St Thomas' Hospital

About: St Thomas' Hospital is a healthcare organization based out in London, United Kingdom. It is known for research contribution in the topics: Population & Pregnancy. The organization has 12105 authors who have published 15596 publications receiving 624309 citations. The organization is also known as: St Thomas's Hospital & St. Thomas's.

Genetic influences on muscle strength, lean body mass, and bone mineral density: a twin study

Abstract: Lean body mass and muscle strength are both associated with bone mineral density (BMD), which is known to be under strong genetic control. In this classical twin study, we examine the size of the genetic component of both muscle strength and lean body mass and to what degree they account for the genetic component of BMD. In all, 706 postmenopausal women were examined; 227 pairs of monozygous (MZ) twins and 126 pairs of dizygous (DZ) twins. Grip strength was measured using a hand-help grip bulb and leg strength using a dynamic leg extensor power rig. Lean body mass and BMD at multiple sites were measured by dual-energy X-ray absorptiometry. BMD correlated with both leg extensor strength (r = 0.16-0.26) and grip strength (r = 0.12-0.21). Lean mass was significantly correlated with BMD at all sites (r = 0.20-0.39). All three muscle variables have a moderate genetic component with heritability estimates of 0.52 for lean body mass, 0.46 for leg extensor strength, and 0.30 for grip strength (all p < 0.05). The genetic component of BMD was not significantly reduced after adjusting for lean mass and muscle strength, with less than 20% of the genetic variance of BMD explained by the muscle variables. In conclusion, these data suggest that the three muscle variables have a modest genetic component, suggesting the potential for clinical intervention and lifestyle modifications. The genetic component to muscle bulk and strength accounts for little of the genetic component to BMD, confirming the rationale for research into bone-specific genes.

The heritability of bone mineral density, ultrasound of the calcaneus and hip axis length: a study of postmenopausal twins.

Abstract: Population based studies have demonstrated that having a first degree relative with a hip fracture is predictive of future hip fractures. Postmenopausal bone mineral density (BMD), ultrasound of calcaneus and hip axis length are associated with hip fracture, with the association for ultrasound and hip axis length being independent of BMD. The aim of this study was to determine the genetic component of these three important risk factors. We performed a classical twin study using 500 normal female twins, 128 identical and 122 non-identical pairs, aged 50 to 70 years. We measured bone mineral density at multiple sites, hip axis length (distance from the inner rim of the acetabulum to the greater trochanter), broadband ultrasound attenuation and velocity of sound of the calcaneus. Bone density had a strong genetic component at all sites with estimates of heritability ranging from 0.46 to 0.84. Hip axis length and velocity of sound had major genetic components with estimates of 0.62 and 0.61 respectively, which remained virtually unchanged after adjustment for bone mineral density. Broadband ultrasound attenuation had a moderate genetic component with an estimate of 0.53, which was reduced further to 0.45 after adjustment for BMD. In summary, all three bone measurements, which are independently associated with hip fracture, are independently heritable. This study suggests that a combination of different genetic factors acting on the structure, dimensions and density of bone may explain the importance of family history as a risk factor for hip fracture.

Erectile dysfunction and the cardiovascular patient: endothelial dysfunction is the common denominator

Abstract: Erectile dysfunction (ED) is a common condition and studies predict that it will become even more common in the future. There is increasing evidence to suggest that it is predominantly a vascular disease and may even be a marker for occult cardiovascular disease. The common pathological process is at the level of the endothelium, and cardiovascular risk factor control may be the key to preventing ED. Many men with established cardiovascular disease have ED. Specific guidelines for the management of ED in these patients have been produced by an expert panel. Cardiovascular risk stratification is an important initial step in managing such patients. In cardiac patients considered to have low cardiovascular risk, the management of ED can be safe and effective.

Molecular epidemiology of community-associated meticillin-resistant Staphylococcus aureus in Europe.

Abstract: Over the past decade, community-associated meticillin-resistant Staphylococcus aureus (MRSA) has emerged in patients without health-care contact, especially in the USA. Although data are limited, the prevalence of community-associated MRSA in Europe seems to be low but is increasing. The organism has been reported in most European countries, including The Netherlands and Nordic countries, which have low rates of health-care-associated MRSA. In Greece, rates of community-associated MRSA in some centres approach those of the USA. By contrast with North America, where the USA300 clone (ST8-IV) predominates, community-associated MRSA in Europe is characterised by clonal heterogeneity. The most common European strain is the European clone (ST80-IV), although reports of USA300 are increasing. Several community-associated MRSA clones have arisen in Europe, most notably the ST398-V pig-associated MRSA clone in The Netherlands and Denmark. An understanding of the epidemiology of community-associated MRSA is essential to guide new control initiatives to prevent these organisms from becoming endemic in Europe.