Muscle mass measures and incident osteoporosis in 149,166 postmenopausal women

Background: Despite several muscle mass measures being used in the current definitions of sarcopenia, their usefulness is uncertain due to limited data on their association with health outcomes. The aim of the study was to compare the performance of different muscle mass measures for predicting incident osteoporosis in postmenopausal women. Methods: This study included data from 149,166 participants (aged 60.3±5.5 years) as part of the UK Biobank cohort. Body composition was assessed using bioelectrical impedance. The muscle mass measures included were total body skeletal muscle (SMM) and appendicular skeletal muscle mass (aSMM) divided by height squared (ht2), derived residuals, SMM, SMM adjusted for body mass (SMM/bm×100) and aSMM normalised for body mass index (aSMM/BMI). Diagnoses of the events were confirmed by primary care physicians and coded according to the World Health Organization’s International Classification of Diseases 10th Revision (ICD-10: M80-M82). Results: Over a median follow-up of 6.75 (5th to 95th percentile interval, 1.53 to 8.37) years. 394 newly diagnosed cases of osteoporosis occurred, with 40 (10.2%) cases being associated with a pathological fracture. SMM/ht2, aSMM/ht2 residual and SMM were lower in postmenopausal women with osteoporosis compared to women without (all P <0.0001), while SMM/bm×100 (P=0.003), but not aSMM/BMI (P=0.59), was higher in the osteoporosis group. The unadjusted rates of osteoporosis increased with decreasing quintiles for SMM/ht2, aSMM/ht2, residuals and SMM (all P trend <0.0001), while the incidence of osteoporosis increased with increasing SMM/bm×100 (P trend =0.001), but not for aSMM/BMI (P=0.45). After minimally adjusting for age, and after full adjustment, SMM/ht2, aSMM/ht2 and SMM were the only measure that consistently predicted osteoporosis in the total group of postmenopausal women (hazard ratio [HR] 0.65–0.67, all P≤0.0001), in lean women (HR 0.62–0.68; all P≤0.001), and women with increased adiposity (HR 0.64–0.68; all P≤0.01). In fully adjusted models, the changes in the R2 statistic were 13.4%, 11.6% and 15.3% for the SMM/ht2 (aSMM/ht2), residual and SMM, but only 4.9% and 1.3% for SMM/bm×100 and aSMM/BMI. Conclusions: Muscle mass measures adjusted for height only (SMM/ht2, aSMM/ht2) appear to be better muscle-relevant risk factors for incident osteoporosis in postmenopausal women, including when stratified into lean participants and participants with increased adiposity

Oral Iron Supplementation—Gastrointestinal Side Effects and the Impact on the Gut Microbiota

Iron deficiency anaemia (IDA) is a worldwide healthcare problem affecting approximately 25% of the global population. The most common IDA treatment is oral iron supplementation, which has been associated with gastrointestinal (GI) side effects such as constipation and bloating. These can result in treatment non-adherence and the persistence of IDA. Intravenous iron does not cause GI side effects, which may be due to the lack of exposure to the intestinal lumen. Luminal iron can cause changes to the gut microbiota, aiding the promotion of pathogenic species and decreasing beneficial protective species. Iron is vital for methanogenic archaea, which rely on iron for growth and metabolism. Increased intestinal methane has been associated with slowing of intestinal transit, constipation, and bloating. Here we explore the literature to understand a potential link between iron and methanogenesis as a novel way to understand the mechanism of oral iron supplementation induced GI side effects

Cross-sectional associations of active transport, employment status and objectively measured physical activity: analyses from the National Health and Nutrition Examination Survey

Background: To investigate associations between active transport, employment status and objectively measured moderate-to-vigorous physical activity (MVPA) in a representative sample of US adults. Methods: Cross-sectional analyses of data from the National Health and Nutrition Examination Survey. A total of 5180 adults (50.2 years old, 49.0% men) were classified by levels of active transportation and employment status. Outcome measure was weekly time spent in MVPA as recorded by the Actigraph accelerometer. Associations between active transport, employment status and objectively measured MVPA were examined using multivariable linear regression models adjusted for age, BMI, race and ethnicity, education level, marital status, smoking status, working hour duration (among the employed only), and self-reported leisure time physical activity. Results: Patterns of active transport were similar between the employed (n=2,897) and unemployed (n=2,283), such that 76.0% employed and 77.5% unemployed engaged in no active transport. For employed adults, those engaging in high levels of active transport (≥90 min/week) had higher amount of MVPA than those who did not engage in active transport. This translated to 40.8 (95% CI: 15.7, 65.9) additional minutes MVPA per week in men and 57.9 (95% CI: 32.1, 83.7) additional minutes MVPA per week in women. Among the unemployed adults, higher levels of active transport were associated with more MVPA among men (44.8 min/week MVPA, 95% CI: 9.2, 80.5), only. Conclusions: Findings from the present study support interventions to promote active transport to increase population level physical activity. Additional strategies are likely required to promote physical activity among unemployed women

The association between blood groups and COVID-19 infection: a study from the UK Biobank

Blood groups might influence susceptibility to COVID‐19 [1‐7]. We investigated associations between blood groups and COVID‐19 infection in UK Biobank participants, a prospective population‐based study that, between 2006 and 2010, enrolled 502,620 people aged 38–73 years in the United Kingdom. All participants gave written informed consent for their data to be used for research purposes, which was also approved by an ethics committee

Drink types unmask the health risks associated with alcohol intake – prospective evidence from the general population

Background & aims: Uncertainty still exists on the impact of low to moderate consumption of different drink types on population health. We therefore investigated the associations of different drink types in the form of beer/cider, champagne/white wine, red wine and spirits with various health outcomes. Methods: Over 500,000 participants were recruited to the UK Biobank cohort. Alcohol consumption was self-reported as pints beer/cider, glasses champagne/white wine, glasses of red wine, and measures of spirits per week. We followed health outcomes for a median of 7.02 years and reported all-cause mortality, cardiovascular events, ischemic heart disease, cerebrovascular events, and cancer. Results: In continuous analysis after excluding non-drinkers, beer/cider and spirits intake associated with an increased risk for all-cause mortality (beer/cider: hazard ratio, 1.56; 95% confidence interval, 1.45–1.68; spirits: 1.47;1.35–1.60), cardiovascular events (beer/cider: 1.25;1.17–1.33; spirits: 1.25;1.16–1.36), ischemic heart disease (beer/cider:1.12;0.99–1.26 [P=0.056]; spirits: 1.17;1.02–1.35), cerebrovascular disease (beer/cider: 1.63;1.32–2.02; spirits: 1.59;1.25–2.02) and cancer (beer/cider: 1.14;1.05–1.24; spirits: 1.14;1.03–1.26), while both champagne/white wine and red wine associated with a decreased risk for ischemic heart disease only (champagne/white wine: 0.84;0.72–0.98; red wine: 0.88;0.77–0.99). Conclusions: Our findings do not support the notion that alcohol from any drink type is beneficial to health. Consuming low levels of beer/cider and spirits already associated with an increased risk for all health outcomes, while wine showed opposite protective relationships only with ischemic heart disease

Bone Resorption and Environmental Exposure to Cadmium in Women: A Population Study

BACKGROUND: Environmental exposure to cadmium decreases bone density indirectly through hypercalciuria resulting from renal tubular dysfunction. OBJECTIVE: We sought evidence for a direct osteotoxic effect of cadmium in women. METHODS: We randomly recruited 294 women (mean age, 49.2 years) from a Flemish population with environmental cadmium exposure. We measured 24-hr urinary cadmium and blood cadmium as indexes of lifetime and recent exposure, respectively. We assessed the multivariate-adjusted association of exposure with specific markers of bone resorption, urinary hydroxylysylpyridinoline (HP) and lysylpyridinoline (LP), as well as with calcium excretion, various calciotropic hormones, and forearm bone density. RESULTS: In all women, the effect sizes associated with a doubling of lifetime exposure were 8.4% (p = 0.009) for HP, 6.9% (p = 0.10) for LP, 0.77 mmol/day (p = 0.003) for urinary calcium, -0.009 g/cm(2) (p = 0.055) for proximal forearm bone density, and -16.8% (p = 0.065) for serum parathyroid hormone. In 144 postmenopausal women, the corresponding effect sizes were -0.01223 g/cm(2) (p = 0.008) for distal forearm bone density, 4.7% (p = 0.064) for serum calcitonin, and 10.2% for bone-specific alkaline phosphatase. In all women, the effect sizes associated with a doubling of recent exposure were 7.2% (p = 0.001) for urinary HP, 7.2% (p = 0.021) for urinary LP, -9.0% (p = 0.097) for serum parathyroid hormone, and 5.5% (p = 0.008) for serum calcitonin. Only one woman had renal tubular dysfunction (urinary retinol-binding protein > 338 mu g/day). CONCLUSIONS: In the absence of renal tubular dysfunction, environmental exposure to cadmium increases bone resorption in women, suggesting a direct osteotoxic effect with increased calciuria and reactive changes in calciotropic hormones

Estimation of Ligament Loading and Anterior Tibial Translation in Healthy and ACL-Deficient Knees During Gait and the Influence of Increasing Tibial Slope Using EMG-Driven Approach

The purpose of this study was to develop a biomechanical model to estimate anterior tibial translation (ATT), anterior shear forces, and ligament loading in the healthy and anterior cruciate ligament (ACL)-deficient knee joint during gait. This model used electromyography (EMG), joint position, and force plate data as inputs to calculate ligament loading during stance phase. First, an EMG-driven model was used to calculate forces for the major muscles crossing the knee joint. The calculated muscle forces were used as inputs to a knee model that incorporated a knee–ligament model in order to solve for ATT and ligament forces. The model took advantage of using EMGs as inputs, and could account for the abnormal muscle activation patterns of ACL-deficient gait. We validated our model by comparing the calculated results with previous in vitro, in vivo, and numerical studies of healthy and ACL-deficient knees, and this gave us confidence on the accuracy of our model calculations. Our model predicted that ATT increased throughout stance phase for the ACL-deficient knee compared with the healthy knee. The medial collateral ligament functioned as the main passive restraint to anterior shear force in the ACL-deficient knee. Although strong co-contraction of knee flexors was found to help restrain ATT in the ACL-deficient knee, it did not counteract the effect of ACL rupture. Posterior inclination angle of the tibial plateau was found to be a crucial parameter in determining knee mechanics, and increasing the tibial slope inclination in our model would increase the resulting ATT and ligament forces in both healthy and ACL-deficient knees

Age- and Tumor Subtype-Specific Breast Cancer Risk Estimates for CHEK2*1100delC Carriers.

PURPOSE: CHEK2*1100delC is a well-established breast cancer risk variant that is most prevalent in European populations; however, there are limited data on risk of breast cancer by age and tumor subtype, which limits its usefulness in breast cancer risk prediction. We aimed to generate tumor subtype- and age-specific risk estimates by using data from the Breast Cancer Association Consortium, including 44,777 patients with breast cancer and 42,997 controls from 33 studies genotyped for CHEK2*1100delC. PATIENTS AND METHODS: CHEK2*1100delC genotyping was mostly done by a custom Taqman assay. Breast cancer odds ratios (ORs) for CHEK2*1100delC carriers versus noncarriers were estimated by using logistic regression and adjusted for study (categorical) and age. Main analyses included patients with invasive breast cancer from population- and hospital-based studies. RESULTS: Proportions of heterozygous CHEK2*1100delC carriers in controls, in patients with breast cancer from population- and hospital-based studies, and in patients with breast cancer from familial- and clinical genetics center-based studies were 0.5%, 1.3%, and 3.0%, respectively. The estimated OR for invasive breast cancer was 2.26 (95%CI, 1.90 to 2.69; P = 2.3 × 10(-20)). The OR was higher for estrogen receptor (ER)-positive disease (2.55 [95%CI, 2.10 to 3.10; P = 4.9 × 10(-21)]) than it was for ER-negative disease (1.32 [95%CI, 0.93 to 1.88; P = .12]; P interaction = 9.9 × 10(-4)). The OR significantly declined with attained age for breast cancer overall (P = .001) and for ER-positive tumors (P = .001). Estimated cumulative risks for development of ER-positive and ER-negative tumors by age 80 in CHEK2*1100delC carriers were 20% and 3%, respectively, compared with 9% and 2%, respectively, in the general population of the United Kingdom. CONCLUSION: These CHEK2*1100delC breast cancer risk estimates provide a basis for incorporating CHEK2*1100delC into breast cancer risk prediction models and into guidelines for intensified screening and follow-up.NIH

Predisposing factors of hypertension in black males in the process of urbanisation

MSc (Physiology), North-West University, Potchefstroom CampusSocial and cultural disruption resulting from urbanisation is a major cause of chronic levels of stress all over the world, especially in developing countries like South Africa. South Africa's black population (77 .2 percent of the total population) is in a major process of ubanisation. It is estimated that urban growth and population increases will double or triple the number of urban residents in the next ten years. Urbanisation is linked to a decrease in the health status of various pop_ulation groups, especially regarding black people. In order to evaluate the possible decrease in cardiovascular health due to the exposure to factors associated with urbanisation, a group of 348 black Setswana speaking men was used in this study. The group consisted of 127 men from monocultural rural environments and 221 men from multicultural urban environments. These groups were further subdivided according to their age as well as their hypertensive and norrnotensive state. The cardiovascular parameters during rest and while challenging the cardiovascular system were registered. Applying 50% of the maximal tractive power of the subject on an isometric hand dynamometer challenged the subject's cardiovascular system. The whole pulse wave was recorded by the Finapres apparatus and the cardiovascular parameters were calculated by making use of the "Modelflow" software program. An urbanisation effect was apparent with the cardiovascular parameters during rest and while challenging the cardiovascular system, although the systolic and diastolic reactivity values showed mixed results. The decrease in cardiovascular health amongst the urbanised groups pointed to the possibility of an underlying peripheral vascular mechanism. The changes in the cardiovascular parameters during urbanisation show the same pattern as the changes observed between the hypertensives and normotensives. The urbanised groups showed an increased systolic blood pressure due to a decreased arterial compliance, and an increased diastolic blood pressure due to an increased total peripheral resistance, resulting in a decreased stroke volume and cardiac output when compared to the rural and normotensive groups. A possible interaction between age and the factors associated with urbanisation was found leading to the decreased arterial compliance observed in the older urbanised group. The conclusion, apart from the above mentioned findings, is that the factors associated with urbanisation has a deleterious effect on the cardiovascular health of black Setswana speaking males in the North West province. This is the first study to determine an interaction between urbanisation and age on arterial compliance.Master