Bone mineral density changes within 11 months of renal transplantation in Iranian patients

BACKGROUND AND AIM: We studied bone mineral density (BMD) changes in Iranian patients with end-stage renal disease (ESRD) within 11 months after renal transplantation. METHODS: Among 68 ESRD candidates for renal transplantation, the BMD at the femur and the spine were assessed using a DEXA Norland scanner. Linear regression analysis was used to identify risk factors associated with low bone density. RESULTS: Mean BMD, T-score and Z-score of femur and spine were significantly reduced (at femur, 0.78 +/- 0.14, -2.4 +/- 1.1, -1.6 +/- 1.0; at spine, 142.25 +/- 105, -1.09 +/- 1.1, -1.07 +/- 0.9). Osteoporosis and osteopenia were found 55.2% and 36.2% at the femur and 8.6% and 58.6% at the spine, respectively. The BMD showed a significant negative association with age (r=0.615), female gender (r=0.394), and corticosteroid intake (r=0.286), and a positive association with weight (r=0.394) and body mass index (r=0.626). There was no significant association between BMD measurements and calcium, phosphorous, or parathyroid hormone levels. At 11 months follow-up, in 20 patients, the subject had lost a mean of 2.4% T-score and 2.8% Z-score at spine (P=.027 and .13, respectively), but did not experience significant declines at the femur. BMD showed a decrease in 80% of recipients in the spine area; there was a 15% BMD increase at the hip. CONCLUSION: Low bone density is common among ESRD Iranian patients. Early screening and treatment of this group is recommended. Significant loss in lumbar density occurred within 11 months of transplantation in more than one third of a prospective cohort of renal transplant recipients.     

Low peak bone mineral density in healthy Lebanese subjects

Osteoporosis is a major public health problem in Western countries and is projected to have a similar impact in the Middle East. It has been suggested that peak bone mineral density (BMD), a major determinant of osteoporotic fractures later in life, may be lower in this part of the world compared with the Western world. However, subjects have not been randomly selected or systematically screened to rule out secondary causes of bone loss. The purpose of this study was to determine peak bone mass and lifestyle risk factors for bone loss in a randomly chosen sample of healthy Lebanese subjects from the greater Beirut area. Subjects 25-35 years of age were randomly selected from greater Beirut, which comprises one third of the Lebanese at large, and studied during the Fall of 1999. BMD was measured at the lumbar spine, hip, forearm, and total body. A questionnaire on lifestyle factors was administered to all subjects. Results were compared with the database of subjects from the USA provided by the manufacturer, and to the NHANES database for the total hip. Two hundred thirteen subjects were studied; 45 subjects rotated at all three centers for cross-calibration purposes. Peak BMD in Lebanese subjects was 0.2-0.9 SD below that of peak BMD in American subjects, depending on skeletal site, gender, and densitometer. These differences persisted after attempting to adjust for body size. Osteoporosis and osteopenia were more prevalent than in healthy young Americans. Height, weight, and total body fat were the most significant correlates of BMD/bone mineral content (BMC), accounting for 0.3-0.7 of the variance in bone mass measurement. Lifestyle factors had a very modest but significant contribution to bone mass variance. This is the first population-based study from the Middle East demonstrating that peak BMD is slightly lower in Lebanese subjects compared as with an established database from the USA. Due to the selection of relatively healthier subjects in our study than in the NHANES study, the actual differences between the two populations may be even greater. The impact of our findings on the epidemiology of osteoporotic fractures in Lebanon remains to be determined.     

Sex differences in peak adult bone mineral density

Osteoporotic fractures are more common in women than men. Although accelerated bone loss following the menopause is recognized as of major importance, it is generally considered that a lower peak adult bone mass in females also contributes to their increased risk of osteoporosis in later life. To examine potential sex differences in peak adult bone mass we studied 29 pairs of dizygotic twins of differing within-pair sex in whom the female twin was premenopausal (mean age 37 years, range 21-55). Bone mineral density (BMD, g/cm2) was measured at the lumbar spine and femoral neck by dual-photon absorptiometry; 22 pairs also had BMD measured in the distal and 21 pairs in the ultradistal radius by single-photon absorptiometry. There was no significant difference in usual dietary calcium intake or tobacco consumption between the twin pairs. Consistent with accepted dogma, BMD at both radial sites were higher (+27%) in the males than their female cotwins. In contrast, there was no sex difference (male versus female) in BMD (mean +/- SEM) in the femoral neck (0.96 +/- 0.02 versus 0.97 +/- 0.03), and surprisingly, the females had a greater lumbar spine BMD than their male cotwins (1.19 +/- 0.03 versus 1.26 +/- 0.03, p less than 0.05). This difference was observed despite the fact that the males were taller (p = 0.033). If the femoral neck BMD values in the females were corrected for this difference in BMI, their values (0.99 +/- 0.03 g/cm2) were significantly higher than those in their male cotwin (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Early rapid loss followed by long-term consolidation characterizes the development of lumbar bone mineral density after kidney transplantation

BACKGROUND: Bone mineral density (BMD) decreases significantly early after renal transplantation. This prospective study was designed to evaluate the long-term lumbar BMD development. METHODS: Sixty-three renal-transplant recipients (mean age 44 +/- 12 years, 37 [59%] male) underwent serial yearly posttransplant laboratory parameter and BMD measurements of the lumbar spine (dual energy x-ray absorptiometry). Combined maintenance immunosuppression included prednisolone in 95% of patients. The minimum number of consecutive scans was three; the maximum number seven (n = 15). Examinations were performed between 3 +/- 2 and 68 +/- 4 months posttransplant. RESULTS: BMD was significantly lower compared with healthy controls at all times after transplantation. t scores were below -1. BMD development revealed a biphasic pattern: between 3 +/- 2 and 10 +/- 2 months, a significant BMD decrease of -0.016 +/- 0.055 g/cm2 (-1.6%, P = 0.024) occurred. Later, a moderate increase resulting in BMD stability until the sixth year posttransplant was detected. Within the first year, posttransplant osteocalcin (from 19 +/- 15 to 32 +/- 23 microg/L) and calcitriol (from 24 +/- 15 to 43 +/- 24 ng/L) displayed a significant increase. Compared with patients with a pronounced decrease, patients with a substantial increase in early posttransplant BMD had a lower baseline BMD (0.989 +/- 0.131 vs. 1.149 +/- 0.202 g/cm2 [P = 0.0122]) and lower creatinine levels (105 +/- 23 vs. 141 +/- 53 mmol/L [P = 0.0227]). CONCLUSION: Our study confirms a significant decrease of lumbar BMD early after renal transplantation. Bone loss was less pronounced than previously described. The longitudinal follow-up verifies a previously assumed biphasic lumbar BMD development: after the first year, no further significant bone loss occurred, and bone density remained relatively stable at significantly lower levels compared with healthy controls.     

Interleukin-6 gene polymorphism is related to bone mineral density during and after puberty in healthy white males: a cross-sectional and longitudinal study.

Bone mineral density (BMD) is under strong genetic control and is the major determinant of fracture risk. The cytokine interleukin-6 (IL-6) is an important regulator of bone metabolism and is involved in mediating the effects of androgens and estrogens on bone. Recently, a G/C polymorphism in position -174 of the IL-6 gene promoter was found. We investigated this genetic polymorphism in relation to BMD during late puberty and to peak bone mass, in healthy white males. We identified the IL-6 genotypes (GG, GC, and CC) in 90 boys, age 16.9 +/- 0.3 years (mean +/- SD), using polymerase chain reaction (PCR). BMD (g/cm2) at the femoral neck, lumbar spine, and total body was measured using dual energy X-ray absorptiometry. The volumetric BMD (vBMD; mg/cm3) of the lumbar spine was estimated. Differences in BMD in relation to the genotypes were calculated using analysis of variance (ANOVA). Subjects with the CC genotype had 7.9% higher BMD of the femoral neck (p = 0.03), 7.0% higher BMD of the lumbar spine (p < 0.05), and 7.6% higher vBMD of the lumbar spine (p = 0.04), compared with their GG counterparts. Using multiple regression, the IL-6 genotypes were independently related to total body BMD (CC > GG; p = 0.03), humerus BMD (CC > GG; p < 0.05), neck BMD (CC > GG; p = 0.01), spine BMD (CC > GG; p = 0.01), and spine vBMD (CC > GG; p = 0.008). At age 19.3 +/- 0.7 years (mean +/- SD; 88 men) the IL-6 genotypes were still independent predictors for total body BMD (CC > GG; p = 0.03), humerus BMD (CC > GG; p = 0.03), spine BMD (CC > GG; p = 0.02), and spine vBMD (CC > GG; p = 0.003), while the IL-6 genotypes were not related to the increase in bone density seen after 2 years. We have shown that polymorphism of the IL-6 gene is an independent predictor of BMD during late puberty and of peak bone mass in healthy white men.     

Bone mineral density in the normal Iranian population: a comparison with American reference data

Summary In order to establish the normative curves for BMD in Iranian individuals, we measured BMDs at the lumbar spine and femoral regions of 760 women and 632 men using dual-energy X-ray absorptiometry. This study provides a baseline normative for Iranian individuals. BMD values of Iranian subjects were generally lower than those of the American population. Introduction In order to establish the normative curves for BMD in Iranian individuals, we measured BMDs at the lumbar spine and femoral regions. The BMDs at the lumbar spine and femoral neck regions of 760 women and 632 men, which were selected by multi-stage random sampling, were measured using dual-energy X-ray absorptiometry (DXA). Results The peak bone mass in the males and females at the lumbar spine was reached around the age of 28.5±1.5 and 30±2 and at the neck of the femur was reached around the age of 24±1.5 and 33±2. About 16.4% and 3% of men aged 50 and older were osteoporotic according to American reference data, respectively, but using Iranian normative data for L2-L4 and the neck of the femur, the corresponding values were only 13.4% and 2.1%. Using American reference data, the respective values in women aged 50 and older for the same regions were 44.4% and 12%, whereas according to the Iranian normative data, the corresponding rates were 41.1% and 10.4%. Conclusions This study provides a baseline normative for Iranian individuals. Due to the differences in ethnicity, diet, lifestyle, and small body size, BMD values of Iranian subjects were generally lower than those of the American population.     

Comparison of bone parameters by dual-energy X-ray absorptiometry and peripheral quantitative computed tomography in Hutterite vs. non-Hutterite women aged 35-60 years

A previous report of elevated dual-energy X-ray absorptiometry (DXA) bone mineral density (BMD) Z scores suggests that Hutterite females might be significantly less likely to develop osteoporosis compared with other U.S. females. In the present study, we sought to determine if high Hutterite DXA BMD Z scores were elevated because of larger bone size. Hutterites reside in isolated, self-sufficient colonies with an emphasis on agricultural production, and girls enter a strenuous task rotation at age 15 years. We obtained cross-sectional bone measurements of the 66% distal tibia using peripheral quantitative computed tomography (pQCT) to compare bone size and geometry on 97 Hutterite and 30 non-Hutterite women, aged 35-60 years. Total body (TB) and lumbar bone mineral content (BMC), BMD, and bone area measurements by DXA were available on a subset of the study population. We identified no differences between groups in pQCT total bone area, cortical bone area, or cortical bone density. Larger bone area by DXA was apparent in Hutterites compared with non-Hutterites at the TB (least square means: 2038 +/- 8 cm2 vs. 1953 +/- 19 cm2, p < 0.05) and lumbar (least square means: 58 +/- 0.5 cm2 vs. 57 +/- 2 cm2, p < 0.01) sites. TB BMC adjusted for TB bone area was marginally higher in Hutterites compared with non-Hutterites (least square means: 2341 +/- 15 g vs. 2281 +/- 30 g, p = 0.08). Hutterites had marginally higher TB BMD Z scores when controlling for weight and age (least square means: 1.3 +/- 0.1 vs. 0.8 +/- 0.2, p = 0.07). Hutterites had higher lumbar BMC adjusted for lumbar bone area and weight (least square means: 65 +/- 1 g vs. 58 +/- 2 g, p < 0.01) and higher weight-and age-adjusted lumbar BMD Z scores (least square means: 1.1 +/- 0.1 vs. 0.1 +/- 0.4, p = 0.01). Our data indicate that a true advantage in trabecular bone density probably exists among Hutterite women aged 35-60 years. Hutterite women might be protected against age-related fractures because of their larger bone size and higher bone density at normally susceptible trabecular sites.     

Evaluation of bone mineral density in postmenopausal women in Kuwait

Menopause is the major risk factor for the loss of bone mineral density (BMD) and bone mineral content (BMC) in women. In this study, we determined the prevalence of osteoporosis in postmenopausal women in Kuwait and compared it with that of other Middle East and west countries. Two thousand two hundred ninety-six postmenopausal women ranging in age from 40 to 87yr were included in the study and divided into 4 age groups by decade. We measured body weight, height, body mass index (BMI), BMD, and BMC. The mean age, height, and weight were 59.1+7.9yr, 154.7+6.5cm, and 77.3+14.9kg, respectively. The mean BMI and BMC were 32.4+6.6kg/m(2) and 0.9+0.14g/cm(2), respectively. The average T-scores for the hip and lumbar spine were -0.280+1.2 and -1.297+1.33, respectively. BMC significantly decreased with age from 0.95 to 0.81g/cm(2). Four hundred forty-four (19.3%) were found to have osteoporosis. The incidence of osteoporosis significantly increased from 4.3% to 39.9% with age, which is lower than that reported for Saudi (40%) and Moroccan women (39.6%) and higher than that for US/European (31%) and Lebanese women (11%).     

Male sex and low physical activity are associated with reduced spine bone mineral density in survivors of childhood acute lymphoblastic leukemia.

Survivors of acute lymphoblastic leukemia (ALL) are at risk of osteoporosis and obesity. We studied bone mineral density (BMD), percent of fat mass (%FM), and activity levels in survivors of ALL treated without radiotherapy. Lumbar and total areal BMD (g/cm2) and %FM were measured in 28 survivors (aged 5.7-14.7 years) of childhood ALL by dual-energy X-ray absorptiometry (DXA) scan (GE Lunar, Prodigy) an average of 5 years after completion of chemotherapy (UK Medical Research Council randomized trial protocol XI [UKALL XI]). One boy fractured his arm during treatment. Apparent volumetric lumbar BMD (BMD(vol); g/cm3) was calculated and %FM was adjusted for sex and age (%FM(adj)). Physical activity was measured by accelerometer and questionnaire. The results were compared with 28 sex- and age-matched healthy controls. Total body and lumbar areal BMD (g/cm2) were not different between the ALL group and the control group. However, mean lumbar BMD(vol) in survivors of ALL was significantly lower than in controls (0.303 +/- 0.036 g/cm3 vs. 0.323 +/- 0.03 g/cm3; p < 0.01), which mostly was caused by the difference in boys (0.287 +/- 0.032 g/cm3 vs. 0.312 +/- 0.027 g/cm3; p < 0.05). Weekly activity score by questionnaire was significantly lower in the ALL group than in the control group (geometric mean 50 vs. geometric mean 74; p < 0.05). Male gender, low activity levels and an intravenous (iv) high dose of methotrexate were associated with low lumbar BMD(vol). Patients who received an iv high dose of methotrexate (n = 18) had significantly higher %FM(adj) than those with intrathecal methotrexate only (n = 10; 141 +/- 70% vs. 98 +/- 37%;p < 0.05). In conclusion, male survivors of childhood ALL have reduced lumbar BMD(vol), whereas no such difference was seen in girls. Overall, survivors of ALL were physically less active than their healthy controls and lower activity correlated with lower lumbar BMD(vol) and higher %FM(adj).     

Antecedent 99mTc-MDP and 99mTc-sestamibi administration corrupts bone mineral density measured by DXA.

Previous reports of the effect of antecedent administration of radionuclide on bone mineral density (BMD) measurements have yielded inconsistent results. Ten subjects scheduled for (99m)Tc-methylene diphosphonate ((99m)Tc-MDP) bone scanning and 10 scheduled for (99m)Tc-sestamibi cardiac scanning had BMD measured by dual X-ray absorptiometry (DXA) (GE/Lunar) before and within 5 hours of diagnostic radionuclide injection. Paired t test and Wilcoxon-signed rank tests were used to compare the measured differences in BMD at multiple skeletal sites. Differences were subjected to multivariate analysis of demographic factors. Mean change in measured BMD following (99m)Tc-sestamibi administration (DeltaBMD-(99m)Tc-sestamibi) was -0.216+/-0.113 g/cm(2) at the total body and -0.348+/-0.300 g/cm(2) at the lumbar spine (p<0.005). Mean change in measured BMD following (99m)Tc-MDP administration (DeltaBMD-(99m)Tc-MDP) was -0.058+/-0.037 g/cm(2) at the total body and -0.053+/-0.049 g/cm(2) at the lumbar spine (p<0.05). Mean DeltaBMD-(99m)Tc-sestamibi exceeded least significant change (LSC) in all skeletal sites except the femoral trochanter. Mean DeltaBMD-(99m)Tc-MDP exceeded LSC only at the lumbar spine. The effect was correlated with (99m)Tc dose but not with gender, age, body mass index, baseline BMD, or time interval from injection to scan acquisition. In conclusion, BMD measured by the GE/Lunar Prodigy densitometer is corrupted by antecedent (99m)Tc-sestamibi and to a lesser extent by (99m)Tc-MDP. This effect is greater at the total body and lumbar spine than at the hip. Caution is warranted in scheduling and interpreting DXA studies when (99m)Tc has been recently administered.     

Influence of bone mineral density on pedicle screw fixation : a study of pedicle screw fixation augmenting posterior lumbar interbody fusion in elderly patients

BACKGROUND CONTEXT: Some biomechanical studies have demonstrated that bone mineral density of the lumbar spine (BMD) affects the stability of pedicle screws in vitro. PURPOSE: To investigate influence of BMD on loosening and related failure of pedicle screws in vivo. STUDY DESIGN/SETTING: A clinical study of 52 patients who underwent pedicle screw fixation augmenting posterior lumbar interbody fusion (PLIF). PATIENT SAMPLE: There were 13 men and 39 women, with an average age of 63 years (range, 45-76 years) at the time of operation. The mean follow-up period was 2.8 years (range, 2-6 years). OUTCOME MEASURES: Relationship between BMD, screw loosening, and its related failures were statistically analyzed. METHODS: BMD was measured by the dual energy X-ray absorptiometry (DEXA) method. Radiographic assessments were done by the first author and independently by another orthopedist who was not informed of the values of BMD. RESULTS: The mean BMD of all patients was 0.879 +/- 0.215 (mean +/- S.D.) g/cm2. The mean BMD in patients with and without screw loosening was 0.720 +/- 0.078 g/cm2 (n=11) and 0.922 +/- 0.221 g/cm2 (n=41). There was a significant difference between the mean BMD of patients with and without screw loosening (P<.01). The mean BMD of patients with "union," "nonunion" and "undetermined union" was 0.934 +/- 0.210 g/cm2 (n=40), 0.674 +/- 0.104 g/cm2 (n=4) and 0.710 +/- 0.116 g/cm2 (n=8), respectively. The mean BMD of patients with "union" was significantly greater than those with "nonunion" and "undetermined union" (P<.05). CONCLUSION: It could be concluded that BMD has a close relation with the stability of pedicle screws in vivo, and BMD value below 0.674 +/- 0.104 g/cm2 suggests a potential increased risk of "nonunion" when pedicle screw fixation is performed in conjunction with PLIF.     

The effect of multiple pregnancies on lumbar bone mineral density in Japanese women

OBJECTIVE: To elucidate the effect of multiple pregnancies on lumbar spine bone mineral density (BMD). METHODS: The BMD of the lumbar spines (L2-L4) of 1,113 healthy women was measured within 7 days of childbirth. In addition 113 women had spine BMD measurements after their next delivery. RESULTS: In the cross-sectional study, there was no apparent effect of parity on lumbar BMD. In the longitudinal study, the mean BMD after the next delivery was significantly higher than that after the initial delivery (1.019 +/- 0.115 g/cm(2) vs. 1.006 +/- 0.117 g/cm(2), P = 0.001, paired t test) with a percent change (DeltaBMD%) of 1.4 +/- 4.2%. Multiple regression analysis to identify independent predictors of DeltaBMD% showed a negative correlation with maternal age at the subsequent delivery (P = 0.033) but no correlation of DeltaBMD% with the length of lactation between the scans. CONCLUSION: Multiple pregnancies may not reduce maternal lumbar BMD, although the percentage decrease in BMD was greater in older women at the subsequent delivery. The length of lactation between the scans had no effect on these results.     

Association between vitamin D and bone mineral density in Iranian postmenopausal women

The role of vitamin-D in determining bone mineral density (BMD), especially in less severe vitamin D deficiency, is still unclear. To investigate the possible association between 25-hydroxyvitamin D [25(OH)D] and BMD, 245 healthy free-living postmenopausal women, aged between 40 and 80, were randomly selected from participants of a population-based study. BMD was measured at the lumbar spine and hip by dual X-ray absorptiometry (Lunar DPXMD 7164). Serum 25(OH)D, parathyroid hormone (PTH), calcium, phosphorus, total and bone alkaline phosphatases, and urine deoxypyridinoline were measured. PTH was logarithmically transformed (LnPTH). Linear regression models were developed to determine the association between serum 25(OH)D and BMD at different sites. Means of age and duration of menopause were 57.7 +/- 7 and 9.4 +/- 6.8 years, respectively. Mean 25(OH)D was 73.0 +/- 62.3 nmol/l; 5.3% (n = 13) had 25(OH)D < 25 nmol/l and 37.6% (n = 92) had 25(OH)D between 25 and 50 nmol/l. Eleven percent of the women (n = 27) were osteoporotic in femoral neck and 25.3% of them (n = 62) were osteoporotic in lumbar spine sites. 25(OH)D correlated inversely with LnPTH (r = -0.25, P < 0.01). In the multivariate analyses, no association was found between 25(OH)D and BMD at any of the skeletal sites after adjusting for age, duration of menopause, body mass index, calcium, and LnPTH. However, BMD was associated inversely with LnPTH only in femoral neck but not in the other sites. This study did not show any association between 25(OH)D and BMD in free-living Iranian postmenopausal women.     

Bone mineral density by age, gender, pubertal stages, and socioeconomic status in healthy Lebanese children and adolescents

Gender, ethnicity, and lifestyle factors affect bone mass acquisition during childhood, thus the need for age- and sex-adjusted Z scores using ethnic-specific data for bone mineral density (BMD) measurement. This study aimed at establishing normative data for BMD in healthy Lebanese children and adolescents. Three hundred sixty-three healthy children aged 10 to 17 years (mean+/-SD: 13.1+/-2.0) were studied. BMD, bone mineral content (BMC), and lean mass were measured by dual-energy X-ray absorptiometry (DXA) using a Hologic 4500A device, and apparent volumetric BMD (BMAD) of the lumbar spine and the femoral neck were calculated. BMD, BMC, and BMAD were expressed by age groups and Tanner stages for boys and girls separately. There was a significant effect of age and puberty on all bone parameters, except at the femoral neck BMAD in boys. BMC and BMD were higher at cortical sites in boys, including subtotal body and hip; whereas, in girls, it was higher at a site more enriched in trabecular bone, namely the lumbar spine. At several skeletal sites, girls had significantly higher BMD adjusted for lean mass than boys. By the end of puberty, adolescents had a mean BMD that was 43-66% higher at the lumbar spine and 25-41% higher at cortical sites than pre-pubertal children, depending on the gender. Mean BMD values in the study group were significantly lower (P<0.01) than Western normative values, with Z scores ranging between -0.2 and -1.1. In both genders, children of lower socioeconomic status tended to have lower BMD than those from a higher socioeconomic background. This study allows additional insight into gender dimorphism in mineral accretion during puberty. It also provides a valuable reference database for the assessment of BMD in children with pubertal or growth disorders who are of Middle Eastern origin.     

Is BMD Sufficient to Explain Different Fracture Rates in Sweden and Turkey?

Osteoporosis and consequent fractures have become an important health problem all over the World. However, there are quite different fracture rates among different populations. In this study, our aim was to obtain the bone mineral density (BMD) values at calcaneus in a healthy Turkish population and compare them with Swedish population data. BMD was measured at the calcaneus using a dual X-ray and laser Calscan (Demetech AB, Stockholm, Sweden) bone densitometer. The total number of subjects was 951 consisting of 639 women and 312 men and age ranged from 15 to 79 yr. Mean BMD value for healthy young women (20-39 yr old) was 0.411+/-0.058 g/cm2 and for healthy young men was 0.504+/-0.068 g/cm2. BMD values tended to decrease with age in both genders. In comparison between the Turkish and Swedish population data, the Turkish population has about 1 standard deviation lower BMD values than the Swedish population in both genders, for all ages. Considering that Swedes have high fracture rates and Turks have the lowest fracture rates in Europe, the opposite difference in BMD values in the calcaneus seems interesting. Further research is needed to explain the difference in fracture rates among different populations.     

Long-term effects of serum cholesterol on bone mineral density in women and men: the Framingham Osteoporosis Study

Laboratory studies have suggested a role for cholesterol in the pathogenesis of both osteoporosis and atherosclerosis. The purpose of this prospective study was to assess whether cholesterol levels, repeatedly measured over three decades in young and middle-aged adult women and men, predicted bone mineral density (BMD) at advanced age. Study participants included 712 women and 450 men enrolled in the Framingham Osteoporosis Study, aged 32-61 years at baseline (1953-55) who underwent bone densitometry 34 years later (1988-1989). BMD was measured at the proximal femur (neck, trochanter, and Ward's triangle) and lumbar spine using dual-photon absorptiometry and at the one-third radial shaft and ultradistal radius using single-photon absorptiometry. Sex-specific multivariable linear regression was used to model each BMD site as a function of total cholesterol level, adjusted for age, cigarette smoking, alcohol consumption, body mass index, systolic blood pressure, diabetes, and estrogen use (women). No significant association between total cholesterol and BMD was found in women for any of the bone sites considered. For example, adjusted mean BMD at the lumbar spine was similar in women from the lowest to highest quartile of total cholesterol, respectively, 1.07, 1.08, 1.06, 1.07 g/cm2; P for trend=0.98. Similarly, the findings in men largely showed no association between cholesterol and BMD, although there was an isolated finding of a statistically significant trend in decreasing mean radial shaft BMD with increasing total cholesterol, 0.73, 0.72, 0.72, 0.70 g/cm2, lowest to highest quartile, P for trend=0.02. Cholesterol levels in women and men from young adulthood to middle age years do not appear to have long-term clinical implications for osteoporosis later in life.     

Growth Hormone Secretion and Bone Mineral Density in Prepubertal Black and White Boys

Racial differences in bone mineral density (BMD) appear to account in part for racial differences in the incidence of osteoporosis and fractures. We previously reported that the greater BMD in adult blacks compared with whites is associated with a higher serum 17 beta-estradiol and greater secretion of growth hormone (GH) in men but not women. To determine whether these racial differences occur in prepubertal boys, we measured spontaneous overnight GH secretion, serum testosterone, 17 beta-estradiol, IGF-I, and IGFBP3, IGF-I/ IGFBP3 ratio, BMD of the total body, forearm, lumbar spine, trochanter, and femoral neck, and lean body mass and body fat in 14 healthy black and 16 white boys ages 6-7 years. Measurements of GH were obtained at 20-minute intervals for 12 hours. Results were analyzed by deconvolution and are expressed as mean +/- SE. Whereas BMD of the hip (0.755 +/- 0.020 vs 0.663 +/- 0.021 g/cm(2), P = 0.0037), trochanter (0.617 +/- 0.014 vs 0.552 +/- 0.018 g/cm(2), P = 0.0102) and femoral neck (0.710+/-0.018 vs 0.6381 +/- 0.021 g/cm(2), P = 0.0157) were significantly greater in black compared with white boys, BMD of the total body (0.768 +/- 0.010 vs 0.741 +/- 0.012 g/cm(2), NS), forearm (0.405 +/- 0.010 vs 0.380 +/- 0.008 g/cm(2), NS), and lumbar spine (0.612 +/- 0.013 vs 0.609 +/- 0.021 g/cm(2), NS) was not different in the two groups. Stepwise regression analysis showed significant correlations between BMD and race at each skeletal site except the lumbar spine and trochanter. Deconvolution analysis revealed no racial difference in any of the GH measurements. Whereas serum testosterone, serum 17 beta-estradiol, and serum IGF-I were not different, serum IGFBP-3 was higher and the molar ratio of serum IGF-l/IGFBP-3 was lower in white than in black males. In summary, prepubertal BMD is higher in black than in white males at the hip, trochanter, and femoral neck, and the racial difference does not result from differences in secretion of GH.     

Study of bone mineral density in Chinese patients with complete androgen insensitivity syndrome

<正> Objective:To explore the characteristics of bone mineral density(BMD)and treatment inChinese patients with complete androgen insensitivity syndrome(CAIS).Methods:Fourteen cases of CAIS were studied retrospectively through analyzing and compa-ring BMD of pre-and post-gonadectomy with healthy Chinese men and women.BMD at the lum-bar spine and the femur were measured by dual energy X-ray absorptiometry(DXA).Results:There were 10 cases of CAIS having pre-gonadectomy DXA,in which 6 cases hadvery significantly reduced lumbar 2-4 BMD[(0.92±0.08)g/cm~2]comparing with both healthymen and women(P<0.01),5 cases had significantly reduced femur neck BMD[(0.89±0.12)g/cm~2]comparing with healthy men(P<0.05).There were 7 cases having 12 post-gonadectomyDXA,in which all lumbar 2-4 BMD[(0.954-0.06)g/cm~2]were reduced very significantly com-paring with both healthy men and women(P<0.01),femur neck BMD[(0.91±0.08)g/cm~2]were also reduced significantly comparing with healthy men(P<0.01)and women(P<0.05).Conclusion:There were different degrees of osteopenia in patients of CAIS,especially inlumbar vertebra.This suggests that both estrogen and androgen play important roles in the ac-quirement and maintenance of peak bone mass.     

Demonstration that bone mass is greater in black than in white children

Osteoporosis and hip fractures are less common and bone mass is greater in black than in white women. To determine if bone mass is greater in black than in white children, bone mineral density (BMD) of the midradius by single-photon absorptiometry and BMD of the lumbar spine (L1-L4), trochanter, and femoral neck by dual-photon absorptiometry were measured in 20 black boys, 18 black girls, 33 white boys, and 35 white girls between the ages of 7 and 12 years. Mean age (10.4 +/- 0.3 versus 10.2 +/- 0.2 years) and body weight (39 +/- 2 versus 38 +/- 2 kg) in the blacks and whites, respectively, were not different in the two groups, and the ages and weights of the boys and girls were not different from each other. BMD were significantly greater in black than in white children at each site, in the black than in white boys at the trochanter and femoral neck, and in the black than in white girls at each site. In both races, BMD varied directly with age and body weight. Multivariate analysis showed that BMD were greater at the midradius, lumbar spine, trochanter, and femoral neck in the black than in the white children, that BMD of the lumbar spine was greater in the girls than in the boys, and that BMD of the trochanter and femoral neck were greater in the boys than in the girls. There were significant partial correlations between race and BMD and between BMD and body weight at each site, between sex and BMD at the lumbar spine, trochanter, and femoral neck, and between age and BMD at the midradius, trochanter, and femoral neck. Race, sex, age, and body weight together accounted for 49-66% of the variation in bone mass. Thus, BMD of the midradius, spine, and hip are greater in black than in white children, body weight and age are important determinants of bone mass, and some sex differences in bone mass are present at this age.     

Prevalence and treatment of decreased bone density in renal transplant recipients: a randomized prospective trial of calcitriol versus alendronate

BACKGROUND: Reduced bone mineral density (BMD) is common in long-term renal transplant recipients and results in a high incidence of fractures. The optimal therapy for these patients is not known. METHODS: Baseline BMD determinations were obtained in 211 long-term adult renal transplant recipients. One hundred and seventeen patients with a reduced BMD (T score < or = -1) were randomly assigned to treatment with alendronate and calcium (n=60) versus calcitriol and calcium (n=57). Of these, 46 and 51 patients, respectively, completed 1 year of treatment. Forty-nine patients who were not eligible or did not consent to the trial were followed prospectively. RESULTS: Reduced baseline BMD (T score < or = -1) was present in 159 (78.7%) of patients at the lumbar spine or femur. There was no significant loss of BMD in the prospectively followed patients during 2.7 years. The average lumbar BMD increased from 0.984+/-0.149 to 1.025+/-0.143 g/cm2 (P<0.001) with alendronate and from 1.014+/-0.15 to 1.034+/-0.146 g/cm2 (P=0.002) with calcitriol. BMD at the femur increased from 0.809+/-0.092 to 0.836+/-0.107 g/cm2 (P<0.001) with alendronate and from 0.830+/-0.144 to 0.857+/-0.125 g/cm2 (P=0.023) with calcitriol. CONCLUSIONS: One year of treatment with alendronate or calcitriol, both with calcium supplementation, resulted in significant increases in BMD at the lumbar spine and femur, with a trend toward alendronate being more effective at the spine (P=0.082). Further studies are needed to determine whether BMDs continue to increase after 1 year and whether there is any additional benefit to combining vitamin D and alendronate. Larger studies are needed to determine whether treatment decreases fracture rates.