Project description:BackgroundAlthough the benefits of low-level laser therapy (LLLT) in soft tissue healing have been demonstrated, the effects of laser on bone have remained controversial. This study investigated the impact of postoperative 660-nm LLLT on the radiographic crestal bone loss of fresh-socket dental implants.MethodsThirty patients referred to the Department of Oral and Maxillofacial Surgery for tooth extraction and placement of fresh-socket implants were selected and assigned to two groups: laser (intervention) and no-laser (control) groups. Immediately after tooth extraction, the implant was inserted into the tooth socket. 660-nm LLLT was immediately started after surgery and was repeated three times per week for two weeks. Bone quantification at the implant site was assessed using periapical intraoral radiographs and computerized software immediately after surgery and after six months.ResultsThis study showed a statistically significant difference in mean bone resorption between the mesial and distal aspects of the two groups, with lower bone resorption in the laser group compared to the no-laser group.ConclusionThe results of this study suggest that LLLT can effectively reduce bone resorption in fresh-socket implant placement. This might indicate the positive effect of LLLT on bone resorption reduction.
Project description:BackgroundOxidative stress has been recently suggested to play a part in the development of osteoporosis. Catalase is a major antioxidant enzyme that detoxifies hydrogen peroxide by converting it into water and oxygen, thereby preventing cellular injury by oxidative stress.AimsTo examine the associations between the catalase gene (CAT) polymorphisms and bone mineral density (BMD) and bone turnover markers in postmenopausal Korean women.MethodsAll exons, their boundaries and the promoter region (approximately 1.5 kb) were directly sequenced in 24 individuals. Among 18 variants identified by a direct sequence method, four polymorphisms were selected and genotyped in all study participants (n = 560). BMD at the lumbar spine and proximal femur was measured using dual-energy x ray absorptiometry. Serum osteocalcin concentrations and bone-specific alkaline phosphatase activity were determined by an immunoradiometric assay and an immunoassay, respectively.ResultsThe mean (standard deviation) age of the participants was 59.4 (7.2) years. Multivariate analysis showed an association of the +22348C-->T polymorphism with BMD at the lumbar spine (p = 0.01 in the dominant model) and at femur neck (p = 0.05 in the dominant model), and with serum osteocalcin level (p = 0.008 in the dominant model). Haplotype analyses showed that HT4 (-20T, +144C, +22348T, +33078A) was significantly associated with higher BMD at various sites (p<0.001-0.03) and with lower serum osteocalcin levels (p = 0.01 in the codominant model).ConclusionsThese findings indicate that the +22348C-->T polymorphism and HT4 of CAT may be useful genetic markers for bone metabolism.
Project description:The present study aims to evaluate the influence of apicocoronal position and immediate and conventional loading in the percentage of bone-implant contact (BIC). Thus, 36 implants were inserted in the edentulous mandible from six dogs. Three implants were installed in each hemimandible, in different positions in relation to the ridge: Bone Level (at crestal bone level), Minus 1 (one millimeter apical to crestal bone), and Minus 2 (two millimeters apical to crestal bone). In addition, each hemimandible was submitted to a loading protocol: immediate (prosthesis installed 24 hours after implantation) or conventional (prosthesis installed 120 days after implantation). Ninety days after, animals were killed, and implant and adjacent tissues were prepared for histometric analysis. BIC values from immediate loaded implants were 58.7%, 57.7%, and 51.1%, respectively, while conventional loaded implants were 61.8%, 53.8%, and 68.4%. Differences statistically significant were not observed among groups (P = 0.10, ANOVA test). These findings suggest that different apicocoronal positioning and loading protocols evaluated did not interfere in the percentage of bone-implant contact, suggesting that these procedures did not jeopardize osseointegration.
Project description:UnlabelledTo determine the association of the Apolipoprotein E (APOE) E4 gene polymorphism with bone mineral density (BMD) and fractures we conducted a meta-analysis of 17 reports. Despite lower trochanteric and lumbar BMD in APOE4 carriers, there is insufficient evidence to support a consistent association of APOE with bone health.IntroductionAPOE has been studied for its potential role in osteoporosis risk. It is hypothesized that genetic variation at APOE locus, known as E2, E3, and E4, may modulate BMD through its effects on lipoproteins and vitamin K transport. The purpose of this study was to determine the association of the APOE-E4 gene polymorphism with bone-related phenotypes.MethodsWe conducted a meta-analysis that combined newly analyzed individual data from two community-based cohorts, the Framingham Offspring Study (N = 1,495) and the vitamin K clinical trial (N = 377), with 15 other eligible published reports. Bone phenotypes included BMD measurements of the hip (total hip and trochanteric and femoral neck sites) and lumbar spine (from the L2 to L4 vertebrae) and prevalence or incidence of vertebral, hip, and other fractures.ResultsIn sex-pooled analyses, APOE4 carriers had a 0.018 g/cm(2) lower weighted mean trochanteric BMD than non carriers (p = 0.0002) with no evidence for between-study heterogeneity. A significant association was also detected with lumbar spine BMD (p = 0.006); however, inter-study heterogeneity was observed. Associations with lumbar spine and trochanteric BMD were observed predominantly in women and became less significant in meta-regression (p = 0.055 and 0.01, respectively). There were no consistent associations of APOE4 genotype with BMD at other skeletal sites or with fracture risk.ConclusionsBased on these findings, there is insufficient evidence to support a strong and consistent association of the APOE genotype with BMD and fracture incidence.
Project description:ObjectiveTo assess the relationship between chronic obstructive pulmonary disease (COPD) severity and bone mineral density (BMD) in the whole body and different body areas.MethodsThis retrospective, cross-sectional study included patients with COPD. Demographic and lung function data, COPD severity scales, BMD, and T scores were collected. Patients were grouped by high (≥-1) and low (<-1) T scores, and stratified by body mass index, airway obstruction, dyspnoea, and exercise capacity (BODE) index. The relationship between whole-body BMD and BODE was evaluated by Kendall's tau-b correlation coefficient. Risk factors associated with COPD severity were identified by univariate analyses. BMD as an independent predictor of severe COPD (BODE ≥5) was verified by multivariate logistic regression. BMD values in different body areas for predicting severe COPD were assessed by receiver operating characteristic curves.ResultsOf 88 patients with COPD, lung-function indicators and COPD severity were significantly different between those with high and low T scores. Whole-body BMD was inversely related to COPD severity scales, including BODE. Multivariate logistic regression revealed that BMD was independently associated with COPD severity. The area under the curve for pelvic BMD in predicting severe COPD was 0.728.ConclusionBMD may be a novel marker in predicting COPD severity, and pelvic BMD may have the strongest relative predictive power.
Project description:Recent studies suggested that long noncoding RNAs (lncRNAs) were widely transcribed in the genome, but their potential roles in the genetic complexity of human disorders required further exploration. The purpose of the present study was to explore genetic polymorphisms of lncRNAs associated with bone mineral density (BMD) and its potential value. Based on the lncRNASNP database, 55,906 lncSNPs were selected to conduct a genome-wide association study meta-analysis among 11,140 individuals of seven independent studies for BMDs at femoral neck (FN), lumbar spine, and total hip (HIP). Promising results were replicated in Genetic Factors for Osteoporosis Consortium (GEFOS Sequencing, n = 32,965). We found two lncRNA loci that were significantly associated with BMD. MEF2C antisense RNA 1 (MEF2C-AS1) located at 5q14.3 was significantly associated with FN-BMD after Bonferroni correction, and the strongest association signal was detected at rs6894139 (P = 3.03 × 10-9 ). LOC100506136 rs6465531 located at 7q21.3 showed significant association with HIP-BMD (P = 7.43 × 10-7 ). MEF2C-AS1 rs6894139 was replicated in GEFOS Sequencing with P-value of 1.43 × 10-23 . Our results illustrated the important role of polymorphisms in lncRNAs in determining variations of BMD and provided justification and evidence for subsequent functional studies.
Project description:Cathepsin K plays an important role in bone resorption. The reports of the association of serum cathepsin K with bone mineral density (BMD) and bone turnover markers are conflicting and the role of serum cathepsin K as a bone turnover marker is unclear. The aims of the study were as follows: (1) to investigate the association of serum cathepsin K with BMD and markers of bone turnover and (2) to evaluate the correlations of single-nucleotide polymorphisms (SNPs) within the CTSK gene with serum cathepsin K, BMD, and markers of bone metabolism in postmenopausal Chinese women. A cross-sectional study was conducted with 1752 postmenopausal Chinese women. Four tagging SNPs (rs12085336, rs12746973, rs4379678, and rs10847) of the CTSK gene were genotyped. Serum cathepsin K of 768 and markers of bone metabolism of 1752 including serum intact PTH, 25-hydroxyvitamin D [25(OH)D], procollagen type 1 N-terminal propeptide (P1NP), and ?-CrossLaps of type I collagen containing cross- linked C-telopeptide (?-CTX) were measured. The BMD of the lumbar spine and proximal femur were measured by dual-energy X-ray absorptiometry (DXA). No significant relationship was detected between serum cathepsin K and age, BMI, BMD or bone metabolic markers (all P > 0.05) after adjustment for age and BMI. We failed to identify any significant association between the genotypes or haplotypes of CTSK and BMD, bone turnover markers, or serum cathepsin K. Neither serum cathepsin K nor CTSK gene polymorphisms was correlated with BMD or bone turnover markers. Genetic polymorphisms of CTSK may not be a major contributor to variations in the serum cathepsin K or BMD in postmenopausal Chinese women. The results implied that serum cathepsin K may not be viewed as a substitute for bone turnover markers.
Project description:RATIONALE:Osteoporosis is common in individuals with chronic obstructive pulmonary disease. Lung-specific factors, including radiographic emphysema, independently associate with low bone mineral density in cross-sectional smoking cohorts. However, factors associated with progressive bone loss in smokers are understudied and largely unknown. OBJECTIVES:To determine the relationship between radiographic emphysema, circulating bone metabolism markers, and pulmonary function and accelerated bone mineral density loss in smokers. METHODS:Two hundred and forty male and female current and former smokers, 40 years of age or older, underwent baseline and 2-year assessments of pulmonary function, computed tomography-assessed emphysema, dual X-ray absorptiometry-measured bone mineral density, and circulating bone metabolism biomarker levels (type I collagen C-telopeptide [CTX], amino-terminal propeptide of type I procollagen [P1NP]). The association of radiographic emphysema, bone metabolism biomarker levels, and pulmonary function with accelerated hip bone mineral density loss, defined by the 75th percentile of annual hip bone mineral density decline, was determined by logistic regression modeling with adjustment for age, sex, inhaled and intermittent steroid use, active smoking, body mass index, and the presence of baseline low hip bone mineral density. RESULTS:Of those participants with accelerated hip bone mineral density loss, 22% had moderate or severe visually assessed emphysema compared with 7.2% of smokers without accelerated bone mineral density decline. Moderate to severe visually assessed emphysema (odds ratio, 2.84; 95% confidence interval, 1.01-7.98 compared with trace/mild or no visually assessed emphysema) and the 75th percentile of CTX levels (odds ratio, 2.38; 95% confidence interval, 1.20-4.72 compared with CTX levels below the 75th percentile), a marker of bone resorption, were associated with accelerated hip bone mineral density decline after adjustment for covariates and the presence of baseline low hip bone mineral density. FEV1% predicted was not associated with accelerated bone mineral density decline after adjustment for covariates. Multivariate modeling showed moderate to severe visually assessed emphysema, and the 75th percentiles of CTX were independently associated with accelerated hip bone mineral density decline after adjustment for covariates. CONCLUSIONS:Emphysema and elevated markers of bone resorption are independently associated with progressive bone mineral density loss in smokers. These clinical markers may guide targeted bone mineral density screening and monitoring in smokers at highest risk.
Project description:BackgroundSleeve gastrectomy is an effective bariatric procedure; however, sleeve gastrectomy-related adverse skeletal outcomes have been increasingly reported. High levels of sex hormone-binding globulin (SHBG) have been documented to be a risk factor of bone mineral density (BMD) loss with different effects observed between sexes. The aim of this study was to identify sex-specific changes in BMD following sleeve gastrectomy and to evaluate the role of SHBG in this process.MethodsThis retrospective study included 19 middle-aged men and 30 non-menopausal women with obesity who underwent sleeve gastrectomy in China. Anthropometrics, bone turnover markers, calciotropic hormones, BMD, SHBG, and gonadal steroids were measured preoperatively and at 6 and 12 months postoperatively. Longitudinal changes in BMD, bone turnover markers and SHBG were compared between sexes by linear mixed models. Multiple stepwise regression analysis was used to identify the predictors of BMD loss at the investigated bone sites.ResultsOver the 12-month study period, total hip and femoral neck BMD decreased, while lumbar spine BMD remained largely unchanged in both sexes. Linear mixed models revealed significant sex × time interaction effects in total hip BMD and SHBG, showing that men had a significantly greater reduction in total hip BMD and less increase in SHBG after sleeve gastrectomy than women. In the multivariate model, SHBG was significantly associated with total hip BMD loss in men (adjusted β = -0.533, P = 0.019) but not women while total estrogen was significantly associated with total hip BMD loss in women (adjusted β = 0.508, P = 0.01) but not men.ConclusionSignificant sex-specific BMD changes were observed after sleeve gastrectomy in the current study. Sleeve gastrectomy-related increase in SHBG may be a specific risk factor for total hip BMD loss in men. Our results indicate that sex-specific screening may be warranted to facilitate personalized postoperative bone care in this population.
Project description:BackgroundHigher protein diets are promoted for effective weight loss. Striated tissues in omnivorous diets contain high-quality protein, but limited data exist regarding their effects on bone.MethodsTo examine the effects of energy restriction-induced weight loss with higher protein omnivorous diets versus lower protein vegetarian diets on bone mineral density in overweight postmenopausal women, two randomized controlled feeding studies were conducted. In Study 1, 28 women consumed 750 kcal/day energy deficit diets with 18% energy from protein via lacto-ovo vegetarian sources (normal protein, n = 15) or 30% energy from protein with 40% of protein from lean pork (higher protein, n = 13, omnivorous) for 12 weeks. In Study 2, 54 women consumed their habitual diet (control, n = 11) or 1,250 kcal/day diets with 16% energy from nonmeat protein sources (n = 14) or 26% energy from protein, including chicken (n = 15) or beef (n = 14) for 9 weeks.ResultsStudy 1: With weight loss (normal protein -11.2%, higher protein -10.1%), bone mineral density was not significantly changed in normal protein (-0.003 ± 0.003 g/cm(2), -0.3%) but decreased in higher protein (-0.0167 ± 0.004 g/cm(2), -1. 4%, group-by-time p < .05). Study 2: The control, nonmeat, chicken, and beef groups lost 1.5%, 7.7%, 10.4%, and 8.1% weight and 0.0%, 0.4%, 1.1%, and 1.4% bone mineral density, respectively. The change of bone mineral density was significant for chicken and beef compared with the control (group-by-time, p < .05). Markers of calcium metabolism and bone homeostasis in blood and urine were not changed over time or differentially affected by diet.ConclusionConsumption of higher protein omnivorous diets promoted decreased bone mineral density after weight loss in overweight postmenopausal women.