Search

Background: Sitting time questionnaires have largely been validated in small convenience samples. The validity of this multi-context sitting questionnaire against an accurate measure of sitting time is reported in a large demographically diverse sample allowing assessment of validity in varied demographic subgroups. Methods: A subgroup of participants of the third wave of the Australian Diabetes, Obesity, and Lifestyle (AusDiab3) study wore activPAL3™ monitors (7 days, 24 hours/day protocol) and reported their sitting time for work, travel, television viewing, leisure computer use and "other" purposes, on weekdays and weekend days (n = 700, age 36-89 years, 45 % men). Correlations (Pearson's r; Spearman's p) of the self-report measures (the composite total, contextual measures and items) with monitor-assessed sitting time were assessed in the whole sample and separately in socio-demographic subgroups. Agreement was assessed using Bland-Altman plots. Results: The composite total had a correlation with monitor-assessed sitting time of r = 0.46 (95 % confidence interval [CI]: 0.40, 0.52); this correlation did not vary significantly between demographic subgroups (all >0.4). The contextual measure most strongly correlated with monitor-assessed sitting time was work (p = 0.25, 95 % CI: 0.17, 0.31), followed by television viewing (p = 0.16, 95 % CI: 0.09, 0.24). Agreement of the composite total with monitored sitting time was poor, with a positive bias (B = 0.53, SE 0.04, p < 0.001) and wide limits of agreement (±4.32 h). Conclusions: This multi-context questionnaire provides a total sitting time measure that ranks participants well for the purposes of assessing health associations but has limited accuracy relative to activPAL-assessed sitting time. Findings did not differ in demographic subgroups. [ABSTRACT FROM AUTHOR]

Background: Few well-controlled studies have comprehensively examined the effects of very-low-carbohydrate diets on type 2 diabetes (T2D). Objective: We compared the effects of a very-low-carbohydrate, high-unsaturated fat, low-saturated fat (LC) diet with a highcarbohydrate, low-fat (HC) diet on glycemic control and cardiovascular disease risk factors in T2D after 52 wk. Design: In this randomized controlled trial that was conducted in an outpatient research clinic, 115 obese adults with T2D [mean 6 SD age: 58 6 7 y; body mass index (in kg/m2): 34.6 6 4.3; glycated hemoglobin (HbA1c): 7.3 6 1.1%; duration of diabetes: 8 6 6 y] were randomly assigned to consume either a hypocaloric LC diet [14% of energy as carbohydrate (carbohydrate ,50 g/d), 28% of energy as protein, and 58% of energy as fat (,10% saturated fat)] or an energymatched HC diet [53% of energy as carbohydrate, 17% of energy as protein, and 30% of energy as fat (,10% saturated fat)] combined with supervised aerobic and resistance exercise (60 min; 3 d/wk). Outcomes were glycemic control assessed with use of measurements of HbA1c, fasting blood glucose, glycemic variability assessed with use of 48-h continuous glucose monitoring, diabetes medication, weight, blood pressure, and lipids assessed at baseline, 24, and 52 wk. Results: Both groups achieved similar completion rates (LC diet: 71%; HC diet: 65%) and mean (95% CI) reductions in weight [LC diet: 29.8 kg (211.7, 27.9 kg); HC diet: 210.1 kg (212.0, 28.2 kg)], blood pressure [LC diet: 27.1 (210.6, 23.7)/26.2 (28.2, 24.1) mm Hg; HC diet:25.8 (29.4,22.2)/26.4 (28.4,24.3) mm Hg], HbA1c [LC diet: 21.0% (21.2%, 20.7%); HC diet: 21.0% (21.3%, 20.8%)], fasting glucose [LC diet: 20.7 mmol/L (21.3, 20.1 mmol/L); HC diet: 21.5 mmol/L (22.1, 20.8 mmol/L)], and LDL cholesterol [LC diet: 20.1 mmol/L (20.3, 0.1 mmol/L); HC diet: 20.2 mmol/L (20.4, 0.03 mmol/L)] (P-diet effect $ 0.10). Compared with the HC-diet group, the LC-diet group achieved greater mean (95% CI) reductions in the diabetes medication score [LC diet: 20.5 arbitrary units (20.7, 20.4 arbitrary units); HC diet: 20.2 arbitrary units (20.4, 20.06 arbitrary units); P = 0.02], glycemic variability assessed by measuring the continuous overall net glycemic action-1 [LC diet: 20.5 mmol/L (20.6, 20.3 mmol/L); HC diet: 20.05 mmol/L (20.2, 20.1 mmol/L); P = 0.003], and triglycerides [LC diet: 20.4 mmol/L (20.5, 20.2 mmol/L); HC diet: 20.01 mmol/L (20.2, 0.2 mmol/L); P = 0.001] and greater mean (95% CI) increases in HDL cholesterol [LC diet: 0.1 mmol/L (0.1, 0.2 mmol/L); HC diet: 0.06 mmol/L (20.01, 0.1 mmol/L); P = 0.002]. Conclusions: Both diets achieved substantial weight loss and reduced HbA1c and fasting glucose. The LC diet, which was high in unsaturated fat and low in saturated fat, achieved greater improvements in the lipid profile, blood glucose stability, and reductions in diabetes medication requirements, suggesting an effective strategy for the optimization of T2D management. This trial was registered at www.anzctr.org.au as ACTRN12612000369820. [ABSTRACT FROM AUTHOR]