Joseph Henson

Breaking Up Prolonged Sitting With Standing or Walking Attenuates the Postprandial Metabolic Response in Postmenopausal Women: A Randomized Acute Study

OBJECTIVE To determine whether breaking up prolonged sitting with short bouts of standing or walking improves postprandial markers of cardiometabolic health in women at high risk of type 2 diabetes. RESEARCH DESIGN AND METHODS Twenty-two overweight/obese, dysglycemic, postmenopausal women (mean ± SD age 66.6 ± 4.7 years) each participated in two of the following treatments: prolonged, unbroken sitting (7.5 h) or prolonged sitting broken up with either standing or walking at a self-perceived light intensity (for 5 min every 30 min). Both allocation and treatment order were randomized. The incremental area under the curves (iAUCs) for glucose, insulin, nonesterified fatty acids (NEFA), and triglycerides were calculated for each treatment condition (mean ± SEM). The following day, all participants underwent the 7.5-h sitting protocol. RESULTS Compared with a prolonged bout of sitting (iAUC 5.3 ± 0.8 mmol/L ⋅ h), both standing (3.5 ± 0.8 mmol/L ⋅ h) and walking (3.8 ± 0.7 mmol/L ⋅ h) significantly reduced the glucose iAUC (both P < 0.05). When compared with prolonged sitting (548.2 ± 71.8 mU/L ⋅ h), insulin was also reduced for both activity conditions (standing, 437.2 ± 73.5 mU/L ⋅ h; walking, 347.9 ± 78.7 mU/L ⋅ h; both P < 0.05). Both standing (−1.0 ± 0.2 mmol/L ⋅ h) and walking (−0.8 ± 0.2 mmol/L ⋅ h) attenuated the suppression of NEFA compared with prolonged sitting (−1.5 ± 0.2 mmol/L ⋅ h) (both P < 0.05). There was no significant effect on triglyceride iAUC. The effects on glucose (standing and walking) and insulin (walking only) persisted into the following day. CONCLUSIONS Breaking up prolonged sitting with 5-min bouts of standing or walking at a self-perceived light intensity reduced postprandial glucose, insulin, and NEFA responses in women at high risk of type 2 diabetes. This simple, behavioral approach could inform future public health interventions aimed at improving the metabolic profile of postmenopausal, dysglycemic women.

Sedentary Time and Markers of Chronic Low-Grade Inflammation in a High Risk Population

Background Sedentary behaviour has been identified as a distinct risk factor for several health outcomes. Nevertheless, little research has been conducted into the underlying mechanisms driving these observations. This study aimed to investigate the association of objectively measured sedentary time and breaks in sedentary time with markers of chronic low-grade inflammation and adiposity in a population at a high risk of type 2 diabetes mellitus. Methods This study reports data from an ongoing diabetes prevention programme conducted in Leicestershire, UK. High risk individuals were recruited from 10 primary care practices. Sedentary time (<25counts per 15s) was measured using Actigraph GT3X accelerometers (15s epochs). A break was considered as any interruption in sedentary time (≥25counts per 15s). Biochemical outcomes included interleukin-6 (IL-6), C-reactive protein (CRP), leptin, adiponectin and leptin:adiponectin ratio (LAR). A sensitivity analysis investigated whether results were affected by removing participants with a CRP level >10 mg/L, as this can be indicative of acute inflammation. Results 558 participants (age = 63.6±7.7years; male = 64.7%) had complete adipokine and accelerometer data. Following adjustment for various confounders, sedentary time was detrimentally associated with CRP (β = 0.176±0.057, p = 0.002), IL-6 (β = 0.242±0.056, p = <0.001), leptin (β = 0.146±0.043, p = <0.001) and LAR (β = 0.208±0.052, p = <0.001). Associations were attenuated after further adjustment for moderate-to-vigorous physical activity (MVPA) with only IL-6 (β = 0.231±0.073, p = 0.002) remaining significant; this result was unaffected after further adjustment for body mass index and glycosylated haemoglobin (HbA1c). Similarly, breaks in sedentary time were significantly inversely associated with IL-6 (β = −0.094±0.047, p = 0.045) and leptin (β = −0.075±0.037, p = 0.039); however, these associations were attenuated after adjustment for accelerometer derived variables. Excluding individuals with a CRP level >10 mg/L consistently attenuated the significant associations across all markers of inflammation. Conclusion These novel findings from a high risk population recruited through primary care suggest that sedentary behaviour may influence markers associated with inflammation, independent of MVPA, glycaemia and adiposity.

Levels of physical activity and relationship with markers of diabetes and cardiovascular disease risk in 5474 white European and South Asian adults screened for type 2 diabetes.

OBJECTIVE Investigate levels of physical activity and their association with health in a white European (WE) and South Asian (SA) population. METHODS This study reports data from a diabetes screening programme, 2004-2007, Leicester, UK. Physical activity was measured using the International Physical Activity Questionnaire; additional outcomes included fasting and 2-h post-challenge glucose, lipid profile, body mass index (BMI) and waist circumference. RESULTS 1164 SA (female=48%) and 4310 WE (female=53%) were included. SAs were more likely fall below the minimum physical activity recommendations for health compared to WEs (age-adjusted OR for SA men=2.35; 95% CI=1.89-2.93, age adjusted OR for SA women=2.25; 95% CI=1.81-2.80). There were significant associations between levels of physical activity and BMI (men and women), waist circumference (men and women), 2-h glucose (women), HDL-cholesterol (men) and triglycerides (men) in WEs and waist circumference (women) and HDL-cholesterol (men) in SAs. Significant interactions between ethnicity and physical activity existed in the relationship with BMI and waist circumference in men. CONCLUSIONS SAs are substantially less physically active than WEs. There may also be differences between SAs and WEs in the health benefits associated with higher physical activity that warrant further investigation.

Implementation of the automated Leicester Practice Risk Score in two diabetes prevention trials provides a high yield of people with abnormal glucose tolerance

Aims/hypothesisThe Leicester Practice Risk Score (LPRS) is a tool for identifying those at high risk of either impaired glucose regulation (IGR), defined as impaired glucose tolerance and/or impaired fasting glucose, or type 2 diabetes from routine primary care data. The aim of this study was to determine the yield from the LPRS when applied in two diabetes prevention trials.MethodsLet’s Prevent Diabetes (LPD) and Walking Away from Diabetes (WAD) studies used the LPRS to identify people at risk of IGR or type 2 diabetes from 54 general practices. The top 10% at risk within each practice were invited for screening using a 75 g OGTT. The response rate to the invitation and the prevalence of IGR and/or type 2 diabetes in each study were calculated.ResultsOf those invited 19.2% (n = 3,449) in LPD and 22.1% (n = 833) in WAD attended. Of those screened for LPD 25.5% (95% CI 24.1, 27.0) had IGR and 4.5% (95% CI 3.8, 5.2) had type 2 diabetes, giving a prevalence of any abnormal glucose tolerance of 30.1% (95% CI 28.5, 31.6). Comparable rates were seen for the WAD study: IGR 26.5% (95% CI 23.5, 29.5), type 2 diabetes 3.0% (95% CI 1.8, 4.2) and IGR/type 2 diabetes 29.5% (95% CI 26.4, 32.6).Conclusions/interpretationUsing the LPRS identifies a high yield of people with abnormal glucose tolerance, significantly higher than those seen in a population screening programme in the same locality. The LPRS is an inexpensive and simple way of targeting screening programmes at those with the highest risk.

Objectively measured sedentary time and associations with insulin sensitivity: Importance of reallocating sedentary time to physical activity

OBJECTIVE The aim of this study is to quantify associations between objectively measured sedentary time and markers of insulin sensitivity by considering allocation into light-intensity physical activity or moderate- to vigorous-intensity physical activity (MVPA). METHODS Participants with an increased risk of impaired glucose regulation (IGR) were recruited (Leicestershire, United Kingdom, 2010-2011). Sedentary, light-intensity physical activity and MVPA time were measured using accelerometers. Fasting and 2-hour post-challenge insulin and glucose were assessed; insulin sensitivity was calculated by HOMA-IS and Matsuda-ISI. Isotemporal substitution regression models were used. Data were analysed in 2014. RESULTS 508 participants were included (average age=65years, female=34%). Reallocating 30min of sedentary time into light-intensity physical activity was associated a 5% (95% CI 1, 9%; p=0.024) difference in Matsuda-ISI after adjustment for measured confounding variables. Reallocation into MVPA was associated with a 15% (7, 25%; p<0.001) difference in HOMA-IS and 18% (8, 28%; p<0.001) difference in Matsuda-ISI. Results for light-intensity physical activity were modified by IGR status with stronger associations seen in those with IGR. CONCLUSIONS Reallocating sedentary time into light-intensity physical activity or MVPA was associated with differences in insulin sensitivity, with stronger and more consistent associations seen for MVPA.

Sedentary behaviour as a new behavioural target in the prevention and treatment of type 2 diabetes

Our modern day society encompasses an ecological niche in which sedentary behaviour, labour‐saving devices and energy dense foods have become the new reference of living. We now spend more time sedentary, defined as sitting, than in all other activities combined. It has recently been confirmed that the consequences of our modern chair dependency are substantial and a direct contributing factor to the ever increasing epidemic of chronic diseases witnessed within industrialized environments. Epidemiological evidence – from both cross‐sectional and prospective observational studies – has indicated that the time spent in sedentary behaviour is a distinct risk factor for several health outcomes, including type 2 diabetes mellitus, insulin resistance, all‐cause and cardiovascular disease mortality, depression and some types of cancer. Importantly, these detrimental associations remain even after accounting for time spent in moderate‐to‐vigorous physical activity, with the strongest and most persistent associations seen between sedentary time and type 2 diabetes mellitus. Importantly, experimental studies have started to confirm the observational associations, with mounting evidence showing that breaking prolonged sitting time with light ambulation is an effective strategy for improving postprandial glucose regulation. Indeed, there is even emerging evidence showing that simply substituting sitting for standing regularly throughout the day may be of sufficient stimulus to improve glucose regulation. We highlight some of the key definitions, issues and evidence underpinning the link between sedentary behaviour and chronic disease in order to better inform clinicians and patients about the importance of incorporating reduced sitting time into type 2 diabetes mellitus management and prevention pathways. Copyright

Body Mass Index and Waist Circumference Cut-Points in Multi-Ethnic Populations from the UK and India: The ADDITION-Leicester, Jaipur Heart Watch and New Delhi Cross-Sectional Studies

Aims To derive cut-points for body mass index (BMI) and waist circumference (WC) for minority ethnic groups that are risk equivalent based on endogenous glucose levels to cut-points for white Europeans (BMI 30 kg/m2; WC men 102 cm; WC women 88 cm). Materials and Methods Cross-sectional data from participants aged 40–75 years: 4,672 white and 1,348 migrant South Asian participants from ADDITION-Leicester (UK) and 985 indigenous South Asians from Jaipur Heart Watch/New Delhi studies (India). Cut-points were derived using fractional polynomial models with fasting and 2-hour glucose as outcomes, and ethnicity, objectively-measured BMI/WC, their interaction and age as covariates. Results Based on fasting glucose, obesity cut-points were 25 kg/m2 (95% Confidence Interval: 24, 26) for migrant South Asian, and 18 kg/m2 (16, 20) for indigenous South Asian populations. For men, WC cut-points were 90 cm (85, 95) for migrant South Asian, and 87 cm (82, 91) for indigenous South Asian populations. For women, WC cut-points were 77 cm (71, 82) for migrant South Asian, and 54 cm (20, 63) for indigenous South Asian populations. Cut-points based on 2-hour glucose were lower than these. Conclusions These findings strengthen evidence that health interventions are required at a lower BMI and WC for South Asian individuals. Based on our data and the existing literature, we suggest an obesity threshold of 25 kg/m2 for South Asian individuals, and a very high WC threshold of 90 cm for South Asian men and 77 cm for South Asian women. Further work is required to determine whether lower cut-points are required for indigenous, than migrant, South Asians.

Associations of Sedentary Time with Fat Distribution in a High-Risk Population

PURPOSE The effect of sedentary behavior on regional fat deposition, independent of physical activity, remains equivocal. We examined the cross-sectional associations between objectively measured sedentary time and markers of regional fat distribution (heart, liver, visceral, subcutaneous, and total body fat) in a population at a high risk of type 2 diabetes mellitus (T2DM). METHODS Participants were recruited from primary care to two diabetes prevention programs. Sedentary time (<25 counts per 15 s) was measured using ActiGraph GT3X accelerometers. Heart, liver, visceral, subcutaneous, and total body fat were quantified using magnetic resonance images. Fat volumes were calculated by multiplying the cross-sectional areas of the fat-containing pixels by the slice thickness. The liver fat percentage was measured using a representative region of interest created in the right lobe of the liver, avoiding the main portal veins. Linear regression models examined the association of sedentary time with markers of regional fat deposition. RESULTS Sixty-six participants (age, 47.9 ± 16.2 yr; male, 50.0%) were included. After adjustment for several covariates, including glycemia, whole-body fat, and moderate-to-vigorous physical activity, each 30 min of sedentary time was associated with 15.7 cm higher heart fat (P = 0.008), 1.2% higher liver fat (P = 0.026), and 183.7 cm higher visceral fat (P = 0.039). CONCLUSIONS This study provides new evidence suggesting that objectively measured sedentary behavior may have an independent association with heart, liver, and visceral fat in individuals at a high risk of T2DM.

Prevalence of diabetes and impaired glucose metabolism in younger ‘at risk’ UK adults: insights from the STAND programme of research

Rising rates of obesity have led to an increasing prevalence of Type 2 diabetes mellitus in young people. Uncertainty exists over the utility of screening younger adults for Type 2 diabetes, as existing data sets have focused on mature (> 40 years) cohorts. The aim of this study was to determine the prevalence of impaired glucose metabolism in higher risk younger adults.

Walking Away from Type 2 diabetes: a cluster randomized controlled trial.

This study aimed to investigate whether an established behavioural intervention, Walking Away from Type 2 Diabetes, is effective at promoting and sustaining increased walking activity when delivered within primary care.