3,885 research outputs found
Genetic and environmental risk factors for sexual distress and its association with female sexual dysfunction
No full textA. Burri, Q. Rahman and T. Spector (2011). Genetic and environmental risk factors for sexual distress and its association with female sexual dysfunction. Psychological Medicine, 41, pp 2435-2445. Copyright © Cambridge University Press 2011. http://dx.doi.org/10.1017/S003329171100049
Patients who have had fractures ?f the distal forearm do not lose bone as expected
No full textEditor - Women's lifetime risk of experiencing a fracture of the distal forearm is 15%.x Such fractures are associated with considerable pain and morbidity. They are also associated with an increased risk of vertebral fracture,2 although these anatomical sites have different bone compositions, with the forearm being composed predominantly of cortical bone whereas the spin
Size at birth, adult intestinal calcium absorption and 1,25(OH)(2) vitamin D
No full textBackground: Adult bone mineral status is modified by early environmental influences, but the mechanism of this phenomenon is unknown. Intestinal calcium absorption and vitamin D metabolism are integrally involved in bone metabolism and may be programmed during early life.Aim: To examine the early-life influences on calcium absorption and its control in 322 post-menopausal female twins.Methods: Intestinal calcium absorption was assessed by the stable strontium (Sr) method. Serum PTH, 25(OH) and 1,25(OH)2 vitamin D were measured and recalled birth weight recorded.Results: Fractional intestinal Sr absorption (alphaSr) was correlated with serum 1,25(OH)2 vitamin D (p<0.001), but not with 25(OH) vitamin D. Birth weight was inversely associated with serum 1,25(OH)2 vitamin D (p=0.04), the association being independent of serum calcium, phosphate, creatinine and PTH. Birth weight was inversely correlated with alphaSr (p=0.03), this association being independent of age, season, customary calcium intake and serum 25(OH) vitamin D; however, when serum 1,25(OH)2 vitamin D was added into the model, the association became non-significant, suggesting that the association was partially mediated via serum 1,25(OH)2 vitamin D.Discussion: We found a significant inverse association between birth weight and intestinal calcium absorption that is partially explained by an association between serum 1,25(OH)2 vitamin D and birth weight. This suggests a mechanism whereby the intra-uterine environment might affect adult skeletal status
Twin studies advance the understanding of gene-environment interplay in human nutrigenomics
No full textInvestigations into the genetic architecture of diet-disease relationships are particularly relevant today with the global epidemic of obesity and chronic disease. Twin studies have demonstrated that genetic makeup plays a significant role in a multitude of dietary phenotypes such as energy and macronutrient intakes, dietary patterns, and specific food group intakes. Besides estimating heritability of dietary assessment, twins provide a naturally unique, case-control experiment. Due to their shared upbringing, matched genes and sex (in the case of monozygotic (MZ) twin pairs), and age, twins provide many advantages over classic epidemiological approaches. Future genetic epidemiological studies could benefit from the twin approach particularly where defining what is 'normal' is problematic due to the high inter-individual variability underlying metabolism. Here, we discuss the use of twins to generate heritability estimates of food intake phenotypes. We then highlight the value of discordant MZ pairs to further nutrition research through discovery and validation of biomarkers of intake and health status in collaboration with cutting-edge omics technologies.</p
Statins as modulators of bone formation
No full textThe use of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) to reduce serum cholesterol is well described. However, the recent finding that statins have direct effects on bone was unexpected. A number of epidemiological studies have recently been published that explore the effects of statins on bone mineral density and risk of fracture in humans. Statins may act by directly stimulating the expression of bone morphogenetic protein-2 and increasing osteoblast differentiation or, like nitrogen-containing bisphosphonates, may have effects on the mevalonate pathway that leads to inhibition of osteoclast activity and osteoblast apoptosis. In addition, the demonstration that statins can inhibit inflammation and encourage angiogenesis offers other possibilities for action
Genetic influence on bone turnover in postmenopausal twins.
No full textPostmenopausal bone mass is determined by both peak bone mass and subsequent bone loss. Previous studies have shown that peak bone mass is under genetic influence mediated partly by factors affecting bone formation. The rate of bone loss increases markedly after the menopause, but is highly variable from subject to subject. The aims of this study were to determine whether postmenopausal bone turnover was under genetic control, which should be linked to the genetic influence on the rate of postmenopausal bone loss. A classical twin study was performed that compared the intraclass correlations in monozygotic (MZ) twins with those in dizygotic (DZ) twins, with any difference assumed to be due to genetic factors. Markers of bone formation and resorption were measured in 240 untreated postmenopausal twins, aged 45-69 yr, on the average 12.3 yr (SD, 6.0) postmenopause, including 61 MZ pairs and 59 DZ pairs. The intraclass correlation coefficient of MZ twin pairs, rMZ (95% confidence interval), for 2 specific markers of bone formation, serum osteocalcin and bone-specific alkaline phosphatase, were higher than the corresponding rDZ [0.67 (range, 0.59-0.75) vs. 0.48 (range, 0.35-0.61; P = 0.06) for osteocalcin and 0.53 (range, 0.41-0.65) vs. 0.21 (range, 0.01-0.41; P = 0.02) for bone-specific alkaline phosphatase]. For serum propeptide of type I collagen, a type I collagen synthesis marker that exhibits only a slight increase after menopause, a high proportion of its variance was explained by genetic factors [rMZ = 0.82 (0.77-0.87), rDZ = 0.33 (0.16-0.50); P < 0.001]. The correlations for bone resorption measured by three distinct urinary markers, total deoxypyridinoline and two cross-linked type I collagen peptides (CrossLaps and NTX), that increase markedly after menopause were higher in MZ than in DZ pairs, but the difference reached significance only for NTX (P = 0.03). For urinary free dexoypyridinoline, a marker reflecting bone collagen degradation that increases moderately after menopause, the proportion of the variance explained by genetic factors was highly significant (P = 0.002). In conclusion, our data indicate that a proportion of the variance in postmenopausal levels of both bone formation and resorption markers are explained by genetic factors, but this contribution was clearly significant only for markers that do not change markedly at the menopause. These data suggest that the contribution of genetic factors to overall postmenopausal bone turnover and possibly bone loss is likely to be small
Determinants of pressure pain threshold in adult twins: evidence that shared environmental influences predominate
No full textThe objective of this study was to examine the relative contribution of genetic and environmental factors in determining pain perception in a classical twin study. Dolorimeter measurements of pressure pain threshold (PPT) were recorded in 609 healthy female-female twin pairs of whom 269 pairs were monozygotic (MZ) and 340 were dizygotic (DZ). There was a strong correlation (R) in PPT in both MZ and DZ pairs (R(MZ) = 0.57, 95% confidence interval (CI): [0.49, 0.65]; R(DZ) = 0.51, 95% CI: [0.42, 0.59]). The slight excess in intraclass correlation observed in MZ when compared with DZ twins corresponds to a heritability for PPT of only 10% and is not statistically significant. Neither estimate of intraclass correlation was substantially altered after adjusting for a range of potential confounding variables including age, current tobacco and alcohol use, current analgesic use, psychological status assessed by the general health questionnaire, and social class. The dolorimeter measurements were shown to be reliable (between observer agreement R = 0.66; within observer agreement R = 0.70-0.76) and stable over time. In conclusion, these data suggest that there is no significant genetic contribution to the strong correlation in PPT that is observed in twin pairs. These findings reinforce the view that learned patterns of behaviour within families are an important determinant of perceived sensitivity to pain.</p
Blood, urine and faecal metabolite profiles in the study of adult renal disease
No full textChronic kidney disease (CKD) is a major public health burden and to date traditional biomarkers of renal function (such as serum creatinine and cystatin C) are unable to identify at-risk individuals before the disease process is well under way. To help preventive strategies and maximize the potential for effective interventions, it is important to characterise the molecular changes that take place in the development of renal damage. Metabolomics is a promising tool to identify markers of renal disease since the kidneys are involved in the handling of major biochemical classes of metabolites. These metabolite levels capture a snap-shot of the metabolic profile of the individual, allowing for the potential identification of early biomarkers, and the monitoring of real-time kidney function. In this review, we describe the current status of the identification of blood/urine/faecal metabolic biomarkers in different entities of kidney diseases including: acute kidney injury, chronic kidney disease, renal transplant, diabetic nephropathy and other disorders.</p
Effect of heeled shoes on joint symptoms and knee osteoarthritis (OA) in older adults: a 5-year follow-up study
No full textObjective: our aims were to examine the effects of heeled shoes on incident knee OA and joint pain. Methods: we used longitudinal data from the Chingford 1000 Women Study (Chingford Study); a prospective cohort of women aged ≥50 years. Participants with musculoskeletal disorders and/or a history of knee-related injury/surgery were excluded. Participants were followed for up to 5-years for incident outcomes including; i) radiographic knee OA (RKOA) and ii) joint pain (feet, knees, hips and back). Footwear data including ever worn heels ≥2 inches and, daytime/evening hours (per week) spent wearing heeled shoes over five-decades (ages <20, 20-30, 30-40, >50 years) were available at Year 10 whilst knee radiographs and joint symptom data were also collected at Year 15. Cumulative time spent wearing heeled shoes was calculated for women reporting ever use of heeled shoes (≥2 inches). Multiple logistic regression was used to examine the relationship between exposures and outcomes (from years 10 to 15).Results: 356 women were eligible at Year 10 with the median (IQR) age 60 (56 to 65) years. Compared to non-use, ever use of heeled shoes (≥2 inches) was not associated with incident RKOA (1.35, 95% CI 0.56 to 3.27). No association was observed between increasing cumulative time spent wearing heels and incident outcomes. Conclusion: compared to the non-use of heeled shoes, ever use of heels (≥2 inches) was not associated with incident RKOA and incident joint symptoms, respectively. Further, increasing cumulative time spent wearing heels was not associated with any of our outcomes
- …
