Constructive effect of exogenous melatonin against osteoporosis after ovariectomy in rats

OBJECTIVE: To analyze histomorphometric, densitometric and biochemical effects of melatonin on osteoporosis in ovariectomized rats. STUDY DESIGN: Wistar rats were divided into 6 groups. Group C: control; Group I: bilateral ovariectomy (OVX); Group II: OVX + vehicle; Group III: OVX + 10 mg/kg/day melatonin (MLT); Group IV: OVX + 30 mg/kg/day MLT; Group V: sham + 10 mg/kg/day MLT. Cortex, trabecula, osteoblast and osteoclast numbers were evaluated on vertebra and femur histomorphometrically. Hydroxyproline analysis was used to determine collagen content of femur and vertebrae. Bone mineral density and bone mineral content were measured. RESULTS: Trabecular thickness and trabecular area of vertebra and femur and cortical thickness of femur showed remarkable decrease after OVX, but increased after MLT treatment in the OVX+MLT groups. Following OVX, no statistically significant difference was found in number of osteoblasts or osteoclasts, trabecular number or levels of hydroxyproline after treatment with MLT. OVX caused significant decrease in bone mineral density, but treatment with MLT was unable to reverse this effect. CONCLUSION: MLT may trigger microscopic changes in bone, and time of application is critical for clinical recovery. It can be effective in helping treat postmenopausal osteoporosis. However, it is contraindicated in women who have normal-functioning ovaries.     

One-year soy isoflavone supplementation prevents early postmenopausal bone loss but without a dose-dependent effect

It is believed that soy isoflavone has much potential effectiveness on the postmenopausal status; however, the optimal dose for preventing postmenopausal bone loss still remains unclear. This open-labeled, self-controlled pilot study was undertaken to determine the effect of 1-year supplementation of different high dosages of soy isoflavone in postmenopausal Taiwanese women. Forty-three women aged 45-67 years were enrolled and randomly assigned into a control (C), 100 mg/day isoflavone (IF100) and 200 mg/day isoflavone (IF200) groups for 1 year. Dual-energy X-ray absorptiometry and other related biochemical markers of bone metabolism were measured. Results indicated that the decrease in bone mineral density (BMD) was significant for lumbar vertebrae L1-3, L1-4 and the femur neck in the C group; surprisingly, the BMD of L1-3 was significantly elevated in the IF100 group; however, there were no consistent responses in the IF200 group. No significant change except loss of the bone mineral content of Ward's triangle (P=.003) was found in the IF200 group after treatment. The percentage change at L1-3 was less (P=.04) in the IF200 group when compared to the IF100 group. A relatively uniform direction of bone formation in expanding the weight and area with different rates of change resulted in different BMD changes. Both indicated a change of bone formation patterns with the higher-dose supplement. A protective effect of IF100 on estrogen-related bone loss was observed. A lack of a benefit such as high safety in the IF200 group for 1-year administration was ensured and lacked undesirable side effects.     

Different involutionary changes in bone mineral density with age in three skeletal sites in healthy Polish women

The aim of the study was to estimate the differences in bone mineral density (BMD) at three skeletal sites, with regard to age and menopausal status.The study was conducted between 2001 and 2006 in the Polish city of Wroc?aw and the sample was comprised of 440 healthy female inhabitants aged 40–88 years. The measurements of bone mineral density were taken at three sites: femoral neck, Ward's triangle and trochanter major. Two bone mineral density characteristics were used in further analysis: absolute measure of bone mineral density (BMD) expressed in g/(100 mm)², and % of BMD of the peak value calculated for young adults (20–45, USA reference population). Pre- and postmenopausal status was defined according to occurrence of menstruation within the last 60 days.The changes in bone mineral density with age showed significantly different patterns in different skeletal sites. While the decrease in bone mineral density in the femoral neck and Ward's triangle were parallel and gradual, the changes in trochanter major were very small and between the age groups 51–55 and 71–75, nearly unnoticeable. A comparison between pre- and postmenopausal women aged 46–55, showed a significant effect of menopausal status. The average bone mineral densities in the three skeletal sites were higher in premenopausal than in postmenopausal women. The highest value of bone mineral density was found in the femoral neck, significantly lower in Ward's triangle, and a little lower (non-significantly) in the trochanter major than in the Ward's triangle. Postmenopausal women had a little higher BMD value in the trochanter major than in the Ward's triangle site.     

Measurement of bone mineral density (BMD) with quantitative computed tomography (QCT) in postmenopausal osteoporosis: effect of estrogen.

To determine the efficacy of the estrogen replacement therapy (ERT) on the bone mineral density (BMD) measured with quantitative computed tomography (QCT) in postmenopausal osteoporosis 16 women aged 46-72 were examined. They were divided into two groups: 8 women treated with conjugated estrogens (Group I) and 8 who did not received ERT (Group II). In all 16 patients the serum hormonal concentrations (LH, FSH and estradiol) were measured with radioimmunological methods. The bone densitometry was performed in all of them using the single-energy computed tomography (QCT) with the computer Picker 1200. Bone mineral density was measured in three lumbar vertebra (L1-L3) and expressed in milligrams K2HPO4 per ml. The bone mineral density (BMD) was statistically significantly higher in the estrogen treated group (Group I) in every vertebra compared with that of controls (Group II). The serum FSH concentration was statistically significantly lower in the ERT group (Group I) and a statistically significant correlation between FSH level and average BMD (Lmean) was present. In conclusion: 1. the ERT is very efficacious in preventing bone loss in postmenopausal women; 2. measurement of BMD in lumbar vertebra L1 or L3 may be a sufficiently reliable and accurate, cost-effective and time-saving method of screening for osteoporosis; 3. the serum FSH determination seems to be useful in monitoring of the estrogen therapy for postmenopausal osteoporosis.     

Fundectomy-evoked osteopenia in pigs is mediated by the gastric-hypothalamic-pituitary axis

The aim of the study was to determine the effects of gastric impairment in pigs on the axial and peripheral skeletal system properties and to test the hypothesis that fundectomy-evoked osteopenia is related to disturbed gastric-hypothalamic-pituitary axis function. Forty-day-old male piglets were subjected to experimental fundectomy (FX group, n = 6) to induce osteopenia, while sham operation was performed in the controls (SHO group, n = 6). At the age of 8 months, serum samples were collected, and the animals were sacrificed to obtain lumbar vertebrae (L1-L6) and right humerus for analysis. Using quantitative computed tomography (QCT) and dual-energy x-ray absorptiometry (DEXA) methods, bone mineral density and bone mineral content of the vertebrae and humerus were measured. The compression and three-point bending tests were applied to determine mechanical properties of lumbar vertebrae and humerus, respectively. Furthermore, geometric properties of humerus were assessed. Serum concentrations of ghrelin, growth hormone (GH), insulin-like growth factor-1 (IGF-1), and selected macro- and microelements were also determined. Performed fundectomy decreased body weight in pigs by 66% compared with pair-fed sham operated pigs (P < 0.0001). Bone weight, bone mineral density, and bone mineral content of the lumbar vertebrae and humerus were significantly decreased in the fundectomized pigs (P < 0.01). Mechanical parameters of the lumbar spine and humerus were decreased after the fundectomy, as well. Serum concentrations of ghrelin, GH, and IGF-1 were lowered by 74.4%, 90.6%, and 54.6% in the fundectomized pigs, respectively (all P < 0.001). Moreover, the serum concentrations of calcium, magnesium, iron and copper in the fundectomized animals were significantly decreased by 15.5%, 45.3%, 26.7%, and 26.2%, respectively (P 相似文献   

Relationships between bone and skin atrophies during aging.

Bone mineral density (BMD) was measured in 133 female subjects (age: 61.7 +/- 16.3 years) by dual energy X-ray absorptiometry (DEXA). Vertebral bone mineral density (BMD; L1-L4) and BMD of the whole upper femoral extremity were taken into account. In addition, skinfold thickness was measured with a callipers on the dorsum of the nondominant hand. A significant negative correlation was found between skinfold thickness and age (r = -0.623, p less than 0.0001). Both vertebral and femoral BMD decreased with age and the slopes were similar to those observed by other authors. Skinfold thickness was significantly correlated with vertebral (r = 0.364, p less than 0.0001) and femoral BMD (r = 0.486, p less than 0.0001). Skin and bone are connective tissues whose extracellular matrix mainly contains type I collagen. It is postulated that age-related skin atrophy and bone atrophy have a common genetic mechanism. Skinfold thickness measurement may help in defining the women at risk for osteoporotic bone fractures who should be referred for a DEXA examination.     

Effect of Simvastatin Use on Bone Mineral Density in Women with Type 2 Diabetes

ObjectiveTo attempt to clarify the effect of simvastatin, a widely used statin, on the bone mineral density in women with type 2 diabetes.MethodsWe performed a cross-sectional, controlled study of 37 women with type 2 diabetes who were taking simvastatin. Each woman was matched with 2 control subjects who were closest in age, years since menopause (if applicable), and duration of diabetes on the date on which the examination was performed. We measured bone mineral density at the spine and the hip with a dual-energy x-ray absorptiometry scanner and compared bone density in the 2 study groups.ResultsThe mean bone mineral density values of patients in the simvastatin group were found to be slightly increased in comparison with those of the control group, both in the lumbar vertebrae and in the femoral neck, but these differences were not statistically significant (P > 0.05).ConclusionIn this cross-sectional study, we could not demonstrate a positive effect of long-term simvastatin treatment on bone mineral density in women with type 2 diabetes and hypercholesterolemia. (Endocr Pract. 2007; 13:114-116)     

Analysis of Bacteria,Parasites, and Heavy Metals in Lettuce (<Emphasis Type="Italic">Lactuca sativa</Emphasis>) and Rocket Salad (<Emphasis Type="Italic">Eruca sativa</Emphasis> L.) Irrigated with Treated Effluent from a Biological Wastewater Treatment Plant

The purpose of this study was to verify the effect of organic gallium on ovariectomized osteopenic rats. Thirty Wistar female rats used were divided into three groups: (1) sham-operation rats (control), (2) ovariectomized (OVX) rats with osteopenia, and (3) OVX rats with osteopenia treated with organic gallium. Treatments were performed over an 8-week period. At sacrifice, the fifth lumbar vertebral body, one tibia, one femur, and the fourth lumbar vertebrae were removed, subjected to micro-CT for determination of trabecular bone structure, and then processed for histomorphometry to assess bone turnover. The femoral neck was used for mechanical compression testing. Treatment with organic gallium increased bone volume in OVX animals. Organic gallium-treated animals had significant increases in trabecular and cortical thickness and bone strength. The plasma total calcium and inorganic phosphate concentrations in OVX rats decreased and bone mineral content in the lumbar vertebrae and femur increased after treatment with organic gallium. These data provide an important proof of concept that organic gallium may represent a powerful approach to treating or reversing severe osteoporosis in humans.     

Study on Bone Density at Various Skeletal Sites for the Diagnosis of Primary Osteoporosis

The objective of this study was to evaluate the diagnostic value of bone density changes in lumbar vertebrae and femoral necks in patients with primary osteoporosis (OP) at various ages. Dual-energy X-ray absorptiometry (DXA) scans were performed on patients who had their primary visits between March 2008 and February 2009. The bone mineral density (BMD) of the lumbar vertebrae 1-4 (L1-L4) in anteroposterior projection and the proximal femoral neck in lateral projection were measured. If the BMD values (T score) of any site is -2.5 or less (T ≤?-2.5), the patients were diagnosed as primary OP, and the T scores were statistically analyzed. The 81 patients who had lumbar vertebrae with a T ≤?-2.5 led to a positive rate of 80.1?% in the diagnosis of primary OP; the 47 patients who had femoral neck with a T ≤?-2.5 gave a positive rate of 47.0?%. The patients with type I or type II primary OP were divided into two age groups of ≤70 and ≥71?years old. The comparison of lumbar spine T score values did not show significant statistical difference (P?>?0.05) between the age groups, while the result of the femoral necks revealed significant difference between the two groups (P?相似文献   

Bone mineral density in hypoparathyroid women on LT4 suppressive therapy. Effect of calcium and 1,25(OH)2 vitamin D3 treatment

Our aim was to study the bone mineral density (BMD) of patients with chronic hypoparathyroidism (hypoPTH) after longterm calcium and vitamin D treatment. Twenty hypoPTH women (mean-/+SD, aged 50-/+15 years, IPTH 4-/+6 pg/ml) and 20 matched euparathyroid women (euPTH) after near total thyroidectomy for thyroid cancer, completed with I-131 ablation and on suppressive therapy with L-Thyroxine (LT(4)), were studied. In addition eight hypoPTH patients who were receiving LT(4) replacement therapy after surgery for compressive goiter were simultaneously studied. The hypoPTH patients were on calcium and 1,25(OH)(2) vitamin D(3) therapy to normalize serum calcium. Bone mineral density (BMD) (DXA, at the lumbar spine [L(2)- L(4), LS], femoral neck [FN] and Ward triangle [WT]), serum and urine calcium, serum phosphorus, TOTALALP and osteocalcin were measured. Patients with hypoPTH showed greater lumbar BMD than euPTH patients on suppressive therapy (Z-score; 1.01-/+1.34 vs. -0.52-/+0.70, p<0.05). Serum osteocalcin levels were higher in hypoPTH patients on suppressive therapy compared to hypoPTH patients on replacement therapy. The LS BMD from hypoPTH patients correlated with calcium supplements (r=0.439; p=0.02), 1,25(OH)(2)D(3) dose (r=0.382; p=0.04) and LT(4) dose (r=0.374; p=0.05). Our data suggest that long-term treatment with calcium and 1,25(OH)(2) vitamin D3 supplements in hypoPTH patients on suppressive LT4 therapy results in increased BMD when compared with patients with normal PTH levels.     

Comparison of the Therapeutic Effects of Yeast-incorporated Gallium with those of Inorganic Gallium on Ovariectomized Osteopenic Rats

The purpose of this study was to verify the effect of organic gallium on ovariectomized osteopenic rats. Thirty Wistar female rats used were divided into three groups: (1) sham-operation rats (control), (2) ovariectomized (OVX) rats with osteopenia, and (3) OVX rats with osteopenia treated with organic gallium. Treatments were performed over an 8-week period. At sacrifice, the fifth lumbar vertebral body, one tibia, one femur, and the fourth lumbar vertebrae were removed, subjected to micro-CT for determination of trabecular bone structure, and then processed for histomorphometry to assess bone turnover. The femoral neck was used for mechanical compression testing. Treatment with organic gallium increased bone volume in OVX animals. Organic gallium-treated animals had significant increases in trabecular and cortical thickness and bone strength. The plasma total calcium and inorganic phosphate concentrations in OVX rats decreased and bone mineral content in the lumbar vertebrae and femur increased after treatment with organic gallium. These data provide an important proof of concept that organic gallium may represent a powerful approach to treating or reversing severe osteoporosis in humans.     

绝经后女性CYP19基因Val80及OPG基因A163G多态性与骨密度的相关性研究

探讨细胞色素P450 19 (CYP19) 基因Val80多态性及护骨素(OPG) 基因A163G多态性与绝经后女性骨密度 (BMD) 的关系。随机选择居住在重庆的绝经后女性200例, 采用多聚酶链反应-限制性片段长度多态性法检测Val80及A163G多态性, 采用Norland公司XR-46系列双能X线骨密度仪测量股骨近端及腰椎BMD。 200名绝经后女性中Val80基因型GG、GA及AA的频率分别为19.5％、44.5％及36.0％; A163G基因型GG、GC 及CC的频率分别为: 13.0％, 42.0％及45.0％; 基因型频率分布均符合Hardy-Weinberg平衡 (P＞0.05)。协方差分析及多元逐步回归分析显示CYP19基因第3外显子Val80多态性与绝经后女性BMD无相关性 (P＞0.05)。除大转子外, A163G位点AG/GG/AG+GG基因型者股骨颈、Ward’s三角及腰椎BMD均较AA基因型者低, A163G基因型与股骨颈、Ward’s三角及腰椎BMD有相关性 (P＜0.05)。OPG基因启动子区A163G多态性分布存在明显的种族差异, 且与绝经后女性BMD有一定关联, AA型对BMD具有一定的保护作用, G等位基因是BMD降低的危险因素。     

Iron restriction negatively affects bone in female rats and mineralization of hFOB osteoblast cells

We previously reported that severe iron deficiency negatively affects bone microarchitecture. Here we determined whether marginal iron restriction that reflects some human consumption patterns could have similar consequences. Thirty-two weanling female rats were randomly divided into four groups and fed the following diets for 10 weeks: (i) iron-adequate, calcium-adequate (FeA:CaA), (ii) calcium-restricted (FeA:CaR), (iii) iron-restricted (FeR:CaA), and (iv) both calcium- and iron-restricted (FeR:CaR) diets. DEXA analysis revealed that CaR decreased bone mineral density (BMD), and FeR decreased whole-body bone mineral content (BMC). Iron-restricted and calcium-restricted groups had lower BMD than did their adequate counterparts. All treatment-restricted groups had lower BMD in the fourth lumbar (L-4) vertebrae than the FeA:CaA group. Vertebrae BMD was lower in all treatment groups compared to the control group, and for BMC, the CaR groups were lower than the CaA groups and the FeR groups were lower that the FeA groups, and BMC were lower in iron- and calcium-restricted groups. The microarchitecture of the L-4 vertebrae was compromised in FeA:CaR, FeR:CaA, and FeR:CaR: (i) the connectivity density was reduced by FeR and by CaR; and (ii) trabecular number was decreased and trabecular separation was increased by FeR. Cortical thickness of the femur was reduced by both FeR and CaR. Finite element analysis revealed that L-4 vertebrae from the FeR:CaA group had greater internal stress with an applied force than the FeA:CaA group and, thus, would be more likely to break. Chelation of iron in cultured osteoblast cells impaired mineralization but had no impact upon Type I collagen deposition. Iron depletion, similar to that occurring among some human populations, reduced bone strength and microarchitecture based on the in vivo and in vitro results reported here. Impaired mineralization with iron depletion appears to be a possible mechanism for the observed bone abnormalities.     

胆固醇对绝经前、后正常女性骨密度影响的初步探讨

目的:观察血清胆固醇对绝经前、后女性骨密度的影响.方法:用常规酶法测定血清总胆固醇(CHOL);用双能X线吸收法(DEXA)骨密度仪测定腰椎前后位正位总体(Ll-4)、左侧髋部总体、股骨大转子区、股骨颈和Ward's三角区骨密度(BMD).结果:胆固醇与绝经前女性Ll-4和Ward's区骨密度呈负相关,与绝经后女性BMD无关,校正年龄和BMI后CHOL与绝经前、后女性BMD均无关.结论:胆固醇对绝经前后女性骨密度可能无影响.     

Impact of Weight‐Cycling History on Bone Density in Obese Women

Objective: The purpose of this study was to examine the effect of weight cycling (as defined by the frequency and magnitude of intentional weight loss) on bone mineral density and bone mineral content in obese sedentary women. Research Methods and Procedures: Bone mineral content and density measured by DXA, submaximal physical fitness assessment, nutrient intake, oral contraceptive use, and weight‐cycling history were assessed in 195 healthy, overweight sedentary women (age, 21 to 45 years; body mass index, 27 to 40 kg/m²) before beginning a behavioral weight‐loss intervention. Results: After controlling for body weight, multivitamin use, oral contraceptive/estrogen use, and calcium and magnesium intake, women who had a history of weight cycling did not have significantly lower total‐body bone mineral content or density or total femur bone mineral density. In addition, 99% of subjects were above or within one SD of age and gender normative data for total femur bone mineral density. Discussion: It does not seem that a history of weight cycling has an adverse affect on total femur and total‐body bone mineral density in overweight sedentary premenopausal women.     

The role of strain in the response of rapidly growing young male rat bones to parathyroid hormone

Human parathyroid hormone (hPTH 1-34) stimulates an anabolic response in human and animal skeletons; however, it is unclear if the effect is strain dependent. To determine if the anabolic response to hPTH (1-34) was dependent upon strain in rats we used 2 outbred strains (Sprague Dawley, Wistar), 2 inbred strains (Fischer 344, Wistar spontaneously hypertensive:SHR), and 2 mutant strains (Zucker obese, Zucker lean) of rats. Male rats, 5 weeks of age, from each strain were treated subcutaneously with 80 microg/kg body weight hPTH (1-34) or vehicle for 12 days. The response to PTH was similar in all strains whereby PTH exerted an anabolic effect on femoral bone mass and cancellous bone histology that was independent of strain differences. Histomorphometric indices of bone volume, mineralized surface and bone formation in lumbar vertebrae increased in all PTH-treated rats. Additionally, femur bone mineral content and bone mineral density measured by dual energy X-ray absorptiometry (DEXA), and ash weight increased in all PTH-treated rats. These increases occurred regardless of strain. In summary, PTH exerted comparable anabolic effects on bone mass, bone mineral density and bone formation in all rat models tested demonstrating that the skeletal responsiveness to PTH was not dependent upon strain.     

Development and validation of the Osteoporosis Risk Assessment Instrument to facilitate selection of women for bone densitometry

BACKGROUND: Although mass screening for osteoporosis is not recommended among postmenopausal women, there is no consensus on which women should undergo testing for low bone mineral density. The objective of this study was to develop and validate a clinical tool to help clinicians identify which women are at increased risk for osteoporosis and should therefore undergo further testing with bone densitometry. METHODS: Using Ontario baseline data from the Canadian Multicentre Osteoporosis Study, we identified all cognitively normal women aged 45 years or more who had undergone testing with dual-energy x-ray absorptiometry (DXA) at both the femoral neck and the lumbar spine (L1-L4). Participants who had a previous diagnosis of osteoporosis or were taking bone active medication other than ovarian hormones were excluded. The main outcome measure was low bone mineral density (T score of 2 or more standard deviations below the mean for young Canadian women) at either the femoral neck or the lumbar spine. Logistic regression analysis and receiver operating characteristic (ROC) analysis were used to identify the simplest algorithm that would identify women at increased risk for low bone mineral density. RESULTS: The study population comprised 1376 women, of whom 926 were allocated to the development of the tool and 450 to its validation. A simple algorithm based on age, weight and current estrogen use (yes or no) was developed. Validation of this 3-item Osteoporosis Risk Assessment Instrument (ORAI) showed that the tool had a sensitivity of 93.3% (95% confidence interval [CI] 86.3%-97.0%) and a specificity of 46.4% (95% CI 41.0%-51.8%) for selecting women with low bone mineral density. The sensitivity of the instrument for selecting women with osteoporosis was 94.4% (95% CI 83.7%-98.6%). Use of the ORAI represented a 38.7% reduction in DXA testing compared with screening all women in our study. INTERPRETATION: The ORAI accurately identifies the vast majority of women likely to have low bone mineral density and is effective in substantially decreasing the need for all women to undergo DXA testing.     

股骨近端三维有限元模型评价髋部骨折患者骨密度

目的：探究骨密度与老年髋部骨折股骨近端三维有限元模型密度的关系。方法：选取8 例老年髋部骨折,其中4 例股骨颈骨 折,4 例股骨转子间骨折;左侧肢体3 例,右侧肢体5 例。分别测定腰椎骨密度和双侧髋关节CT 资料,运用Mimics软件和abaqus 软件对健侧股骨近端进行重建和计算出该模型的密度。结果：股骨转子间骨折组腰椎骨密度为(-4.05± 0.24) g/cm2,三维有限元模 型密度为[(1.15± 0.02)× 106],均低于股骨颈骨折组的(-3.15± 0.54) g/cm2,[(1.34± 0.06)× 106],两组比较差异均有统计学意义（均 P<0.05）。腰椎的骨密度与三维有限元模型密度成线性正相关（r=0.881,P=0.004）。结论：骨密度与老年髋部骨折股骨近端三维有限 元模型密度成线性正相关的关系,可为进一步用有限元分析法探讨老年髋部骨折部位与骨密度的关系提供理论依据。     

Relationship between serum albumin and bone mineral density in postmenopausal women and in patients with hypoalbuminemia.

Some discrepancies exist about the relationship between serum albumin level and the pathogenesis of osteoporosis; moreover, most of the studies available have especially concerned patients with osteoporosis, often associated with fractures. Our study, therefore, aims to investigate the presence of a relationship between serum albumin level and bone mineral density in a group of healthy women (n=650; mean age 59.0 +/- 7.4 years) who voluntarily underwent screening for osteoporosis only because they were menopausal (11.2 +/- 7.4 years since menopause) and, for comparison, in a group of outpatients (n = 44; mean age 57.6 +/- 7.0 years; 9.1 +/- 6.7 years since menopause) with hypoalbuminemia associated with diseases. The results show a lack of any relationship in healthy women between serum albumin value and bone mineral density; the lack of correlation was also shown when the postmenopausal women were down into normal, osteopenic and osteoporotic (WHO criteria) or in hypo, normal and hyperalbuminemic. The only significant parameters associated with lower bone mineral density, in fact, were age and years since menopause (p<0.0001 and p<0.0001 respectively at lumbar spine and p<0.02 and p<0.001 at femoral neck level). In the group of patients with hypoalbuminemia associated with diseases, on the other hand, a relationship between reduced bone mineral density and hypoalbuminemia was found (p<0.01 and p<0.05 respectively at lumbar spine and femoral neck). In conclusion, in healthy postmenopausal women the serum albumin level does not play a significant role in the pathogenesis of bone density reduction, which is mainly due to the number of years since menopause and advancing age. The hypoalbuminemia may be related to the reduction of bone mass only in the subjects affected by diseases associated with a significant albumin reduction.     

Exercise,smoking, and calcium intake during adolescence and early adulthood as determinants of peak bone mass. Cardiovascular Risk in Young Finns Study Group.

OBJECTIVE--To evaluate the contribution to peak bone mass of exercise, smoking, and calcium intake in adolescents and young adults. DESIGN--Prospective cohort study with end point measurement (bone mineral density) after 11 years'' follow up for lifestyle. SETTING--Five university hospital clinics. SUBJECTS--264 (153 females, 111 males) subjects aged 9 to 18 years at the beginning of the follow up and 20 to 29 years at the time of measurement of bone mineral density. MAIN OUTCOME MEASURE--Bone mineral density of lumbar spine and femoral neck by dual energy x ray absorptiometry; measures of physical activity and smoking and estimates of calcium intake repeated three times during follow up. RESULTS--In the groups with the lowest and highest levels of exercise the femoral bone mineral densities (adjusted for age and weight) were 0.918 and 0.988 g/cm2 for women (P = 0.015, analysis of covariance) and 0.943 and 1.042 g/cm2 for men (P = 0.005), respectively; at the lumbar spine the respective values were 1.045 and 1.131 (P = 0.005) for men. In men the femoral bone mineral densities (adjusted for age, weight, and exercise) were 1.022 and 0.923 g/cm2 for the groups with the lowest and highest values of smoking index (P = 0.054, analysis of covariance). In women the adjusted femoral bone mineral density increased by 4.7% together with increasing calcium intake (P = 0.089, analysis of covariance). In multiple regression analysis on bone mineral density of the femoral neck, weight, exercise, age, and smoking were independent predictors for men; with weight, exercise, and age for women. These predictors together explained 38% of the variance in bone mineral density in women and 46% in men. At the lumbar spine, weight, smoking, and exercise were predictors for men; and only weight for women. CONCLUSIONS--Regular exercise and not smoking is important in achieving maximal peak bone mass in adolescents and young adults.