40 research outputs found
Association between depot medroxyprogesterone acetate (DMPA), physical activity and bone health
Physical activity has been advocated for women in the hope of offsetting progestin-only contraceptive-related loss in bone mineral density. There is limited evidence for the beneficial effect of physical activity on bone health of hypo-oestrogenic premenopausal women. The aim of this cross-sectional study was to examine the relationship between physical activity and bone health [as measured by quantitative ultrasound (QUS)] of depot-medroxyprogesterone acetate (DMPA) users, and to investigate whether QUS measurements of DMPA users and non-users differed according to physical activity. Bone health of 48 DMPA users and 48 age-matched controls (22.83 ± 3.2 years) was assessed using calcaneal broadband ultrasound attenuation (BUA). Participants were categorised into low and high levels of physical activity based on their exposure to bone-loading exercise. Analysis of covariance was conducted to determine if QUS measurements of DMPA users and non-DMPA users differed within levels of bone-loading physical activity after controlling for body mass index. The duration of DMPA use ranged from 6 to 132 months. Participants’ reference bone-loading exposure time averaged 3.3 ± 1.8 years. Data analysis revealed that DMPA users had significantly lower BUA by 6.54 dB/MHz (t (95) = −2.411, p = 0.018) compared to non-users of DMPA. Concurrently high levels of physical activity and DMPA use led to 1.996 dB/MHz decreases in BUA. A cycle of prolonged DMPA use and concurrent engagement in high levels of physical activity appears detrimental to bone health. It is suggested that the lack of oestrogen may counteract the effects of physical activity by inhibiting bone formation in response to mechanical bone-loading
Clinical Assessment of Anti-Viral CD8+ T Cell Immune Monitoring Using QuantiFERON-CMV® Assay to Identify High Risk Allogeneic Hematopoietic Stem Cell Transplant Patients with CMV Infection Complications
The reconstitution of anti-viral cellular immunity following hematopoietic stem cell transplantation (HSCT) is crucial in preventing cytomegalovirus (CMV)-associated complications. Thus immunological monitoring has emerged as an important tool to better target pre-emptive anti-viral therapies. However, traditional laboratory-based assays are too cumbersome and complicated to implement in a clinical setting. Here we conducted a prospective study of a new whole blood assay (referred to as QuantiFERON-CMV®) to determine the clinical utility of measuring CMV-specific CD8+ T-cell responses as a prognostic tool. Forty-one evaluable allogeneic HSCT recipients underwent weekly immunological monitoring from day 21 post-transplant and of these 21 (51.2%) showed CMV reactivation and 29 (70.7%) developed acute graft-versus-host disease (GvHD). Patients with acute GvHD (grade≥2) within 6 weeks of transplant showed delayed reconstitution of CMV-specific T-cell immunity (p = 0.013) and a higher risk of CMV viremia (p = 0.026). The median time to stable CMV-specific immune reconstitution was 59 days and the incidence of CMV reactivation was lower in patients who developed this than those who did not (27% versus 65%; p = 0.031). Furthermore, a failure to reconstitute CMV-specific immunity soon after the onset of CMV viraemia was associated with higher peak viral loads (5685 copies/ml versus 875 copies/ml; p = 0.002). Hence, QuantiFERON-CMV® testing in the week following CMV viremia can be useful in identifying HSCT recipients at risk of complicated reactivation