Pathogenesis of osteoporosis

The Association between Bone Mineral Density and Periodontal Disease in Middle-Aged Adults

The association between osteoporosis and periodontal disease (PD) has been revealed by previous studies, but there have been few studies on the association in younger adults. We enrolled a total of 7298 adults aged 40 to 44 who underwent PD screening between 2003 and 2008. Data on quantitative ultrasound for the measurement of bone mineral density (BMD) were collected for the diagnostic criteria of osteopenia and osteoporosis. The Community Periodontal Index (CPI) was measured for defining PD. A multiple logistic regression model was used to assess the effect of low bone mass on the risk of PD. Of 7298 enrollees, 31% had periodontal pockets >3 mm, 36.2% had osteopenia, and 2.1% had osteoporosis. The 39.8% of PD prevalence was high in adults with osteoporosis, followed by 33.3% in osteopenia. A negative association was found between BMD and CPI value (p < 0.0001). Low bone mass was associated with the risk of PD (adjusted OR: 1.13; 95% CI:1.02–1.26) after adjusting the confounding factors, including age, gender, education level, overweight, smoking status, past history of osteoporosis, and diabetes mellitus. An association between BMD and PD among young adults was found. An intervention program for the prevention of PD and osteoporosis could be considered starting in young adults.

Effects of Lemon Beverage Containing Citric Acid with Calcium Supplementation on Bone Metabolism and Mineral Density in Postmenopausal Women: Double-Blind 11-Month Intervention Study

A critical factor for preventing osteoporosis after menopause is attenuation of the accelerated turnover rate of bone metabolism. The present randomized controlled study was conducted to clarify the effects of a lemon beverage with calcium (Ca) supplementation that makes use of the chelating action of citric acid. Comprehensive evaluations of bone were performed by assessments of bone mineral density (BMD) and biomarkers related to bone turnover. Seventy-nine postmenopausal women were enrolled and asked to participate in an 11-month continuous intake of the test beverages. The subjects were divided into three groups: those who consumed a lemon beverage containing citric acid with Ca supplementation (LECA group), those who consumed a lemon beverage containing citric acid without Ca supplementation (LE group), and those who consumed no test beverage (control group). Using a double-blind protocol, subjects in the LECA and LE groups consumed one bottle containing 290 mL of the test beverage each day. The ratio of change in BMD after 11 months was significantly higher in the LECA group as compared to the control and LE groups. The LECA group also showed significant decreases in concentrations of tartrate-resistant acid phosphatase 5b (TRACP-5b), a bone resorption marker, and bone alkaline phosphatase (BAP) as compared to the other groups, as well as a significant decrease in concentration of osteocalcin (OC), a bone formation marker, as compared to the LE group. Based on our findings, we speculated that bone resorption and bone formation in postmenopausal women might be suppressed along with an increase in Ca resorption caused by chelation of citric acid in association with continuous ingestion of a Ca-supplemented lemon beverage containing citric acid, resulting in suppression of high bone metabolic turnover. In addition, the results provide information regarding BMD maintenance in the bones of the trunk, including the lumbar spine and proximal femur.

Variation in serum biomarkers with sex and female hormonal status: implications for clinical tests

Few serum biomarker tests are implemented in clinical practice and recent reports raise concerns about poor reproducibility of biomarker studies. Here, we investigated the potential role of sex and female hormonal status in this widespread irreproducibility. We examined 171 serum proteins and small molecules measured in 1,676 participants from the Netherlands Study of Depression and Anxiety. Concentrations of 96 molecules varied with sex and 66 molecules varied between oral contraceptive pill users, postmenopausal females, and females in the follicular and luteal phases of the menstrual cycle (FDR-adjusted p-value <0.05). Simulations of biomarker studies yielded up to 40% false discoveries when patient and control groups were not matched for sex and up to 41% false discoveries when premenopausal females were not matched for oral contraceptive pill use. High accuracy (over 90%) classification tools were developed to label samples with sex and female hormonal status where this information was not collected.

Apigenin inhibits osteoblastogenesis and osteoclastogenesis and prevents bone loss in ovariectomized mice

Polyphenol have been reported to have physiological effects with respect to alleviating diseases such as osteoporosis and osteopetrosis. We recently reported that the olive polyphenol hydroxytyrosol accelerates bone formation both in vivo and in vitro. The present study was designed to evaluate the in vivo and in vitro effects of apigenin (4′,5,7-trihydroxyflavone), one of the major polyphenols in olives and parsley, on bone formation by using cultured osteoblasts and osteoclasts and ovariectomized (OVX) mice, respectively. Apigenin markedly inhibited cell proliferation and indices of osteoblast differentiation, such as collagen production, alkaline phosphatase activity, and calcium deposition in osteoblastic MC3T3-E1 cells at concentrations of 1–10 μM. At 10 μM, apigenin completely inhibited the formation of multinucleated osteoclasts from mouse splenic cells. Moreover, injection of apigenin at 10 mg kg⁻¹ body weight significantly suppressed trabecular bone loss in the femurs of OVX mice. Our findings indicate that apigenin may have critical effects on bone maintenance in vivo.

Effect of lactoferrin on osteogenic differentiation of human adipose stem cells

PURPOSE

Many in vitro studies of the analysis of the lactoferrin (LF) effect on cells have been reported. However, no study has yet investigated the effect of LF on osteogenic differentiation of human adipose-derived stem cells (hADSCs). The aim of this study was to evaluate the effect of LF on osteogenic differentiation of human adipose stem cells.

METHODS

The hADSCs were cultured in an osteogenic medium with 0, 10, 50 and 100 μg/ml LF, respectively. hADSC proliferation was analysed by Cell Counting Kit-8 (CCK-8) assay, and cell osteogenic differentiation was evaluated by alkaline phosphatase (ALP) activity assay, von Kossa staining and real-time polymerase chain reaction (RT-PCR).

RESULTS

Cell proliferation was significantly increased by LF in a dose-dependent manner from days 4 to 14. Cells cultured with 100 μg/ml LF presented a higher activity compared with the control. The deposition of calcium was increased after the addition of LF. The mRNA expression of type I collagen (COL-I), ALP, osteocalcin (OCN) and RUNX2 increased markedly as a result of LF treatment.

CONCLUSIONS

We have shown for the first time that LF could promote the proliferation and osteogenic differentiation of hADSCs, which could be a promising approach for enhancing osteogenic capacity of cell-based construction in bone tissue engineering.

Olive polyphenol hydroxytyrosol prevents bone loss

Polyphenols reportedly exert physiological effects against diseases such as cancer, arteriosclerosis, hyperlipidemia and osteoporosis. The present study was designed to evaluate the effects of oleuropein, hydroxytyrosol and tyrosol, the major polyphenols in olives, on bone formation using cultured osteoblasts and osteoclasts, and on bone loss in ovariectomized mice. No polyphenols markedly affected the proliferation of osteoblastic MC3T3-E1 cells at concentrations up to 10μM. Oleuropein and hydroxytyrosol at 10 to 100μM had no effect on the production of type I collagen and the activity of alkaline phosphatase in MC3T3-E1 cells, but stimulated the deposition of calcium in a dose-dependent manner. In contrast, oleuropein at 10 to 100μM and hydroxytyrosol at 50 to 100μM inhibited the formation of multinucleated osteoclasts in a dose-dependent manner. Furthermore, both compounds suppressed the bone loss of trabecular bone in femurs of ovariectomized mice (6-week-old BALB/c female mice), while hydroxytyrosol attenuated H(2)O(2) levels in MC3T3-E1 cells. Our findings indicate that the olive polyphenols oleuropein and hydroxytyrosol may have critical effects on the formation and maintenance of bone, and can be used as effective remedies in the treatment of osteoporosis symptoms.

Excess iron inhibits osteoblast metabolism

Hemochromatosis is an iron overload disorder associated with osteopenia and osteoporosis. To learn more about the effects of iron on bone cells, we examined the effects of ferric ion on the proliferation, differentiation, and mineralization of two types of cultured osteoblasts, the cell line MC3T3-E1 and rat calvarial osteoblast-like (ROB) cells. We used ferric ammonium citrate (FAC) as a donor of ferric ion, and FAC inhibited the proliferation of MC3T3-E1 cells in a dose-dependent manner. FAC (0.1-1 microg/ml) inhibited indices of osteoblast differentiation, such as the expression of type I collagen (mRNA and protein), the activity of alkaline phosphatase, and the deposition of calcium by osteoblasts. These results suggest that iron overload might give rise to osteoporosis by inhibiting osteoblast proliferation and differentiation.

Age-related decline in trabecular and cortical density: a 5-year peripheral quantitative computed tomography follow-up study of pre- and postmenopausal women

This 5-year prospective study assessed changes in trabecular and cortical volumetric bone density at the non-weight-bearing radius and weight-bearing tibia among clinically healthy pre- and postmenopausal women. Altogether 79 premenopausal (mean age +/- SD at baseline 33 +/- 2 years) and 108 postmenopausal (68 +/- 2 years) women participated in the baseline and follow-up measurements. Trabecular density (TrD) of the distal radius and tibia and cortical density (CoD) of the radial and tibial shafts were assessed by peripheral quantitative computed tomography (pQCT). Repeated measures analysis of variance was used to analyze differences of means and mean changes between the age groups. As expected, TrD and CoD values were greater among premenopausal than postmenopausal women. Changes in radial TrD were similar in both age groups: mean (95% confidence interval) TrD of the distal radius declined by 3.0 mg/cm(3) (-0.9 to 7.0) and 5.1 mg/cm(3) (1.8-8.5) in the younger and older age groups, respectively. The respective declines in TrD of the distal tibia were 4.1 mg/cm(3) (2.1-6.0) and 2.8 mg/cm(3) (1.2-4.3). Decline in CoD was greater in the older than younger age group at both the radial and tibial shafts (P < 0.001). The mean absolute declines in radial CoD were 33.3 mg/cm(3) (27.9-38.7) and 49.4 mg/cm(3) (44.9-53.9) in younger and older women, and the declines in tibial CoD were 16.5 mg/cm(3) (12.6-20.2) and 28.1 mg/cm(3) (25.0-31.2), respectively. In conclusion, volumetric TrD in the weight-bearing tibia and non-weight-bearing radius showed similar age-related declines among pre- and postmenopausal women, while the decline in CoD was greater among postmenopausal women.

Prevalência de osteoporose: uma revisão crítica

A queda da mortalidade, seguida da redução da fecundidade e aumento da expectativa de vida, resulta no envelhecimento da população e no aumento das taxas de doenças crônico-degenerativas, entre as quais a osteoporose. Pesquisas epidemiológicas vêm sendo desenvolvidas com a finalidade de estimar sua prevalência na população empregando diferentes técnicas. O propósito dessa investigação foi revisar os estudos de prevalência de osteoporose e discutir suas implicações do ponto de vista da Saúde Coletiva. Foi realizada revisão da literatura mediante a qual foram incluídas publicações contendo estimativas de prevalência da osteoporose calculadas a partir da densidade mineral óssea aferida pela absorção de raios X de dupla energia. Os dados foram classificados segundo o ano, a região ou o país, autor, características da população investigada, e sítio esquelético. Os resultados mostraram ampla dispersão entre as taxas, com os valores variando entre 0,4% e 40,0% de acordo com o sítio pesquisado, o grupo etário, o sexo e o tipo de estudo. Nos estudos de base populacional, os valores das estimativas por ponto variaram de 7,9% a 16,0% considerando DMO no sítio femoral de mulheres com 50 e mais anos de idade. Nas áreas brasileiras mais desenvolvidas é necessário implementar projetos para conhecer sua prevalência incluindo-a na agenda dos formuladores de políticas públicas.

Curcumin inhibits the proliferation and mineralization of cultured osteoblasts

The effects of curcumin, which is an important constituent of rhizomes of the plant Curcuma longa Linn, on the metabolism of osteoblasts were examined in cultures of rat calvarial osteoblastic cells (ROB cells). The proliferation of cells was markedly inhibited upon exposure of cells to curcumin at 5x10(-6) to 1x10(-5) M. Curcumin at 1x10(-5) M did not induce apoptosis in ROB cells but arrested cells at the G1 phase of the cell cycle. In addition, curcumin stimulated the expression of mRNA for p21(WAF1/CIP1), which inhibits the activity of cyclin-dependent kinases, and inhibited the phosphorylation of histone H1. Furthermore, curcumin reduced the rate of deposition of calcium and the formation of mineralized nodules. Our results indicate that curcumin might inhibit the proliferation and mineralization of osteoblastic cells through the expression of p21(WAF1/CIP1).

Quercetin, a bioflavonoid, accelerates TNF-α-induced growth inhibition and apoptosis in MC3T3-E1 osteoblastic cells

The bioflavonoid quercetin is believed to play an important role in preventing bone loss by affecting osteoclastogenesis and regulating many systemic and local factors including hormones and cytokines. This study examined how quercetin acts on tumor necrosis factor-alpha (TNF-alpha)-mediated growth inhibition and apoptosis in MC3T3-E1 osteoblastic cells. Tritium uptake assay showed that a quercetin treatment accelerated TNF-alpha-induced inhibition of DNA synthesis in the cells in a dose-dependent manner. Both the 3-(4,5-dimethylthiazol-2yl-)-2,5-diphenyl tetrazolium bromide and trypan blue staining assays also showed the quercetin-mediated facilitation of TNF-alpha-induced cytotoxicity in the cells. Apoptosis assays revealed an accelerating effect of quercetin on TNF-alpha-induced apoptosis in MC3T3-E1 cells. In addition, Fas activation and poly (ADP ribose) polymerase cleavage are thought to be closely associated with the TNF-alpha-induced apoptosis and its acceleration by the quercetin treatment in the cells. Collectively, this study showed that quercetin accelerates the TNF-alpha-induced growth inhibition and apoptosis in MC3T3-E1 osteoblastic cells.

Overweight postmenopausal women lose bone with moderate weight reduction and 1 g/day calcium intake

Overweight postmenopausal women may be more susceptible to bone loss with weight reduction than previously studied obese women. The influence of energy restriction and Ca intake on BMD was assessed in 66 individuals. Weight reduction resulted in bone loss at several sites in women consuming 1 g Ca/day and was mitigated with higher calcium intake at 1.7 g/day.

INTRODUCTION

Bone loss is associated with weight loss in obese postmenopausal women and can be prevented with calcium (Ca) supplementation. However, because bone loss caused by weight loss may be greater in overweight than obese women, it is not clear whether Ca supplementation is also beneficial in overweight women.

MATERIALS AND METHODS

We assessed the influence of caloric restriction at two levels of Ca intake on BMD and BMC in 66 overweight postmenopausal women (age, 61 +/- 6 years; body mass index, 27.0 +/- 1.8 kg/m2). Subjects completed either a 6-month energy-restricted diet (WL, n = 47) and lost 9.3 +/- 3.9 % weight or maintained weight (WM; 1 g Ca/day, n = 19). Participants in the WL group were randomly assigned to either normal (1 g/day; WL NL-Ca) or high (1.7 g/day; WL Hi-Ca) Ca intake. Regional BMD and BMC were measured at baseline and after 6 months.

RESULTS

During normal Ca intake, trochanter BMD and BMC and total spine BMD were decreased more in WL than WM women (p < 0.05). The WL NL-Ca group lost more trochanter BMD (-4.2 +/- 4.1%) and BMC (-4.8 +/- 7.1%) than the WL Hi-Ca group (-1.4 +/- 5.6% and -1.1 +/- 8.1%, respectively; p < 0.05). There were no significant changes in BMD or BMC at the femoral neck in any group. Weight loss correlated with trochanter BMD loss (r = 0.687, p < 0.001) in the WL NL-Ca group.

CONCLUSION

Despite an intake of 1 g Ca/day, bone loss occurred at some sites because of weight loss. Calcium intake of 1.7 g/day will minimize bone loss during weight loss in postmenopausal overweight women.

Quercetin, a flavonoid, inhibits the proliferation, differentiation, and mineralization of osteoblasts in vitro

It is possible that the flavonoids that are found in many foods might have a protective effect against osteoclastic activity. However, little information is available about the effects of flavonoids on osteoblastogenesis. Therefore, we investigated the effects of quercetin, a flavonoid, on the metabolism of rat calvarial osteoblast-like cells (ROB cells) in culture. The proliferation of cells was markedly inhibited upon exposure of cells to quercetin at 5 x 10(-6) to 1 x 10(-5) M. Quercetin at 1 x 10(-5) M did not induce apoptosis in ROB cells but arrested cells at the G1 phase of the cell cycle. In addition, quercetin stimulated the expression of mRNA for p21(waf1/cip1), which inhibits the activity of cyclin-dependent kinases, and inhibited the phosphorylation of histone H1. Furthermore, after cells had ceased to proliferate, quercetin reduced the activity of alkaline phosphatase, the level of expression of mRNA for osteocalcin, the rate of deposition of Ca(2+), and the formation of mineralized nodules, all of which are markers of osteoblast differentiation. These findings indicate that quercetin inhibits the proliferation, differentiation, and mineralization of osteoblastic cells.

A osteoporose e os distúrbios endócrinos da tireóide e das gônadas

Apesar da dedicação incessante dos pesquisadores no estudo da osteoporose, muito ainda necessita ser elucidado. A deficiência dos esteróides sexuais, principalmente a de estrógeno, é considerada a principal causa de osteoporose, embora existam inúmeros outros fatores envolvidos. O hipertireoidismo, por exemplo, é considerado um dos fatores de risco para indução ou agravamento da osteoporose e tem despertado o interesse para o estudo dos efeitos de T3 e T4 sobre o metabolismo ósseo. Embora o hipotireoidismo e a afuncionalidade das gônadas seja uma associação freqüente na mulher, a hipofunção da tireóide não é considerada fator de risco para a osteoporose da menopausa. Assim, o estudo da inter-relação entre os distúrbios endócrinos, tão comuns na idade avançada, e a osteoporose é fundamental, pois deste conhecimento poderão advir meios de controle e tratamento adequados, bem como a definição da real natureza do distúrbio ósseo. O objetivo desta revisão é apresentar e discutir alguns aspectos da osteoporose e sua inter-relação com os distúrbios endócrinos da tireóide e das gônadas.

Osteoprotegerin abrogates chronic alcohol ingestion-induced bone loss in mice

To investigate the role of osteoprotegerin (OPG) on alcohol (ethanol)-mediated osteoporosis, we measured a variety of bone remodeling parameters in mice that were either on a control diet, an ethanol (5%) diet, or an ethanol (5%) diet plus OPG administration. OPG diminished the ethanol-induced (1) decrease in bone mineral density (BMD) as determined by dual-energy densitometry, (2) decrease in cancellous bone volume and trabecular width and the increase of osteoclast surface as determined by histomorphometry of the femur, (3) increase in urinary deoxypyridinolines (Dpd's) as determined by ELISA, and (4) increase in colony-forming unit-granulocyte macrophage (CFU-GM) formation and osteoclastogenesis as determined by ex vivo bone marrow cell cultures. Additionally, OPG diminished the ethanol-induced decrease of several osteoblastic parameters including osteoblast formation and osteoblast culture calcium retention. These findings were supported by histomorphometric indices in the distal femur. Taken together, these data show that OPG diminishes ethanol-induced bone loss. Furthermore, they suggest that OPG achieves this through its ability to abrogate ethanol-induced promotion of osteoclastogenesis and promote osteoblast proliferation.

The relationship between bone mineral density and periodontitis in postmenopausal women

BACKGROUND

Systemic bone loss has been proposed as a risk factor for periodontal disease; however, the relationship between these two diseases is still not clear. The objective of this study was to assess the relationship between systemic bone mineral density and periodontal disease, controlling for known confounders.

METHODS

The study population included 70 postmenopausal Caucasian women aged 51 to 78 (mean +/- SD: 62.10 +/- 7.1 years). Skeletal bone mineral density (BMD) was assessed by dual energy x-ray absorptiometry (DXA) at the neck, trochanter, intertrochanter, Ward's triangle, and total regions of the femur, and from the anterior-posterior view of the lumbar spine. Periodontal disease severity was represented by clinical attachment loss (CAL) and interproximal alveolar bone loss (ABL). Other measures of periodontal status included probing depth (PD), supragingival plaque, gingival bleeding on probing, and calculus. DXA and oral examinations were performed by calibrated examiners. Partial correlation coefficients (r) were obtained from multiple linear regression analysis adjusting for age, age at menopause, estrogen supplementation, cigarette smoking, body mass index, and supragingival plaque.

RESULTS

Mean ABL was significantly correlated with BMD of the trochanter (r =- 0.27), Ward's triangle (r = -0.26), and total regions of the femur (r = -0.25). Mean CAL appeared to be related to BMD consistently at all regions of the skeleton, although the association did not reach statistical significance.

CONCLUSIONS

We can conclude that skeletal BMD is related to interproximal alveolar bone loss and, to a lesser extent, to clinical attachment loss, implicating postmenopausal osteopenia as a risk indicator for periodontal disease in postmenopausal Caucasian women.

Selected orthopedic problems in the elderly

The changes that occur in the body as part of the normal aging process and the degenerative changes that often accompany them predispose the elderly to various orthopedic problems. Age, general health, and functional level are all important factors in determining the optimum management of these patients. Treatments are aimed at restoring patient independence and activity to preinjury levels, while at the same time minimizing the risks of treatment complications.

Hormone replacement therapy use in urban older women attending meal sites: associations with sociodemographic and health characteristics and use of preventive services

OBJECTIVE

To examine sociodemographic, health and preventive health practices associated with hormone replacement therapy (HRT) use in urban community-dwelling older women.

DESIGN

Survey.

SETTING

Community-based meal sites throughout the city of Los Angeles.

PARTICIPANTS

A convenience sample of 705 community-dwelling women older than age 60 who completed questionnaires for the Prevention for Elderly Persons Program.

MEASUREMENTS

Demographic and life style characteristics, functional status, preventive practices, and current and past use of HRT.

RESULTS

Among the 705 women surveyed, 13% reported current use and 17% reported past use of HRT. Current users were more likely to be younger and more likely to report a history of osteoporosis, hysterectomy, and calcium use than never users. White women were more likely to be current users than black women.

CONCLUSIONS

Only a small proportion of the older urban women studied are currently using HRT. In particular, efforts to increase the use of these preventive services need to focus on black women and women who do not have a prior history of osteoporosis.

Effects of nicotine on cultured cells suggest that it can influence the formation and resorption of bone

The acute effects of nicotine [1-methyl-2-(3-pyridyl)pyrrolidine] on the formation and resorption of bone were examined in cultures of clonal rat calvarial osteogenic cells (ROB-C26) and clonal mouse calvarial preosteoblastic cells (MC3T3-E1), as well as in osteoclast-like cells formed during coculture of mouse bone marrow cells and clonal stromal cells from mouse bone marrow, ST2 cells, at concentrations that occur in the saliva of smokeless tobacco users. Nicotine stimulated the rate of deposition of Ca(2+) by ROB-C26 cells, as well as the alkaline phosphatase activity of these cells, in a dose-dependent manner. However, both activities decreased in MC3T3-E1 cells that had been exposed to nicotine. These results indicate that nicotine affected osteoblastic differentiation in osteoblast-like cells. By contrast, nicotine reduced, in a dose-dependent manner, the formation of tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells (MNCs) and the formation of pits on slices of dentine, both of which are typical characteristics of osteoclasts. Our results suggest that nicotine might have critical effects on bone metabolism.

Effects of physical activity, body weight and composition, and muscular strength on bone density in young women

OBJECTIVE

The purpose of this study was to examine the relationship between body weight and composition, muscular strength, physical activity, and bone mineral density (BMD) in eumenorrheic college-aged women.

METHODS

BMD and bone mineral content (BMC) of the total body, and BMD of the lumbar spine (L2-L4) and femoral neck (via dual energy x-ray absorptiometry), as well as body composition and muscular strength, were measured in 60 college-aged women. The women were divided into three groups: 1) low body weight athletes involved in weight-bearing, collegiate sports (N = 20), 2) matched low body weight and sedentary (N = 20), and 3) average body weight and sedentary (N = 20). All groups were matched for height, age, and age at menarche.

RESULTS

The athletes had significantly greater (P < 0.05) (mean +/- SD) total body BMD (1.164 +/- 0.06 g x cm[-2]), L2-L4 BMD (1.240 +/- 0.13 g x cm[-2]), femoral neck BMD (1.144 +/- 0.13 g x cm[-2]) and total body BMC (2.44 +/- 0.30 kg) than the low body weight, sedentary (LWS) group, but were only greater than the average body weight sedentary group (AWS) for femoral neck BMD. Significant correlations were found between lean body mass (LBM) and all BMD variables (P < 0.001). A significant correlation (P < 0.01) was found between fat mass and all BMD variables in the sedentary subjects alone (N = 40), but with inclusion of the athletes (N = 60), none of the correlations between fat mass and BMD were significant. Arm and leg strength isometric torque values corrected for muscle + bone cross-sectional area (M + B CSA) were not significantly different between the athletes and LWS group, but the athletes were greater (P < 0.05) than the AWS group for both arm and leg strength/M + B CSA. No significant, site-specific correlations were found between strength/M + B and BMD.

CONCLUSIONS

In summary, the athletes had significantly greater BMD, BMC, and LBM than the LWS group and, except for a greater femoral neck BMD, similar BMD, BMC, and LBM as the AWS group. These results suggest that LBM and weight-bearing exercise both enhance BMD in eumenorrheic young adult women.

Patients with femoral neck and intertrochanteric fractures. Are they the same?

A prospective analysis was performed involving 680 geriatric patients with hip fractures to determine whether the demographic profile of patients with femoral neck fractures was similar to that of patients with intertrochanteric fractures. All patients were community dwelling, cognitively intact, previously ambulatory elderly with femoral neck or intertrochanteric fracture. Three hundred fifty-eight patients (52.6%) sustained a femoral neck fracture; 322 (47.4%), an intertrochanteric fracture. Patients with an intertrochanteric fracture were significantly older, more likely to be limited to home ambulation, and were more dependent regarding basic and instrumental activities of daily living. After stratification by gender and adjustment for age, these differences remained significant in women only. There were no differences in age, prefracture ambulatory ability, or dependence in activities of daily living in men with either type of fracture.

Effects of androgens on subpopulations of the human osteosarcoma cell line SaOS2

Previously, we showed that androgens stimulate murine and human osteoblast-like cell proliferation and differentiation by mechanisms involving increased responses to mitogenic growth factors (GF) and increased GF production. To explain this dual action of androgens on primary osteoblastic cell populations we advanced the hypothesis that androgens exert differential effects on osteoblastic subpopulations. We subcloned a human osteosarcoma cell line (SaOS2) into subpopulations expressing high (HAS) and low (LAS) levels of alkaline phosphatase (ALP). The obtained subclones differed significantly in their ALP production and expressed a high and low ALP phenotype, respectively, for the entire experimental period. Dihydrotestosterone (DHT) increased specific ALP activity and type-I procollagen peptide secretion in both HAS and LAS. DHT pretreatment enhanced the mitogenic action of basic fibroblast growth factor (bFGF) and insulinlike growth factor 2 (IGF2) only in HAS. The enhanced mitogenic effect of IGF2 in HAS after DHT pretreatment was associated with increased IGF2-receptor mRNA levels. Therefore, we conclude that androgens exert their osteoanabolic action (1) by stimulating differentiated functions of osteoblastic cells with a high and a low ALP phenotype, and (2) via increased growth factor receptor expression and thereby enhancing mitogenic growth factor responses only in HAS.

Factors in implant integration failure after bone grafting: an osteometric and endocrinologic matched analysis

In a retrospective analysis of 49 patients who received bone graft augmentation to the maxillary sinuses in conjunction with implant insertion, 11 patients had a significantly reduced success rate. The aim of the present study was to determine whether bone quality, as assessed by osteometry and selected haematologic and urinary tests, influences the integration of implants, and whether such data can be prognostically useful. Relative bone mass density (BMD%) differed significantly among these patients as compared to age- and sex-matched control patients receiving the same reconstructive treatment (P=0.01). Other parameters tested did not demonstrate any significant differences. In addition to local complications, general disorders, such as osteoporosis, must be considered in cases of excessive implant loss.

Osteoporosis: a risk factor in periodontal disease

Osteoporosis is suspected as a risk factor in periodontal disease, but previous studies have failed to establish a relationship. Possible explanations for this could be lack of precise methods for assessment of osteoporosis in the jaws and confounding of the result by other factors such as age, gender, or smoking. In the present study 12 female patients with osteoporotic fractures (Group O) and 14 normal women (Group N) were examined clinically for plaque (VPI), gingival bleeding (GBI), and loss of attachment on the 6 Ramfjord index teeth. Bone mineral content (BMC) of the mandible and forearm was determined by dual photon scanning. Results were presented as arithmetic means +/- standard error, and differences between groups were tested by 2-sample t-test. The two groups were comparable with respect to age (O: 68.3 +/- 1.8 years, N: 68.1 +/- 1.5 years), menopausal age (O: 47.5 +/- 1.8 years, N: 47.2 +/- 1.3 years), and smoking habits (O: 4 smokers, N: 3 smokers). The osteoporotic women had significantly lower BMC values than controls in the mandible (O: 0.63 +/- 0.04 in U/cm2; N: 0.78 +/- 0.02 in U/cm2, P < 0.01) and forearm (O: 1.05 +/- 0.05 in U/cm; N: 1.28 +/- 0.05 in U/cm, P < 0.01). No significant differences were found with respect to plaque (O: 46.67 +/- 10.00%, N: 36.67 +/- 6.67%) and gingival bleeding (O: 46.67 +/- 11.67%, N: 43.33 +/- 10.00%), whereas significantly greater loss of attachment was seen in osteoporotic women (O: 3.65 +/- 0.18 mm, N: 2.86 +/- 0.19 mm, P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of treatment on established osteoporosis in young women with amenorrhoea

BACKGROUND AND OBJECTIVE

Amenorrhoea in women of reproductive age causes loss of bone mineral. This study assessed the effect of treatment of amenorrhoea on bone mineral density.

DESIGN

Serial measurements of bone mineral density were obtained in women receiving treatment for amenorrhoea.

PATIENTS

Eighty-five women aged 17-40 with a past or current history of amenorrhoea, from various causes, with median duration of 46.5 months (range 8 months-21 years).

MEASUREMENTS

Bone mineral density in the lumbar spine was measured by dual-energy X-ray absorptiometry.

RESULTS

Initial vertebral bone mineral density was low, mean 0.85 (SD 0.10) g/cm2. After an interval of 19.6 (SD 7.5) months on treatment there was a highly significant increase to 0.89 (SD 0.10) g/cm2 (P < 0.0005). This was equivalent to a gain in bone mass of 2.1% per year (95% confidence interval 1.5-2.8%). Improvement was seen in all diagnostic groups (except polycystic ovary syndrome) and with all types of therapy. We observed no difference in the response of previously untreated patients compared with those already on treatment, nor any change in response with increasing duration of treatment. No new fractures were reported during the study.

CONCLUSIONS

Bone mineral density in young women with amenorrhoea is improved by appropriate treatment, but recovery is not substantial. Hence early diagnosis and therapy is essential to prevent bone loss.

Management of postmenopausal osteoporosis

More than 25% of postmenopausal women are at risk of osteoporosis. In order to avoid its consequences, it is necessary to find an appropriate prevention and/or treatment. We studied: (1) 15 postmenopausal women treated with percutaneous estradiol (50 micrograms/24 h) plus MPA (10 mg/10 days/month); (2) 15 postmenopausal women treated with synthetic calcitonin nasal spray at the daily dose of 100 IU; (3) 10 postmenopausal women treated with nandrolone decanoate (50 mg every 3 weeks); (4) 10 postmenopausal women treated with ipriflavone (600 mg/day); and (5) 10 postmenopausal women treated with sodium fluoride (20 mg) plus calcium (600 mg). Clinical examination, bone mass measurement (total BMD), hematochemical and urinary parameters of bone metabolism (calcium, urinary hydroxyproline, PTH) and growth factors (as IGF-I and TNF-beta) were evaluated. After 6 months of therapy, a complete prevention of bone resorption was achieved. In agreement with current literature, we observed that the various therapeutic approaches have all some positive effect on BMD, with different results on pain, blood biochemical parameters and growth factors' concentrations.

Influence of early age at menopause on vertebral bone mass

Menopause leads to rapid bone loss, mainly as a result of estrogen deficiency superimposed on the age-related linear bone loss. The influence of age at menopause on bone loss is unclear, although early menopause is widely considered a risk factor for osteoporosis. Vertebral bone mineral density (BMD) was measured in 1667 women divided into five groups according to hormonal status and age at menopause. Menopausal status was an independent predictor of BMD in a multiregression analysis, along with current age, years since menopause (YSM), weight, and height. For the same chronologic age (55 years), women with early menopause had a 15% lower BMD and a higher YSM than women whose menopause occurred later ("normal" menopause). After adjusting for the interval since menopause, postmenopausal women with early menopause were found to have lower vertebral BMD than postmenopausal women with normal menopause. Finally, after the age of 60, 66% of the women with early menopause had a BMD that was below the fracture threshold compared to 18% of the women with normal menopause. The results of this cross-sectional study suggest that early menopause is associated with a quantitatively higher bone loss than in women with menopause of later onset and thus constitutes a risk factor for osteoporosis.

The effect of previous oral contraceptive use on bone mineral density in perimenopausal women

The bone mineral density (BMD) of the lumbar vertebrae L2-4 and femoral neck was determined by dual-energy X-ray absorptiometry (DXA) in 3222 perimenopausal women-a random stratified sample of the population-based Kuopio Osteoporosis Study (OSTPRE). The mean age of the women was 53.4 years (range 47.9-59.6 years). Twenty-nine percent of the women were past users of oral contraceptives (OC) containing 50 micrograms or less of ethinyl estradiol and 7.4% (n = 250) of the women reported OC use for more than 6 years. There was a slight but statistically significant difference between OC users (n = 939) and non-users (n = 2283) in lumbar BMD (1.134 +/- 0.155 g/cm2 v 1.123 +/- 0.161 g/cm2, p = 0.014). A statistically significant difference was recorded also after adjustment for years since menopause, duration of hormonal replacement therapy (HRT) and present weight (p = 0.044). When the analysis was performed among women who had never used oestrogen replacement therapy (n = 1427) and among premenopausal women (n = 387), no differences in BMD were found between OC users and non-users. Similarly, femoral neck BMD did not differ between the groups. This population-based study demonstrated a slightly higher lumbar BMD among past OC users. However, OC users and non-users differed from each other in many behavioral characteristics. Thus, the differences in BMD may be accounted for more by other factors than by past OC use itself. The low-dosage estrogen OCs used today would not be expected to have any positive bone effects among future perimenopausal women.

Long-term exercise of young and adult female rats: effect on femoral neck biomechanical competence and bone structure

The present study was designed to examine the effect of exercise on femoral neck bone structure and strength in female rats after 4 and 10 months of exercise. Female Fischer rats aged 2 months were exercised for 4 h a day, 5 days a week on a motor-driven treadmill the speed of which was gradually increased until a daily distance of 2 km was reached. The training level was maintained for 4 months (n = 15) and 10 months (n = 15). Sedentary age-matched rats served as controls (n = 30). At death the proximal third of both femora was obtained from each rat. The left femoral neck was tested in a materials-testing machine, and the right was used for either trabecular bone mass measurement (BV/TV) or scanning electron microscopy (SEM). Biomechanical testing revealed a significant training-induced increase in femoral neck bone strength after 4 months of exercise, which although not accelerated was preserved after 10 months of exercise. Histologic investigation revealed a significant training-induced increase in BV/TV, accounted for by a significantly smaller proportion of marrow space. No difference in cortical area was found. Both histology and SEM revealed a tendency to an earlier closure of the growth line in the exercised animals. However, the exercised animals aged 6 months had a significantly increased total femoral length compared with the sedentary rats. No difference was found in total femoral length between sedentary and exercised rats aged 12 months. On the basis of this study, it is concluded that exercise has a positive effect on femoral neck bone strength.(ABSTRACT TRUNCATED AT 250 WORDS)

Osteoporosis risk factors, gynaecological history and fractures in perimenopausal women--the results of the baseline postal enquiry of the Kuopio Osteoporosis Risk Factor and Prevention Study

The Kuopio Osteoporosis Risk Factor and Prevention (OSTPRE) Study examines the risk factors of osteoporosis, the relationship of risk factors to bone density and fractures, as well as the possibility to prevent bone loss by administering certain hormones. The baseline postal enquiry in 1989 was sent to all the 14,220 women aged 47-56 years residing in the Kuopio Province, Finland. The questionnaire included questions about their gynaecological history, physical exercise and smoking habits, calcium intake, body weight and height, history of bone fractures, health disorders, their current and previous use of drugs, as well as their willingness to participate in bone densitometry and in a clinical hormone trial. The response rate was 92.8%. In all, 56% reported some previous use of female hormones. Strong contraindications for oestrogen replacement therapy were found in 9.3% of the women. Almost half of the respondents reported lack of regular physical exercise, 11.9% were smokers, and 17.0% reported a calcium intake from milk products of less than 500 mg daily. The incidence of fractures increased steadily with age. The incidence of premenopausal fractures within the last 10 years was 7.65 per 1000 person/years and that of postmenopausal fractures was 17.40 per 1000 person/years (P = 0.000). The effect of menopause on fracture incidence was stronger than the effect of a 5-year age increase. Of the respondents, 84.4% were willing to participate in bone densitometry and 68.3% for long-term prevention of osteoporosis with oestrogen.

Influence of the climacteric on the bone mass of the spine and femur

OBJECTIVE

To determine the correlation between the bone mass of the lumbar spine and the neck of the femur in Spanish climacteric women.

METHOD

Bone mass was measured using quantitative digital radiology in 200 climacteric women who had no record of receiving hormone replacement therapy.

RESULT

A statistically significant correlation (P < 0.05) is observed between the bone mineral density and content of the lumbar spine and the femur in all the groups of climacteric women, although only in the postmenopausal women does it approach 70%. A direct relationship is observed between the loss of bone mass and the onset of the menopause, as well as with the patients' body mass index.

CONCLUSION

When the different parameters are analyzed, the results show that measurement of the lumbar spine is essential, and measurement of the femur should not be used as a substitute, but rather in addition to it.

Reproductive factors as predictors of bone density and fractures in women at the age of 70

The importance of reproductive and other health and social factors as predictors of bone mineral density (BMD) and fractures was investigated in a longitudinal study of 70-year-old women. At 70 years of age there was no correlation between menarcheal age, menopausal age, duration of fertile period and parity and BMD or a history of fractures. Bilateral oophorectomy (mean age at surgery 45.3 +/- 3.6 years) and the duration of tobacco smoking were negatively correlated to BMD at 70 years of age. Tobacco smoking was positively correlated to a history of fractures and body mass index (BMI) was negatively correlated to a history of fractures at 70 years of age. In a stepwise multiple regression model, height, body mass index and a history of hysterectomy were found to have a contributory, positively-correlated independent explanatory value for BMD at 70 years. In a logistic multiple regression analysis, bilateral oophorectomy was the only independent explanatory factor for fractures at 70 years of age. BMD was lower in women who had undergone bilateral oophorectomy compared with controls at 70 years of age. Hysterectomized women without bilateral oophorectomy showed a higher BMD in the right calcaneus at 70 years of age compared with controls. When comparing the reduction in bone mineral density between 70 and 76 years of age, the fifth quintile (women with the highest BMD) at 70 years of age decreased 2.7 times more (P < 0.01) than the first quintile. A longitudinal examination between 70 and 76 years revealed that BMD at the age of 70 was a significant (P < 0.01) predictor for fractures occurring between 70 and 76 years of age.

Osteoporosis and normal weight bulimia nervosa--which patients are at risk?

This study assesses the degree of bone mineral loss in women with active DSM IIIR bulimia nervosa. The subjects in this study were 20 GP-referred female patients of normal weight who met criteria for bulimia nervosa and 16 healthy age, sex and weight matched controls. Dual energy X-ray densitometry of lumbar L1-L4 vertebrae was performed on all subjects. The patients with bulimia nervosa had a significantly lower mean lumbar bone mineral density (0.964 g/cm2) than the control group (1.043 g/cm2, p < 0.01). Within the patient group only subjects with a past history of anorexia nervosa had a significantly lower mean bone mineral density (BMD) than the controls. Small sample sizes limit the power of the study, however significant correlations were found between duration of amenorrhoea, low BMI and lumbar BMD. Bulimic patients do suffer from osteoporosis. Risk factors for this may be; a past history of anorexia nervosa, prolonged secondary amenorrhoea, and a persistently low body mass index.

Symptomatic osteoporosis: a risk factor for residual ridge reduction of the jaws

The purpose of this study was to clarify if symptomatic osteoporosis is a risk factor for severe residual ridge reduction of the jaws. The analysis included 12 edentulous women with osteoporotic fractures, otherwise normal, and 16 normal edentulous women matched with respect to age, menopausal age, and period of edentulousness. The bone mineral content measured in vivo by dual-photon scanner was significantly lower in the mandible and the forearm bones (that is, in the skeleton) of the osteoporotic group than it was in the normal group. No significant difference between the two groups was demonstrated with respect to the size of the mandibular sagittal area, measured on identical lateral cephalograms, while the sagittal maxillary area was significantly smaller in the osteoporotic group. Symptomatic osteoporosis therefore seems to be a severe risk factor for smaller residual ridge reduction off the maxillae, while this does not seem to be the case in the mandible.

The effect of hormone replacement therapy on postmenopausal bone loss

Eighty-four postmenopausal women who were randomly allocated to one of four groups, completed a 1 year follow-up. The first group (n = 20) received 0.625 mg/day conjugated estrogens cyclically (CE; 25 days/month). The second (n = 23) received 0.625 mg/day of CE continuously, and the third (n = 17) received 50 micrograms/day of transdermal 17 beta-estradiol cyclically (24 days/month). All these groups also received 2.5 mg of medroxiprogesterone acetate sequentially for the last 12 days of hormone replacement therapy, while the fourth group (n = 24) constituted a treatment-free control group. Dual photon absorptiometry was carried out before therapy and was repeated after 1 year. Serum calcium, phosphate and osteocalcine levels, and the urinary calcium/creatinine and hydroxyproline/creatinine ratios, were measured prior to treatment and 6 and 12 months thereafter. All treatment groups showed an increase in bone mineral content. This increase was higher in the continuous CE treatment group (4.4%, P less than 0.05) and in transdermal group (7.1%, P less than 0.01). Concomitant biochemical effects at 6 and 12 months, reduction in urine calcium and hydroxyproline, reduction in blood calcium, phosphate and osteocalcine, were compatible with the observed effects on bone mineral.

Effect of ipriflavone and estrogen on the differentiation and proliferation of osteogenic cells

The effect of ipriflavone (IP) on the proliferation and differentiation of rat osteoblast-like (ROB) cells and human periodontal ligament fibroblasts (HPLF) was studied in the presence and absence of estrogen. ROB cells were isolated from newborn rat calvaria by sequential collagenase digestion and HPLF from the outgrowth of human periodontal ligament in culture. The alkaline phosphatase (ALP) activity, employed as a marker of bone cell differentiation, was significantly enhanced by IP in both cell types; however, the concentration at which IP had a maximal effect was lower in ROB cells than in HPLF (10(-10) versus 10(-7) M, respectively). Cell proliferation judged by DNA content was either constant (ROB cells) or slightly increased (HPLF) by IP up to 10(-10) M, and decreased significantly above that concentration. In addition, the dose-dependent effect of estrogen on the growth and differentiation of each cell type in the presence and absence of IP was also tested. At the concentrations of IP which showed maximum effects in the induction of ALP, 10(-10) M for ROB cells and 10(-7) M for HPLF, IP inhibited DNA increase in an estrogen-independent manner. Estradiol (10(-11)-10(-9) M) itself increased the growth rate of both cell types significantly in a dose-dependent manner. Regardless of the concentrations of estradiol tested, ALP activities of both ROB cells and HPLF were elevated by the addition of IP. The ratio of ALP in the presence and absence of IP was similar over the range of estradiol concentrations tested.(ABSTRACT TRUNCATED AT 250 WORDS)

Endogenous factors affecting bone mineral content in post-menopausal women

Eighty-eight healthy post-menopausal women were divided into two groups, one of 35 subjects who had undergone menopause up to 9 years previously and the second of 53 subjects who were 10 or more years post-menopausal. In each individual we related the bone mineral content (BMC), measured by single photon absorptiometry in the distal forearm, to anthropometric variables and urinary oestrogen excretion. There was a positive association between BMC and both urinary oestrogen excretion and anthropometric variables, but this was statistically significant only in the older women. As expected, BMC in the distal forearm decreased with advancing age, the fall being greatest in the first 9 years after the menopause. We concluded that although a single measurement of urinary oestrogen and anthropometric variables does not provide enough information to predict an individual's BMC, the values obtained may prove of use, along with a single BMC determination, in helping to predict the rate of bone loss.

The impact of menopausal age on future fragility fracture risk

Altogether 733 postmenopausal women were interviewed with regard to their age at menopause. Subsequent fragility fractures over an 11 year period were recorded. Fragility fractures had occurred in 212 women. These women had an earlier menopause, but the deviation from the nonfracture group was significant only in those who were less than 70 years at the beginning of the fracture catchment period. Women 50-69 years of age, in the lowest quartile of menopausal age, sustained 50% more fragility fractures than those in the highest quartile. In older women menopausal age does not predict fragility fractures. Women less than 70 with an early menopause had a significantly lower initial bone mass.

Prevalence and determinants of estrogen replacement therapy in elderly women

To better understand which women use estrogen replacement therapy, we examined the prevalence and determinants of estrogen replacement therapy in 9704 nonblack women, age greater than or equal to 65 years, who participated in the multicenter prospective Study of Osteoporotic Fractures. Overall, 13.7% of women reported current use of oral estrogen; 10.9% took estrogen alone and 2.8% took estrogen opposed by progestin. Four percent currently used parenteral estrogen compounds. Current use declined sharply with age from 17% at age 65 to 4% at age greater than or equal to 85. The primary determinant of estrogen replacement therapy was the type of menopause; the odds of using estrogen replacement therapy in current users compared with never users were approximately five times higher in women with a surgical menopause. Estrogen use was more common among women who had higher levels of education and were less obese. Furthermore, estrogen replacement therapy users were more likely to drink alcohol and to participate in sports and recreation. A diagnosis of osteoporosis was the major determinant of continued estrogen use, but only 24% of women with a diagnosis of osteoporosis used estrogen replacement therapy. We conclude that only a small proportion of elderly women in the United States use estrogen replacement therapy. Selection factors for use of estrogen are evident and may introduce bias in studies of estrogen and disease. In consideration of the distribution of these selection factors, estrogen users will tend to be at lower risk of coronary disease and possibly breast cancer but at greater risk for hip fractures.