Diurnal patterns of objectively measured sedentary time and interruptions to sedentary time are associated with glycaemic indices in type 2 diabetes.

OBJECTIVES: To investigate diurnal patterns of sedentary time and interruptions to sedentary time and their associations with achievement of pre-meal glucose, post-meal glucose, bedtime glucose and the dawn phenomenon targets and with duration of hypoglycaemia, euglycaemia, hyperglycaemia and above target range. DESIGN: Intensive longitudinal study. METHODS: In 37 adults with type 2 diabetes, the FreeStyle Libre and activPAL3 were used to monitor glucose and sedentary time and interruptions to sedentary time in the morning (07:00-12:00), afternoon (12:00-17:00) and evening (17:00-23:00) for 14 days. Diurnal patterns of sedentary behaviour and associations with glycaemic indices were assessed using repeated measures ANOVA and linear regressions. RESULTS: Sedentary time was significantly higher in the evening (43.47±7.37min/h) than the morning (33.34±8.44min/h) and afternoon (37.26±8.28min/h). Interruptions to sedentary time were significantly lower in the evening (2.64±0.74n/h) than the morning (3.69±1.08n/h) and afternoon (3.06±0.87n/h). Sedentary time in the morning and afternoon was associated with lower achievement of the dawn phenomenon target. Sedentary time in the evening was associated with lower achievement of post-lunch glucose target. Interruptions to sedentary time in the morning and afternoon were associated with higher achievement of pre-dinner glucose target. Interruptions to sedentary time in the evening showed beneficial associations with achievement of post-dinner glucose and bedtime glucose targets and euglycaemia. CONCLUSIONS: Prolonged sedentary behaviour is high in the evening. Interruptions to sedentary time, particularly in the evening, have beneficial associations with glycaemic indices. Interventions targeting interruptions to sedentary time in the evening may be more clinically relevant.

Impact of free-living pattern of sedentary behaviour on intra-day glucose regulation in type 2 diabetes.

PURPOSE: To investigate how the pattern of sedentary behaviour affects intra-day glucose regulation in type 2 diabetes. METHODS: This intensive longitudinal study was conducted in 37 participants with type 2 diabetes (age, 62.8 ± 10.5 years). Glucose and sedentary behaviour/physical activity were assessed with a continuous glucose monitoring (Abbott FreeStyle Libre) and an activity monitor (activPAL3) for 14 days. Multiple regression models with generalised estimating equations (GEEs) approach were used to assess the associations of sedentary time and breaks in sedentary time with pre-breakfast glucose, pre-lunch glucose, pre-dinner glucose, post-breakfast glucose, post-lunch glucose, post-dinner glucose, bedtime glucose, the dawn phenomenon, time in target glucose range (TIR, glucose 3.9-10 mmol/L) and time above target glucose range (TAR, glucose > 10 mmol/L). RESULTS: Sedentary time was associated with higher pre-breakfast glucose (p = 0.001), pre-dinner glucose (p < 0.001), post-lunch glucose (p = 0.005), post-dinner glucose (p = 0.013) and the dawn phenomenon (p < 0.001). Breaks in sedentary time were associated with lower pre-breakfast glucose (p = 0.023), pre-dinner glucose (p = 0.023), post-breakfast glucose (p < 0.001) and the dawn phenomenon (p = 0.004). The association between sedentary time and less TIR (p = 0.022) and the association between breaks in sedentary time and more TIR (p = 0.001) were also observed. CONCLUSIONS: Reducing sedentary time and promoting breaks in sedentary time could be clinically relevant to improve intra-day glucose regulation in type 2 diabetes.

Dose-response between frequency of breaks in sedentary time and glucose control in type 2 diabetes: A proof of concept study.

OBJECTIVES: This study aimed to investigate dose-response between frequency of breaks in sedentary time and glucose control. DESIGN: Randomised three-treatment, two-period balanced incomplete block trial. METHODS: Twelve adults with type 2 diabetes (age, 60±11years; body mass index, 30.2±4.7kg/m2) participated in two of the following treatment conditions: sitting for 7h interrupted by 3min light-intensity walking breaks every (1) 60min (Condition 1), (2) 30min (Condition 2), and (3) 15min (Condition 3). Postprandial glucose incremental area under the curves (iAUCs) and 21-h glucose total area under the curve (AUC) were measured using continuous glucose monitoring. Standardised meals were provided. RESULTS: Compared with Condition 1 (6.7±0.8mmolL-1×3.5h-1), post-breakfast glucose iAUC was reduced for Condition 3 (3.5±0.9 mmolL-1×3.5h-1, p˂0.04). Post-lunch glucose iAUC was lower in Condition 3 (1.3±0.9mmolL-1×3.5h-1, p˂0.03) and Condition 2 (2.1±0.7mmolL-1×3.5h-1, p˂0.05) relative to Condition 1 (4.6±0.8mmolL-1×3.5h-1). Condition 3 (1.0±0.7mmolL-1×3.5h-1, p=0.02) and Condition 2 (1.6±0.6mmolL-1×3.5h-1, p˂0.04) attenuated post-dinner glucose iAUC compared with Condition 1 (4.0±0.7mmolL-1×3.5h-1). Cumulative 10.5-h postprandial glucose iAUC was lower in Condition 3 than Condition 1 (p=0.02). Condition 3 reduced 21-h glucose AUC compared with Condition 1 (p<0.001) and Condition 2 (p=0.002). However, post-breakfast glucose iAUC, cumulative 10.5-h postprandial glucose iAUC and 21-h glucose AUC were not different between Condition 2 and Condition 1 (p˃0.05). CONCLUSIONS: There could be dose-response between frequency of breaks in sedentary time and glucose. Interrupting sedentary time every 15min could produce better glucose control.

Are glucose profiles well-controlled within the targets recommended by the International diabetes Federation in type 2 diabetes? A meta-analysis of results from continuous glucose monitoring based studies.

AIMS: To assess continuous glucose monitoring (CGM) derived intra-day glucose profiles using global guideline for type 2 diabetes recommended by the International Diabetes Federation (IDF). METHODS: The Cochrane Library, MEDLINE, PubMed, CINAHL and Science Direct were searched to identify observational studies reporting intra-day glucose profiles using CGM in people with type 2 diabetes on any anti-diabetes agents. Overall and subgroup analyses were conducted to summarise mean differences between reported glucose profiles (fasting glucose, pre-meal glucose, postprandial glucose and post-meal glucose spike/excursion) and the IDF targets. RESULTS: Twelve observational studies totalling 731 people were included. Pooled fasting glucose (0.81 mmol/L, 95% CI, 0.53-1.09 mmol/L), postprandial glucose after breakfast (1.63 mmol/L, 95% CI, 0.79-2.48 mmol/L) and post-breakfast glucose spike (1.05 mmol/L, 95% CI, 0.13-1.96 mmol/L) were significantly higher than the IDF targets. Pre-lunch glucose, pre-dinner glucose and postprandial glucose after lunch and dinner were above the IDF targets but not significantly. Subgroup analysis showed significantly higher fasting glucose and postprandial glucose after breakfast in all groups: HbA1c <7% and ≥7% (53 mmol/mol) and duration of diabetes <10 years and ≥10 years. CONCLUSIONS: Independent of HbA1c, fasting glucose and postprandial glucose after breakfast are not well-controlled in type 2 diabetes.

The associations of sedentary time and breaks in sedentary time with 24-hour glycaemic control in type 2 diabetes.

The aim of this study was to investigate the associations of accelerometer-assessed sedentary time and breaks in sedentary time with 24-h events and duration of hypoglycaemia (<3.9 mmol/l), euglycaemia (3.9-7.8 mmol/l), hyperglycaemia (>7.8 mmol/l) and above target glucose (>9 mmol/l). Thirty-seven participants with type 2 diabetes (age, 62.8 ±â€¯10.5 years; body mass index, 29.6 ±â€¯6.8 kg/m2) in Glasgow, United Kingdom were enrolled between February 2016 and February 2017. Participants wore an activity monitor (activPAL3) recording the time and pattern of sedentary behaviour and a continuous glucose monitoring (CGM, Abbott FreeStyle Libre) for up to 14 days. Linear regression analyses were used to investigate the associations. Participants spent 3.7%, 64.7%, 32.1% and 19.2% of recording h/day in hypoglycaemia, euglycaemia, hyperglycaemia and above target, respectively. There was a negative association between sedentary time and time in euglycaemia (ß = -0.44, 95% CI -0.86; -0.03, p = 0.04). There was a trend towards a positive association between sedentary time and time in hyperglycaemia (ß = 0.36, 95% CI -0.05; 0.78, p = 0.08). Breaks in sedentary time was associated with higher time in euglycaemia (ß = 0.38, 95% CI 0.00; 0.75, p = 0.04). To conclude, in individuals with type 2 diabetes, more time spent in unbroken and continuous sedentary behaviour was associated with poorer glucose control. Conversely, interrupting sedentary time with frequent breaks appears to improve glycaemic control. Therefore, this should be considered as a simple adjunct therapy to improve clinical outcomes in type 2 diabetes.

Promoting and maintaining physical activity in people with type 2 diabetes.

BACKGROUND: Limited research has investigated how to promote physical activity in people with type 2 diabetes. This study evaluated physical activity counseling over 12 months in people with type 2 diabetes. DESIGN: Participants were given standard exercise information and randomly assigned to receive physical activity counseling or not. Data were collected from September 2000 through to September 2002 and analyzed from October 2002 to February 2003. SETTING/PARTICIPANTS: Diabetes outpatient clinic. Seventy inactive people with type 2 diabetes. INTERVENTION: Physical activity counseling, based on the transtheoretical model, combined motivational theory and cognitive behavioral strategies into an individualized intervention to promote physical activity. Consultations were delivered at baseline and 6 months, with phone calls at 1 and 3 months post-consultation. MAIN OUTCOME MEASURES: Changes from baseline at 12 months in physical activity (7-day recall and accelerometer), stages and processes of exercise behavior change. RESULTS: Between-group differences were recorded in physical activity (recall and accelerometer) at 12 months (p <0.01). Experimental participants significantly increased total activity (median difference, 115 minutes; 95% confidence interval [CI]=73-150 minutes). Control participants recorded no significant change (median difference, -15 minutes; 95% CI=-53-13 minutes). The accelerometer experimental participants recorded no significant change (mean difference, 416,632 counts; 95% CI=-27,743, 1,051,007 counts/week), while control participants recorded a significant decrease (mean difference, -669,061 counts; 95% CI=-1,292,285, -45,837 counts/week). At 12 months, more experimental participants compared to controls were in active stages of behavior(6-month chi(2)=26.4, p <0.01; 12-month chi(2)=19.9, p <0.01, respectively). Between-group differences were recorded at 12 months for the frequency of using all processes (p <0.01), except dramatic relief and stimulus control. CONCLUSIONS: Physical activity counseling was effective for promoting physical activity over 12 months in people with type 2 diabetes.