Cadence (steps/min) and intensity during ambulation in 6-20 year olds: The CADENCE-kids study

Background: Steps/day is widely utilized to estimate the total volume of ambulatory activity, but it does not directly reflect intensity, a central tenet of public health guidelines. Cadence (steps/min) represents an overlooked opportunity to describe the intensity of ambulatory activity. We sought to establish thresholds linking directly observed cadence with objectively measured intensity in 6-20 year olds.Methods: One hundred twenty participants completed multiple 5-min bouts on a treadmill, from 13.4 m/min (0.80 km/h) to 134.0 m/min (8.04 km/h). The protocol was terminated when participants naturally transitioned to running, or if they chose to not continue. Steps were visually counted and intensity was objectively measured using a portable metabolic system. Youth metabolic equivalents (METy) were calculated for 6-17 year olds, with moderate intensity defined as >/=4 and /=6 METy. Traditional METs were calculated for 18-20 year olds, with moderate intensity defined as >/=3 and /=6 METs. Optimal cadence thresholds for moderate and vigorous intensity were identified using segmented random coefficients models and receiver operating characteristic (ROC) curves.Result: Participants were on average (+/- SD) aged 13.1 +/- 4.3 years, weighed 55.8 +/- 22.3 kg, and had a BMI z-score of 0.58 +/- 1.21. Moderate intensity thresholds (from regression and ROC analyses) ranged from 128.4 steps/min among 6-8 year olds to 87.3 steps/min among 18-20 year olds. Comparable values for vigorous intensity ranged from 157.7 steps/min among 6-8 year olds to 119.3 steps/min among 18-20 year olds. Considering both regression and ROC approaches, heuristic cadence thresholds (i.e., evidence-based, practical, rounded) ranged from 125 to 90 steps/min for moderate intensity, and 155 to 125 steps/min for vigorous intensity, with higher cadences for younger age groups. Sensitivities and specificities for these heuristic thresholds ranged from 77.8 to 99.0%, indicating fair to excellent classification accuracy.Conclusions: These heuristic cadence thresholds may be used to prescribe physical activity intensity in public health recommendations. In the research and clinical context, these heuristic cadence thresholds have apparent value for accelerometer-based analytical approaches to determine the intensity of ambulatory activity.Peer reviewedCommunity Health Sciences, Counseling and Counseling Psycholog

Rheumatoid arthritis: pathological mechanisms and modern pharmacologic therapies.

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease that primarily affects the lining of the synovial joints and is associated with progressive disability, premature death, and socioeconomic burdens. A better understanding of how the pathological mechanisms drive the deterioration of RA progress in individuals is urgently required in order to develop therapies that will effectively treat patients at each stage of the disease progress. Here we dissect the etiology and pathology at specific stages: (i) triggering, (ii) maturation, (iii) targeting, and (iv) fulminant stage, concomitant with hyperplastic synovium, cartilage damage, bone erosion, and systemic consequences. Modern pharmacologic therapies (including conventional, biological, and novel potential small molecule disease-modifying anti-rheumatic drugs) remain the mainstay of RA treatment and there has been significant progress toward achieving disease remission without joint deformity. Despite this, a significant proportion of RA patients do not effectively respond to the current therapies and thus new drugs are urgently required. This review discusses recent advances of our  understanding of RA pathogenesis, disease modifying drugs, and provides perspectives on next generation therapeutics for RA

SEDENTARY TIME IN THE UNITED STATES CALCULATED BY THE SEDENTARY SPHERE METHOD: NHANES 2011-2014

Jaemyung Kim, John M. Schuna Jr. Oregon State University, Corvallis, OR The 2011-2012 and 2013-2014 cycles of the National Health and Nutrition Examination Survey (NHANES) implemented a wrist-worn accelerometer protocol to objectively assess physical activity among Americans. Unfortunately, there remains few validated approaches for translating wrist-worn accelerometer data into meaningful estimates of physical behavior which has limited opportunities to describe Americans’ physical activity and sedentary behavior using 2011-2014 NHANES accelerometer data. One previously validated method for assessing sedentary time (ST) via wrist-worn accelerometry is known as the Sedentary Sphere (SS) method. The SS method has yet to be used to describe ST in US adults. PURPOSE: To describe ST in US adults (age ≥ 18 y) using the SS method. METHODS: US adults (N = 9,298) who completed a wrist-worn accelerometer protocol during the 2011-2014 NHANES were included in analyses. ST was quantified using the SS method whereby participant posture is estimated from derived arm elevation and movement intensity. Wear-time adjusted means and standard errors of average daily ST were calculated and compared using survey regression procedures across groupings of sex (male vs. female), age (18-29y, 30-44y, 45-59y, 60+y), and quartiles of total physical activity (\u3c 10,425.7, 10,425.7 – 12,874.6, 12,874.7 – 15,563.5, \u3e 15,563.5 MIMS/day). Survey procedures were used for all analyses to account for the complex, multi-stage design of NHANES. RESULTS: Mean daily ST among American adults was 489 ± 1.5 min/day. ST was higher among males than females (510 ± 1.6 vs. 470 ± 1.8 min/day, p \u3c 0.001). ST was positively associated with age. Those Americans 60+y had the highest ST while those 18-29y had the lowest values (511 ± 2.3 vs. 459 ± 2.1 min/day, p \u3c 0.001). ST was inversely associated with total physical activity. ST in the most active grouping (\u3e 15,563.5 MIMS/day: 422 ± 2.3 min/day) was dramatically lower than ST in the least active grouping (\u3c 10,425.7 MIMS/day: 556 ± 3.3 min/day, p \u3c 0.001). CONCLUSION: ST calculated by the SS method significantly varied across groupings of sex, age, and total physical activity among American adults. Future research should focus on examining associations between ST calculated by the SS method and health outcomes of interest

LEVELS OF WRIST-MEASURED PHYSICAL ACTIVITY CORRESPONDING TO SELF-REPORTED COMPLIANCE WITH PHYSICAL ACTIVITY GUIDELINES: NHANES 2011-2014

H. Rosas, J. M. Schuna Jr. Oregon State University, Corvallis, OR The 2018 Physical Activity Guidelines for Americans (PAGA), specifically the aerobic component, advises adults to accumulate ≥ 150 min/week of moderate-to-vigorous physical activity (MVPA). The necessary amount of daily wrist-measured accelerometer-determined physical activity volume, expressed in monitor independent movement summary units (MIMS units/day), that best delineates compliance vs. non-compliance with the 2018 PAGA remains unknown. PURPOSE: To identify an optimal wrist-measured accelerometer-determined threshold of MIMS units/day that delineates self-reported compliance vs. non-compliance with the 2018 PAGA (≥ 150 vs. \u3c 150 min/week of MVPA). METHODS: We conducted a secondary data analysis among 9,306 adults (ages: 18-85+; sex: 52.4% female) who provided self-reported physical activity data and ≥ 1 valid day of wrist-measured accelerometer data collected during the 2011-2014 National Health and Nutrition Examination Survey. A receiver operating characteristic curve was fit to identify optimal thresholds of mean MIMS units/day for delineating self-reported compliance vs. non-compliance to the 2018 PAGA. RESULTS: Mean MIMS units/day was a significant predictor of self-reported compliance with the 2018 PAGA (p \u3c 0.001); however, the ability to discriminate between compliance and non-compliance was poor as evidenced by an overall area under the curve of 0.616 (95% CI: 0.603 – 0.629). The optimal threshold of wrist-measured accelerometer-determined physical activity for delineating compliance vs. non-compliance with the 2018 PAGA was 12,171.8 MIMS units/day (95% CI: 12,099.2 – 12,752.1 MIMS units/day) corresponding to a sensitivity of 63.8% (95% CI: 58.9 - 65.2%) and a specificity of 54.2% (95% CI: 52.7 - 59.1%). CONCLUSION: The optimal threshold of wrist-measured accelerometer-determined MIMS units/day identified herein should be interpreted with caution, despite its potential to have some value in describing the objectively-monitored behavior of individuals reporting compliance or non-compliance to the 2018 PAGA. Future research is needed to aid the development of physical activity guidelines derived from wrist-measured accelerometer-determined estimates of physical activity

New therapies for rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic, systemic inflammatory disease, which continues to cause significant morbidity in affected persons. In the past few years, a number of new exciting therapeutic options have become available. These reflect the application of knowledge obtained from advancements in understanding of disease pathogenesis and underlying molecular mechanisms. A number of these therapies are outlined in the following review, including the various biological modifiers, in particular, anti-tumour necrosis factor-α agents and interleukin-1 (IL-1) receptor antagonists, which have been developed in recognition of the role of pro-inflammatory cytokines in RA. Also notable, is the current interest centring on the development and trials with B cell depletion therapies, specifically rituximab, in patients with RA. This demonstrates acknowledgment for a more significant role for B cells in the aetiology of RA, in contrast to the long held view that RA was a predominantly T cell mediated disease. To evaluate this therapeutic option for RA, salient features from recent rituximab trials have been collated. Finally, a selection of other therapeutic alternatives, including anti-IL-6 receptor monoclonal antibody and tacrolimus, and newer anti-rheumatic therapies presently in development are summarized