Disparities in osteoporosis treatments

Osteoporosis treatment rates within 2 years following an index event (fragility fracture, osteoporotic bone mineral density (BMD) T-score, or osteoporosis ICD-9 codes) were determined from 2005 to 2011. Most patients were not treated. Fracture patients had the lowest treatment rate. Low treatment rates also occurred in patients that were male, black, or had non-commercial insurance.

INTRODUCTION

Clinical recognition of osteoporosis (osteoporotic BMD, assignment of an ICD-9 code, or the occurrence of fragility fractures) provides opportunities to treat patients at risk for future fracture.

METHODS

A cohort of 36,965 patients was identified from 2005 to 2011 in the Indiana Health Information Exchange, with index events after age 50 of either non-traumatic fractures, an osteoporosis ICD-9 code, or a BMD T-score ≤ -2.5. Patients with osteoporosis treatment in the preceding year were excluded. Medication records during the ensuing 2 years were extracted to identify osteoporosis treatments, demographics, comorbidities, and co-medications. Predictors of treatment were evaluated in a multivariable logistic regression model.

RESULTS

The cohort was 78 % female, 11 % black, 91 % urban-dwelling, and 53 % commercially insured. The index events were as follows: osteoporosis diagnosis (47 % of patients), fragility fracture (44 %), and osteoporotic T-scores (9 %). Within 2 years after the index event, 23.3 % received osteoporosis medications (of which, 82.2 % were oral bisphosphonates). Treatment rates were higher after osteoporosis diagnosis codes (29.3 %) or osteoporotic T-score (53.9 %) than after fracture index events (10.5 %) (p < 0.001). Age had an inverted U-shaped effect for women with highest odds around 60-65 years. Women (OR 1.86) and non-black patients (OR 1.52) were more likely to be treated (p < 0.001). Patients with public (versus commercial) insurance (OR 0.86, p < 0.001) or chronic comorbidities (ORs about 0.7-0.9, p < 0.001) were less likely to be treated.

CONCLUSION

Most osteoporosis treatment candidates remained untreated. Men, black patients, and patients with fracture or chronic comorbidities were less likely to receive treatment, representing disparity in the recognition and treatment of osteoporosis.

The p53-Bak apoptotic signaling axis plays an essential role in regulating differentiation of the ocular lens

The tumor suppressor p53 is a master regulator of apoptosis and also plays a key role in cell cycle checking. In our previous studies, we demonstrated that p53 directly regulates Bak in mouse JB6 cells (Qin et al. 2008. Cancer Research. 68(11):4150) and that p53-Bak signaling axis plays an important role in mediating EGCG-induced apoptosis. Here, we demonstrate that the same p53-Bak apoptotic signaling axis executes an essential role in regulating lens cell differentiation. First, during mouse lens development, p53 is expressed and differentially phosphorylated at different residues. Associated with p53 expression, Bak is also significantly expressed during mouse lens development. Second, human p53 directly regulates Bak promoter and Bak expression in p53 knockout mice (p53-/-) was significantly downregulated. Third, during in vitro bFGF-induced lens cell differentiation, knockdown of p53 or Bak leads to significant inhibition of lens cell differentiation. Fourth, besides the major distribution of Bak in cytoplasm, it is also localized in the nucleus in normal lens or bFGF-induced differentiating lens cells. Finally, p53 and Bak are co-localized in both cytoplasm and nucleus, and their interaction regulates the stability of p53. Together, these results demonstrate for the first time that the p53-Bak apoptotic signaling axis plays an essential role in regulating lens differentiation.

Temperature-Dependent Magnetic Properties of SiO2-Coated Ni75Fe25 Nanoparticles

SiO2-coated Ni75Fe25 nanoparticles were prepared using a wet chemical method and their structure and magnetic properties were investigated using x-ray diffraction, high-resolution transmission electron microscopy, and a superconducting quantum interference device magnetometer. The SiO2 material was in an amorphous state. The Ni75Fe25 nanoparticles were in a simple cubic state and contained inner oxide (Ni-oxide and Fe-oxide) cores whose size decreased with increasing calcination temperature. The nanoparticles were basically in the ferromagnetic state. Their saturation magnetization increased with increasing calcination temperature, whereas their coercivity decreased with increasing calcination temperature. The nanoparticles exhibited strong temperature-dependent magnetic behaviors. The Bloch exponent fell from 1.5 for the bulk to smaller values and decreased with increasing oxide content, while the Bloch constant was much bigger than that for bulk and increased significantly with oxide content. The value of coercivity decreased with increasing temperature, and this decrease was more pronounced for the nanoparticles containing high oxide content. The exchange anisotropy arising from the exchange coupling across the Ni75Fe25/oxide interfaces was examined and was used to interpret the observed temperature-dependent behaviors.

(E)-N′-(1,3-Benzodioxol-5-ylmethylene)nicotinohydrazide monohydrate

In the title compound, C₁₄H₁₁N₃O₃·H₂O, the planar [maximum deviation 0.135 (1) Å] 1,3-benzodioxole ring system is oriented at a dihedral angle of 13.93 (7)° with respect to the pyridine ring. Extensive inter­molecular N—H⋯O, O—H⋯O, O—H⋯N and weak C—H⋯O hydrogen bonding is present in the crystal structure.

(E)-N′-(3,4-Dichlorobenzylidene)nicotinohydrazide monohydrate

In the title compound, C₁₃H₉Cl₂N₃O·H₂O, the 3,4-dichloro­benzene ring is nearly coplanar with the pyridine ring, making a dihedral angle of 4.78 (8)°. Inter­molecular O—H⋯O, O—H⋯N, N—H⋯O and weak C—H⋯O hydrogen bonding is present in the crystal structure.

Race and sex differences in bone mineral density and geometry at the femur

INTRODUCTION

Differences in osteoporotic hip fracture incidence between American whites and blacks and between women and men are considered to result, in part, from differences in bone mineral density and geometry at the femur. The aim of this study was to quantify differences in femoral bone density and geometry between a large sample of healthy American white and black women and men.

SUBJECTS AND METHODS

Healthy American white (n=612) and black (n=164) premenopausal women, aged 23 to 57 years, and healthy American white (n=492) and black (n=169) men, aged 20 to 63 years, had volumetric bone mineral density (vBMD) and geometry variables measured at the femur by computerized tomography (CT), and areal bone mineral density (aBMD) at femoral neck measured by dual X-ray absorptiometry (DXA).

RESULTS

American blacks had higher vBMD at the femoral neck and femoral shaft cortex than American whites whereas femoral axis length and femoral neck area were not different. Men had lower vBMD at the femoral neck and femoral cortex than women but had greater femoral axis length and femoral neck area than women. The higher aBMD in American blacks than whites persisted after correction for measured area whereas the higher aBMD in men than women disappeared.

CONCLUSIONS

At the femoral neck, American whites have lower bone density than American blacks but similar geometry. Women have higher bone density than men in both races but have smaller geometry variables. The differences in bone density may account in part for the differences in hip fracture incidence between American blacks and whites, whereas the differences in femur size may account for the differences in hip fracture rates between men and women.

PCA and clustering reveal alternate mtDNA phylogeny of N and M clades

Phylogenetic trees based on mtDNA polymorphisms are often used to infer the history of recent human migrations. However, there is no consensus on which method to use. Most methods make strong assumptions which may bias the choice of polymorphisms and result in computational complexity which limits the analysis to a few samples/polymorphisms. For example, parsimony minimizes the number of mutations, which biases the results to minimizing homoplasy events. Such biases may miss the global structure of the polymorphisms altogether, with the risk of identifying a "common" polymorphism as ancient without an internal check on whether it either is homoplasic or is identified as ancient because of sampling bias (from oversampling the population with the polymorphism). A signature of this problem is that different methods applied to the same data or the same method applied to different datasets results in different tree topologies. When the results of such analyses are combined, the consensus trees have a low internal branch consensus. We determine human mtDNA phylogeny from 1737 complete sequences using a new, direct method based on principal component analysis (PCA) and unsupervised consensus ensemble clustering. PCA identifies polymorphisms representing robust variations in the data and consensus ensemble clustering creates stable haplogroup clusters. The tree is obtained from the bifurcating network obtained when the data are split into k = 2,3,4,...,kmax clusters, with equal sampling from each haplogroup. Our method assumes only that the data can be clustered into groups based on mutations, is fast, is stable to sample perturbation, uses all significant polymorphisms in the data, works for arbitrary sample sizes, and avoids sample choice and haplogroup size bias. The internal branches of our tree have a 90% consensus accuracy. In conclusion, our tree recreates the standard phylogeny of the N, M, L0/L1, L2, and L3 clades, confirming the African origin of modern humans and showing that the M and N clades arose in almost coincident migrations. However, the N clade haplogroups split along an East-West geographic divide, with a "European R clade" containing the haplogroups H, V, H/V, J, T, and U and a "Eurasian N subclade" including haplogroups B, R5, F, A, N9, I, W, and X. The haplogroup pairs (N9a, N9b) and (M7a, M7b) within N and M are placed in nonnearest locations in agreement with their expected large TMRCA from studies of their migrations into Japan. For comparison, we also construct consensus maximum likelihood, parsimony, neighbor joining, and UPGMA-based trees using the same polymorphisms and show that these methods give consistent results only for the clade tree. For recent branches, the consensus accuracy for these methods is in the range of 1-20%. From a comparison of our haplogroups to two chimp and one bonobo sequences, and assuming a chimp-human coalescent time of 5 million years before present, we find a human mtDNA TMRCA of 206,000 +/- 14,000 years before present.