Osteopenia is common in the era of effective antiretroviral therapy (ART), yet the etiology is unclear. We evaluated the association of host factors, disease severity, and ART to changes in total body bone mineral density (total BMD) over time in HIV-infected men (n = 283) and women (n = 96).
Total BMD was measured annually by whole-body dual-energy absorptiometry (DXA), and medical, dietary, and behavioral history was collected. The median time from first to last DXA was 2.5 years (range 0.9-6.8 years). Using a repeated measures regression model, we identified variables independently associated with percent change in total BMD between consecutive DXA exams (n = 799 intervals), adjusted for age, race, sex, menopause, and smoking. We estimated percent change in total BMD over an average interval (1 year) standardized for representative levels of each determinant in males, premenopausal women, and postmenopausal women.
Median baseline age, CD4, and viral load were 42 years, 364 cells per cubic millimeter, and 2.7 log10 copies per milliliter, respectively. The estimated change in total BMD for those not on ART was -0.37% per year [95% confidence interval (CI) -0.76 to -0.02] for men, -0.08% per year (95% CI -0.49 to 0.33) for premenopausal women, and -1.07% per year (95% CI -1.86 to -0.28) for postmenopausal women. Greater loss of total BMD was associated with lower albumin, lower body mass index, prednisone/hydrocortisone use, tenofovir use, and longer duration of didanosine. Strength training and long duration of d4T and saquinavir prevented or mitigated bone loss. For those on ART for 3 years (not including the above agents), the rate of loss was -0.57% per year (95% CI -1.00 to -0.14) for men, -0.28% (95% CI -0.71 to 0.15) for premenopausal women, and -1.27% (95% CI -2.07 to -0.47) for postmenopausal women. Postmenopausal women had greater loss than premenopausal women and men.
Low body weight, low albumin, catabolic steroid use, and menopause may accelerate bone loss, and strength training may be protective. Tenofovir and didanosine may also have a deleterious effect on BMD.
"HIV-infected individuals have an increased risk of osteopenia compared to HIV-uninfected people. This risk is increased further by the use of TDF [Jacobson et al., 2008]. It is not yet clear whether patients receiving TDF also have an increased bone-fracture risk. "
[Show abstract][Hide abstract] ABSTRACT: We present the negative- and positive-feedback circuit configurations of continuous-time floating-gate MOS circuits. We start by reviewing the dynamics of our pFET and nFET single-transistor synapses. We present the range of possible stabilizing and destabilizing types of feedback in circuits with one floating-gate synapse, including data from nFET and pFET synapses. We then show examples of competitive and cooperative behavior in multiple-synapse circuits. We present experimental data from circuits fabricated in the 2 μm n-well Orbit CMOS process available through MOSIS
Circuits and Systems, 1998. ISCAS '98. Proceedings of the 1998 IEEE International Symposium on; 01/1998
[Show abstract][Hide abstract] ABSTRACT: The purpose of this study was to assess the one-year efficacy of highly active antiretroviral therapy (HAART) administered by general practitioners in a primary care community clinic in rural South Africa. We performed an observational cohort study of 675 treatment-naive human immunodeficiency virus (HIV)-infected patients (including 66 children) who began HAART at least 12 months prior to the data analyses. Throughout treatment, the CD4+ T-cell count (percentage of CD4+ T-cells in children) and plasma HIV-RNA level were determined and the patient's weight was recorded. The primary outcome was mortality. Secondary outcomes were viral suppression, immunological response, and weight gain. One year after the start of HAART, 100 of the 675 (15%) patients were lost to follow-up and 119 patients (18%), including six children, died. Mortality was highest during the first few months of treatment. Based on an on-treatment analysis at one year after the start of therapy, 83% of adults and 71% of children had a viral load <400 copies/ml; the viral load was <50 copies/ml in 70% of adults and 61% of children. At one year, the mean CD4+ T-cell count in adults had increased by 236/mm(3), and the mean body mass index (BMI) had increased by 3.5 kg/m(2). In children, the mean CD4% had increased by 17.6. A low Karnofsky score and a low baseline CD4+ T-cell count were independently associated with death. In addition to these factors, a low baseline BMI and gender were predictive of a poor immunological outcome. Our study shows that adequately monitored HIV/acquired immunodeficiency syndrome (AIDS) care administered by general practitioners and their staff is feasible and leads to good results in a rural, primary care center in sub-Saharan Africa. In order to achieve even better results, early mortality should be reduced and efforts should be made to start HAART earlier.
European Journal of Clinical Microbiology 10/2008; 27(10):977-84. DOI:10.1007/s10096-008-0534-2 · 2.67 Impact Factor
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