A Miniaturized MicroRNA Sensor Identifies Targets Associated with Weight Loss in a Diet and Exercise Intervention among Healthy Overweight Individuals.

Weight loss through dietary and exercise intervention is commonly prescribed but is not effective for all individuals. Recent studies have demonstrated that circulating microRNA (miR) biomarkers could potentially be used to identify individuals who will likely lose weight through diet and exercise and attain a healthy body weight. However, accurate detection of miRs in clinical samples is difficult, error-prone, and expensive. To address this issue, we recently developed iLluminate-a low-cost and highly sensitive miR sensor suitable for point-of-care testing. To investigate if miR testing and iLluminate can be used in real-world obesity applications, we developed a pilot diet and exercise intervention and utilized iLluminate to evaluate miR biomarkers. We evaluated the expression of miRs-140, -935, -let-7b, and -99a, which are biomarkers for fat loss, energy metabolism, and adipogenic differentiation. Responders lost more total mass, tissue mass, and fat mass than non-responders. miRs-140, -935, -let-7b, and -99a, collectively accounted for 6.9% and 8.8% of the explained variability in fat and lean mass, respectively. At the level of the individual coefficients, miRs-140 and -935 were significantly associated with fat loss. Collectively, miRs-140 and -935 provide an additional degree of predictive capability in body mass and fat mass alternations.

Prevalence and Trends of Basic Activities of Daily Living Limitations in Middle-Aged and Older Adults in the United States.

BACKGROUND: Population-level surveillance of the prevalence and trends of basic self-care limitations will help to identify the magnitude of physical disablement in the rapidly growing older American demographic. We sought to evaluate the prevalence and trends of activities of daily living (ADL) limitations in the United States. METHODS: The analytic sample included 30,418 Americans aged ≥50 years from the 2006-2018 waves of the Health and Retirement Study. ADLs were self-reported. Weighted prevalence estimates were presented, and trends analyses were performed. RESULTS: Although overall ADL disability prevalence was 16.5% (95% confidence interval: 15.8-17.2) in 2018, there were no changes in limitations during the study period (p = 0.52). Older adults had a greater ADL disability prevalence than middle-aged adults (p < 0.001). While older persons experienced a declining trend of ADL limitations (p < 0.001), middle-aged persons had an increasing trend (p < 0.001). Males had a lower ADL limitation prevalence than females (p < 0.001). Hispanic and non-Hispanic Black had a higher ADL disability prevalence than non-Hispanic White (p < 0.001). CONCLUSIONS: This investigation revealed that while the estimated prevalence of ADL limitations in the United States was substantial, changes in such limitations were not observed. Our findings can help guide ADL screening, target sub-populations with an elevated ADL limitation prevalence, and inform interventions.

Reliability of a Novel Automated Ultrasound Technology for Body Composition Assessment and Comparisons with Dual Energy X-Ray Absorptiometry.

Body composition tools vary in reliability, portability, and accessibility. The purpose of this study was to evaluate test-retest reliability of MuscleSound® (MS) and dual-energy x-ray absorptiometry (DXA) for both two compartment (region) and three compartment (tissue) models. A secondary aim was to compare body composition values produced by both devices. Fifty participants (n = 25 male, n = 25 female) aged 18-39 years completed two body composition assessments, twice in a single session. Participants arrived at the lab after a 12-hour fast. DXA required participants to lay supine for 10-15 minutes during the scanning process. Thereafter, MS was utilized to measure subcutaneous adipose tissue thickness at seven sites: chest, subscapula, triceps, axilla, suprailium, abdomen, and mid-thigh. MS automatically estimated body composition utilizing a modified Jackson-Pollock equation and the Siri equation within the software. The sequence of assessments was then repeated. Statistical analysis included paired T-tests with Pearson correlations, intraclass correlation coefficients (ICC), and least significant change (LSC). Both methods were strongly reliable (ICCMS = .997, ICCDXA-region = .999, ICCDXA-tissue = .999). MS and DXA-region body fat percentages were significantly different (mean difference (%): 2.60 ± 1.32, p < .001) but highly correlated (r = .928, p < .001). Notably, the mean difference was within DXA-region's calculated least significant change of 3.24%. MS is reliable for assessing body fat percentage in young and middle-aged adults and operators can utilize MS to collect body composition data in the field.

Barriers and Strategies for Type 1 Diabetes Management Among Emerging Adults: A Qualitative Study.

Purpose: Individuals in the emerging adult age group (18-30 years) with type 1 diabetes (T1DM) have unique medical and social needs. The purpose of this study was to observe barriers and strategies for diabetes management among emerging adults with T1DM. Methods: A qualitative grounded theory model was utilized. An open-ended approach with a telephone interview was designed to allow a deeper understanding of the T1DM experience. The participants were from a larger survey-volunteer participant group and were asked to complete 1 interview in spring 2020 (n = 21, diagnosed age: mean 15.00 ± 8.00, females, n = 19). The data were analyzed for cohesive themes using grounded theory. Results: Participants indicated three main barrier themes (physiology, environment, and insurance) and 3 barrier subthemes (mental health, lack of social support, and weather). Three main strategy themes to diabetes management were recognized (medical technology, access to social support, and physical activity). There were 2 strategy subthemes (social media and social accountability). Conclusions: Regular use of social media can be a key tool for social accountability while lack of social support and physiological shifts can be barriers to management of T1DM. Physical activity should be considered as part of an individualized plan for management of diabetes.

Animal-Based Dietary Protein Intake Is Not A Risk Factor For Metabolic Syndrome Among Young Or Middle-Aged Females.

Background: Metabolic syndrome (MetS) increases risk for morbidity and premature mortality. Blood pressure, waist circumference, and fasting triglycerides (TG), blood glucose (BG), and high-density lipoprotein cholesterol (HDL) are factors for determining MetS. The Simple Method for Quantifying Metabolic Syndrome (siMS) score and risk score estimate risk of MetS. The purpose for this study was to exam the relationship of animal-based (ABP) and plant-based protein (PLP) with MetS as estimated by siMS score and risk score. Physical activty is another important consideration in MetS as it can reduce blood pressure, waist circumference and blood glucose, and affect blood lipid and lipoprotein concentrations. Methods: A cross-sectional study examined whether physical activity (PA) level and dietary protein source (i.e., animal- or plant-based) among young (18-24 years) and middle-aged (45-60 years) females were associated with siMS score and siMS risk score. Average time spent in sedentary, light, and moderate-to-vigorous PA (MVPA; min/wk), steps (steps/day), energy intake (kcal/day), percent dietary protein to total energy intake, ABP and PLP dietary intake, and ABP:PLP ratio (g/day) were included in the analysis. Volunteers were recruited from North Dakota and Minnesota from 2017 to 2019. Results: Eighty-one female participants (mean ± SD; young, n = 38, 20.4 ± 1.7 years, middle-aged, 52.5 ± 4.8 years) were included in the independent t-tests used to examine group differences in age, body mass index, HDL, BG, TG, systolic blood pressure, waist circumference, energy intake, energy intake percentage of total carbohydrates, fat, protein, ABP, and PLP, ABP:PLP, siMS score, and siMS risk score. Stepwise linear regressions were used to evaluate whether PA level and dietary protein source were predictors of siMS score and siMS risk score among young and middle-aged adult females. There was an inverse relationship between PLP intake and siMS score. The model explained 6.9% of the variance in siMS risk score (F1, 80 = 5.93). Plant-based protein intake was inversely related to siMS risk score while light PA was positively associated with siMS risk score. The model explained 16% of the variance in siMS risk score (F1, 80 = 7.53). Animal-based dietary protein intake did not impact siMS score (p = 0.180) and siMS risk score (p = 0.283). Conclusions: Plant-based protein intake was associated with a lower risk of MetS via siMS scores, while ABP was not associated. Given the nature of the cross-sectional design of this study, no causal relationship can be determined, but longitudinal studies or randomized control trials to confirm the results from this study are needed in the future.

Evenness of Dietary Protein Intake Is Positively Associated with Lean Mass and Strength in Healthy Women.

Background: Evenness of protein intake is associated with increased lean mass, but its relationship with muscle strength and performance is uncertain. Objectives: We determined the association of evenness of protein intake with lean mass, muscle strength and endurance, and functional ability. Design: This was a cross-sectional study. Setting: Data were collected at a research university in the upper midwestern United States. Participants: One hundred ninety-two healthy women, aged 18 to 79 years, mean ± SEM 41.9 ± 1.3, completed the study. Measurements: Dietary intake was assessed using 3-day food diaries verified with food frequency questionnaires. To assess evenness of protein intake, the day was divided into 3 periods: waking to 11:30, 11:31 to 16:30, and after 16:30. Lean mass was measured with dual energy X-ray absorptiometry. Lower-body muscle strength and endurance were determined using isokinetic dynamometry. Upper-body muscle strength was maximal handgrip strength. Functional ability was assessed using 6-m gait speed and 30-second chair stand tests. Accelerometry measured physical activity. Results: Intakes of 25 g or more of protein at 1 or more of the 3 periods was positively associated with lean mass (ß ± S.E.; 1.067 ± 0.273 kg, P < .001) and upper-body (3.274 ± 0.737 kg, P < .001) and lower-body strength (22.858 ± 7.918 Nm, P = .004) when controlling for age, body mass index, physical activity, and energy and protein intakes. Consuming at least 0.24 g/kg/period for those under 60 years and 0.4 g/kg/period for those 60 years and older was related to lean mass (0.754 ± 0.244 kg, P = .002), upper-body strength (2.451 ± 0.658 kg, P < .001), and lower-body endurance (184.852 ± 77.185 J, P = .018), controlling for the same variables. Conclusions: Evenness of protein intake is related to lean mass, muscle strength, and muscular endurance in women. Spreading protein intake throughout the day maximizes the anabolic response to dietary protein, benefiting muscle mass and performance.

Moderate to vigorous physical activity, leucine, and protein intake contributions to muscle health in middle age.

Objective: Identify contributors to differences in the muscle size and strength of sedentary and active young and middle-aged adults. Methods: This cross-sectional study included 98 participants aged 20-65 years. Participants were categorized based on age and self-reported physical activity (PA) habits. Participants completed a strength assessment of knee extensors (KEPT), knee flexors (KFPT), plantar flexors (PFPT), and dorsiflexors (DFPT), a 3-day dietary intake log, 7-day accelerometry, and a magnetic resonance imaging (MRI) scan for muscle cross-sectional area analysis of the right quadriceps (CSAq). Results: There were significant age and activity-related group effects for relative protein intake (p<0.001), relative energy intake (p=0.04), KEPT (p=0.01), CSAq (p=0.002), PFPT (p=0.004) and DFPT (p=0.003). Moderate, moderate-to-vigorous, and vigorous PA were positively associated with CSAq (R2=0.69- 0.71; p<0.05), KEPT (R2=0.61-0.63; p<0.05), and PFPT (R2=0.31-0.36; p<0.05). Relative protein intake and daily leucine intake were significantly and positively associated with CSAq (R2=0.70 and 0.67 respectively; p<0.05), KEPT (R2=0.62 and 0.65 respectively; p<0.05), and PFPT (R2=0.29 and 0.28 respectively; p<0.05). Conclusion: Muscle size and strength were lower in middle age relative to younger age, but increased PA, protein intake, and leucine intake was associated with the preservation of muscle size and strength in larger muscle groups of the lower body.

Time-restricted eating and concurrent exercise training reduces fat mass and increases lean mass in overweight and obese adults.

The purpose of this study was to determine whether time-restricted eating (TRE), also known as time-restricted feeding, was an effective dietary strategy for reducing fat mass and preserving fat-free mass while evaluating changes in cardiometabolic biomarkers, hormones, muscle performance, energy intake, and macronutrient intake after aerobic and resistance exercise training in physically inactive and overweight or obese adults. This study was a randomized, controlled trial. Overweight and obese adults (mean ± SD; age: 44 ± 7 years; body mass index [BMI]: 29.6 ± 2.6 kg/m2 ; female: 85.7%) were randomly assigned to a TRE or normal eating (NE) dietary strategy group. The TRE participants consumed all calories between 12:00 p.m. and 8:00 p.m., whereas NE participants maintained their dietary habits. Both groups completed 8 weeks of aerobic exercise and supervised resistance training. Body composition, muscle performance, energy intake, macronutrient intake, physical activity, and physiological variables were assessed. A total of 21 participants completed the study (NE: n = 10; TRE: n = 11). A mild energy restriction was observed for TRE (~300 kcal/day, 14.5%) and NE (~250 kcal/day, 11.4%). Losses of total body mass were significantly greater for TRE (3.3%) relative to NE (0.2%) pre- to post-intervention, of which TRE had significantly greater losses of fat mass (9.0%) compared to NE (3.3%). Lean mass increased during the intervention for both TRE (0.6%) and NE (1.9%), with no group differences. These data support the use of TRE and concurrent exercise training as a short-term dietary strategy for reducing fat mass and increasing lean mass in overweight and obese adults.

Measures Derived from Panoramic Ultrasonography and Animal-Based Protein Intake Are Related to Muscular Performance in Middle-Aged Adults.

Ultrasonography advantageously measures skeletal muscle size and quality, but some muscles may be too large to capture with standardized brightness mode (B-mode) imaging. Panoramic ultrasonography can capture more complete images and may more accurately measure muscle size. We investigated measurements made using panoramic compared to B-mode ultrasonography images of the rectus femoris with muscular performance. Concurrently, protein intake plays an important role in preventing sarcopenia; therefore, we also sought to investigate the association between animal-based protein intake (ABPI) and muscular performance. Ninety-one middle-aged adults were recruited. Muscle cross-sectional area (CSA) and thickness were obtained using B-mode and panoramic ultrasound and analyzed with Image J software. Muscular performance was assessed using isokinetic dynamometry, a 30-s chair test, and handgrip strength. Three-day food diaries estimated dietary intakes. Linear regression models determined relationships between measures from ultrasonography and muscular performance. Mixed linear models were used to evaluate the association between ABPI and muscular performance. Muscle CSA from panoramic ultrasonography and ABPI were positively associated with lower-body strength (ß ± S.E.; CSA, 42.622 ± 20.024, p = 0.005; ABPI, 65.874 ± 19.855, p = 0.001), lower-body endurance (ß ± S.E.; CSA, 595 ± 200.221, p = 0.001; ABPI, 549.944 ± 232.478, p = 0.020), and handgrip strength (ß ± S.E.; CSA, 6.966 ± 3.328, p = 0.004; ABPI, 0.349 ± 0.171, p = 0.045). Panoramic ultrasound shows promise as a method for assessing sarcopenia. ABPI is related to better muscular performance.

The Impact of a Telehealth Intervention on Activity Profiles in Older Adults during the COVID-19 Pandemic: A Pilot Study.

BACKGROUND: Physical inactivity during the COVID-19 pandemic is a public health concern for older adults. Telehealth presents a safe platform for conducting health-related interventions that may have additional benefits such as widespread reach. Our pilot study sought to examine how a telehealth intervention changed activity profiles in older adults during the COVID-19 pandemic. METHODS: There were n =13 adults aged 70.6 ± 4.5 years that participated in a 6 week telehealth intervention during the COVID-19 pandemic. The didactic intervention contents were shared online, and participants worked with trained interviewers over the telephone to discuss physical activity. At baseline and post-intervention, the Multimedia Activity Recall for Children and Adults examined activity profiles, while accelerometry estimated time spent sedentary and in physical activity. RESULTS: Relative to the baseline measures, there was an 88 min/day (95% confidence interval (CI): 39, 137) increase in computer time and 36 min/day (CI: 10, 62) reduction in time spent in active transport at post-intervention. Moderate-to-vigorous physical activity participation also increased by an estimated 2 min/day (CI: -21, 26) and 12 min/week (CI: -154, 180), but this trend was not statistically significant. CONCLUSION: We recommend that support be provided to older adults transitioning to telehealth, especially as migration to telehealth progresses.

Daily Protein Intake and Distribution of Daily Protein Consumed Decreases Odds for Functional Disability in Older Americans.

Objective: We sought to determine whether daily protein intake and protein distribution across eating occasions were associated with functional disability in a national sample of older Americans. Methods: Data from 8,070 adults aged ≥60 years from the 2007-2016 waves of the National Health and Nutrition Examination Survey were included. Protein intake and functional capacity was self-reported. A daily protein recommendation of ≥1.0 g/kg/day was utilized. The daily protein recommendation was then spread-out across four meals, whereby a ≥0.25 g/kg/meal threshold was used. Results: Those meeting the daily protein recommendation had 0.78 (95% confidence interval [CI] = [0.65, 0.93]) decreased odds for functional disability. Persons meeting the protein intake threshold per eating occasion for one, two, three, and four occasions had 0.60 (CI = [0.38, 0.95]), 0.48 (CI = [0.30, 0.77]), 0.47 (CI = [0.29, 0.77]), and 0.39 (CI = [0.20, 0.75]) decreased odds for functional disability, respectively. Discussion: Protein consumption seems to be important for preserving function in older Americans.

Neither a Multi-Ingredient Pre-Workout Supplement nor Caffeine Were Effective at Improving Markers of Blood Flow or Upper-Body Resistance Exercise Performance.

Few studies have measured the effects of multi-ingredient pre-workout supplements on blood flow or heart rate variability or have compared a multi-ingredient pre-workout supplement to a matched single ingredient. This study examined the effects of a multi-ingredient pre-workout supplement, an equivalent amount of caffeine, and placebo on markers of resistance training performance, blood flow, blood pressure, and heart rate variability. The study utilized a randomized, placebo-controlled, repeated-measures, crossover design. Twelve resistance-trained males (22.75 ± 4.51 yrs; 183.4 ± 7.37 cm; 91.05 ± 17.77 kg) completed the study. Resistance exercise performance was defined as total work performed during elbow flexion and extension on an isokinetic dynamometer. Blood flow was calculated using time-averaged mean velocity and blood vessel diameter of the right brachial artery, which were measured via Doppler ultrasound. Heart rate was recorded using an electrocardiogram. Neither a multi-ingredient pre-workout supplement nor caffeine alone improved upper-body resistance exercise performance or markers of blood flow relative to placebo. No differences in heart rate variability were observed across treatments. A multi-ingredient pre-workout supplement was not effective at improving performance or blood flow and did not alter autonomic nervous system function.

Handgrip Strength Asymmetry and Weakness are Differentially Associated with Functional Limitations in Older Americans.

Background: Handgrip strength (HGS) is a convent measure of strength capacity and associated with several age-related health conditions such as functional disability. Asymmetric strength between limbs has been linked to diminished function. Therefore, both HGS asymmetry and weakness could be associated with functional disability. We examined the associations of HGS asymmetry and weakness on functional limitations in a nationally representative sample of older Americans. Methods: Data were analyzed from 2689 adults ≥ 60 years who participated in the 2011-2012 and 2013-2014 waves of the National Health and Nutrition Examination Survey. Weakness was defined as HGS < 26 kg for men and < 16 kg for women. Asymmetry was determined from the ratio of the dominant and non-dominant HGS. Those with HGS ratio 0.9-1.1 were considered as having HGS symmetry, and those outside this range had asymmetry. Results: Compared to those with symmetric HGS and were not weak, those with weakness alone, and both weakness and HGS asymmetry had 2.47 (95% confidence interval [CI]: 1.14-5.35) and 3.93 (CI: 1.18-13.07) greater odds for functional limitations, respectively. However, HGS asymmetry alone was not associated with functional limitations (odds ratio: 0.80; CI: 0.62-1.03). Conclusion: The use of HGS asymmetry in protocols could improve the prognostic value of handgrip dynamometers.

Endothelial, Cardiovascular, and Performance Responses to L-Arginine Intake and Resistance Exercise.

The purpose of this study was to examine the acute endothelial, cardiovascular, and performance responses to L-arginine intake by assessing flow-mediated dilation (FMD) and various indicators (e.g., heart rate, heart rate variability (HRV), blood pressure, torque) both before and after resistance exercise. Thirty (15 male, 15 female) physically active participants (mean ± SD: age 20.4 ± 1.8 years, height 176.9 ± 10.2 cm, body mass 76.0 ± 12.2 kg) volunteered for a randomized, cross-over, double-blind, placebo-controlled clinical trial. Participants completed five sets of elbow extension-flexion exercise after consumption of either 3 g L-arginine or 3 g of placebo. There was a significant decline in post-exercise elbow extension (p = 0.014) and flexion peak torque (p < 0.001). FMD response after exercise was ~5.8% less than before resistance exercise (L-arginine and placebo data pooled, p < 0.001). Baseline brachial artery diameter significantly increased post-FMD (p < 0.001), post-resistance exercise (p < 0.001), and post-resistance exercise FMD (p < 0.001). There were significant time effects for HRV when expressed as the square root of the mean of the sum of squares of differences between adjacent RR intervals (RMSSD) or the proportion of differences between adjacent normal (NN) RR intervals that exceed 50 ms (pNN50) (all p-values < 0.05), but there were no treatment or interaction effects (all p-values > 0.05). We conclude the increased vasodilation due to acute resistance exercise was not enhanced by acute supplementation with L-arginine nor was exercise performance augmented. Further, the relative contribution of sympathetic nervous system input increased with resistance exercise but was not influenced by the addition of L-arginine.

Barriers and Strategies for Healthy Food Choices among American Indian Tribal College Students: A Qualitative Analysis.

BACKGROUND: American Indian and Alaskan Native individuals experience disproportionate levels of chronic health conditions such as type 2 diabetes and overweight and obesity that are influenced by dietary patterns and food choices. Understanding factors that influence healthy food choices among tribal college students can enrich education and programs that target dietary intake. OBJECTIVE: To build an understanding of factors that influence healthy food choices among tribal college students at increased risk for college attrition. DESIGN: A nonexperimental cohort design was used for qualitative descriptive analysis. PARTICIPANTS/SETTING: Participants (N=20) were purposively sampled, newly enrolled, academically underprepared tribal college students enrolled in a culturally relevant life skills course at an upper Midwest tribal college between September 2013 and May 2015. Participant demographic characteristics included various tribal affiliations, ages, and number of dependents. MAIN OUTCOME MEASURES: Participant responses to qualitative research questions about dietary intake, food choices, self-efficacy for healthy food choices, psychosocial determinants, and barriers to healthy food choices during telephone interviews were used as measures. ANALYSIS: Qualitative analysis included prestudy identification of researcher bias/assumptions, audiorecording and transcription, initial analysis (coding), secondary analysis (sorting and identifying meaning), and verification (comparative pattern analysis). RESULTS: Qualitative analysis revealed a variety of themes and subthemes about healthy food choices. Main themes related to barriers included taste, food gathering and preparation, and difficulty clarifying healthy food choices. Main themes related to strategies included taste, cultural traditions and practices, and personal motivation factors. CONCLUSIONS: Qualitative analysis identified barrier and strategy themes that may assist nutrition and dietetics practitioners working with tribal/indigenous communities, tribal college educators and health specialists, and tribal community health workers who target health and dietary intake of American Indian and Alaskan Native students.