Acquisition of peak bone mass in a Norwegian youth cohort: longitudinal findings from the Fit Futures study 2010-2022.

In a Norwegian youth cohort followed from adolescence to young adulthood, bone mineral density (BMD) levels declined at the femoral neck and total hip from 16 to 27 years but continued to increase at the total body indicating a site-specific attainment of peak bone mass. PURPOSE: To examine longitudinal trends in bone mineral density (BMD) levels in Norwegian adolescents into young adulthood. METHOD: In a prospective cohort design, we followed 980 adolescents (473 (48%) females) aged 16-19 years into adulthood (age of 26-29) on three occasions: 2010-2011 (Fit Futures 1 (FF1)), 2012-2013 (FF2), and 2021-2022 (FF3), measuring BMD (g/cm2) at the femoral neck, total hip, and total body with dual x-ray absorptiometry (DXA). We used linear mixed models to examine longitudinal BMD changes from FF1 to FF3. RESULTS: From the median age of 16 years (FF1), femoral neck BMD (mean g/cm2 (95% CI)) slightly increased in females from 1.070 (1.059-1.082) to 1.076 (1.065-1.088, p = 0.015) at the median age of 18 years (FF2) but declined to 1.041 (1.029-1.053, p < 0.001) at the median age of 27 years (FF3). Similar patterns were observed in males: 16 years, 1.104 (1.091-1.116); 27 years, 1.063 (1.050-1.077, p < 0.001); and for the total hip in both sexes (both p < 0.001). Total body BMD increased from age 16 to 27 years in both sexes (females: 16 years, 1.141 (1.133-1.148); 27 years, 1.204 (1.196-1.212), p < 0.001; males: 16 years, 1.179 (1.170-1.188); 27 years, 1.310 (1.296-1.315), p < 0.001). CONCLUSION: BMD levels increased from 16 to 18 years at the femoral and total hip sites in young Norwegian females and males, and a small decline was observed at the femoral sites when the participants were followed up to 27 years. Total body BMD continued to increase from adolescence to young adulthood.

Cross-sectional associations between accelerometer-measured physical activity and hip bone mineral density: the Tromsø Study 2015-2016.

Positive associations between physical activity and bone health have been found in population-based studies, however, mostly based on self-reported physical activity. Therefore, we investigated the association between accelerometer-measured physical activity, measured in steps per day and minutes of moderate to vigorous physical activity (MVPA) per day, and total hip areal BMD (aBMD) measured by DXA in a general population, utilizing multiple regression models. The study participants, 1560 women and 1177 men aged 40-84 yr, were part of the seventh survey of the Tromsø Study (2015-2016). In both genders, we found a positive association between the number of daily steps and aBMD adjusted for age, BMI, and smoking status (P < .001). In women, an increase of 1000 steps per day was associated with 0.005 g/cm2 higher aBMD. For men, a polynomial curve indicated a positive association with aBMD up to 5000 steps per day, plateauing between 5000 and 14 000 steps, and then increasing again. Additionally, MVPA duration was positively associated with aBMD in both women (P < .001) and men (P = .004) when adjusted for age, BMI, and smoking status. Specifically, each 60-min increase in daily MVPA was associated with 0.028 and 0.023 g/cm2 higher aBMD in women and men, respectively. Despite positive associations, the clinical impact of physical activity on aBMD in this general population of adults and older adults was relatively small, and a large increase in daily MVPA might not be achievable for most individuals. Therefore, further longitudinal population-based studies incorporating device-based measures of physical activity could add more clarity to these relationships.

Social inequality in prevalence of NCD risk factors: a cross-sectional analysis from the population-based Tromsø Study 2015-2016.

OBJECTIVE: We aimed to examine associations between educational level, serving as an indicator of socioeconomic position, and prevalence of WHO-established leading behavioural and biological risk factors for non-communicable diseases (NCDs), in middle-aged to older women and men. DESIGN: Population-based cross-sectional study. SETTING: All inhabitants of the municipality of Tromsø, Norway, aged ≥40 years, were invited to the seventh survey (2015-2016) of the Tromsø Study; an ongoing population-based cohort study. PARTICIPANTS: Of the 32 591 invited; 65% attended, and a total of 21 069 women (53%) and men aged 40-99 years were included in our study. OUTCOME MEASURES: We assessed associations between educational level and NCD behavioural and biological risk factors: daily smoking, physical inactivity (sedentary in leisure time), insufficient fruit/vegetable intake (<5 units/day), harmful alcohol use (>10 g/day in women, >20 g/day in men), hypertension, obesity, intermediate hyperglycaemia and hypercholesterolaemia. These were expressed as odds ratios (OR) per unit decrease in educational level, with 95% CIs, in women and men. RESULTS: In women (results were not significantly different in men), we observed statistically significant associations between lower educational levels and higher odds of daily smoking (OR 1.69; 95% CI 1.60 to 1.78), physical inactivity (OR 1.38; 95% CI 1.31 to 1.46), insufficient fruit/vegetable intake (OR 1.54, 95% CI 1.43 to 1.66), hypertension (OR 1.25; 95% CI 1.20 to 1.30), obesity (OR 1.23; 95% CI 1.18 to 1.29), intermediate hyperglycaemia (OR 1.12; 95% CI 1.06 to 1.19), and hypercholesterolaemia (OR 1.07; 95% CI 1.03 to 1.12), and lower odds of harmful alcohol use (OR 0.75; 95% CI 0.72 to 0.78). CONCLUSION: We found statistically significant educational gradients in women and men for all WHO-established leading NCD risk factors within a Nordic middle-aged to older general population. The prevalence of all risk factors increased at lower educational levels, except for harmful alcohol use, which increased at higher educational levels.

The need for nonuniform risk acceptability across climate change scenarios.

Climate change risk assessment studies focus on identifying and analyzing different risks considering several climate change scenarios and on evaluating the cost-effectiveness of different adaptation measures. However, risk acceptability is often not reflected on in the context of climate change risk studies. Noting that the different climate change scenarios depict drastically contrasting images of the future in terms of population growth, economic development, and changes to life expectancy, this article uses risk acceptance criteria that are based on socioeconomic considerations to highlight the need for nonuniform risk acceptability across climate change scenarios. For this purpose, the optimum implied cost of averting a fatality derived based on the life quality index concept and the value of a quality-adjusted life year derived based on the time principle of acceptable life risk are assessed in three different climate change scenarios for Sweden. Additionally, an illustrative example that assesses the acceptable probability of failure of a steel rod under axial tension in the different climate change scenarios is presented. It is shown that risk acceptance criteria can vary considerably across the different climate change scenarios (e.g., more than 190% variation in the acceptable probability of failure for Sweden in the considered example). This article demonstrates that the ability of societies to afford risk-reducing measures may vary considerably across the different climate change scenarios. Hence, it can be concluded that (1) in the context of climate change risk assessments, risk acceptance criteria need to be developed to account for the different climate change scenarios, and (2) these criteria may vary considerably across the different climate change scenarios. Finally, relevant challenges and research needs are also provided.

Rheumatoid arthritis, disease-modifying antirheumatic drugs and risk of major osteoporotic fracture: prospective data from the HUNT Study, Norway.

OBJECTIVES: Rheumatoid arthritis has been associated with increased fracture risk. New treatments have improved the course of the disease substantially, but it is not clear if this influences fracture risk. We examined if rheumatoid arthritis, overall and according to disease-modifying antirheumatic drugs (DMARDs), is associated with a risk of major osteoporotic fractures. METHODS: Overall, 92 285 participants in the population-based Nord-Trndelag Health Study (HUNT), Norway were included and linked with hospital records for a validated rheumatoid arthritis diagnosis (n=605), type of DMARD treatment and fracture diagnosis. Participants were followed up until the first major osteoporotic fracture, death, emigration or end of follow-up. Cox regression was used to estimate HRs for fractures among individuals with rheumatoid arthritis, overall and by DMARD treatment, compared with participants without rheumatoid arthritis. RESULTS: A total of 9670 fractures were observed during follow-up, of which 88 were among those with rheumatoid arthritis. Compared with the reference group of participants without rheumatoid arthritis, those with the disease had an HR of fracture of 1.41 (95% CI 1.13 to 1.74). The association was largely similar for users of csDMARDs (HR 1.44; 95% CI 1.15 to 1.81), whereas the association for bDMARD users was weaker and less precise (HR 1.19; 95% CI 0.64 to 2.21). CONCLUSION: Participants with rheumatoid arthritis had a 40% higher risk of fracture than participants without the disease. A similar fracture risk was observed for conventional synthetic DMARD use, whereas there was weak evidence that the use of biological DMARDs may be associated with a somewhat lower fracture risk.

Comparing associations of handgrip strength and chair stand performance with all-cause mortality-implications for defining probable sarcopenia: the Tromsø Study 2015-2020.

BACKGROUND: Widely adopted criteria suggest using either low handgrip strength or poor chair stand performance to identify probable sarcopenia. However, there are limited direct comparisons of these measures in relation to important clinical endpoints. We aimed to compare associations between these two measures of probable sarcopenia and all-cause mortality. METHODS: Analyses included 7838 community-dwelling participants (55% women) aged 40-84 years from the seventh survey of the Tromsø Study (2015-2016), with handgrip strength assessed using a Jamar + Digital Dynamometer and a five-repetition chair stand test (5-CST) also undertaken. We generated sex-specific T-scores and categorised these as "not low", "low", and "very low" handgrip strength or 5-CST performance. Cox Proportional Hazard regression models were used to investigate associations between these two categorised performance scores and time to death (up to November 2020 ascertained from the Norwegian Cause of Death registry), adjusted for potential confounders including lifestyle factors and specific diseases. RESULTS: A total of 233 deaths occurred (median follow-up 4.7 years) with 1- and 5-year mortality rates at 3.1 (95% confidence interval [CI] 2.1, 4.6) and 6.3 (95% CI 5.5, 7.2) per 1000 person-years, respectively. There was poor agreement between the handgrip strength and 5-CST categories for men (Cohen's kappa [κ] = 0.19) or women (κ = 0.20). Fully adjusted models including handgrip strength and 5-CST performance mutually adjusted for each other, showed higher mortality rates among participants with low (hazard ratio [HR] 1.22, 95% CI 0.87, 1.71) and very low (HR 1.68, 95% CI 1.02, 2.75) handgrip strength compared with the not low category. Similar associations, although stronger, were seen for low (HR 1.88, 95% CI 1.38, 2.56) and very low (HR 2.64, 95% CI 1.73, 4.03) 5-CST performance compared with the not low category. CONCLUSIONS: We found poor agreement between T-score categories for handgrip strength and 5-CST performance and independent associations with mortality. Our findings suggest that these tests identify different people at risk when case-finding probable sarcopenia. As discussions on an international consensus for sarcopenia definitions proceed, testing both handgrip strength and chair stand performance should be recommended rather than viewing these as interchangeable assessments.

Device-measured physical activity, sedentary time, and risk of all-cause mortality: an individual participant data analysis of four prospective cohort studies.

OBJECTIVES: To examine whether moderate-to-vigorous physical activity (MVPA) modifies the association between sedentary time and mortality and vice versa, and estimate the joint associations of MVPA and sedentary time on mortality risk. METHODS: This study involved individual participant data analysis of four prospective cohort studies (Norway, Sweden, USA, baseline: 2003-2016, 11 989 participants ≥50 years, 50.5% women) with hip-accelerometry-measured physical activity and sedentary time. Associations were examined using restricted cubic splines and fractional polynomials in Cox regressions adjusted for sex, education, body mass index, smoking, alcohol, study cohort, cardiovascular disease, cancer, and/or diabetes, accelerometry wear time and age. RESULTS: 6.7% (n=805) died during follow-up (median 5.2 years, IQR 4.2 years). More than 12 daily sedentary hours (reference 8 hours) was associated with mortality risk only among those accumulating <22 min of MVPA per day (HR 1.38, 95% CI 1.10 to 1.74). Higher MVPA levels were associated with lower mortality risk irrespective of sedentary time, for example, HR for 10 versus 0 daily min of MVPA was 0.85 (95% CI 0.74 to 0.96) in those accumulating <10.5 daily sedentary hours and 0.65 (95% CI 0.53 to 0.79) in those accumulating ≥10.5 daily sedentary hours. Joint association analyses confirmed that higher MVPA was superior to lower sedentary time in lowering mortality risk, for example, 10 versus 0 daily min of MVPA was associated with 28-55% lower mortality risk across the sedentary time spectrum (lowest risk, 10 daily sedentary hours: HR 0.45, 95% CI 0.31 to 0.65). CONCLUSIONS: Sedentary time was associated with higher mortality risk but only in individuals accumulating less than 22 min of MVPA per day. Higher MVPA levels were associated with lower mortality risk irrespective of the amount of sedentary time.

Geometric control of diffusing elements on InAs semiconductor surfaces via metal contacts.

Local geometric control of basic synthesis parameters, such as elemental composition, is important for bottom-up synthesis and top-down device definition on-chip but remains a significant challenge. Here, we propose to use lithographically defined metal stacks for regulating the surface concentrations of freely diffusing synthesis elements on compound semiconductors. This is demonstrated by geometric control of Indium droplet formation on Indium Arsenide surfaces, an important consequence of incongruent evaporation. Lithographic defined Aluminium/Palladium metal patterns induce well-defined droplet-free zones during annealing up to 600 °C, while the metal patterns retain their lateral geometry. Compositional and structural analysis is performed, as well as theoretical modelling. The Pd acts as a sink for free In atoms, lowering their surface concentration locally and inhibiting droplet formation. Al acts as a diffusion barrier altering Pd's efficiency. The behaviour depends only on a few basic assumptions and should be applicable to lithography-epitaxial manufacturing processes of compound semiconductors in general.

Information-to-work conversion in single-molecule experiments: From discrete to continuous feedback.

We theoretically investigate the extractable work in single molecule unfolding-folding experiments with applied feedback. Using a simple two-state model, we obtain a description of the full work distribution from discrete to continuous feedback. The effect of the feedback is captured by a detailed fluctuation theorem, accounting for the information aquired. We find analytical expressions for the average work extraction as well as an experimentally measurable bound thereof, which becomes tight in the continuous feedback limit. We further determine the parameters for maximal power or rate of work extraction. Although our two-state model only depends on a single effective transition rate, we find qualitative agreement with Monte Carlo simulations of DNA hairpin unfolding-folding dynamics.

Branched-gallium phosphide nanowires seeded by palladium nanoparticles.

Palladium nanoparticles were produced by a chemical reagent-free and versatile method called spark ablation with control over particle size and density. These nanoparticles were used as catalytic seed particles for gallium phosphide nanowire growth by metalorganic vapour-phase epitaxy. Controlled growth of GaP nanowires using significantly small Pd nanoparticles between 10 and 40 nm diameter was achieved by varying several growth parameters. Low V/III ratios below 2.0 promote higher Ga incorporation into the Pd nanoparticles. Moderate growth temperatures under 600 °C avoid kinking and undesirable GaP surface growth. In addition, a second batch of palladium nanoparticles of concentration up to 1000 particlesµm-2was deposited onto the GaP nanowires. Subsequently, three-dimensional nanostructures evolved, with branches growing along the surface of the GaP nanowires. The GaP nanowires revealed a zinc blende structure with multiple twinning and a PdGa phase at the tip of the nanowires and branches.

Characterization of the radiation field surrounding the Leksell Gamma Knife® and shielding applications.

The aim of this study is to improve the characterization and modeling of the radiation field surrounding the Leksell Gamma Knife®-PerfexionTM. The improved characterization of the radiation field enables more accurate shielding calculations to be performed for the areas adjacent to the treatment room. With the aid of a high-purity germanium detector and a satellite dose rate meter, γ-ray spectra and ambient dose equivalent H*(10) data were acquired at various locations in the field of a Leksell Gamma Knife unit in a treatment room at Karolinska University Hospital, Sweden. These measurements were used to validate the results of the PEGASOS Monte Carlo simulation system with a PENELOPE kernel. The levels of the radiation that passes through the shielding of the machine (leakage radiation) are shown to be much lower than what is suggested by various bodies, e.g. the National Council on Radiation Protection and Measurements, to be used when calculating radiation shielding barriers. The results clearly indicate that Monte Carlo simulations may be used in structural shielding design calculations for γ rays from the Leksell Gamma Knife.

Health Research Requires Efficient Platforms for Data Collection from Personal Devices.

Data from consumer-based devices for collecting personal health-related data could be useful in diagnostics and treatment. This requires a flexible and scalable software and system architecture to handle the data. This study examines the existing mSpider platform, addresses shortcomings in security and development, and suggests a full risk analysis, a more loosely coupled component- based system for long term stability, better scalability, and maintainability. The goal is to create a human digital twin platform for an operational production environment.

Collecting health-related research data using consumer-based wireless smart scales.

BACKGROUND: Serious public-health concerns such as overweight and obesity are in many cases caused by excess intake of food combined with decreases in physical activity. Smart scales with wireless data transfer can, together with smart watches and trackers, observe changes in the population's health. They can present us with a picture of our metabolism, body health, and disease risks. Combining body composition data with physical activity measurements from devices such as smart watches could contribute to building a human digital twin. OBJECTIVE: The objectives of this study were to (1) investigate the evolution of smart scales in the last decade, (2) map status and supported sensors of smart scales, (3) get an overview of how smart scales have been used in research, and (4) identify smart scales for current and future research. METHOD: We searched for devices through web shops and smart scale tests/reviews, extracting data from the manufacturer's official website, user manuals when available, and data from web shops. We also searched scientific literature databases for smart scale usage in scientific papers. RESULT: We identified 165 smart scales with a wireless connection from 72 different manufacturers, released between 2009 and end of 2021. Of these devices, 49 (28%) had been discontinued by end of 2021. We found that the use of major variables such as fat and muscle mass have been as good as constant over the years, and that minor variables such as visceral fat and protein mass have increased since 2015. The main contribution is a representative overview of consumer grade smart scales between 2009 and 2021. CONCLUSION: The last six years have seen a distinct increase of these devices in the marketplace, measuring body composition with bone mass, muscle mass, fat mass, and water mass, in addition to weight. Still, the number of research projects featuring connected smart scales are few. One reason could be the lack of professionally accurate measurements, though trend analysis might be a more feasible usage scenario.

Vertebral Fractures Assessed by Dual-Energy X-Ray Absorptiometry and All-Cause Mortality: The Tromsø Study, 2007-2020.

Vertebral fractures have been associated with increased mortality, but findings are inconclusive, and many vertebral fractures avoid clinical attention. We investigated this association in a general population of 2,476 older adults aged ≥55 years from Tromsø, Norway, who were followed over 2007-2020, using dual-energy x-ray absorptiometry (DXA) at baseline to evaluate vertebral fractures (mild, moderate, or severe). We used multiple Cox regression models to estimate hazard ratios (HRs) for all-cause mortality, adjusted for age, sex, body mass index, education, smoking, alcohol intake, cardiovascular disease, and respiratory disease. Mean follow-up in the cohort was 11.2 (standard deviation, 2.7) years; 341 participants (13.8%) had ≥1 vertebral fracture at baseline, and 636 participants (25.7%) died between baseline and follow-up. Full-adjustment models showed a nonsignificant association between vertebral fracture status (yes/no) and mortality. Participants with ≥3 vertebral fractures (HR = 2.43, 95% confidence interval: 1.57, 3.78) or ≥1 severe vertebral fracture (HR = 1.65, 95% confidence interval: 1.26, 2.15) had increased mortality compared with those with no vertebral fractures. Dual-energy x-ray absorptiometry-based screening could be a potent and feasible tool in detecting vertebral fractures that are often clinically silent yet independently associated with premature death. Our data indicated that detailed vertebral assessment could be warranted for a more accurate survival estimation.

A 15-year follow-up study of hip bone mineral density and associations with leisure time physical activity. The Tromsø Study 2001-2016.

AIMS: The aim was to investigate the long-term association between leisure time physical activity and hip areal bone mineral density (aBMD), in addition to change in hip aBMD over time, in 32-86 years old women and men. METHODS: Data were retrieved from the 2001, 2007-2008, and 2015-2016 surveys of the Tromsø Study, a longitudinal population study in Norway. Leisure time physical activity was assessed by the four-level Saltin-Grimby Physical Activity Level Scale which refers to physical exertion in the past twelve months. Hip aBMD was assessed by Dual-Energy X-ray Absorptiometry. Linear Mixed Model analysis was used to examine long-term associations between physical activity and hip aBMD (n = 6324). In addition, the annual change in hip aBMD was analyzed in a subsample of 3199 participants. RESULTS: Physical activity was significantly and positively associated with total hip aBMD in the overall cohort (p<0.005). Participants who reported vigorous activity had 28.20 mg/cm2 higher aBMD than those who were inactive (95% CI 14.71; 41.69, controlled for confounders), and even light physical activity was associated with higher aBMD than inactivity (8.32 mg/cm2, 95% CI 4.89; 11.76). Associations between physical activity and femoral neck aBMD yielded similar results. Hip aBMD decreased with age in both sexes, although more prominently in women. From 2001 to 2007-2008, aBMD changed by -5.76 mg/cm2 per year (95% CI -6.08; -5.44) in women, and -2.31 mg/cm2 (95% CI -2.69; -1.93), in men. From 2007-2008 to 2015-2016, the change was -4.45 mg/cm2 per year (95% CI -4.84; -4.06) in women, and -1.45 mg/cm2 (95% CI -1.92; -0.98) in men. CONCLUSIONS: In this cohort of adult men and women, physical activity levels were positively associated with hip aBMD in a dose-response relationship. Hip aBMD decreased with age, although more pronounced in women than men.

Simulating Vapor-Liquid-Solid Growth of Au-Seeded InGaAs Nanowires.

Ternary III-V nanowires are commonly grown using the Au-seeded vapor-liquid-solid method, wherein the solid nanowires are grown from nanoscale liquid seed particles, which are supplied with growth species from the surrounding vapor phase. A result of the small size of these seed particles is that their composition can vary significantly during the cyclical layer-by-layer growth, despite experiencing a constant pressure of growth species from the surrounding vapor phase. Variations in the seed particle composition can greatly affect the solid nanowire composition, and these cyclical dynamics are poorly understood for ternary nanowire growth. Here, we present a method for simulating nanowire growth which captures the complex cyclical dynamics using a kinetic Monte Carlo framework. In the framework, a nanowire grows through the attachment or detachment of one III-V pair at the time, with rates that are based on the momentary composition of the seed particle. The composition of the seed evolves through the attachment and detachment of III-V pairs to the solid nanowire and through the impingement or evaporation of single atoms to the surrounding vapor. Here, we implement this framework using the As-Au-Ga-In materials system and use it to simulate the growth of Au-seeded InGaAs nanowires with an average solid Ga/III ratio around 0.5. The results show that nucleation preferentially occurs via clusters of InAs and that the compositional hierarchy of the liquid seed (X As < X Ga < X In) determines much of the dynamics of the system. We see that imposing a constraint on the simulation, that only the most recently attached III-V pair can be detached, resulted in a significant narrowing of the compositional profile of the nanowire. In addition, our results suggest that, for ternary systems where the two binaries are heavily mismatched, the dynamics of the seed particle may result in an oscillating compositional profile.

Between-study differences in grip strength: a comparison of Norwegian and Russian adults aged 40-69 years.

BACKGROUND: Identifying individuals with low grip strength is an initial step in many operational definitions of sarcopenia. As evidence indicates that contemporaneous Russian populations may have lower mean levels of grip strength than other populations in northern Europe, we aimed to: compare grip strength in Russian and Norwegian populations by age and sex; investigate whether height, body mass index, education, smoking status, alcohol use and health status explain observed differences and; examine implications for case-finding low muscle strength. METHODS: We used harmonized cross-sectional data on grip strength and covariates for participants aged 40-69 years from the Russian Know Your Heart study (KYH) (n = 3833) and the seventh survey of the Norwegian Tromsø Study (n = 5598). Maximum grip strength (kg) was assessed using the same protocol and device in both studies. Grip strength by age, sex and study was modelled using linear regression and between-study differences were predicted from these models. Sex-specific age-standardized differences in grip strength and in prevalence of low muscle strength were estimated using the European population standard of 2013. RESULTS: Normal ranges of maximum grip strength in both studies combined were 33.8 to 67.0 kg in men and 18.7 to 40.1 kg in women. Mean grip strength was higher among Tromsø than KYH study participants and this difference did not vary markedly by age or sex. Adjustment for covariates, most notably height, attenuated between-study differences but these differences were still evident at younger ages. For example, estimated between-study differences in mean grip strength in fully adjusted models were 2.2 kg [95% confidence interval (CI) 1.4, 3.1] at 40 years and 1.0 kg (95% CI 0.5, 1.5) at 65 years in men (age × study interaction P = 0.09) and 1.1 kg (95% CI 0.4, 1.9) at age 40 years and -0.2 kg (95% CI -0.7, 0.3) at 65 years in women (age × study interaction P < 0.01). CONCLUSIONS: We found between-study differences in mean grip strength that are likely to translate into greater future risk of sarcopenia and poorer prospects of healthy ageing for Russian than Norwegian study participants. For example, the average Russian participant had a similar level of grip strength to a Norwegian participant 7 years older. Our findings suggest these differences may have their origins in childhood highlighting the need to consider interventions in early life to prevent sarcopenia.

Anthropometric measures are satisfactory substitutes for the DXA-derived visceral adipose tissue in the association with cardiometabolic risk-The Tromsø Study 2015-2016.

BACKGROUND: Body mass index (BMI) increases while cardiometabolic risk factors decrease in individuals in high-income countries. This paradoxical observation raises the question of whether current measures of overweight and obesity properly identify cardiometabolic risk. METHODS: A total of 3675 participants (59% women) aged 40-84 years with whole-body dual-energy x-ray absorptiometry scans from the seventh survey of the Tromsø Study were included to examine the association between visceral adipose tissue (VAT) in grams and BMI, waist circumference (WC), waist-to-hip ratio (WHR), and waist-to-height ratio (WHtR). Further, their association with single cardiometabolic risk factors (blood pressure, triglycerides, total cholesterol, high-density lipoprotein [HDL] cholesterol, glycated hemoglobin, high-sensitivity C-reactive protein), modified single components from the ATP Ⅲ criteria for metabolic syndrome (hypertension, diabetes, high triglycerides, and low HDL cholesterol), and metabolic syndrome were examined. RESULTS: VAT mass was strongly correlated with BMI (r ≥ 0.77), WC (r ≥ 0.80), WHR (r ≥ 0.58), and WHtR (r ≥ 0.78). WC was the strongest predictor for VAT (area under the curve: 0.90). Compared to anthropometric measures, the associations between VAT and metabolic syndrome as well as single components of metabolic syndrome were statistically significantly stronger, but the clinical differences were likely minor. CONCLUSION: Although VAT mass showed statistically stronger associations with cardiometabolic risk compared to traditional anthropometrics, the clinical importance was likely small. Simple, clinically available tools seem to satisfactory substitute for VAT to identify cardiometabolic risk.

Complex lifestyle intervention among inactive older adults with elevated cardiovascular disease risk and obesity: a mixed-method, single-arm feasibility study for RESTART-a randomized controlled trial.

BACKGROUND: Physical inactivity and obesity are global public health challenges. Older adults are important to target for prevention and management of disease and chronic conditions. However, many individuals struggle with maintaining increased physical activity (PA) and improved diet. This feasibility study provides the foundation for the RESTART trial, a randomized controlled trial (RCT) to test a complex intervention to facilitate favourable lifestyle changes older adults can sustain. The primary objective of this study was to investigate study feasibility (recruitment, adherence, side-effects, and logistics) using an interdisciplinary approach. METHODS: This 1-year prospective mixed-method single-arm feasibility study was conducted in Tromsø, Norway, from September 2017. We invited by mail randomly selected participants from the seventh survey of the Tromsø Study (2015-2016) aged 55-75 years with sedentary lifestyle, obesity, and elevated cardiovascular risk. Participants attended a 6-month complex lifestyle intervention program, comprising instructor-led high-intensive exercise and nutritionist- and psychologist-led counselling, followed by a 6-month follow-up. All participants used a Polar activity tracker for daily activity monitoring during the intervention. Participants were interviewed three times throughout the study. Primary outcome was study feasibility measures. RESULTS: We invited potential participants (n=75) by mail of which 27 % (n=20) agreed to participate. Telephone screening excluded four participants, and altogether 16 participants completed baseline screening. The intervention and test procedures of primary and secondary outcomes were feasible and acceptable for the participants. There were no exercise-induced injuries, indicating that the intervention program is safe. Participants experienced that the dietary and psychological counselling were delivered too early in the intervention and in too close proximity to the start of the exercise program. Minor logistic improvements were implemented throughout the intervention period. CONCLUSION: This study indicates that it is feasible to conduct a full-scale RCT of a multi-component randomized intervention trial, based on the model of the present study. No dropouts due to exercise-induced injury indicates that the exercises were safe. While minor improvements in logistics were implemented during the intervention, we will improve recruitment and adherence strategies, rearrange schedule of intervention contents (exercise, diet, and psychology), as well as improve the content of the dietary and behavioural counselling to maximize outcome effects in the RESTART protocol. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03807323 Registered 16 January 2019 - retrospectively registered.

Secular and longitudinal trends in body composition: The Tromsø Study, 2001 to 2016.

OBJECTIVE: Overweight, defined as excessive fat mass, is a long-standing worldwide public health challenge. Traditional anthropometric measures used to identify overweight and obesity do not assess body composition. The aim of this study was to examine population trends in general and abdominal fat mass during the past two decades. METHODS: This study included participants from one or more consecutive surveys of the population-based Tromsø Study, including Tromsø 5 (conducted in 2001, n = 1,662, age 40-84 years), Tromsø 6 (2007-2008, n = 901, age 40-88 years), and Tromsø 7 (2015-2016, n = 3,670, age 40-87 years), with total body dual-energy x-ray absorptiometry scans. Trends in total fat and visceral adipose tissue (VAT) were analyzed by generalized estimation equation models in strata of sex and age groups. RESULTS: Total fat and VAT mass increased during 2001 to 2016, with a larger increase during 2007 to 2016 than from 2001 to 2007 and among the youngest age group (40-49 years), particularly in women. Women had higher total fat mass than men, whereas men had higher VAT mass than women. CONCLUSIONS: General and abdominal dual-energy x-ray absorptiometry-derived fat mass increased during the past two decades in this general population. Of particular concern is the more pronounced increase in the past decade and in the younger age groups.