Rate In Healthy Adults Research Articles

Rate of decline in kidney function with age: a systematic review

ObjectiveTo determine the distribution of kidney function values as measured by glomerular filtration rate (GFR), and the rate of decline with age in male and female healthy subjects without pre-existing...

Dissecting the dynamics of SARS-CoV-2 reinfections in blood donors with pauci- or asymptomatic COVID-19 disease course at initial infection

Background Understanding the dynamics of SARS-CoV-2 reinfections is crucial for public health policy, vaccine development, and long-term disease management. However, data on reinfections in the general population remains scarce. Objectives This study aimed to investigate SARS-CoV-2 antibody dynamics among Austrian blood donors, representing healthy adults, over two years following primary infection and to evaluate the reinfection risk. Methods 117,895 blood donations were analysed for SARS-CoV-2 total anti-N levels from June 2020 to December 2023. We examined anti-N and anti-S antibody dynamics and in vitro functionality in 230 study participants at five defined times during 24 months, assessing associations with demographics, vaccination status, and reinfection awareness. Results The seroprevalence of SARS-CoV-2 infection-derived anti-N antibodies increased over time, reaching 90% by February 2023 and remaining at that level since then. According to serological screenings, we found an 88% reinfection rate, which is in contrast to participants’ reports indicating a reinfection rate of 59%. Our data further reveal that about 26% of reinfections went completely unnoticed. Antibody dynamics were independent of age, sex, and ABO blood group. Interestingly, individuals with multiple reinfections reported symptoms more frequently during their primary infection. Our results further show that vaccination modestly affected reinfection risk and disease course. Conclusion SARS-CoV-2 reinfections were uncommon until the end of 2021 but became common with the advent of Omicron. This study highlights the underestimation of reinfection rates in healthy adults and underscores the need for continued surveillance, which is an important support for public health policies and intervention strategies.

The effects of omega-3 polyunsaturated fatty acids on muscle and whole-body protein synthesis: a systematic review and meta-analysis.

Sarcopenia describes the age-related decline in skeletal muscle mass and strength that is driven, at least in part, by an imbalance between rates of muscle protein synthesis (MPS) and muscle protein breakdown. An expanding body of literature has examined the effect of omega-3 polyunsaturated fatty acid (n-3 PUFA) ingestion on MPS rates in older adults, with mixed findings. The aim of this systematic review and meta-analysis was to investigate the effectiveness of n-3 PUFA ingestion in stimulating rates of MPS and whole-body protein synthesis in healthy adults and clinical populations. Searches were conducted of the PubMed, Web of Science, Cochrane Library, and Scopus databases from inception until December 2022 for articles on randomized controlled trials comparing the effect of n-3 PUFA ingestion vs a control or placebo on rates of MPS and whole-body protein synthesis. The search yielded 302 studies, of which 8 were eligible for inclusion. The random effects inverse-variance model was used and standardized mean differences (SMDs) with 95%CIs were calculated to assess the pooled effect. Risk of bias was assessed by the Cochrane Risk-of-Bias 2 tool. The main analysis indicated no effect of n-3 PUFA supplementation on MPS rates (k = 6; SMD: 0.03; 95%CI, -0.35 to 0.40; I2 = 30%; P = .89). Subgroup analysis based on age, n-3 PUFA dose, duration of supplementation, and method used to measure fractional synthetic rate also revealed no effect of n-3 PUFA ingestion on MPS. In contrast, the main analysis demonstrated an effect of n-3 PUFA ingestion on increasing whole-body protein synthesis rates (k = 3; SMD: 0.51; 95%CI, 0.12-0.90; I2 = 0%; P = .01). n-3 PUFA ingestion augments the stimulation of whole-body protein synthesis rates in healthy adults and clinical populations. PROSPERO registration no. 42022366986.

Postabsorptive and postprandial myofibrillar protein synthesis rates at rest and after resistance exercise in women with postmenopause.

Feeding and resistance exercise stimulate myofibrillar protein synthesis (MPS) rates in healthy adults. This anabolic characterization of "healthy adults" has been namely focused on males. Therefore, the purpose of this study was to examine the temporal responses of MPS and anabolic signaling to resistance exercise alone or combined with the ingestion of protein in postmenopausal females and compare postabsorptive rates with young females. Sixteen females [60 ± 7 yr; body mass index (BMI) = 26 ± 12 kg·m-2] completed an acute bout of unilateral resistance exercise before consuming either: a fortified whey protein supplement (WHEY) or water. Participants received primed continuous infusions of L-[ring-13C6]phenylalanine with bilateral muscle biopsies before and after treatment ingestion at 2 h and 4 h in nonexercised and exercised legs. Resistance exercise transiently increased MPS above baseline at 0-2 h in the water condition (P = 0.007). Feeding after resistance exercise resulted in a late phase (2-4 h) increase in MPS in the WHEY condition (P = 0.005). In both conditions, resistance exercise did not enhance the cumulative (0-4 h) MPS response. In the nonexercised leg, MPS did not differ at 0-2 h, 2-4 h, or 0-4 h of the measurement periods (all, P > 0.05). Likewise, there were no changes in the phosphorylation of p70S6K, AMPKα, or total and phosphorylated yes-associated protein on Ser127. Finally, postabsorptive MPS was lower in premenopausal versus postmenopausal females (P = 0.023). Our results demonstrate that resistance exercise-induced changes in MPS are temporally regulated, but do not result in greater cumulative (0-4 h) MPS in postmenopausal women.NEW & NOTEWORTHY An adequate quality and quantity of skeletal muscle is relevant to support physical performance and metabolic health. Muscle protein synthesis (MPS) is an established remodeling marker, which can be hypertrophic or nonhypertrophic. Importantly, protein ingestion and resistance exercise are two strategies that support healthy muscle by stimulating MPS. Our study shows postmenopause modulates baseline MPS that may diminish the MPS response to the fundamental anabolic stimuli of protein ingestion and resistance exercise in older females.

Seroconversion following Heplisav-B, hepatitis B vaccine (recombinant), adjuvanted, in patients with end-stage renal disease at an urban safety net hospital.

Heplisav-B is a novel recombinant adjuvanted vaccine for hepatitis B virus (HBV) that has been approved as a 2-dose regimen and shown to have similar seroconversion rates in healthy adults as single-antigen HBV vaccines. More data are needed to determine whether similarly high rates of seroconversion and immunity are observed in immunocompromised patient populations such as in patients with end-stage renal disease (ESRD) on hemodialysis. Patients with ESRD who presented for emergency-only hemodialysis and either were HBV vaccine naive or had a hepatitis B surface antibody (anti-HBs) titer of less than 10 IU/mL received 3 standard 20-μg doses of Heplisav-B at week 0, week 4 (±2 weeks), and week 24 (±2 weeks), with anti-HBs titer measured at week 28 (±2 weeks). Thirty-two patients received at least one dose in the study timeframe, with 24 patients completing the vaccine series and measurement of anti-HBs titer. The mean age of the patients was 46 years, and 58% of patients were male. Of the 24 patients who completed the vaccine series, 20 (83%) seroconverted after the third dose. Three of the 4 patients who did not seroconvert after 3 doses were revaccinated with an additional 20-μg dose, and 2 of the 3 patients had an anti-HBs titer of greater than 10 IU/mL 4 weeks after this dose. Patients with ESRD who received three 20-μg doses of recombinant HBV vaccine had a seroconversion rate of 83%, representing a similar seroconversion rate and fewer doses of vaccine as compared to the standard HBV vaccine regimen for patients with ESRD.

Repeatability, Reproducibility, and Concurrent Validity of a Stethoscope and Health App System for the Quantification of Breath Rate in Healthy Adults: Repeatability and Validity Study.

Apps for smartphones that can measure the breathing rate easily can be downloaded. The aim of this study was to demonstrate agreement in measuring breath rates between the stethoscope and Breath Counter health app. We performed a repeatability study with 56 healthy volunteers. The patient's demographic data and breathing rates per minute were collected. Breathing rates were measured via two methods: (1) using a stethoscope placed in the upper area of the right lung and (2) a Breath Counter app developed by Vadion on a Samsung Fold smartphone. This study demonstrated high repeatability and validity with respect to the breathing rate parameter of healthy adults using the aforementioned 2 systems. Intrasession repeatability measure using the intraclass correlation coefficient was >0.962, indicating excellent repeatability. Moreover, the intraclass correlation coefficient between methods was 0.793, indicating good repeatability, and coefficients of variation of method errors values were 1.83% with very low values in terms of other repeatability parameters. We found significant correlation coefficients and no systematic differences between the app and stethoscope methods. The app method may be attractive to individuals who require repeatability in a recreational setting.

Wearable in-ear pulse oximetry validly measures oxygen saturation between 70% and 100%: A prospective agreement study.

Postoperative monitoring outside intensive and post-anaesthesia care units is seldom, partly due to lack of suitable and approved systems. We therefore aim to validate the oxygen saturation (SpO2) and pulse rate measurement of the in-ear sensor c-med° alpha with a reference pulse oximeter. This prospective agreement study was conducted in 12 healthy (ASA 1) adult (18-50 years) volunteers according to the EN ISO 80601-2-61. The sitting volunteers were equipped with the finger pulse oximeter Rad-5 and two c-med° alpha sensors in each ear. The inspiratory oxygen content was reduced via a tight-fitting breathing mask to achieve five defined plateaus with stable SpO2 between 99% and 70%. The deviation of the SpO2 and pulse rate measurements of the c-med° alpha from those of the Rad-5 was calculated using the mean square error (Arms). Bias and limits of agreement between both devices were calculated using the Bland-Altman technique. The precision was compared based on the repeatability coefficients. The c-med° alpha measured SpO2 had an Arms = 1.9% relative to the Rad-5, a non-significant bias (-0.1% (-0.2% to 0.0%)), levels of agreement from -4.0% to 3.8%, and the same repeatability coefficient (0.8% vs. 0.8%). The c-med° alpha measured pulse rate did not deviate from the one measured with the certified finger pulse oximeter (bias: 0.1 min-1 (0 to 0.1 min-1), level of agreement: -3.6 to 3.7 min-1, Arms: 1.8 min-1). The c-med° alpha fulfils the EN ISO 80601-2-61 standard and is sufficiently accurate for measuring SpO2 and pulse rate in healthy adults at rest. EUDAMED No. CIV-21-03-036033.

Pharmacokinetics and Pharmacodynamics of Nipocalimab Administered at Different Rates of Intravenous Infusion in Healthy Participants: Results of a Phase 1 Placebo-Controlled Single-Dose Study

Background: Warm autoimmune hemolytic anemia (wAIHA) is a rare autoimmune condition driven by autoantibodies that can significantly impact a patient's quality of life. wAIHA is characterized by the premature destruction of red blood cells (RBCs) in the presence of autoantibodies which preferentially bind to RBCs at 37°C. There is currently no approved treatment for wAIHA. Patients with severely symptomatic anemia are typically managed with corticosteroids and rituximab, both of which are associated with potential relapse and adverse events. Nipocalimab, which is in clinical development for the treatment of wAIHA (NCT04119050), is a fully human, aglycosylated, effectorless IgG1 monoclonal antibody that targets the IgG binding site on the neonatal Fc receptor (FcRn) with high affinity to lower circulating IgG levels. This study assessed the pharmacokinetics (PK) and pharmacodynamics (PD) of single doses of nipocalimab administered at different IV infusion rates in healthy adults to support the potential use of shortened infusions in future studies. Nipocalimab was generally safe and well-tolerated at all doses and infusion rates; detailed safety results have been presented separately [Leu JH, et al. EHA 2022. Presentation P1534]. Methods: The trial was a single dose, sequential, randomized, double-blind, placebo-controlled, escalating dose and infusion rate study. Eligible participants were males or females aged 18-55 years with no clinically significant medical or physical conditions. Participants were randomized to 1 of 5 cohorts (n=8 per cohort [6 nipocalimab, 2 placebo]) to receive nipocalimab 30 mg/kg IV infused over 60, 30, 15 or 7.5 min (0.5, 1, 2, or 4 mg/kg/min), nipocalimab 60 mg/kg IV infused over 15 min (4 mg/kg/min) or matching placebo. Escalation to the next dose level was permitted following review by a safety monitoring committee. Pharmacokinetic sampling of nipocalimab was conducted predose, midpoint of infusion (MOI), end of infusion (EOI), EOI + 0.083h, EOI + 0.25h, EOI + 1h, start of infusion + 24h, Day 8, and Day 15 postdose; MOI and EOI varied for each dose. In terms of PD, total serum IgG was assessed. Results: A total of 40 participants (70% female, 93% white) received study drug, of which 30 were included in the PK analysis; 39 completed the study. Mean serum nipocalimab concentration-time profiles were similar following all 30 mg/kg doses regardless of infusion rate; mean serum concentrations were ~2 times higher following a 60 mg/kg infusion. Nipocalimab remained detectable up to ~169 hours postdose for 30 mg/kg groups and ~337 hours postdose for the 60 mg/kg group. Geometric mean peak (Cmax) and overall exposure (AUC) to nipocalimab were unaffected by infusion rate when administered at 30 mg/kg. Following a 60 mg/kg infusion, AUCs were 2.4-2.8 times higher and Cmax was 2.0-2.2 times higher than with 30 mg/kg infusions. Median Tmax was approximately at EOI following the 60 mg/kg infusion. Mean half-life (t½) values were similar in all treatment groups. In terms of total serum IgG, changes from baseline were decreased among all nipocalimab cohorts at all postdose time points. The maximum decrease in mean serum IgG levels was 79% at day 15 with nipocalimab 60 mg/kg. Conclusion: Nipocalimab Cmax and AUC were not affected by infusion rates when given at a dose of 30 mg/kg, but Tmax was delayed at the fastest infusion rates. Following the 60 mg/kg infusion, peak and overall nipocalimab exposures were 2-2.8 times higher than following 30 mg/kg infusions.

A PHASE 1 PLACEBO-CONTROLLED SINGLE-DOSE STUDY OF NIPOCALIMAB ADMINISTERED AT DIFFERENT RATES OF INTRAVENOUS INFUSION IN HEALTHY ADULTS

Warm autoimmune hemolytic anemia (wAIHA) is a rare, life-threatening disorder characterized by the destruction of red blood cells by pathogenic IgG autoantibodies. There is currently no approved treatment for wAIHA. Nipocalimab is a fully human, aglycosylated, effectorless IgG1 monoclonal antibody that blocks the IgG binding site on the neonatal Fc receptor (FcRn) with high affinity, which is in clinical development for the treatment of wAIHA. In a prior phase 1 study in healthy adults receiving single and multiple ascending doses infused intravenously (IV) over 2 hours, nipocalimab was well-tolerated with an adverse event profile comparable to placebo. However, shorter durations of nipocalimab infusion may be more convenient for patients. Here we assess the safety and tolerability of single doses of nipocalimab administered at different IV infusion rates in healthy adults to support the potential use of shortened infusions in future studies. The trial was a single dose, sequential, randomized, double-blind, placebo-controlled, escalating dose and infusion rate study. Eligible participants were males or females aged 18-55 years with no clinically significant medical or physical conditions. Participants were randomized to 1 of 5 cohorts (n = 8 per cohort [6 nipocalimab, 2 placebo]) to receive nipocalimab 30 mg/kg IV infused over 60, 30, 15 or 7.5 min (0.5, 1, 2, or 4 mg/kg/min), nipocalimab 60 mg/kg IV infused over 15 min (4 mg/kg/min) or matching placebo. Escalation to the next dose level was permitted following review by a safety monitoring committee. Safety was assessed by the frequency and nature of treatment-emergent adverse events (TEAEs). A total of 40 participants (70% female, 93% white) received study drug and were included in the safety analysis; 39 completed the study. A total of 12 participants (40%) experienced TEAEs across all nipocalimab dosing cohorts and 1 (10%) participant experienced TEAEs following administration of placebo. The most frequently reported TEAE was headache, reported by 6 participants with nipocalimab and 1 participant with placebo. Nausea was reported by 3 participants receiving nipocalimab. Grade 2 injection site reactions were reported by 2 participants but were considered unrelated to the investigational agent. None of the TEAEs were severe, and no participants discontinued treatment due to TEAEs; there were no serious adverse events or deaths. Only 4 participants experienced AEs that occurred within 24 hours after the infusion that were considered related to the study drug. Lower rates of nipocalimab infusion were associated with fewer TEAEs, while participants receiving 4 mg/kg/min (as either 30 mg/kg infused over 7.5 min or 60 mg/kg infused over 15 min) reported more TEAEs. Single doses of nipocalimab, when administered at doses up to 60 mg/kg and infusion rates up to 4 mg/kg/min were safe and well-tolerated in healthy adults. The frequency of reported TEAEs was lower in participants receiving IV nipocalimab at rates of 1 or 2 mg/kg/min, providing a target infusion rate for current and future studies. JHL, AV, LEL are employees of Janssen Research & Development, LLC, and AMBP is an employee of Janssen Latin America, which are a wholly owned subsidiaries of Johnson & Johnson, and may own stock or stock options in Johnson & Johnson.

Performance evaluation of the BC-720 auto hematology analyzer and establishment of the reference intervals of erythrocyte sedimentation rate in healthy adults.

BackgroundErythrocyte sedimentation rate (ESR) is a new reporting parameter of the BC-720 auto hematology analyzer; however, no biological reference interval for healthy adults has been established for this parameter.MethodsOutpatients or hospitalized patients with ESR test orders were selected. The ESR was measured by the standard method of ESR (Westergren) recommended by the International Council for Standardization in Hematology (ICSH), the BC-720 hematology analyzer, and the LBY-XC40B auto ESR analyzer. The data were statistically analyzed and compared among different methods. The repeatability and carryover rate (CR) of the BC-720 were assessed in randomly selected samples for each range segment. Blood Samples from three hospitals in China were collected, and the reference interval of the BC-720 ESR was determined.ResultsThe ESR results measured by the BC-720 correlated well with the Westergren method (r=0.957, y = 0.359 + 1.016x), and there was no significant difference between these two methods (P>0.05). The correlation between LBY-XC40B auto ESR analyzer and Westergren was y = 1 + 1.25x and r=0.856. The BC-720 ESR has good repeatability [standard deviation (SD) ≤1 mm/h, coefficient of variation (CV) ≤5%], and the CR was less than 1%. The 95th percentile of the biological reference interval for BC-720 ESR is 15 mm/h for men and 24 mm/h for women.ConclusionsThe Mindray BC-720 ESR showed high accuracy and good repeatability, which provided a faster, safer, and more reliable method to measure ESR. The reference intervals for BC-720 ESR could guide better clinical decisions for the laboratories utilizing this new method.

Gustatory Function and Salivary Flow Rate in Healthy Adults.

In this study, we assessed gustatory function and whole-mouth saliva in healthy adults and investigated the association between gustatory function, salivary flow rate (SFR), and dry mouth. Descriptive clinical study. We recruited 413 participants who reported a normal sense of smell-taste, comprising 206 females and 207 males with an age range of 19 to 80 years. Taste scores were obtained using whole-mouth tests to evaluate the gustatory function, SFR was assessed using the spitting method, and dry mouth was measured with the visual analog scale. The total taste score (TTS) and SFR were significantly negatively correlated with age (rtaste =-0.522, P < .001; rSFR =-0.200, P < .001): TTS was significantly lower after the age of 50 and SFR decreased significantly after age 65. Women exhibited a significantly higher TTS than men (P < .001). However, there was no effect of sex on SFR. Dry mouth was negatively correlated with TTS (r=-0.223, P < .01) and SFR (r=-0.218, P < .01). Multiple regression analysis showed the independent variables of age, sex, and dry mouth predicted 34% of the variation in taste, while the independent variables of age and dry mouth predicted 6.1% of the variation in whole-mouth saliva. TTS was not significantly correlated with the SFR in healthy adults (r=0.094, P=.056). Age and dry mouth are important factors affecting gustatory function and whole-mouth saliva, with women exhibiting better taste sensitivity than men. Furthermore, there is no direct correlation between SFR and gustatory function in healthy adults. 3 Laryngoscope, 132:844-848, 2022.

Heatwave, heart rate and blood pressure in adults from Santiago, Chile

BACKGROUND AND AIM: Studies have described associations between ambient temperature and blood pressure and heart rate in the population with comorbidities. However, the evidence is scant regarding the effect of heatwaves in healthy adults. We aim to explore the effect of a heatwave on blood pressure and heart rate in healthy adults. METHODS: Longitudinal study with 35 adults from Santiago, Chile. We measured heart rate (HR), systolic blood pressure (SBP), and diastolic blood pressure (DBP) in two moments; a day after a heatwave in February and another day without heatwave in March 2021. The indoor temperature was collected the day before the measurements and an average of 12 hours was calculated. Sociodemographic data, home characteristics, and health-related quality of life were obtained from a questionnaire. The bivariate analysis was used to compare both measurements. Multilevel regression models were performed to explore the association between heatwave and heart rate and blood pressure. RESULTS:The mean (SD) of SBP, DBP, and HR were 121.97 (12.68) mmHg, 77.86 (10.02) mmHg and 75.43 (12.02) mmHg one day after the heatwave and 120.29 (11.88) mmHg, 75.91 (10.02) mmHg and 75.14 (10.25) mmHg after a non-heatwave day, respectively. No statistically significant differences were found between the measurements for SBP (p-value 0.093), DBP (p-value 0.058) and HR (p-value 0.521). The median indoor temperature before the first measurement was 25.8°C (p75, p95 26.8, 27.9°C) and 22.0°C (p75, p95 22.5, 23.6°C) for the second measurement. The mean indoor temperature was positively associated with SBP (β 0.13 IC95% -2.95, 3.19), DBP (β 0.65 IC95% -2.23, 3.54) and HR (β 2.17 IC95% -0.87, 5.21) adjusted for indoor humidity, sex, age and income. CONCLUSIONS:The data supports the hypothesis that heatwaves may play a role in heart rate and blood pressure in healthy adults. However, this exploratory study did not provide statistically significant evidence. KEYWORDS: blood pressure, indoor temperature, heart rate, heatwave.

Diurnal Variability of Peak Expiratory Flow Rate in Healthy Adult Employees of a Medical College of Kathmandu

Introduction Peak expiratory flow measurement is a simple measure of respiratory capacity to diagnose airflow obstruction and monitor treatment response in patients with pulmonary diseases. But there is wide diurnal variability in its values. The objectives of this study was to determine the diurnal variability of peak expiratory flow rate in healthy adults.&#x0D; MethodsThis cross-sectional study was done in employees of Kathmandu Medical College, Duwakot between March to August 2020. A total of 74 subjects of 30-45 years were included in the study. After adequate training, subjects were asked to record their own peak expiratory flow five times a day by Mini-Wright peak flow meter. Diurnal variability was expressed as amplitude percent mean and standard deviation percent mean. Data analysis was done by student’s unpaired t-test and one-way ANOVA.&#x0D; ResultsThe mean peak expiratory flow rate (in L/min) were lowest in morning (male: 478.75±45.91; female: 362.86±20.51) followed by progressive rise throughout the day and highest at evening (male: 531.88 ±43.95; female: 415.71±20.97) with slight fall at bedtime (male: 486.88±46.38; female: 362.86±20.51). The difference in peak expiratory flow rate at different time periods was statistically significant in both males and females (p&lt;0.001). The diurnal variability as calculated by amplitude percent mean and standard deviation percent mean were found to be significantly higher in females (p=0.001 and 0.004 respectively).&#x0D; ConclusionThere is a variation of peak expiratory flow rate recorded during different time points of the day in healthy adults.

Diurnal Variability of Peak Expiratory Flow Rate in Healthy Adult Employees of a Medical College of Kathmandu

Introduction: Peak expiratory flow measurement is a simple measure of respiratory capacity to diagnose airflow obstruction and monitor treatment response in patients with pulmonary diseases. But there is wide diurnal variability in its values. The objectives of this study was to determine the diurnal variability of peak expiratory flow rate in healthy adults. Methods: This cross-sectional study was done in employees of Kathmandu Medical College, Duwakot between March to August 2020. A total of 74 subjects of 30-45 years were included in the study. After adequate training, subjects were asked to record their own peak expiratory flow five times a day by Mini-Wright peak flow meter. Diurnal variability was expressed as amplitude percent mean and standard deviation percent mean. Data analysis was done by student’s unpaired t-test and one-way ANOVA. Results: The mean peak expiratory flow rate (in L/min) were lowest in morning (male: 478.75±45.91; female: 362.86±20.51) followed by progressive rise throughout the day and highest at evening (male: 531.88 ±43.95; female: 415.71±20.97) with slight fall at bedtime (male: 486.88±46.38; female: 362.86±20.51). The difference in peak expiratory flow rate at different time periods was statistically significant in both males and females (p&lt;0.001). The diurnal variability as calculated by amplitude percent mean and standard deviation percent mean were found to be significantly higher in females (p=0.001 and 0.004 respectively). Conclusion: There is a variation of peak expiratory flow rate recorded during different time points of the day in healthy adults.

Bag Carrying Method during Level Walking Affects Perceived Exertion Ratings without Altering Energy Cost, Oxygen Consumption, and Heart Rate in Healthy Adults: A Randomized Crossover Trial

Bag Carrying Method during Level Walking Affects Perceived Exertion Ratings without Altering Energy Cost, Oxygen Consumption, and Heart Rate in Healthy Adults: A Randomized Crossover Trial

Life stress and background anxiety are not associated with resting metabolic rate in healthy adults.

This study examined associations between anxiety, stress, and resting metabolic rate (RMR). Thirty women and 23 men had RMR measured at two visits. Participants also had body composition assessed and completed several questionnaires: State-Trait Inventory for Cognitive and Somatic Anxiety (STICSA), Anxiety Sensitivity Index (ASI)-3, and Perceived Stress Scale (PSS)-14. The state version of the STICSA was completed at both visits, while the other questionnaires were completed at visit one. RMR was expressed in kilocalories per day and relative to lean mass (RMRrelative). Participants were divided into low-, medium-, and high-anxiety groups based on STICSA trait scores, and RMR was compared among groups using one-way ANOVA. Changes between visits were evaluated using paired t tests and Wilcoxon signed-rank tests. RMR did not change from visit one to visit two (1589 to 1586 kcal/day, p = 0.86) even though STICSA state scores slightly declined (Z-statistic = -2.39, p = 0.017). RMRrelative values were 30.3 ± 3.7, 29.0 ± 1.9, and 29.9 ± 3.6 kcal/kg of lean mass among low, medium, and high trait anxiety groups, respectively (F = 0.70, p = 0.50). No RMR variable significantly correlated with PSS-14, ASI-3, or STICSA scores. This study provides evidence that trait anxiety and life stress do not impact RMR. Whether an association between these factors exists in anxiety disorders remains to be evaluated. Novelty Contrary to previous research, this study found no associations between anxiety and RMR. It is doubtful whether practitioners need to account for healthy subjects' trait anxiety and stress when analyzing RMR data.

Reference Values of Glomerular Filtration Rate in Healthy Adults in Southern China: A Cross-Sectional Survey

Reference Values of Glomerular Filtration Rate in Healthy Adults in Southern China: A Cross-Sectional Survey

2205. Clinical Burden of Pneumococcal Disease in US Adults Aged 65 Years and Above with Chronic or Immunocompromising Conditions

BackgroundThe presence of chronic and immunocompromising conditions is associated with a disproportionately high risk of developing pneumococcal disease at older ages. The objective of this study was to quantify the risk of all-cause pneumonia (ACP) and invasive pneumococcal disease (IPD) in older US adults aged 65 years and older with underlying medical conditions.MethodsA retrospective observational study was conducted using the Humana claims database. The study cohorts were identified at January 1 of each calendar year of observation from 2012 to 2017 and comprised adults aged 65 years and older with continuous enrollment for at least one year before and at least one year after January 1 of each year. For each yearly cohort, medical conditions were identified during the one year before each calendar year and episodes of ACP and IPD were identified during the corresponding 1-year follow-up period from January 1 to December 31. Individuals were stratified into 3 groups: those without any medical conditions of interests (healthy), those with chronic conditions (at-risk) and those with immunocompromising conditions (high-risk). Rate of ACP or IPD was expressed as the number of cases per 100,000 person-years and the rate ratio (RR) was expressed as the rate of pneumococcal disease of patients with medical conditions divided by the rate of pneumococcal disease in healthy adults.ResultsOf the 10,766,827 adults included in the study, 75% of adults had an underlying medical condition linked to an increased risk of pneumococcal disease. In adults with at-risk conditions, rates of ACP and IPD were 3.1 and 3.6 times the rate in healthy adults, respectively. In adults with high-risk conditions, rates of ACP and IPD were 4.1 and 5 times the rate in healthy adults, respectively. Rate of pneumococcal disease increased substantially with the addition of medical conditions: RR for ACP and IPD increased from 2.1 and 2.2, respectively, in adults with one at-risk conditions to 4.8 and 6.2, respectively, among adults with 2 or more at-risk conditions.ConclusionDespite recommendations of universal pneumococcal vaccination in older adults aged 65 years and above in the United States, the burden of pneumococcal disease remains high, particularly among those with chronic and immunocompromising conditions.Disclosures All authors: No reported disclosures.

Influence of Circumference Measurements and Body Composition on Estimating Resting Metabolic Rate in Healthy Adults

Measurement of resting metabolic rate (RMR) is an important factor for weight management. Previous research has reported several variables to estimate RMR such as body size, percent fat (%BF), age, and sex; however, little is known regarding the effect of circumference measures in estimating RMR. PURPOSE: The purpose of this study was to develop a model to estimate RMR using waist circumference (WC), an easily obtainable measure, and cross-validate it to previously published models. METHODS: Subjects were 140 adult men and women, ages 18-65 years. RMR was measured through indirect calorimetry, %BF was measured through air displacement plethysmography, and fat mass and fat-free mass were determined from %BF and weight. Other variables collected were: weight, height, age, sex, ethnicity, body mass index, WC, hip circumference, waist-to-hip ratio, waist-to-height ratio, and %BF estimated from bioelectrical impedance analysis. Subjects were randomly divided into derivation and cross-validation samples. A multiple regression model was developed to determine the most accurate estimation of RMR in the derivation sample. The cross-validation sample was used to confirm the accuracy of the model and to compare the accuracy to published models. RESULTS: The best predictors for estimating RMR were body weight, r = 0.70, p= 0.031, age, r = -0.30, p= 0.012, and sex, r = 0.51, p= 0.018. Other factors failed to account for significant variation in the model. The derived equation for estimating RMR is: RMR (kcal/day) = 843.11 + 8.77(weight) - 4.23(age) + 228.54(sex, M = 1, F = 0), R2= 0.68, SEE = 173 kcal/day. Cross-validation statistics were: R2= 0.54, p ≤0.05, SEE = 199 kcal/day, and total error = 198 kcal/day. In published models, R2ranged from 0.47 to 0.57, SEE ranged from 192 to 213 kcal/day, and total error ranged from 212 to 1311 kcal/day. CONCLUSIONS: Cross-validation to published models for estimating RMR were similar to those of the derived model; however, the total error in the derived equation was lower than any of the previously published models. Several published models considerably overestimate RMR compared to the current model. The results of this study suggest that RMR can be reasonably estimated with easily obtainable measures which allow for estimation and implementation of RMR for weight management in clinical practice.

Clinical and economic burden of pneumococcal disease in US adults aged 19\u201364\xa0years with chronic or immunocompromising diseases: an observational database study

BackgroundDespite the widespread availability of pneumococcal vaccines, rates of pneumococcal disease are disproportionately high in adults with chronic and immunocompromising conditions. This study investigated pneumococcal disease rates and associated resource utilization and costs in this group.MethodsA retrospective, observational study was conducted using the Truven Health MarketScan® Commercial Claims and Encounters database. The study population was adults aged 19–64 years with continuous health plan enrollment for at least one year before and at least one day after January 1st 2012, 2013 and/or 2014. Medical conditions were identified using ICD-9-CM diagnosis codes and grouped into at-risk (chronic) and high-risk (immunocompromising) conditions. Pneumococcal disease was stratified into all-cause pneumonia (ACP) and invasive pneumococcal disease (IPD).ResultsThirty-six million adults aged 19–64 years were included in the study. 17% had a condition that put them at increased risk for pneumococcal disease. Rates of ACP and IPD in adults with at-risk conditions were 3.6 and 4.6 times the rate in healthy adults, respectively, and 5.3 and 10.5 for adults with high-risk conditions. Risk was particularly high in adults with ≥2 medical conditions: rates of ACP and IPD were 8.1 and 10.6 times higher in adults with at-risk conditions than healthy adults and 6.3 and 13.4 times higher in adults with high-risk conditions, respectively. Resource use and costs were substantially higher per episode of ACP in at-risk and high-risk adults, with costs reaching $6,534 and $9,168, compared to $4,725 for healthy adults.ConclusionsPneumococcal disease rates in at-risk and high-risk adults are significantly higher than healthy adults leading to substantial economic burden.