Association of Primary Biliary Cirrhosis with Vitamin D Receptor BsmI Genotype Polymorphism in a Hungarian Population

We sought to determine the distribution of vitamin D receptor genotypes defined by the BsmI polymorphism and to investigate their association with bone mineral density in patients with primary biliary cirrhosis. Vitamin D receptor genotype and bone mineral density at the lumbar spine was determined in 31 female Hungarian patients with primary biliary cirrhosis and 51 age-matched healthy female controls. The genotype frequency (BB: 45%, Bb: 32%, bb: 22%) of the patients was significantly different from the control group (P = 0.01) due to an overrepresentation of the BB genotype. There was an apparent trend, not reaching statistical significance, for a lower bone mineral density in both the patient and control groups carrying a B allele. In conclusion, we found a strikingly high frequency of the BB genotype in patients with primary biliary cirrhosis, which raises questions about hormonal influences on the development of primary biliary cirrhosis.     

Incidence of vertebral fractures in the first three months after orthotopic liver transplantation

BACKGROUND AND OBJECTIVES: High rates of bone loss and increased fracture incidence have been reported in patients undergoing liver transplantation, mainly within the first post-operative year. The pathogenesis of post-transplantation bone disease has not been clearly established, but the high doses of glucocorticoids used for immunosuppression may contribute. The use of lower doses in recent years has been associated, in some studies, with lower rates of bone loss and decreased fracture incidence. The aim of this prospective study was to establish the incidence of vertebral fractures in the first 3 months in patients undergoing liver transplantation for chronic liver disease and to identify risk factors for fracture in these patients. DESIGN AND METHODS: Thirty-seven adults with end-stage liver disease were studied prospectively prior to and 3 months after liver transplantation. Vertebral fractures were assessed semi-quantitatively from lateral spine X-rays and bone mineral density measured using dual energy X-ray absorptiometry. RESULTS: Prior to transplantation, prevalent vertebral fractures were present in 13 patients (35%). New fractures developed after transplantation in 10 patients (27% of total) and were significantly more common in those with a prevalent vertebral fracture pre-operatively (P<0.02). Osteoporosis, defined as a bone mineral density T score below -2.5, was present in 39% of patients prior to transplantation, but bone mineral density was not helpful in predicting incident fracture, whether measured before or after transplantation. Over the 3-month study period, significant bone loss occurred in the femoral neck (P<0.05) but not the lumbar spine. CONCLUSIONS: Our results demonstrate a high incidence of vertebral fracture in the first 3 months after liver transplantation and indicate that prevalent vertebral fracture is an important risk factor for the subsequent development of fracture in these patients. Prevention of post-transplantation bone disease should focus both on optimizing bone mass prior to transplantation and preventing bone loss in the early post-operative period.     

The vitamin D receptor gene variant is associated with the prevalence of type 2 diabetes mellitus and coronary artery disease.

AIMS: Vitamin D can influence lipolysis and insulin secretion. A common genetic polymorphism of the vitamin D receptor, which has been found to be associated with bone mineral density, has also been reported to be associated with insulin-dependent diabetes mellitus. To test the influence of the vitamin D receptor polymorphism on the prevalence of Type 2 diabetes mellitus and coronary artery disease we studied a population of high-risk patients, who were referred to our clinic for diagnostic coronary angiography. METHODS: A total of 293 patients considered at high risk for coronary artery disease because of angina pectoris and known hypercholesterolaemia underwent diagnostic coronary angiography. The BsmI vitamin D receptor polymorphism was analysed by polymerase chain reaction. RESULTS: Prevalence of Type 2 diabetes mellitus and coronary artery disease was gradually dependent on the number of B alleles (BB 28%, Bb 13%, bb 8% for Type 2 diabetes mellitus, P = 0.002; BB 88% Bb 72%, bb 66% coronary artery disease, P = 0.01). Patients with the BB genotype had an odds ratio of 3.64 (95% confidence interval 1.53-8.55, P = 0.002) to have Type 2 diabetes mellitus compared with patients with the bb genotype. CONCLUSIONS: The genotype of the vitamin D receptor polymorphism determines the prevalence of Type 2 diabetes mellitus and coronary artery disease in a high-risk cohort population.     

Vitamin D receptor gene polymorphism in rheumatoid arthritis and associated osteoporosis

Rheumatoid arthritis (RA) is commonly associated with decreased bone mineral density (BMD) due to numerous factors. BsmI polymorphism of the vitamin D receptor (VDR) gene has been implicated in the pathogenesis of osteoporosis. Vitamin D has several immunomodulatory effects and thus may play a role in the course of arthritis. However, little data is available on the possible relationship between RA and VDR gene polymorphisms. In this study, the frequency of BsmI polymorphism genotypes were compared with that found in other countries. In this study, 64 RA patients and 40 healthy controls were tested for VDR gene BsmI polymorphism genotypes. Frequencies of B and b alleles were associated with markers of bone metabolism and RA. Among control subjects, the frequency of the BB genotype is relatively high (27.5%). In RA with secondary osteopenia/osteoporosis the BB genotype was more rare, the bb was more common than in control subjects. Markers of bone metabolism were associated with the B allele. RA patients carrying the B allele had lower BMD and increased bone loss over 1 year. The B allele was also correlated with increased osteoclast and osteoblast function, as determined by the assessment of biochemical markers of bone metabolism. Rheumatoid factor titer, which is an independent marker for disease progression in RA, was higher in bb patients. Our data suggest, that the imbalance in B and b allele expression may be involved in the pathogenesis of RA-associated osteoporosis. The possible involvement of vitamin D and VDR gene polymorphisms in the development and progression of RA needs further elucidation.Financial support: ETT 314/96 and ETT 60/2001 grants from the Medical Research Council of Hungary (Z.S.), and FKFP 18/2000 grant from the Research and Development in Highest Education Council (Z.S.).     

Vitamin D receptor,oestrogen receptor-alpha gene and interleukin-1 receptor antagonist gene polymorphisms in Hungarian patients with primary biliary cirrhosis

BACKGROUND : Genetic factors have been implicated in the pathogenesis of osteoporosis, a common disorder in primary biliary cirrhosis. Oestrogen receptor-alpha gene, vitamin D receptor gene and interleukin-1 receptor antagonist gene are all attractive candidates for osteoporosis susceptibility. We investigated the polymorphisms of the above genes and bone disease in Hungarian patients with primary biliary cirrhosis. PATIENTS AND METHODS : Thirty-three female patients with primary biliary cirrhosis were enrolled (age range, 39-72 years; anti-mitochondrial antibody M2 positive, stage II-IV). Eighty-four healthy and 76 osteoporotic age matched female subjects served as controls. Vitamin D receptor BsmI, interleukin-1 receptor antagonist gene variable- number tandem repeat and oestrogen receptor-alpha PvuII and XbaI polymorphisms were determined. Bone mineral density was measured by dual energy X-ray absorptiometry (XR26, Norland) in lumbar spine and femoral neck. RESULTS : The genotype frequency of vitamin D receptor BsmI (BB, 57.5%; Bb, 33.3%; bb, 9.1%) and oestrogen receptor-alpha PvuII (PP, 18.2%; Pp, 75.6%; pp, 6.2%) and XbaI (XX, 9.1%; Xx, 90.9%; xx, 0%) of the primary biliary cirrhosis patients was different from that of the healthy and osteoporotic control groups (P < 0.03 for each). Osteoporosis (t score < -2.5) was present in 42.4% of the patients. Osteoporotic primary biliary cirrhosis patients were older and had a longer disease history (P = 0.01 for both). No association was found between the polymorphisms and bone mineral density values at either position. CONCLUSIONS : We confirmed previous findings concerning the higher frequency of vitamin D receptor BsmI BB genotype in patients with primary biliary cirrhosis. The oestrogen receptor-alpha PvuII and XbaI Pp and Xx genotypes were more frequent in primary biliary cirrhosis patients, while interleukin-1 receptor antagonist gene variable-number tandem repeat polymorphism was not different. Since none of the polymorphisms was associated with bone mineral density, it is unlikely that these polymorphisms are essential in predicting bone mineral density in primary biliary cirrhosis.     

Osteoporosis after solid organs transplantation

Osteoporosis is a common complication following kidney, heart, liver and lung transplantation. Immunosuppressive regimens to prevent graft rejection after transplantation commonly include glucocorticoids, cyclosporin A and tacrolimus which are detrimental to bone and mineral homeostasis and are superimposed on an already compromised skeleton. Additional factors likely to contribute to post-transplantation osteoporosis pathogenesis are vitamin D insufficiency, secondary hyperparathyroidism and hypogonadism. Measures should be taken to optimize bone health prior transplantation: bone mineral density and spinal X-rays should be performed, and vitamin D and gonadal status assessed. Prophylaxis against bone loss after transplantation should be considered for all patients. Data from clinical trials suggest that bisphosphonates are the most promising agents for the prevention and treatment of post-transplantation osteoporosis.     

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.     

Secondary osteoporosis in liver transplant recipients: a longitudinal study in patients with and without cholestatic liver disease

BACKGROUND: Metabolic bone disease is one of the major long-term complications in liver transplant recipients, but it remains unclear which patients are at highest risk for developing severe bone disease following transplantation. METHODS: A total of 46 consecutive, adult patients with chronic liver disease accepted for a liver transplantation waiting list were prospectively included in the study. The patients were classified into two groups: group A--chronic cholestatic liver disease (n = 28), and group B--chronic non-cholestatic liver disease (n = 18). Bone mineral density (BMD) was measured at acceptance for the waiting list and at 3, 12 and 36 months following transplantation. Markers of bone turnover (serum-bone specific alkaline phosphatases (bALP), s-osteocalcin, s-1-collagen-C-terminal telopeptide (1-CTP) and urine N-terminal telopeptides u-Ntx) were measured at acceptance and at 3, 6, 12, 24 and 36 months following transplantation. BMD and markers of bone turnover were compared with similar values in a matched control group of 42 healthy individuals. RESULTS: BMD decreased significantly during the early post-transplantation period (median bone loss femoral neck (FN) 3 months post-transplant 8.5%). BMD levels declined slightly from 3 to 12 months following transplantation and increased thereafter. The relative bone loss was greatest among group B patients (relative bone loss FN 3 months post-transplant: group A, 8% versus group B, 13%; P = 0.04). At 36 months, 8/17 group A and 2/9 group B patients had BMD levels that exceeded the pretransplant levels (P = 0.12). The early bone loss was positively correlated with an increase in resorption markers (s-1-CTP and u-Ntx). Group B had higher levels of both s-1-CTP and u-Ntx at 3 and 6 months post-transplant than group A patients (P = 0.03). Bone formation markers increased slowly from 6 months post-transplant and onwards. Relative bone loss was positively correlated to total glucocorticoid dose during the first 3 months post-transplant. There were no differences in BMD between patients receiving tacrolimus versus those receiving cyclosporin A. CONCLUSION: Bone loss following liver transplantation is considerable in patients with both cholestatic and non-cholestatic liver disease, the first group has the poorest starting-point while the latter group has the greatest bone loss following transplantation. Bone loss is closely correlated with biochemical markers of bone resorption and total dose of glucocorticoids given post-transplant.     

Vitamin D receptor gene polymorphisms are associated with the risk of fractures in postmenopausal women, independently of bone mineral density

CONTEXT: Osteoporosis is a systemic disease with a strong genetic component. Vitamin D receptor (VDR) gene polymorphisms explain only a small part of the genetic influence on the level of bone mineral density (BMD), whereas their effect on fracture remains uncertain. OBJECTIVE: The objective of this study was to investigate the relationships between VDR genotypes and fracture risk. DESIGN: A prospective population-based cohort was studied. SUBJECTS: A total of 589 postmenopausal women (mean age, 62 yr) were followed prospectively during a median (interquartile) of 11 (1.1) yr. MAIN OUTCOME MEASURE: The study measured incidents of vertebral and nonvertebral fractures. RESULTS: VDR allele B was significantly and dose dependently overrepresented in women who fractured, including 34 and 86 women with first incident vertebral and nonvertebral fragility fractures, respectively. This corresponded to an odds ratio of 1.5 (95% confidence interval, 0.95-2.40) for heterozygous carriers (bB, n = 286) and 2.10 (95% confidence interval, 1.16-3.79) for homozygous carriers (BB, n = 90) of the B allele, compared with women with the bb genotype (n = 213). VDR genotype groups did not differ for demographics, physical activity, grip strength, personal and maternal history of fracture, and calcium intake. The association was independent of BMD of the spine, hip, and radius, and of the BMD loss at the radius. The relationship between VDR polymorphisms and fracture risk was not altered after adjustment for baseline circulating levels of bone turnover markers, estradiol, dehydroepiandrosterone sulfate, SHBG, IGF-I, intact PTH, and 25 hydroxyvitamin D. CONCLUSION: VDR genotypes are associated with the risk of fracture in postmenopausal women independently of BMD, rate of postmenopausal forearm BMD loss, bone turnover, and endogenous hormones. The mechanisms by which VDR genotypes influence bone strength remain to be determined.     

维生素D受体基因型与骨密度的关系

目的　了解维生素D受体 (VDR)基因的BsmI多态性在中国人群中的分布 ,并进一步探讨其与骨密度 (BMD)的关系。方法　应用聚合酶链反应 -限制性片断长度多态性解析 (PCR RFLPs)技术检测了 1 86例在长春地区生活 1 0年以上的无亲缘关系的绝经前健康汉族女性VDR基因型 ,用双能X线骨密度仪 (DEXA)测腰椎BMD ,同时考察它们之间的关系。结果　VDR基因型分布频率为Bb:2 3例 (1 2 .4% ) ,bb :1 63例(87.6 % ) ,BB型缺如。b等位基因在本组人群中分布高达 93 .8%。各型的BMD值分别为 :Bb型 (1 .1 87± 0 .0 88) g/cm2 ,bb型 (1 .1 53± 0 .1 1 2 ) g/cm2 ,两组比较差异无统计学意义 (P >0 .0 5)。结论　中国长春地区绝经前汉族女性的VDR基因的BsmI多态性与骨密度间无相关关系。     

Vitamin D receptor gene polymorphism in patients with sarcoidosis.

The active form of vitamin D, 1,25-dihydroxyvitamin D(3), is known to be produced at sites of granulomatous reactions in sarcoidosis. 1, 25-dihydroxyvitamin D(3) has multiple immunomodulatory effects, and acts as a promoter of multinucleated giant cell formation. Polymorphism of the vitamin D receptor (VDR) gene has recently been shown to be related to bone mineral density, and also associated with hyperparathyroidism and risk of prostatic carcinoma. Considering that this might affect sarcoidosis, we investigated polymorphism of the VDR gene in 101 patients with sarcoidosis and 105 healthy control subjects. Their genotypes were determined using polymerase chain reaction (PCR) and restriction fragment length polymorphism. In the patients with sarcoidosis, the BB, Bb, and bb genotypes accounted for 1.0%, 37.6%, and 61.4%, whereas in healthy control subjects the figures were 1.0%, 20.0%, and 79.0%, respectively. The difference in the genotype distribution between healthy control subjects and sarcoidosis patients was significant (p < 0.05) with the frequency of the B allele being elevated (p < 0.05). From the result, we suggest that in VDR gene polymorphism the B allele might be a genetic risk factor for sarcoidosis.     

611例汉族人维生素D受体基因多态性与骨密度关系研究

采用PCR-RFLP分析了611名上海地区汉族人的维生素D受体(VDR)基因型,并测量其骨密度(BMD),统计分析发现男女性VDR基因分布差异存在统计学意义,Bb基因型在男性中的分布频率(26.9%)高于女性(12.7%,P<0.01)。不同基因型的人群BMD差异无统计学意义。     

The vitamin D receptor gene variant and physical activity predicts fasting glucose levels in healthy young men.

AIMS: Vitamin D can influence lipolysis and insulin secretion. A common genetic polymorphism of the vitamin D receptor (VDR), which has been found to be associated with bone mineral density, has been reported to be also associated with Type 2 diabetes mellitus (DM). To test the influence of the VDR polymorphism on fasting glucose in healthy young men before the onset of Type 2 DM, we studied a homogeneous population of aircrew members. METHODS: A total of 1539 individuals were recruited during routine medical qualification for flying duty. Physical activity was assessed in all individuals and categorized into low physical activity ( 3 h per week). The BsmI VDR polymorphism was analysed by polymerase chain reaction. On the day of blood testing the individuals were fasting for at least 8 h overnight. Serum glucose was measured within 60 min after sampling venous blood. RESULTS: In young males with low physical activity (n = 752) gene carriers with the VDR genotype BB (n = 137) have significantly (P < 0.001) higher levels of fasting glucose (5.61 +/- 0.49 mmol/l) than gene carriers with the genotype Bb (n = 370; 5.44 +/- 0.44 mmol/l) or bb (n = 245; 5.38 +/- 0.44 mmol/l). Of BB gene carriers, 47% had fasting glucose levels > 5.55 mmol/l compared with 36% of Bb gene carriers and 34% of bb gene carriers (P = 0.018). This effect is absent in gene carriers with high physical activity (n = 787). CONCLUSIONS: The VDR genotype is associated with altered fasting glucose levels in young men with low physical activity. If this association is confirmed in other populations it might be worthwhile studying the particular benefits of an exercise programme in dependents of the VDR genotype.     

Secondary Osteoporosis in Liver Transplant Recipients: a Longitudinal Study in Patients With and Without Cholestatic Liver Disease

Background: Metabolic bone disease is one of the major long-term complications in liver transplant recipients, but it remains unclear which patients are at highest risk for developing severe bone disease following transplantation. Methods: A total of 46 consecutive, adult patients with chronic liver disease accepted for a liver transplantation waiting list were prospectively included in the study. The patients were classified into two groups: group A—chronic cholestatic liver disease (n = 28), and group B—chronic non-cholestatic liver disease (n = 18). Bone mineral density (BMD) was measured at acceptance for the waiting list and at 3, 12 and 36 months following transplantation. Markers of bone turnover (serum-bone specific alkaline phosphatases (bALP), s-osteocalcin, s-l-collagen-C-terminal telopeptide (1-CTP) and urine N-terminal telopeptides u-Ntx) were measured at acceptance and at 3, 6, 12, 24 and 36 months following transplantation. BMD and markers of bone turnover were compared with similar values in a matched control group of 42 healthy individuals. Results: BMD decreased significantly during the early post-transplantation period (median bone loss femoral neck (FN) 3 months post-transplant 8.5%). BMD levels declined slightly from 3 to 12 months following transplantation and increased thereafter. The relative bone loss was greatest among group B patients (relative bone loss FN 3 months post-transplant: group A, 8% versus group B, 13%; P = 0.04). At 36 months, 8/17 group A and 2/9 group B patients had BMD levels that exceeded the pretransplant levels (P = 0.12). The early bone loss was positively correlated with an increase in resorption markers (s-1-CTP and u-Ntx). Group B had higher levels of both s-1-CTP and u-Ntx at 3 and 6 months post-transplant than group A patients (P = 0.03). Bone formation markers increased slowly from 6 months post-transplant and onwards. Relative bone loss was positively correlated to total glucocorticoid dose during the first 3 months post-transplant. There were no differences in BMD between patients receiving tacrolimus versus those receiving'cyclosporin A. Conclusion: Bone loss following liver transplantation is considerable in patients with both cholestatic and non-cholestatic liver disease, the first group has the poorest starting-point while the latter group has the greatest bone loss following transplantation. Bone loss is closely correlated with biochemical markers of bone resorption and total dose of glucocorticoids given post-transplant.     

广西壮、汉族绝经后妇女维生素D 受体基因型与骨密度、骨代谢的关系

目的探讨维生素D受体基因(VDR)型在壮、汉族绝经后妇女中的分布及其与骨密度、骨代谢的关系.方法在广西居住20年以上的绝经后汉族妇女116名,壮族妇女82名.记录年龄、绝经年龄,测量身高、体重.采用双能X线吸收法测定骨密度(BMD);用聚合酶链反应-限制性片段长度多态性(PCR -RFLP)法测定受试者的VDR基因型;测定血清骨钙素(osteocalcin,OC)、尿脱氧吡啶啉(deoxypyridinoline,DPD)和尿肌酐(creatinine,Cr).结果壮、汉族妇女年龄、绝经年限、体重、体重指数、BMD、VDR基因型频率分布无显著性差异(P>0.05);BB、Bb、bb基因型检出率分别为6.57%、66.16%和27.27%;BB基因型组第2腰椎(L2)BMD比bb基因型组低10.03%,第4腰椎(L4)BMD分别较bb、Bb基因型组低9.63%和12.44%(P<0.05);BB基因型组骨质疏松发生率最高(46.15%),Bb基因型组次之(19.85%),bb基因型组最低(14.81%)(P<0.05);BB基因型组OC最低,与Bb、bb 基因型组比较也有显著性差异(P<0.05);三组间尿DPD排泄率(DPD/Cr)差异无统计学意义.结论 VDR基因型可作为预测广西壮、汉族绝经后妇女骨质疏松危险性的遗传学标志.     

Vitamin D receptor gene polymorphism is associated with birth height, growth to adolescence, and adult stature in healthy caucasian men: a cross-sectional and longitudinal study

Vitamin D receptor (VDR) polymorphism has been associated with bone mineral density (BMD), but recent data indicate association to parameters of body constitution and growth. We investigated VDR gene polymorphism, defined by BsmI and TaqI, in 90 healthy Caucasian males and any relation with parameters of body constitution at birth, and to parameters of body constitution, BMD and bone area, at age 16.9 +/- 0.3 yr (mean +/- SD) and at age 19.2 +/- 0.7. Using PCR and the restriction enzyme BsmI and TaqI, the allelic variants BB, Bb, and bb, and TT, Tt, and tt were identified. Height (cm) and weight (kg) were measured using standardized equipment, and BMD of the total body, lumbar spine, and femoral neck, and bone area (cm2) of the total body, humerus, femur was measured using dual-energy x-ray absorptiometry. BsmI and TaqI genotypes were related in 89 of the 90 cases; hence, the same associations were found for both genotypes. Boys with the BB genotype were shorter at birth (P = 0.01) and grew less from birth to age 16.9 +/- 0.3 (P = 0.01) than their Bb and bb counterparts. Both during puberty (age 16.9 +/- 0.3) and after puberty (age 19.3 +/- 0.7), the BB boys were shorter (P = 0.005-0.008) and had lower bone area of the humerus, femur, and total body (P < 0.05) than the Bb and bb boys. The allelic variants were not related to BMD at any site. A prediction model including parental height, birth height, birth weight, and VDR alleles could predict up to 39% of the total variation in adult height in our population. The VDR allelic variants alone contributed to 8% of the total variation.     

Bone metabolism alterations after kidney transplantation

Early after renal transplantation (RT) a rapid decrease in bone mineral density at the lumbar spine, femoral neck, and femoral shaft has been documented. In addition, an appreciable proportion of patients still remain losing bone late after RT. As a consequence, RT patients are at a high risk of bone fractures as compared to general population. Most fractures involve appendicular skeleton, particularly the feet and ankles, and the diabetic patient is at increased risk of fractures. Thus, early institution of preventive measures and treatment of established osteoporosis are central. The major cause of post-transplantation bone loss is corticosteroid treatment, and this should be used at the lower dose compatible with graft survival. Preexisting hyperparathyroidism also affects the early cancellous bone loss at the spine, and post-transplantation bone loss reflects variable individual susceptibility, resembling the polygenic determination of bone mineral density in general. Clinical trials have demonstrated that bisphosphonates or vitamin D plus calcium supplementation, prevent post-transplantation bone loss during the first 6-12 months. However, their role in preventing bone fractures has not been proven. Finally, recommendations for management, prevention and treatment, are summarized.     

Parathyroid hormone gene polymorphisms in primary hyperparathyroidism

OBJECTIVE: Genetic contributions to bone mineral density (BMD) and bone turnover are well known. In the present study, we analysed the relationship between restriction fragment length polymorphisms of the PTH gene and the development of primary hyperparathyroidism (pHPT) as well as its severity. PATIENTS: Seventy-nine pHPT patients and 104 age-matched healthy controls were analysed. DESIGN AND MEASUREMENTS: PTH genotypes were determined by polymerase chain reaction and BstB I or Dra II restriction fragment length polymorphisms. The presence and absence of BstB I or Dra II restriction sites of the PTH gene were indicated by B and b or D and d, respectively. BMD levels at the lumbar spine and at the radius were measured in all subjects. Serum levels of calcium, phosphorus, alkaline phosphatase and intact PTH were measured in pHPT patients. RESULTS: There were no differences in the frequencies of these PTH genotypes between pHPT patients and controls. In control subjects, lumbar BMD was significantly higher in BB genotype than in Bb/bb genotypes. In pHPT patients, there was no difference of BMD between BB and Bb/bb genotypes. In pHPT patients, serum calcium level was significantly higher in those with the BB genotype than Bb/bb genotypes. On the other hand, there was no association between Dra II polymorphism and BMD in both controls and pHPT patients, but serum intact PTH level was significantly higher in DD genotype than Dd/dd genotype in pHPT patients. Moreover, serum levels of ALP and intact PTH were significantly higher in the PTH BBDD haplotype, compared to those in haplotypes other than BBDD. CONCLUSIONS: The present study suggests that the BstB I polymorphism of PTH gene is closely related to bone mineral density and that PTH gene polymorphisms do not seem to affect the development of primary hyperparathyroidism but may relate to the severity of primary hyperparathyroidism.     

Rates of vertebral bone loss before and after liver transplantation in women with primary biliary cirrhosis.

Atraumatic fractures caused by osteoporosis may be a serious complication of primary biliary cirrhosis. Mean (+/- S.D.) bone mineral density in the lumbar spine in 210 ambulatory women with primary biliary cirrhosis was 1.02 +/- 0.19 gm/cm2, 7% lower than that in 139 age-matched normal women (after adjustment for age and body weight) (p less than 0.001). Bone mineral density in the lumbar spine was inversely related to a risk score index of liver disease severity (r = -0.29, p less than 0.001). The mean rate of bone loss in 105 of these 210 women was 2%/yr +/- 4%/yr, twice as great as in the 139 normal women (p less than 0.02). In 20 women with primary biliary cirrhosis followed up after orthotopic liver transplantation, bone mineral density in the lumbar spine decreased at 3 mo (p less than 0.01), and this decrease may have resulted in atraumatic fractures in 13 of them. Bone mineral density in the lumbar spine then increased (p less than 0.01) so that by 12 mo the median bone mineral density in the lumbar spine was similar to that before transplantation and by 24 mo it was 5% above it. Therefore we conclude that the progressive bone loss observed in primary biliary cirrhosis (which is further accentuated immediately after transplantation) may be halted, and the bone mass may be restored toward normal within 2 to 3 yr after orthotopic liver transplantation.     

Bone mineral metabolism in adults with beta-thalassaemia major and intermedia

Bone disease is an important cause of morbidity in older patients with beta-thalassaemia major and intermedia. We studied 27 women and 23 men with beta-thalassaemia major (37) and intermedia (13) whose mean age was 32.3 +/- 9.7 years. Bone mineral density (BMD) of the lumbar spine, femoral neck and distal radius was determined by dual-energy X-ray absorbiometry (DXA). The longitudinal change in BMD over a mean of 5.6 years was determined in 19 patients. Serum 25-hydroxyvitamin D, insulin growth factor-1 (IGF-1), bone formation markers bone-alkaline phosphatase, osteocalcin and the resorption marker urinary N-telopeptide cross-linked type 1 collagen (NTx) were determined. The BsmI vitamin D receptor (VDR) gene polymorphism was analysed. Reduced BMD (Z-score < -2) was present in 89%, 62% and 73% of patients in the spine, hip and radius respectively. Vitamin D deficiency was found in 62%, decreased IGF-1 in 72% and increased urinary NTx in 84% of patients. Serum IGF-1 correlated with spine and hip BMD (r = 0.4, r = 0.39, P < 0.01 respectively), and NTx correlated with the hip BMD Z-score (r = 0.35 P < 0.05). The mean annual percentage change in spine BMD was -1.36%. Patients with the VDR BB genotype had lower spine BMD than patients with the bb genotype. In conclusion, bone loss continues in adult thalassaemia patients and is associated with increased bone resorption and decreased IGF-1. The BsmI VDR gene polymorphism is associated with osteopenia in thalassaemia.