Background-Vitamin D is crucial for maintaining musculoskeletal health. Recently, vitamin D insufficiency has been linked to a number of extraskeletal disorders, including diabetes, cancer, and cardiovascular disease. Determinants of circulating 25-hydroxyvitamin D (25-OH D) include sun exposure and dietary intake, but its high heritability suggests that genetic determinants may also play a role.Methods-We performed a genome-wide association study of 25-OH D among ∼30,000 individuals of European descent from 15 cohorts. Five cohorts were designated as discovery cohorts (n=16,125), five as in silico replication cohorts (n=9,366), and five as de novo replication * rs2282679 in Framingham, rs4588 in 1958 Birth Cohort (r 2 between SNPs >0.99).
Exogenous glucocorticoids are known to increase the risk of osteoporosis. However, the contribution made by endogenous circulating cortisol concentrations to adult skeletal status remains unknown. We examined this issue in a sample of 34 healthy men, aged 61-72 yr. Venous blood samples were obtained under standard conditions every 20 min over a 24-h period. Measurements were made of serum cortisol and cortisol-binding globulin. Bone mineral density was measured at the lumbar spine and proximal femur using dual energy x-ray absorptiometry. Measurements were made at baseline and 4 yr later. There was a weak negative association between integrated cortisol concentration and lumbar spine bone density (r = -0.37; P < 0.05); similar relationships (P < 0.05) existed at three of five proximal femoral sites. There were also statistically significant positive associations between the trough cortisol concentration and bone loss rate at the lumbar spine (r = 0.38; P < 0.05), femoral neck (r = 0.47; P < 0.001), and the trochanteric region (r = 0.41; P = 0.02) over the 4-yr follow-up period. The cross-sectional relationships between cortisol concentration and bone density were removed by adjustment for body mass index, but the influence on bone loss rate remained significant after adjusting for adiposity, cigarette smoking, alcohol consumption, dietary calcium intake, physical activity, and serum testosterone and estradiol levels. These observations suggest that the endogenous cortisol profile of healthy elderly men is a determinant of their bone mineral density and their rate of involutional bone loss.
Osteoporosis constitutes a major public health problem through its association with age-related fractures. These fractures typically occur at the hip, spine and distal forearm. It has been estimated that the lifetime risk of a hip fracture in white women is 17.5%, with a comparable risk in men of 6%. Hip fractures lead to an overall reduction in survival of about 15% (relative or observed/expected survival at 5 years of 0.83), and the majority of excess deaths occur within the first 6 months following the fracture. Such fractures are also associated with considerable morbidity. Although all vertebral deformities do not come to clinical attention, the lifetime risk of clinically diagnosed vertebral fractures is about 15% in white women. Vertebral fractures tend to be associated with back pain and kyphosis, and also with an impairment of survival, though this is likely to be due to clustering of comorbidity. About one-quarter of clinically diagnosed vertebral deformities result in hospitalization.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.