Prevalence of vertebral fracture in oldest old nursing home residents

Summary: We evaluated vertebral fracture prevalence using DXA-based vertebral fracture assessment and its influence on the Fracture Risk Assessment (FRAX) tool-determined 10-year fracture probability in a cohort of oldest old nursing home residents. More than one third of the subjects had prevalent vertebral fracture and 50% osteoporosis. Probably in relation with the prevailing influence of age and medical history of fracture, adding these information into FRAX did not markedly modify fracture probability. Introduction: Oldest old nursing home residents are at very high risk of fracture. The prevalence of vertebral fracture in this specific population and its influence on fracture probability using the FRAX tool are not known. Methods: Using a mobile DXA osteodensitometer, we studied the prevalence of vertebral fracture, as assessed by vertebral fracture assessment program, of osteoporosis and of sarcopenia in 151 nursing home residents. Ten-year fracture probability was calculated using appropriately calibrated FRAX tool. Results: Vertebral fractures were detected in 36% of oldest old nursing home residents (mean age, 85.9 ± 0.6years). The prevalence of osteoporosis and sarcopenia was 52% and 22%, respectively. Ten-year fracture probability as assessed by FRAX tool was 27% and 15% for major fracture and hip fracture, respectively. Adding BMD or VFA values did not significantly modify it. Conclusion: In oldest old nursing home residents, osteoporosis and vertebral fracture were frequently detected. Ten-year fracture probability appeared to be mainly determined by age and clinical risk factors obtained by medical history, rather than by BMD or vertebral fractur

Pubertal timing and body mass index gain from birth to maturity in relation with femoral neck BMD and distal tibia microstructure in healthy female subjects

Summary: Childhood body mass index (BMI) gain is linked to hip fracture risk in elderly. In healthy girls, menarcheal age is inversely related to BMI gain during childhood and to femoral neck areal bone mass density (aBMD) and distal tibia structural components at maturity. This study underscores the importance of pubertal timing in age-related fragility fracture risk. Introduction: Recent data point to a relationship between BMI change during childhood and hip fracture risk in later life. We hypothesized that BMI development is linked to variation in pubertal timing as assessed by menarcheal age (MENA) which in turn, is related to peak bone mass (PBM) and hip fracture risk in elderly. Methods: We studied in a 124 healthy female cohort the relationship between MENA and BMI from birth to maturity, and DXA-measured femoral neck (FN) aBMD at 20.4year. At this age, we also measured bone strength related microstructure components of distal tibia by HR-pQCT. Results: At 20.4 ± 0.6year, FN aBMD (mg/cm2), cortical thickness (μm), and trabecular density (mgHA/cm3) of distal tibia were inversely related to MENA (P = 0.023, 0.015, and 0.041, respectively) and positively to BMI changes from 1.0 to 12.4years (P = 0.031, 0.089, 0.016, respectively). Significant inverse (P < 0.022 to <0.001) correlations (R = −0.21 to -0.42) were found between MENA and BMI from 7.9 to 20.4years, but neither at birth nor at 1.0year. Linear regression indicated that MENA Z-score was inversely related to BMI changes not only from 1.0 to 12.4years (R = −0.35, P = 0.001), but also from 1.0 to 8.9years, (R = −0.24, P = 0.017), i.e., before pubertal maturation. Conclusion: BMI gain during childhood is associated with pubertal timing, which in turn, is correlated with several bone traits measured at PBM including FN aBMD, cortical thickness, and volumetric trabecular density of distal tibia. These data complement the reported relationship between childhood BMI gain and hip fracture risk in later lif

Pubertal timing and body mass index gain from birth to maturity in relation with femoral neck BMD and distal tibia microstructure in healthy female subjects

Childhood body mass index (BMI) gain is linked to hip fracture risk in elderly. In healthy girls, menarcheal age is inversely related to BMI gain during childhood and to femoral neck areal bone mass density (aBMD) and distal tibia structural components at maturity. This study underscores the importance of pubertal timing in age-related fragility fracture risk

Fractures in healthy females followed from childhood to early adulthood are associated with later menarcheal age and with impaired bone microstructure at peak bone mass

Background: Whether fractures observed in healthy children are associated with microstructural alterations and strength deficit that persists by the end of the growth period is not established. Considering the importance of pubertal timing in bone development, we also quantified the fracture risk related to later menarcheal age (MENA). Participants and Methods: We followed 124 healthy girls from mean ± sd age 7.9 ± 0.5 to 20.4 ± 0.6 yr. Fractures, MENA, and radius areal bone mineral density (aBMD) were recorded at regular intervals. At a mean age of 20.4 yr, microstructural and strength variables of the distal radius were determined by high-resolution peripheral computerized tomography and micro-finite element analysis. Results: Sixty-one fractures occurred in 42 subjects. At 20.4 yr, subjects with fractures had lower aBMD at radial diaphysis (P = 0.005) and metaphysis (P = 0.008), lower distal radius trabecular volumetric density (vBMD) (P = 0.010) and thickness (P = 0.014), and reduction in stiffness (P = 0.013), failure load (P = 0.013), and apparent modulus (P = 0.046). Odds ratios revealed an increased risk of fracture for a 1-sd reduction in radial aBMD diaphysis [1.97 (P = 0.006)] and metaphysis [1.97 (P = 0.008)] and distal radius trabecular vBMD [1.89 (P = 0.011)], thickness [1.97 (P = 0.017)], stiffness [2.02 (P = 0.014)], failure load [2.00 (P = 0.014)], and apparent modulus [1.79 (P = 0.043)]. MENA occurred at a later age in subjects with fractures (P = 0.003). For MENA 1 sd (1.2 yr) later, the increase of fracture risk was 2.1 (P = 0.002). Conclusions: In healthy young women, low trabecular vBMD and thickness in the distal radius are associated with reduced bone strength and increased fracture risk during growth. This study also documents that later pubertal timing is associated with increased incidence of fracture during childhood and adolescence

On Proper Polynomial Maps of C2.\mathbb{C}^2.

Two proper polynomial maps $f_1, f_2 \colon \mathbb{C}^2 \longrightarrow \mathbb{C}^2$ are said to be \emph{equivalent} if there exist $\Phi_1, \Phi_2 \in \textrm{Aut}(\mathbb{C}^2)$ such that $f_2=\Phi_2 \circ f_1 \circ \Phi_1$. We investigate proper polynomial maps of arbitrary topological degree $d \geq 2$ up to equivalence. Under the further assumption that the maps are Galois coverings we also provide the complete description of equivalence classes. This widely extends previous results obtained by Lamy in the case $d=2$.Comment: 15 pages. Final version, to appear in Journal of Geometric Analysi

Socioeconomic and living conditions are determinants of hip fracture incidence and age occurrence among community-dwelling elderly

Summary: In this prospective, 10-year study in community-dwelling elderly aged 50years and over, hip fracture incidence and accordingly age at hip fracture were inversely associated with the area-level income, independently of the geographical area. Age at hip fracture also depended of marital status but in a gender-specific way. Purpose: The purpose of this study is to investigate the impact of socioeconomic and living conditions on hip fracture incidence and age occurrence among community-dwelling elderly. Method: Between January 1991 and December 2000, 2,454 hip fractures were recorded in community-dwelling adults aged 50years and over in the Geneva University Hospital, State of Geneva, Switzerland. Median annual household income by postal code of residence (referred to as area-level income) based on the 1990 Census was used as a measure of socioeconomic condition and was stratified into tertiles (<53,170; 53,170-58,678; and ≥58,678 CHF). Hip fracture incidence and age occurrence were calculated according to area-level income categories and adjusted for confounding factors among community-dwelling elderly. Results: Independently of the geographical area (urban versus rural), community-dwelling persons residing in areas with the medium income category presented a lower hip fracture incidence [OR 0.91 (0.82-0.99), p = 0.049] compared to those from the lowest income category. Those in the highest income category had a hip fracture at a significant older age [+1.58 (0.55-2.61) year, p = 0.003] as compared to those in the lowest income category. Age at hip fracture also depended on marital status but in a gender-specific way, with married women fracturing earlier. Conclusions: These results indicate that incidence and age occurrence of hip fracture are influenced by area-level income and living conditions among community-dwelling elderly. Prevention programs may be encouraged in priority in communities with low incom

A planar extrapolation of the correlation problem that permits pairing

It was observed previously that an SU(N) extension of the Hubbard model is dominated, at large N, by planar diagrams in the sense of 't Hooft, but the possibility of superconducting pairing got lost in this extrapolation. To allow for this possibility, we replace SU(N) by U(N,q), the unitary group in a vector space of quaternions. At the level of the free energy, the difference between the SU(N)and U(N,q) extrapolations appears only to first nonleading order in N.Comment: 8 pages, 2 figure

Reversal of the hip fracture secular trend is related to a decrease in the incidence in institution-dwelling elderly women

Summary: In this prospective 10-year study in elderly aged 60years and over, there was a 1.3% per year reduction in the standardized incidence of hip fracture in women but not in men. This decrease was mainly due to changes in the standardized incidence of hip fracture in institution-dwelling women. Introduction: A decrease in age-adjusted hip fracture incidence has been recently demonstrated in some countries. Since a large proportion of hip fractures occur in nursing homes, we analyzed whether this decreasing trend would be more detectable in institution-dwelling elderly compared with community-dwelling elderly. Methods: All hip fracture patients aged 60years and over were identified in a well-defined area. Incidence of hip fracture, age- and sex-adjusted to the 2000 Geneva population, was computed in community- and institution-dwelling elderly. Results: From 1991 to 2000, 1,624 (41%) hip fractures were recorded in institutionalized-dwelling elderly and 2,327 (59%) in community-dwelling elderly. The standardized fracture incidence decreased by 1.3% per year in women (p = 0.039), but remained unchanged in men (+0.5%; p = 0.686). Among institution-dwelling women, hip fracture incidence fell by 1.9% per year (p = 0.044), whereas it remained stable among community-dwelling women (+0.0%, p = 0.978). In men, no significant change in hip fracture incidence occurred among institution- or community-dwelling elderly. Conclusions: The decrease in the standardized hip fracture incidence in institution-dwelling women is responsible for the reversal in secular trend. Future research should include stratification according to the residential status to better identify the causes responsible for the trend in hip fracture incidenc

Cosmology, cohomology, and compactification

Ashtekar and Samuel have shown that Bianchi cosmological models with compact spatial sections must be of Bianchi class A. Motivated by general results on the symmetry reduction of variational principles, we show how to extend the Ashtekar-Samuel results to the setting of weakly locally homogeneous spaces as defined, e.g., by Singer and Thurston. In particular, it is shown that any m-dimensional homogeneous space G/K admitting a G-invariant volume form will allow a compact discrete quotient only if the Lie algebra cohomology of G relative to K is non-vanishing at degree m.Comment: 6 pages, LaTe

Alterations of bone microstructure and strength in end-stage renal failure

Summary: End-stage renal disease (ESRD) patients have a high risk of fractures. We evaluated bone microstructure and finite-element analysis-estimated strength and stiffness in patients with ESRD by high-resolution peripheral computed tomography. We observed an alteration of cortical and trabecular bone microstructure and of bone strength and stiffness in ESRD patients. Introduction: Fragility fractures are common in ESRD patients on dialysis. Alterations of bone microstructure contribute to skeletal fragility, independently of areal bone mineral density. Methods: We compared microstructure and finite-element analysis estimates of strength and stiffness by high-resolution peripheral quantitative computed tomography (HR-pQCT) in 33 ESRD patients on dialysis (17 females and 16 males; mean age, 47.0 ± 12.6years) and 33 age-matched healthy controls. Results: Dialyzed women had lower radius and tibia cortical density with higher radius cortical porosity and lower tibia cortical thickness, compared to controls. Radius trabecular number was lower with higher heterogeneity of the trabecular network. Male patients displayed only a lower radius cortical density. Radius and tibia cortical thickness correlated negatively with bone-specific alkaline phosphatase (BALP). Microstructure did not correlate with parathyroid hormone (PTH) levels. Cortical porosity correlated positively with "Kidney Disease: Improving Global Outcomes” working group PTH level categories (r = 0.36, p < 0.04). BMI correlated positively with trabecular number (r = 0.4, p < 0.02) and negatively with trabecular spacing (r = −0.37, p < 0.03) and trabecular network heterogeneity (r = −0.4, p < 0.02). Biomechanics positively correlated with BMI and negatively with BALP. Conclusion: Cortical and trabecular bone microstructure and calculated bone strength are altered in ESRD patients, predominantly in women. Bone microstructure and biomechanical assessment by HR-pQCT may be of major clinical relevance in the evaluation of bone fragility in ESRD patient