In hoeverre geldt niet of nauwelijks bewegen als een onafhankelijke risicofactor voor hart- en vaatziekten?

Lichamelijke activiteit beïnvloedt hart en vaatziekten (HVZ). Lichamelijke activiteit (LA) kan gedefinieerd worden als iedere spierbeweging van het lichaam resulterend in meer energieverbruik dan het basaal metabolisme. Regelmatige LA, waarbij veel spieren gebruikt worden, zoals wandelen, hardlopen of zwemmen, leidt tot lichamelijke, cardiovasculaire, pulmonale en musculaire aanpassingen waardoor conditie ofwel inspanningstolerantie, uithoudingsvermogen en spierkracht toenemen. Training is gestructureerde, herhaalde LA, gericht op het op peil houden dan wel verbeteren van de lichamelijke conditie. Conditie, hart- en longfunctie, lichaamssamenstelling, spierkracht en souplesse, bepalen het vermogen tot LA. Vooral aerobe training, zoals lopen en fietsen, in tegenstelling tot krachttraining, zoals gewichtheffen, vermindert de ontwikkeling van hart- en vaatziekten

Effects of sex steroid hormones on regional fat depots as assesses by magnetic resonance imaging in transsexuals

We investigated prospectively the effect of sex steroids on regional fat depots and thigh muscle mass in adult transsexuals. Ethinyl estradiol in combination with cyproterone acetate, a progestational antiandrogen, was given to 20 male-to-female (M-F) transsexuals, and parenteral testosterone esters were given to 17 female-to-male (F-M) transsexuals. Before and after 12 mo of cross-sex hormone administration, several anthropometric measurements (weight, skinfolds, body circumferences, and bioimpedance) were performed, and transverse magnetic resonance images were obtained at the level of the abdomen, hip, and thigh to quantify fat depots (subcutaneous and visceral) and muscle areas. We observed that treatment with ethinyl estradiol in M-F transsexuals induced a significant increase in all subcutaneous fat depots, with a lesser but proportional and significant increase in the visceral fat depot and a decrease in thigh muscle area. Testosterone administration in F-M transsexuals markedly increased thigh muscle area, reduced subcutaneous fat deposition at all levels measured, but slightly increased the visceral fat area. We conclude that sex steroid hormones are important determinants of the sex-specific localization of body fat

Anxiety and blood pressure prior to dental treatment.

Assessed dental anxiety and blood pressure immediately prior to a dental appointment in 24 patients attending a university dental clinic or a clinic for anxious dental patients in the Netherlands. Blood pressure was assessed by 2 independent methods, and the interchangeability of the blood-pressure measurement methods was also assessed. Ss completed 3 self-assessment inventories for dental anxiety, including the Dental Anxiety Scale. No relationship was demonstrated among scores on the dental anxiety questionnaires and blood-pressure values. The blood-pressure measurement methods delivered comparable values for diastolic and mean arterial blood pressure only

Reproducibility of fat area measurements in young non-obese subjects using MRI

OBJECTIVE: To assess reproducibility, expressed as both inter-observer variability and intra-observer variability, of fat area measurements on images obtained by magnetic resonance (MR); to compare variability between fat area measurements, calculated from a single image per body region and from the average fat area of three images, and to determine reproducibility of image acquisition at the abdominal level. SUBJECTS: Thirty young, non-obese subjects (reproducibility of image analysis) and nine young, non-obese subjects (reproducibility of image acquisition). METHODS: Three MR images at the level of the abdomen (in 30 subjects) and at the level of the hip and thigh (in 14 of them). Quantification of subcutaneous fat depots (abdomen, hip and thigh) and visceral fat depots using an image-analyzing computer program. Assessment of variability of image analysis for fat area measurements between two observers and within observers. Assessment of reproducibility of image acquisition at the abdominal level (in nine subjects). RESULTS: Subcutaneous fat areas in all body regions were quantified with coefficients of variation (CV) ranging from only 2.1%-4.9%. By contrast, visceral fat area measurements showed markedly higher CVs (range: 9.4%-17.6%). Moreover, relative variability was much larger in small visceral fat areas (CVs up to 25.6%). The majority of CVs, calculated for intra-observer variability and calculated from the average fat area measurements of three images, was lower than calculated for inter-observer variability and for one single image, respectively. In particular, for the visceral fat depot, this reduction in variability had practical consequences for the number of subjects required for a study. Variation of repeated image acquisition was in the same range as variation of repeated measurements on the same image. CONCLUSION: One image per body site is sufficient to obtain a reliable estimate of subcutaneous fat depots. For estimations of the visceral fat depot, the average area measurements of three images reduces variability and increases statistical power. The availability of one single experienced observer during a study adds to accuracy

Long term testosterone administration increases visceral fat mass in female-to-male transsexuals

The amount of intraabdominal (visceral) fat is an important determinant of disturbances in lipid and glucose metabolism. Cross-sectional studies in women have found associations between high androgen levels and visceral fat accumulation. The causal relation between these phenomena is unknown. We, therefore, studied prospectively the effect of testosterone administration on body fat distribution in 10 young, nonobese, female to male transsexuals undergoing sex reassignment. Before, after 1 yr, and after 3 yr of testosterone administration, magnetic resonance images were obtained at the level of the abdomen, hip, and thigh to quantify both sc and visceral fat depots. After 1 yr of testosterone administration, sc fat depots at all levels showed significant reductions compared to baseline measurements. The mean visceral fat area did not change significantly, but subjects who gained weight in the first year after testosterone administration showed an increase in, visceral fat. After 3 yr of testosterone administration, sc fat depots were no longer significantly lower compared to pretreatment measurements, but the mean visceral fat depot had increased significantly by 13 c