The effect of behavioural risk factors on osteoporosis in Irish women

Background Osteoporosis constitutes a major public health concern and its underlying pathogenesis is complex and multifactorial. Although hereditary factors strongly contribute to bone health, behavioural factors can modulate the genetically determined pattern of skeletal modelling and remodelling. Aims The aim of this study was to investigate the effect(s) of behavioural risk factors on osteoporosis in Irish women. Methods Pre- and post-menopausal adult women (n = 189; 44 ± 15y) participated in this cross-sectional study. Demographic, anthropometric and lifestyle data were collected during a single clinic visit. Dietary calcium intake and lifetime physical activity (PA) was assessed for each subject. Lumbar and femoral bone mineral density (BMD) was measured by dual energy X-ray absorptiometry (DXA). Multivariate analysis was used to determine the independent predictors of low BMD. Results Low BMD was present in 59% of subjects (42% pre- and 77% postmenopausal). Smoking was the strongest behavioural predictor of lumbar and femoral BMD. Age, height, family history, smoking, metabolic (MET) and mechanical (MECH) PA (lifetime) and weight (body mass) accounted for 39% of the variance in lumbar BMD. Age, height, family history, alcohol consumption, MET and MECH PA (lifetime) and weight accounted for 41% of the variance in femoral BMD. Conclusions Prevalence of osteopenia and osteoporosis is high in Irish women and is associated with modifiable risk factors. A clearer focus should be paid to educating Irish women on preventative health behaviours for osteoporosis in order to curb the prevalence of this disease and the human and fiscal costs associated with it

The major genetic determinants of HIV-1 control affect HLA class I peptide presentation.

Infectious and inflammatory diseases have repeatedly shown strong genetic associations within the major histocompatibility complex (MHC); however, the basis for these associations remains elusive. To define host genetic effects on the outcome of a chronic viral infection, we performed genome-wide association analysis in a multiethnic cohort of HIV-1 controllers and progressors, and we analyzed the effects of individual amino acids within the classical human leukocyte antigen (HLA) proteins. We identified >300 genome-wide significant single-nucleotide polymorphisms (SNPs) within the MHC and none elsewhere. Specific amino acids in the HLA-B peptide binding groove, as well as an independent HLA-C effect, explain the SNP associations and reconcile both protective and risk HLA alleles. These results implicate the nature of the HLA-viral peptide interaction as the major factor modulating durable control of HIV infection