Michael M. Morris

Standing-based office work shows encouraging signs of attenuating post-prandial glycaemic excursion

Objectives The main aim of this study was to compare two days of continuous monitored capillary blood glucose (CGM) responses to sitting and standing in normally desk-based workers. Design, setting and participants This open repeated-measures study took place in a real office environment, during normal working hours and subsequent CGM overnight measures in 10 participants aged 21–61 years (8 female). Main outcomes Postprandial (lunch) measures of: CGM, accelerometer movement counts (MC) heart rate, energy expenditure (EE) and overnight CGM following one afternoon of normal sitting work compared with one afternoon of the same work performed at a standing desk. Results Area-under-the-curve analysis revealed an attenuated blood glucose excursion by 43% (p=0.022) following 185 min of standing (143, 95% CI 5.09 to 281.46 mmol/L min) compared to sitting work (326; 95% CI 228 to 425 mmol/L min). Compared to sitting, EE during an afternoon of standing work was 174 kcals greater (0.83 kcals/min; p=0.028). The accelerometer MC showed no differences between the afternoons of seated versus standing work; reported differences were thus a function of the standing work and not from additional physical movements around the office. Conclusions This is the first known ‘office-based’ study to provide CGM measures that add some of the needed mechanistic information to the existing evidence-base on why avoiding sedentary behaviour at work could lead to a reduced risk of cardiometabolic diseases.

Physiologic responses and energy expenditure of kinect active video game play in schoolchildren.

OBJECTIVE To evaluate the physiologic responses and energy expenditure of active video gaming using Kinect for the Xbox 360. DESIGN Comparison study. SETTING Kirkby Sports College Centre for Learning, Liverpool, England. PARTICIPANTS Eighteen schoolchildren (10 boys and 8 girls) aged 11 to 15 years. MAIN EXPOSURE A comparison of a traditional sedentary video game and 2 Kinect activity-promoting video games, Dance Central and Kinect Sports Boxing, each played for 15 minutes. Physiologic responses and energy expenditure were measured using a metabolic analyzer. MAIN OUTCOME MEASURES Heart rate, oxygen uptake, and energy expenditure. RESULTS Heart rate, oxygen uptake, and energy expenditure were considerably higher (P < .05) during activity-promoting video game play compared with rest and sedentary video game play. The mean (SD) corresponding oxygen uptake values for the sedentary, dance, and boxing video games were 6.1 (1.3), 12.8 (3.3), and 17.7 (5.1) mL · min-1 · kg-1, respectively. Energy expenditures were 1.5 (0.3), 3.0 (1.0), and 4.4 (1.6) kcal · min-1, respectively. CONCLUSIONS Dance Central and Kinect Sports Boxing increased energy expenditure by 150% and 263%, respectively, above resting values and were 103% and 194% higher than traditional video gaming. This equates to an increased energy expenditure of up to 172 kcal · h-1 compared with traditional sedentary video game play. Played regularly, active gaming using Kinect for the Xbox 360 could prove to be an effective means for increasing physical activity and energy expenditure in children.

PREDICTING MAXIMAL OXYGEN UPTAKE VIA A PERCEPTUALLY REGULATED EXERCISE TEST (PRET)

Recent research has yielded encouraging, yet inconsistent findings concerning the validity and reliability of predicting maximal oxygen uptake ( O 2max ) from a graded perceptually regulated exercise test (PRET). Accordingly, the purpose of the present study was to revisit the validity and reliability of this application of ratings of perceived exertion (RPE) using a modified PRET protocol. Twenty-three volunteers (mean age, 31 ± 9.9 years) completed four counter-balanced PRETs (involving two 2-minute and two 3-minute bouts administered over 9 days, each separated by 48 hours) on an electromagnetically braked cycle ergometer and one maximal graded exercise test. Participants self-regulated their exercise at RPE levels 9, 11, 13, 15 and 17 in a randomized order. Oxygen uptake ( O 2 ) was recorded continuously during each bout. The O 2 values for the RPE ranges 9–17, 9–15 and 9–13 were extrapolated to RPE 20 using regression analysis to predict individual O 2max scores. The concordance of the predicted and actual O 2max scores and the trial-to-trial reliability of the predicted scores were analyzed using the limits of agreement (LoA) technique. The LoA between actual (41.5 ± 8.0 mL·kg −1 ·min −1 ) and predicted O 2max scores for the RPE range 9–17 were −2.6 ± 10.1 and −1.3 ± 7.4 mL·kg −1 ·min −1 (2-minute bout) and −1.0 ± 9.2 and 0.2 ± 7.2 mL·kg −1 ·min −1 (3-minute bout) for trials 1 and 2, respectively. Reliability analysis yielded LoA of −1.3 ± 9.2 mL·kg −1 ·min −1 (2-minute bout) and −0.8 ± 5.7 mL·kg −1 ·min −1 (3-minute bout). The modified PRET provided acceptable and repeatable estimates of O 2max , suggesting its application in environments where maximal tests are inappropriate, and is worthy of further investigation.

System Accuracy Evaluation of the GlucoRx Nexus Voice TD-4280 Blood Glucose Monitoring System

Use of blood glucose (BG) meters in the self-monitoring of blood glucose (SMBG) significantly lowers the risk of diabetic complications. With several BG meters now commercially available, the International Organization for Standardization (ISO) ensures that each BG meter conforms to a set degree of accuracy. Although adherence to ISO guidelines is a prerequisite for commercialization in Europe, several BG meters claim to meet the ISO guidelines yet fail to do so on internal validation. We conducted a study to determine whether the accuracy of the GlucoRx Nexus TD-4280 meter, utilized by our department for its cost-effectiveness, complied with ISO guidelines. 105 patients requiring laboratory blood glucose analysis were randomly selected and reference measurements were determined by the UniCel DxC 800 clinical system. Overall the BG meter failed to adhere to the ≥95% accuracy criterion required by both the 15197:2003 (overall accuracy 92.4%) and 15197:2013 protocol (overall accuracy 86.7%). Inaccurate meters have an inherent risk of over- and/or underestimating the true BG concentration, thereby risking patients to incorrect therapeutic interventions. Our study demonstrates the importance of internally validating the accuracy of BG meters to ensure that its accuracy is accepted by standardized guidelines.