高血糖状态对骨形成和骨吸收作用及骨密度的影响

目的 探讨不同血糖水平对骨形成、骨吸收和骨密度的影响.方法 对糖尿病组(DM)148例,葡萄糖耐量低减组(IGT)30例,空腹血糖受损组(IFG)30例,健康对照组(Control)50例,分别测定血浆葡萄糖(BG)、糖化血红蛋白(HbA1c)、血清骨钙素(BGP)、尿脱氧吡啶啉(DPD)/肌酐(Cr)、腰椎(L2、L3、L4)和髋部(股骨颈、Ward三角、大转子)骨密度(BMD),并对上述指标进行T检验和方差分析.结果 四组间方差分析显示BMD在Ward三角、L4差异有统计学意义(P<0.05).血清BGP水平在四组呈递增趋势,尿DPD/Cr水平在四组呈递减趋势,方差分析显示尿DPD/Cr水平差异有显著统计学意义(P<0.001).尿DPD/Cr水平随HbA1c水平递增逐渐增高.结论 糖尿病的前期阶段(IGT),骨吸收已呈现高于同龄正常人水平,糖尿病患者骨形成低于同龄正常人而骨吸收高于同龄正常人,骨平衡呈现负平衡,骨量逐渐丢失;IGT开始骨密度已较正常人低,良好的血糖控制对减少骨吸收和延缓骨量下降具有保护作用.应在糖调节受损的早期阶段对骨质疏松进行干预治疗.     

Environmental and genetic factors affecting bone mass similarity of bone density among members of healthy families

Objective. To evaluate the relative importance of environmental and genetic factors in the determination of bone mineral density (BMD) and to quantify the risk of low BMD in healthy young adults in relation to the BMD of their parents. Methods. Dual-energy x-ray absorptiometry study of a series of 129 nuclear families (441 subjects), including 183 children over age 15, was performed. Correlation of BMD in children with BMD in their parents was studied in a linear model, taking into account environmental factors. Logistic regression was used to quantify the relative risk of lower BMD according to the parents' BMD level. Results. BMD was significantly correlated with weight, height, and body mass index (BMI) in all family members, and with parents' alcohol consumption and with physical activity in fathers and sons. The BMD of the children correlated with that of their parents (r = 0.27). The child's BMI, his/her father's BMD and daily calcium intake, and his/her mother's BMD, BMI, and body fat accounted for 41.4% of the variance in the child's BMD. A son had a 3.8 times higher risk of having a low BMD if his father had a low BMD, and a daughter had a 5.1 times higher risk if her mother had a low BMD. Conclusion. The BMD of children in healthy families was related to the BMD of their parents as well as to environmental factors, confirming the contribution of genetic inheritance in the determination of bone density in young adults, especially in girls.     

Effect of body mass index on bone mineral density is age-specific

Background and aimsObesity and osteoporosis are two important and growing public health problems worldwide. Body mass index (BMI) has been found to be inversely related to the risk of osteoporotic fracture. We aimed to assess the association of BMI with thoracic vertebral bone mineral density (BMD) measured from a quantitative computed tomography (QCT).Methods and resultsWe retrospectively evaluated the data from 15,758 consecutive patients (5675 females and 10,083 males) between age 20–90 years, who underwent Coronary Artery Calcium (CAC) scoring. Quantitative data analyses of thoracic trabecular BMD (mg/cm³) was performed with a phantom system or phantomless using validated software. The gender-specific subgroup was divided based on age (<45, 45–55, 55–65, >65 yrs in females; <40,40–60,>60 yrs in Males) and weight by BMI (kg/m²) as < 25 (normal or low weight), >25 - <30 (overweight) and >30 (obesity). Analysis of variance (ANOVA) and Scheffe's post hoc procedure tested the association of body weight/BMI on BMD. A significant positive association between the body weight and BMD existed in obese population in elder groups in both genders (p < 0.05). There was no significant difference in BMD in 40–60 years in men and <55 years in women with normal or low weight compared to overweight or obese cohorts.ConclusionsWe concluded that the effect of weight on BMD is age-specific and the BMD should be monitored routinely with a cardiac CT scan in the senile population.     

Effects of Depot medroxyprogesterone acetate on bone density and bone metabolism before and after peak bone mass: a case-control study

INTRODUCTION: Depot medroxyprogesterone acetate (DMPA; Depo-Provera, Tadworth, UK) contraception is used by more than 9 million women worldwide and has a high usage among teenagers in the United Kingdom and the United States. Previous studies have found that DMPA use is associated with a bone density deficit. OBJECTIVES: This case-control matched study aims to eliminate potential confounding factors, identify whether the effect of DMPA on the skeleton is age specific, and determine the effects of DMPA on hormones and bone turnover. DESIGN/PARTICIPANTS: We measured bone density, bone turnover, and hormones in individually matched case-control pairs of women: 50 pairs aged 18-25 yr and 50 pairs aged 35-45 yr. RESULTS: DMPA use was associated with a 5% bone density deficit at the lumbar spine and hip in women who started DMPA use before age 20 yr but not after age 34 yr. Bone turnover was increased in DMPA users in both age groups. DMPA users had lower estradiol and higher IGF-I than controls, and younger DMPA users had higher dehydroepiandrosterone sulfate than controls. In a multiple regression model, estradiol and IGF-I were associated with bone turnover, but addition of DMPA to the model made the association with estradiol nonsignificant. CONCLUSIONS: DMPA use is associated with a bone density deficit at the spine and hip when used before peak bone mass. DMPA acts on the skeleton mainly through estrogen deficiency.     

Fat body mass, leptin and femur bone mineral density in hip-fractured women

Fat body mass (FBM) is a strong predictor of both bone mineral density (BMD) and risk of hip fracture, but the mechanisms responsible are not completely understood. We addressed whether leptin is the link between FBM and BMD in hip-fractured women. Sixty-two of 74 women with hip fractures were evaluated. Serum leptin was measured by radioimmunoassay, 23.4+/-9.1 days (mean+/-SD) after fracture occurrence. BMD and body composition were assessed by dual-energy X-ray absorptiometry (DXA). As expected, a positive linear correlation was found between FBM and both leptin (r=0.782; p<0.001) and femur BMD measured at five sites (r value ranging from 0.293 to 0.498 depending on the site of the femur BMD assessment, p<0.05). A positive correlation between leptin and BMD measured at the intertrochanteric area (r=0.259; p<0.05) but not at the other four sites was shown. At linear multiple regression [dependent variable = femur BMD; independent variables = age, weight, height, body mass index, fracture type, term fracture-DXA, Barthel index score, FBM, lean body mass, serum PTH, serum 25(OH)vitamin D and leptin], FBM was positively associated with BMD measured at all the five sites. The association between leptin and BMD was inverse and it was significant at four of the five sites of the BMD assessment. In conclusion, in a sample of hip-fractured women, the positive association between FBM and femur BMD was not explained by serum leptin. On the contrary, after adjustment for FBM and other confounding variables, an inverse association between leptin and BMD was found.     

Hidden depletion of fat-free mass and bone mineral density in adults with cystic fibrosis

BACKGROUND: Weight loss is associated with reduced survival in patients with cystic fibrosis (CF). OBJECTIVE: We hypothesized that some adult patients with a normal body mass index (BMI) have evidence of hidden fat-free mass (FFM) and bone mineral density (BMD) depletion that is linked to more severe disease. DESIGN: Fat mass (FM), FFM, and BMD were determined by dual-energy x-ray absorptiometry (DXA) and by bioelectric impedance in 56 adults in clinically stable condition and 20 age-matched healthy subjects. FM index and FFM index (FFMI) [kilograms per meter squared] of the right arm, leg, and trunk (ratio to height squared) were calculated. Lung function, including the maximum inspiratory pressure (MIP) and sustained MIP (SMIP), physical activity, serum C-reactive protein (CRP) and the number of exacerbations in the previous year were recorded. RESULTS: Patients had a lower total FFM than healthy subjects (p < 0.01), while FM was similar. Of the 56 patients, 30 patients had a normal BMI, of which 12 patients had a low FFM (hidden loss) by DXA. The right arm, leg, and trunk FFMI and BMD at hip sites were less in these patients than in those with a normal BMI and normal FFM (all p < 0.01). This group had a lower FEV(1), SMIP, more frequent exacerbations, and greater circulating CRP (all p < 0.05). CONCLUSIONS: In adults with CF, apparent or hidden loss of FFM, rather than weight loss, was related to overall disease severity. Hidden depletion of FFM was associated with increased loss of BMD and systemic inflammatory activity.     

Associated loss of fat-free mass and bone mineral density in chronic obstructive pulmonary disease

We hypothesized that in patients with chronic obstructive pulmonary disease, loss of fat-free mass (FFM) and loss of bone mineral density (BMD) were related to (1) each other and may be clinically inapparent, (2) urinary markers of cellular and bone collagen protein breakdown, and (3) severity of lung disease. Eight-one patients and 38 healthy subjects underwent dual-energy X-ray absorptiometry to determine body composition and BMD. Urinary protein breakdown markers, inflammatory mediators, and their soluble receptors were determined. Thirty-three patients had a low fat-free mass index (kg/m(2)), 17 of whom had a normal body mass index. Thirty-two percent of patients (13% of healthy subjects) had osteoporosis at the hip or lumbar spine. The marker of cellular protein breakdown was elevated in patients and related to lung disease severity and body composition. The marker of bone collagen breakdown was greater in patients with osteoporosis. Inflammatory mediators were elevated in patients. Loss of FFM and loss of BMD were related, occurred commonly, and could be subclinical in patients with chronic obstructive pulmonary disease. Loss of both was greatest with severe lung disease. Increased excretion of cellular and bone collagen protein breakdown products in those with low FFM and BMD indicates a protein catabolic state in these patients.     

Lean mass and fat mass predict bone mineral density in middle-aged individuals with noninsulin-requiring type 2 diabetes mellitus

Objective Despite high bone mineral density (BMD), persons with type 2 diabetes are at greater risk of fracture. The relationship between body composition and BMD in noninsulin‐requiring diabetes is unclear. The aim was to examine how fat and lean mass independently affect the skeleton in this population. Research design and methods Subjects for this cross‐sectional analysis were men (n = 78) and women (n = 56) aged 40–65 years (56 ± 6 years) with uncomplicated, noninsulin‐requiring type 2 diabetes. Total body fat and lean mass, total body, hip and lumbar spine BMD were measured with dual energy X‐ray absorptiometry. Magnetic resonance imaging measured total abdominal, visceral and subcutaneous (SQ) fat. Results Subjects had normal all‐site BMD and were obese to overweight (body mass index 29–41 kg/m²) with controlled diabetes (HbA1c women 6·6 ± 1·2%, men 6·7 ± 1·6%). Lean mass was positively associated with total body, hip, femoral neck and hip BMD in both sexes. Fat mass, abdominal total and SQ fat were associated with total body and hip BMD in women. In multivariate analyses adjusted for sex, lean mass significantly predicted total, hip and femoral neck BMD in men and women. In unadjusted models, lean mass continued to predict BMD at these sites in men; fat mass also predicted total body, femoral and hip BMD in women. Conclusions In men and women with uncomplicated, noninsulin‐requiring diabetes, lean mass significantly predicted BMD at the total body, hip and femoral neck. Further research is needed to determine whether acquisition or maintenance of lean mass in T2DM can prevent hip fracture in this at‐risk population.     

Determinants of bone density in young women. I. Relationships among pubertal development, total body bone mass, and total body bone density in premenarchal females.

Bone mass accretion during puberty appears to be critical in the development of peak bone mass, which, in turn, is believed to be a major determinant of osteoporosis risk. Although genetics may be the primary determinant of peak bone mass, modifiable secondary factors, such as nutrition and hormone exposure, may significantly affect bone mass accretion during the second decade of life. As part of a longitudinal study of major determinants of bone development during puberty, we obtained cross-sectional measurements from 112 premenarchal caucasian females (mean +/- SD age, 11.9 +/- 0.49 yr at study entry). Total body bone mineral density (TBBMD) and total body bone mineral content (TBBMC) were measured by dual energy x-ray absorptiometry and compared to anthropometric, pubertal development, urinary steroid and gonadotropin levels, and nutrient intake. An integrated estrogen exposure index was developed and used to evaluate the cumulative effect of circulating estrogen levels on both development. Compared to normative reference data for adults, our subjects possessed 90% of adult height, 68% of adult weight, 83% of adult TBBMD, and 53% of TBBMC. The strongest combined predictors of prepubertal TBBMD and TBBMC were body weight, followed by height and pubertal development. Urinary estradiol levels were positively correlated with dietary intake of iron and vitamin B6.     

体重、体重指数对健康绝经后妇女骨密度的影响

目的探讨体重和体重指数（BMI）对健康绝经后妇女骨密度（BMD）的影响。方法采用双能X线骨密度仪测量591例健康绝经后女性不同部位的BMD，按BMI不同分为低体重组、正常体重组和肥胖组进行分析。结果各部位的BMD随BMI的增加而增高（P〈0．01）。BMD随年龄的增长而降低（P〈0．01）。肥胖组各部位BMD均比正常体重组和低体重组高（P〈0．05或P〈0．01）。年龄和体重是决定BMD变异的主要因素，年龄与BMD呈负相关，体重与BMD呈正相关，绝经年龄与腰椎正位BMD呈正相关；BMI与BMD无相关性。结论体重是影响绝经后妇女BMD的重要因素。对低体重的绝经后妇女定期监测BMD，有助于早期干预。     

Predicting bone mineral density of postmenopausal healthy and cirrhotic Italian women using age and body mass index

The objective of the present report was to develop mathematical prediction formulae for the lumbar spine, pelvis and total bone mineral density (BMD) based on the osteoporosis risk factors age and BMI in healthy and cirrhotic postmenopausal women. The study population comprised 20 postmenopausal cirrhotic women (late PM cirrhotic women), 20 postmenopausal healthy women matched for age and BMI (late PM healthy women), and 19 younger postmenopausal healthy women matched for BMI (early PM healthy women). Segmental and total bone mineral content and BMD, total bone-free lean body mass and total fat mass were measured for all women using dual X-ray absorptiometry (DXA). The prediction formulae for late PM cirrhotic women had higher cumulative correlation coefficients ( r=0.71, p=0.05 for spine BMD, r=0.84, p=0.013 for pelvis BMD, and r=0.89, p=0.004 for total BMD) than those for early PM healthy women ( r=0.64, p=0.015 for spine BMD, r=0.69, p=0.002 for pelvis BMD, and r=0.62, p=0.022 for total BMD) and late PM healthy women ( r=0.29, p=NS for spine BMD, r=0.39, p=NS for pelvis BMD, and r=0.54, p=NS for total BMD). The mathematical formulae based on the variables age and BMI were capable of predicting lumbar spine BMD, pelvis BMD, and total BMD by DXA for the three groups of postmenopausal women.     

Association between muscle mass,bone mineral density and osteoporosis in type 2 diabetes

Aims/IntroductionType 2 diabetes mellitus is associated with an increased incidence of osteoporosis and sarcopenia. However, the relationship between osteoporosis and sarcopenia in patients with type 2 diabetes mellitus remains to be unclear. Appendicular skeletal muscle was adjusted by height (appendicular skeletal muscle mass [ASM]/height²) as a marker of sarcopenia. This study aimed to explore the relationship between ASM/height², osteoporosis and bone mineral density (BMD) in this population.Materials and MethodsA total of 192 women and 225 men with type 2 diabetes mellitus were recruited. General information, laboratory and BMD data were collected. Spearman’s correlation, multiple regression analyses and receiver operating characteristic curve analysis were used to explore the correlation between ASM/height², BMD and bone metabolism markers.ResultsSpearman’s correlation analysis showed that ASM/height² had a positive correlation with serum calcium and BMD (r = 0.209–0.404, P < 0.01). In multivariate regression analysis, we found significant correlations between ASM/height² and total lumbar spine, hip and femur neck BMD. According to the receiver operating characteristic curve, ASM/height² was the best marker of osteoporosis, with a cut‐off value of 7.87 kg/m² for men and 5.94 kg/m² for women. When these cut‐off values were used to identify sarcopenia, the risk of osteoporosis increased 6.036‐fold in men and 4.079‐fold in women, respectively.ConclusionsIn patients with type 2 diabetes mellitus, ASM/height² was positively correlated with BMD, and negatively correlated with osteoporosis.     

女性围绝经期骨密度和E2、PTH、CT相关性分析

目的 本文分析了女性在围绝经期血清雌二醇(E2)、甲状旁腺素(PTH)、降钙素(CT)水平的变化对骨密度(BMD)的影响. 方法 测定绝经前期正常体检(A)组、绝经期(B)组和绝经时间＞1年(C)组的腰椎L2～L4、股骨颈、大转子、华氏三角区正侧位的BMD及血清中E2、PTH、CT的浓度,对BMD与多个变量之间的关系进行相关性分析. 结果 与A组比较,B组及C组BMD、E2及CT 水平显著降低,而 PTH水平显著升高.C组BMD、E2水平显著低于B组,而CT及PTH在2组间差异无统计学意义.相关性分析显示在绝经期妇女中E2、CT与BMD呈正相关;PTH与BMD呈负相关. 结论 女性E2、PTH、CT水平影响骨形成、骨吸收和BMD,使骨代谢趋向于负平衡,是女性易发骨质疏松的重要原因.