Andrea MacIntosh

This study determined the interindividual variation in the cardiometabolic response to 6 months of moderate or vigorous intensity exercise training (ET) among youth at risk for type 2 diabetes mellitus. Youth were randomized to moderate intensity ET (45–55% heart rate reserve; n = 31), vigorous intensity ET (70–85% heart rate reserve; n = 37), or control (n = 36). Only those attending ≥70% of ET sessions were included. Cardiometabolic measures included insulin sensitivity, hepatic triglyceride content, visceral adipose area, and cardiorespiratory fitness. The contribution of ET to interindividual variation was determined using the standard deviation of individual responses (SD_IR) and considered meaningful if the SD_IR surpassed the smallest worthwhile difference (SWD), calculated as 0.2 × the standard deviation of the control group baseline values. ET meaningfully contributed to the interindividual variation among changes in peak oxygen uptake following moderate (SD_IR: 2.04) and vigorous (SD_IR: 3.43) ET (SWD: 1.17 mL·kg fat free mass⁻¹·min⁻¹), body fat percentage and hepatic triglyceride content following moderate-intensity ET (SD_IR: 1.64, SWD: 1.05%; SD_IR: 10.08, SWD: 1.06%, respectively), and visceral fat mass following vigorous ET (SD_IR: 11.06, SWD: 7.13 cm²). Variation in the changes in insulin sensitivity were not influenced by ET. The contribution of ET to interindividual variation appears to be influenced by the desired outcome and prescribed intensity. Trial registration at ClinicalTrials.gov (identifier no.: NCT00755547). Novelty: The contribution of exercise to interindividual variation following training depends on the outcome and exercise intensity. Increasing exercise intensity does not systematically reduce non-response among youth at risk for type 2 diabetes.

Objectives: Examine the characteristics of patient engagement (PE) practices in exercise-based randomized trials in type 1 diabetes (T1D), and facilitate T1D stakeholders in determining the top ten list of priorities for exercise research. Design: Two methodological approaches were employed: a scoping review and a modified James Lind Alliance priority-setting partnership. Methods: Published (Medline, Embase, CINAHL, and Central databases) and grey literature ( www.clinicaltrials.gov ) were searched to identify randomized controlled trials of exercise interventions lasting minimum four weeks and available in English. We extracted information on PE and patient-reported outcomes (PROMs) to identify if patient perspectives had been implemented. Based on results, we set out to determine exercise research priorities as a first step towards a patient-engaged research agenda. An online survey was distributed across Canada to collect research questions from patients, caregivers and healthcare providers. We qualitatively analyzed submitted questions and compiled a long-list that a twelve-person stakeholder steering committee used to identify the top ten priority research questions. Results: Of 9,962 identified sources, 19 published trials and 4 trial registrations fulfilled inclusion criteria. No evidence of PE existed in any included study. Most commonly measured PROMs were frequency of hypoglycemia (n=7) and quality of life (n=4). The priority-setting survey yielded 194 submitted research questions. Steering committee rankings identified 10 priorities focused on lifestyle factors and exercise modifications to maintain short-term glycemic control. Conclusion: Recent exercise-based randomized trials in T1D have not included PE and PROMs. Patient priorities for exercise research have yet to be addressed with adequately designed clinical trials.

To develop a screening algorithm to detect hepatic steatosis in overweight and obese adolescents. We performed a cross sectional study of 129 overweight adolescents 13–18 yrs. The primary outcome, hepatic steatosis was defined as an intracellular triglyceride content > 5.5 mg/g and quantified using 1H-magenetic resonance spectroscopy. Primary predictor variables included, alanine and aspartate transaminases (ALT/AST) and features of the metabolic syndrome. Hepatic steatosis was present in 33 % of overweight and obese adolescents. Adolescents with hepatic steatosis were more likely to be boys (adjusted OR: 4.8; 95 % CI: 2.5–10.5), display a higher waist circumference (111 ± 12 vs 100 ± 13 cm, p < 0.001) and have metabolic syndrome (adjusted OR: 5.1; 95 % CI: 1.6–16.4). Serum ALT predicted hepatic steatosis in boys (AUC: 0.82; 95 % CI: 0.70–0.95; p < 0.001) but not girls (AUC = 0.63; 95 % CI: 0.46–0.75, p = 0.16). An ALT >20 U/L, combined with the presence of metabolic syndrome, male gender and an elevated waist circumference provided the best model (AUC 0.85) with high sensitivity (72 %) and specificity (82 %) and positive and negative predictive values of 61 % and 89 % respectively. Serum transaminases provide modest predictive value for hepatic steatosis in youth. The ALT threshold for predicting hepatic steatosis is significantly lower than current clinical thresholds for predicting non-alcoholic fatty liver disease. The addition of ALT, presence of the metabolic syndrome and male gender significant improve the ability to predict hepatic steatosis.