patients at the University Hospital of Zurich, Switzerland. METHODS: The BMD was determined by dual-energy X-ray absorptiometry at the lumbar spine and femoral neck in 88 IBD patients (55 with Crohn's disease, 30 with ulcerative colitis, and 3 with indeterminate colitis). Z scores were obtained by comparison with age- and sex-matched normal values, and T scores by comparison with sex-matched healthy young adults. Osteopenia and osteoporosis were defined according to the WHO guidelines. Predictive factors for BMD were analyzed by group comparison and stepwise regression analysis. RESULTS: Osteopenia was present in 43% of the patients at the lumbar spine and in 42% of them at the femoral neck. Osteoporosis was present in 14% of the patients at the lumbar spine and in 5% of them at the femoral neck. At the lumbar spine, stepwise regression analysis showed that body mass index, age, number of bowel resections, topic steroids, and azathioprine correlated with the Z scores. Cumulative steroid dose, topic steroids, age and bowel resection were found to be predictors for a pathological T score. At the femoral neck, regression analysis showed that body mass index, age, topic steroids, and azathioprine correlated with the Z scores. Only a low body mass index was a significant predictor for pathological femoral T scores. CONCLUSIONS: Osteopenia and osteoporosis are commonly found in IBD patients. Steroid treatment and bowel resection were significant risk factors for osteoporosis of the lumbar spine. However, disease-inherent factors also appear to confer a major risk, indicating that the BMD should be determined in all IBD patients, irrespective of steroid treatment.     

Ultrasound measurements of calcaneus for estimation of skeletal status in patients with inflammatory bowel disease.

BACKGROUND: Patients with inflammatory bowel disease (IBD) are at risk of developing metabolic bone disease. In diagnosing osteoporosis, bone mineral density (BMD) measurements play a key role. Our aims in this study were to assess the skeletal status with quantitative ultrasound (QUS) and to evaluate the ability of this method to predict BMD as measured by dual-energy X-ray absorptiometry (DXA) in IBD patients. METHODS: Altogether 53 patients with Crohn disease (CD) and 57 with ulcerative colitis (UC) were studied by using a Lunar Achilles ultrasound bone densitometer. The ultrasound variables are broadband ultrasound attenuation (BUA) and speed of sound (SOS). The lumbar spine, femoral neck, and total body BMD were measured with DXA. The age- and sex-adjusted values (Z-scores) were obtained by comparison with age- and sex-matched normal values. RESULTS: In CD patients Z-scores for both BUA and SOS were significantly less than zero, and Z-score for SOS was significantly lower than that for UC patients. Z-scores for BMD measured with DXA were significantly lower at all measurements in patients with CD. QUS and DXA measurements were significantly correlated. However, the agreement between the measurements in each individual patient was poor. Body mass index (BMI) was a major determinant for both BUA and SOS. In CD patients low QUS variables were associated with corticosteroid therapy, and both CD and UC patients with previous fractures had low SOS values. CONCLUSIONS: Our study indicates that QUS and DXA are not interchangeable methods for estimation of bone status. QUS variables are insufficient to provide accurate prediction of BMD values and should therefore not be recommended as a screening test for osteoporosis in IBD patients.     

Bone mineral density in ankylosing spondylitis

Summary Vertebral osteoporosis is a well-recognized feature of ankylosing spondylitis (AS) and also the vertebral compression fractures due to osteoporosis are a common but frequently unrecognized complication of AS. Both may contribute to the pathogenesis of spinal deformity and back pain. The aim of this study was to measure vertebral and femoral neck bone mass in patients with AS by dual photon absorptiometry, to determine the prevalence of compression fractures and to examine the relationship between bone density and disease severity. We found that the bone mass was diminished in the lumbar spine in moderate AS versus mild forms but the patients with advanced disease had the highest BMD values. Examination of spinal radiographs revealed compression and biconcave fractures in 9 (40.9%) cases. Neither the duration of the disease and the degree of sacroiliitis, nor the disease activity assessed by laboratory and clinical parameters was found to significantly affect the results.     

The role of quantitative ultrasound in predicting osteoporosis defined by dual X-ray absorptiometry

The aim of this study was to establish whether quantitative ultrasound (QUS) parameters could identify patients classified as osteoporotic and osteopenic on the basis of dual energy X-ray absorptiometry (DEXA). One hundred and twenty-three patients (39 male, 84 female) with osteoporosis and suspected of having osteoporosis were included in this study. Broadband ultrasound attenuation (BUA) and speed of sound (SOS) were measured and bone mineral densities (BMD) of the lumbar spine and left hip was measured by DEXA. Subjects were classified into three groups (normal, osteopenic and osteoporotic) on the basis of BMD T-scores measured by DEXA. QUS parameters of the osteoporotic group were significantly lower than those of osteopenic and normal groups; there was no difference in QUS parameters between the normal and osteopenic groups. Correlations of both right and left SOS and BUA with the spine and femoral neck BMD were moderate (r = 0.343-0.539, P < 0.001). There was also reasonable correlation between DEXA and QUS T-scores (r = 0.364-0.510, P < 0.001). QUS had a sensitivity of 21% and a specificity of 95% for diagnosing osteoporosis. We concluded that, although DEXA and QUS parameters were significantly correlated, QUS parameters can not predict osteopenia as defined by DEXA, and sensitivities and specificities of QUS parameters were not sufficiently high for QUS to be used as an alternative to DEXA.     

Quantitative computed tomography of the lumbar spine,not dual x-ray absorptiometry,is an independent predictor of prevalent vertebral fractures in postmenopausal women with osteopenia receiving long-term glucocorticoid and hormone-replacement therapy

OBJECTIVE: To determine which measurement of bone mineral density (BMD) predicts vertebral fractures in a cohort of postmenopausal women with glucocorticoid-induced osteoporosis. METHODS: We recruited 114 subjects into the study. All had osteopenia of the lumbar spine or hip, as demonstrated by dual x-ray absorptiometry (DXA), and were receiving long-term glucocorticoids and hormone replacement therapy (HRT). Measurements of BMD by DXA of the lumbar spine, hip (and subregions), and forearm (and subregions), quantitative computed tomography (QCT) of the spine and hip (n = 59), and radiographs of the thoracolumbar spine were performed on all subjects to assess prevalent vertebral fractures. Vertebral fracture prevalence, as determined by morphometry, required a >or=20% (or >or=4-mm) loss of vertebral body height. Demographic information was obtained by questionnaire. Multiple regression and classification and regression trees (CART) analyses were used to assess predictors of vertebral fracture. RESULTS: Twenty-six percent of the study subjects had prevalent fractures. BMD of the lumbar spine, total hip and hip subregions, as measured by QCT, but only the lumbar spine and total hip, as measured by DXA, were significantly associated with prevalent vertebral fractures. However, only lumbar spine BMD as measured by QCT was a significant predictor of vertebral fractures. CART analysis showed that a BMD value <0.065 gm/cm(3) was associated with a 7-fold higher risk of fracture than a BMD value >or=0.065 gm/cm(3).CONCLUSION: In postmenopausal women with osteoporosis induced by long-term glucocorticoid treatment who are also receiving HRT, BMD of the lumbar spine as measured by QCT, but not DXA, is an independent predictor of vertebral fractures.     

Usefulness of bone densitometry in postmenopausal women with clinically diagnosed vertebral fractures

OBJECTIVE: To analyse whether bone mineral density (BMD) assessment is required in postmenopausal women presenting with low trauma vertebral fracture. METHODS: Women with vertebral fracture diagnosed over a 10 year period were recruited from our database. The following were excluded: (a) patients with high energy trauma; (b) patients with malignancies; (c) patients with a metabolic bone disease other than osteoporosis. All postmenopausal women were included in whom BMD had been evaluated at both the lumbar spine and femoral neck by dual energy x ray absorptiometry during the six months after the diagnosis. Patients with a potential cause of osteoporosis other than age and menopause were not considered. A total of 215 patients were identified. RESULTS: The mean (SD) age of the patients was 65.9 (6.9) years. BMD at the lumbar spine was 0.725 (0.128) g/cm(2) and the T score was -2.94 (1.22); BMD at the femoral neck was 0.598 (0.095) g/cm(2) and the T score was -2.22 (0.89). The BMD of the patients was significantly lower than that of the general population at both the lumbar spine and femoral neck. When the lowest value of the two analysed zones was considered, six patients (3%) showed a normal BMD, 51 (23.5%) osteopenia, and 158 (73.5%) osteoporosis. The prevalence of osteoporosis at the femoral neck increased with age; it was 25% in patients under 60, 35% in patients aged 60-70, and 60% in patients over 70. CONCLUSION: These results indicate that bone densitometry is not required in postmenopausal women with clinically diagnosed vertebral fractures if it is performed only to confirm the existence of a low BMD.