Regional Gene Expression of Inflammation and Oxidative Stress Responses Does Not Predict Neurodegeneration in Aging

Brain aging is accompanied by increased oxidative stress and what has been termed "neuroinflammation," which might contribute to age-related neurodegenerative diseases. We analyzed expression in the transcription of innate inflammatory response genes in eleven representative regions including frontal, parietal, inferior temporal, cingulate, occipital, entorhinal cortex, caudate, putamen, thalamus, substantia nigra, and cerebellar vermis in aging human brains. We probed members of the complement system, colony stimulating factor receptors, toll-like receptors, and pro- and anti-inflammatory cytokines in the brains of subjects with no neurological disease and neurofibrillary tangles (mean age: 47.1  ±  5.7 years) and those with no neurological disease and neurofibrillary pathology stages I-II (mean age: 70.6  ±  6.3 years). Although the entorhinal and frontal cortex were most altered, gene regulation patterns did not match regions with increased vulnerability. Analysis of false discovery rate thresholds revealed no differences for any gene in any region between the 2 groups, including cases in which individual comparisons analyzed using Student t or nonparametric tests showed apparent differences between groups. Moreover, gene expression of major anti-oxidative stress responses did not match neuroinflammation in aging or increased regional susceptibility to major neurodegenerative diseases.

Validation of the FRAX predictive model for major osteoporotic fracture in a historical cohort of Spanish women

FRAX is a fracture risk assessment tool to estimate the 10-yr probability of a major osteoporotic fracture or a hip fracture. The aim of the study was to assess the predictive ability of FRAX for major osteoporotic fracture in a cohort of Spanish women. The study was based on a retrospective cohort of women aged 40-90 yr. Patients were followed from their first bone densitometry to the first major osteoporotic fracture event (forearm, proximal humerus, clinical spine, or hip fracture) or for 10 yr whichever comes first. A total of 1231 women were included. Bone mineral density data and self-reported data on risk factors for fracture were obtained. The predictive ability of FRAX was assessed by analyzing calibration and discrimination, with the calculation of observed-to-expected (O/E) fracture ratios and the receiver operating characteristic (ROC) curve, respectively. A total of 222 women (18.1%) reported at least 1 fracture after the first assessment. The incidence of fracture was 14 (95% confidence interval [CI]: 10-17), 19 (95% CI: 15-23), 28 (95% CI: 21-36), and 67 (95% CI: 8-125) cases per 1000 woman-years in women aged <55, 55-64, 65-74, and ≥75 yr, respectively. The O/E ratio was 3.9 (95% CI: 3.4-4.5; p<0.0001). The area under the ROC curve was 61% (95% CI: 57-65%). FRAX underestimated the risk of major osteoporotic fracture in this cohort of Spanish women, particularly in those with a low risk of fracture according to the clinical factors used in the FRAX tool. Our findings highlight the need for validation studies of FRAX in Spain.