Short-termed changes in quantitative ultrasound estimated bone density among young men in an 18-weeks follow-up during their basic training for the Swiss Armed Forces.

Background: Quantitative Ultrasound (QUS) methods have been widely used to assess estimated bone density. This study aimed to assess changes in estimated bone density in association with changes in body composition, physical activity, and anthropometry. Methods: We examined changes in anthropometry, body composition, and physical activity associated with changes in estimated bone mineral density (measured using quantitative ultrasound with a heel ultrasound device indicating broadband ultrasound attenuation BUA and speed of sound SOS) in a follow-up sample of n = 73 young men at the beginning and again 18 weeks later at the end of basic military training. Results: At the end of the basic training, the subjects were on average significantly heavier (+1.0%), slightly taller (+0.5%) and had a higher fat mass (+6.6%) and grip strength (+8.6%). A significant decrease in mean physical activity (-49.5%) and mean estimated bone density calculated with BUA (-7.5%) was observed in the paired t-test. The results of the multivariable linear regressions (backward selection) show that changes in skeletal muscle mass (delta = 2nd measurement minus 1st measurement) have negative and body weight (delta) have positive association with the speed of sound SOS (delta), while fat mass (delta) and physical activity (delta) had the strongest negative associations with estimated bone mineral density (delta). In particular, we found a negative association between fat mass (delta) and estimated bone mineral density (delta, estimated with BUA). Conclusion: Our study suggests that estimated bone density from the calcaneus can change within a few months even in young and mostly healthy individuals, depending upon physical activity levels and other co-factors. Further studies including other troop types as control groups as well as on women should follow in order to investigate this public health relevant topic in more depth. To what extent the estimated bone density measurement with quantitative ultrasound is clinically relevant needs to be investigated in further studies.

Sex difference in the immunogenicity of the quadrivalent Human Papilloma Virus vaccine: Systematic review and meta-analysis.

BACKGROUND: Immunological differences between males and females in response to viral vaccines are well known. This the first review to examine them for the Human Papilloma Virus. METHODS: We conducted a systematic review and meta-analysis of the immunogenicity of the Quadrivalent Human Papilloma Virus Vaccine qHPVV. We searched Medline, Embase, and CENTRAL for trials published until September 17, 2019. Inclusion criteria were 3-doses and reporting geometric mean titers (GMTs). We performed random-effects meta-analyses and meta-regression separated by age group and sex. RESULTS: Our search yielded 1809 unique studies. 334 full texts were screened and data from 18 studies were extracted. Females had higher pooled geometric mean titers than males in all age groups. Log transformed GMTs in male children (<16) years were: against HPV6: 6·62 (95% CI 6·29-6·94; I2 = 86·0%), against HPV11: 7·07 (95% CI 6·90-7·23; I2 = 63.1%), against HPV16: 8·53 (95% CI 8·28-8·78; I2 = 73·0%), and against HPV18 7·21 (95% CI 7·08-7·34; I2 = 26·4%). In females: against HPV6 7·10 (95% CI 6·79-7·41; I2 = 96·6%), HPV11: 7·32 (95% CI 7·15-7·50; I2 = 90·6%), HPV16: 8·71 (95% CI 8·52-8·91; I2 = 90·2%), and HPV18 7·35 (95% CI 7·11-7·58; I2 = 92·7%). In the meta-regression, the sexual difference was significant for HPV6 (p = 0·022) with a similar tendency for HPV11 (p = 0·066) and HPV18 (p = 0·079). Immunogenicity was significantly higher in children (<16) than in adults (p < 0·001). CONCLUSION: Females have higher antibody titers against HPV after receiving the qHPVV than do males. The difference is bigger in low-risk HPV strains. Adjusting the doses and schedules for each sex should be explored further.

National guidelines on nutrient reference values for the healthy adult population and for pregnant or lactating women are based on heterogeneous sources of evidence: review of guidelines.

Many countries provide dietary guidelines for health practitioners and/or the general population. However, there is no general, international guideline serving as a template for national dietary guidelines, and there is little to no consensus regarding reference values for different nutrients. The present review compared 27 national dietary guidelines for healthy adults as well as for pregnant and/or breastfeeding women, and analysed their quality and the evidence behind their recommendations. The guidelines were evaluated for their quality using the instrument Agree II, and found to be heterogeneous (overall quality score 14%-100%) and often insufficient (quality score < 50%) due to missing information about their methodology and sources of evidence. We analysed the evidence (number of studies, study types and publication years) of reference values of a number of nutrients using the five guidelines that provided the highest scores in the Agree II assessment. The reference values varied among guidelines, were rarely based on up-to-date meta-analyses, and were often based on insufficiently reported evidence (22/27 guidelines with quality score < 50%). We recommend systematic reviews of high quality studies to formulate future guidelines, and to use guidelines on how to write guidelines.

Body height and waist circumference of young Swiss men as assessed by 3D laser-based photonic scans and by manual anthropometric measurements.

Overweight and obesity are considered among the major health concerns worldwide. The body mass index is a frequently used measure for overweight and obesity and is associated with common non-communicable diseases such as diabetes type II, cardiovascular diseases and certain cancers. However, the body mass index does not account for the distribution of body fat and relative fat to muscle mass. 3D laser-based photonic full body scans provide detailed information on various body circumferences, surfaces, and volumes as well as body height and weight (using an integrated scale). In the literature, body scans showed good feasibility, reliability, and validity, while also demonstrating a good correlation with health parameters linked to the metabolic syndrome. However, systematic differences between body scan derived measurements and manual measurements remain an issue. This study aimed to assess these systematic differences for body height, waist circumference, and body mass index using cross-sectional data from a homogenous sample of 52 young Swiss male volunteers. In addition to 3D laser-based photonic full body scans and correlative manual measurements, body fat distribution was assessed through bioelectrical impedance analysis. Overall, an excellent correlation was found between measurements of waist circumference and body mass index, and good correlation between body mass index and total fat mass, as well as between waist circumference and visceral fat mass as assessed by bioelectrical impedance analysis. Volunteers were shorter in height measured by body scan when compared to manual measurements. This systematic difference became smaller when volunteers stood in the scanner in a completely upright position with their feet together. Waist circumference was slightly smaller for manual measurements than for body scan derived values. This systematic difference was larger in overweight volunteers compared to leaner volunteers.

Mindful eating and common diet programs lower body weight similarly: Systematic review and meta-analysis.

Common strategies for reducing body weight rely on limiting energy intake and restricting food choices. However, these strategies have often been proven ineffective in achieving long-term and sustainable weight reduction. More recently, mindful eating as an alternative weight management strategy has gained increasing attention, yet systematic reviews on intuitive or mindful eating published so far present contradictory results. We performed a systematic review and meta-analysis on randomized controlled trials on weight loss programs based on mindful or intuitive eating. We analyzed results using meta-regressions. We included a total of 10 studies and found a significant weight loss effect of mindful/intuitive eating strategies compared with nonintervention controls (-0.348 kg, 95% CI: -0.591 to -0.105, P = 0.005). However, there was no difference compared with conventional diet programs (P = 0.99). Reduction of BMI (-0.137 kg/m2 , 95% CI: -0.365 to 0.091, P = 0.240) or waist circumference (-0.358 cm, 95% CI: -0.916 to 0.200, P = 0.209) were not statistically significant. Mindful/intuitive eating could be a practical approach to weight control. Limitations of this study include the unbalanced sex, origin, place of residence of the participants, and the short duration of interventions. Future research should aim at investigating long-term effects and include a more heterogeneous study population.

Network structure and local adaptation in co-evolving bacteria-phage interactions.

Numerous theoretical and experimental studies have investigated antagonistic co-evolution between parasites and their hosts. Although experimental tests of theory from a range of biological systems are largely concordant regarding the influence of several driving processes, we know little as to how mechanisms acting at the smallest scales (individual molecular and phenotypic changes) may result in the emergence of structures at larger scales, such as co-evolutionary dynamics and local adaptation. We capitalized on methods commonly employed in community ecology to quantify how the structure of community interaction matrices, so-called bipartite networks, reflected observed co-evolutionary dynamics, and how phages from these communities may or may not have adapted locally to their bacterial hosts. We found a consistent nested network structure for two phage types, one previously demonstrated to exhibit arms race co-evolutionary dynamics and the other fluctuating co-evolutionary dynamics. Both phages increased their host ranges through evolutionary time, but we found no evidence for a trade-off with impact on bacteria. Finally, only bacteria from the arms race phage showed local adaptation, and we provide preliminary evidence that these bacteria underwent (sometimes different) molecular changes in the wzy gene associated with the LPS receptor, while bacteria co-evolving with the fluctuating selection phage did not show local adaptation and had partial deletions of the pilF gene associated with type IV pili. We conclude that the structure of phage-bacteria interaction networks is not necessarily specific to co-evolutionary dynamics, and discuss hypotheses for why only one of the two phages was, nevertheless, locally adapted.