Julie-Anne Nazare

Visceral Adipose Tissue Indicates the Severity of Cardiometabolic Risk in Patients with and without Type 2 Diabetes: Results from the INSPIRE ME IAA Study

BACKGROUND Visceral adiposity is an important correlate of cardiometabolic risk, yet its association after the diagnosis of type 2 diabetes remains unclear. METHODS Our objective was to assess the independent and combined associations of visceral adiposity and type 2 diabetes to cardiometabolic risk. The INternational Study of Prediction of Intra-abdominal adiposity and its RElationships with cardioMEtabolic risk/Intra-Abdominal Adiposity (INSPIRE ME IAA) is a cross-sectional computed tomography imaging study with data collected from June 2006 to May 2008. General physicians, cardiologists, and diabetologists (n = 297) in 29 countries recruited 4144 (51.8% men) men (39-71 yr) and women (44-71 yr). Patients were categorized according to visceral adiposity tertiles, type 2 diabetes status, and sex. All results were adjusted for age, body mass index, region, and physicians specialty. RESULTS Markers of insulin resistance, lipid/lipoproteins, inflammatory markers, and liver fat increased with visceral adiposity in men and women with and without type 2 diabetes. Prevalent cardiovascular disease increased with visceral adiposity tertiles, regardless of type 2 diabetes status. Visceral adiposity [odds ratio = 1.25 (1.09-1.44) for men and 1.78 (1.50-2.12) for women] was positively associated with type 2 diabetes, whereas liver attenuation (inversely related to liver fat) was negatively associated with type 2 diabetes [odds ratio = 0.66 (0.59-0.75) for men and 0.63 (0.55-0.72) for women]. Subcutaneous adipose tissue was inversely related to type 2 diabetes in women [0.76 (0.0.66-0.88)] and not associated with type 2 diabetes in men [0.97 (0.85-1.11)]. CONCLUSIONS Visceral, but not sc, abdominal adiposity is strongly related to cardiometabolic risk factors and to the prevalence of cardiovascular disease and may be an important driver of cardiometabolic risk in patients regardless of type 2 diabetes status.

Visceral and Not Subcutaneous Abdominal Adiposity Reduction Drives the Benefits of a 1‐Year Lifestyle Modification Program

Excess visceral adipose tissue (VAT) is associated with an increased cardiometabolic risk. The study examined whether changes in cardiometabolic risk markers after a 1‐year lifestyle intervention in viscerally obese men were associated with changes in VAT or with changes in subcutaneous abdominal adipose tissue (SAT). The relative contributions of changes in global adiposity vs. changes in cardiorespiratory fitness to changes in VAT were also quantified. One hundred and forty four men were selected on the basis of an increased waist circumference (≥90 cm) associated with dyslipidemia (triglycerides ≥1.69 and/or high‐density lipoprotein (HDL)‐cholesterol <1.03 mmol/l); 117 men completed the 1‐year intervention which consisted in a healthy eating, physical activity/exercise program. Body weight, body composition, and fat distribution were assessed by anthropometry and dual‐energy X‐ray absorptiometry (DEXA)/computed tomography. Cardiorespiratory fitness, plasma adipokine/inflammatory markers, fasting lipoprotein‐lipid profile, and oral glucose tolerance test (OGTT) were assessed. VAT volume decreased by 26%, cardiorespiratory fitness improved by 20% (P < 0.0001) after 1 year. Plasma adipokine/inflammatory markers, lipids/lipoproteins, and glucose homeostasis were improved. One‐year changes in triglyceride (r = 0.29), apolipoprotein B (r = 0.21), 120‐min OGTT‐glucose (r = 0.27), and fasting insulin (r = 0.27) levels correlated with changes in VAT (all P < 0.05) after adjustment for changes in SAT. Using a multilinear regression model, VAT reduction was independently associated with SAT reduction and with improvement in cardiorespiratory fitness (R2 = 0.58, P < 0.0001). Therefore, this healthy eating‐physical activity/exercise program improved the cardiometabolic risk profile of viscerally obese men in relation to the reduction of VAT. Furthermore, the reduction in VAT was independently related to the reduction in global adiposity and to the improvement in cardiorespiratory fitness.

Daily intake of conjugated linoleic acid-enriched yoghurts: effects on energy metabolism and adipose tissue gene expression in healthy subjects

Conjugated linoleic acid (CLA) is a group of positional and geometric isomers of conjugated dienoic derivatives of linoleic acid. The present study was designed to determine whether 14-week CLA supplementation as triacylglycerols (3.76 g) with a 50 : 50 combination of the two main isomers (35 % cis-9, trans-11 and 35 % trans-10, cis-12) added to flavoured yoghurt-like products was able to alter body composition in healthy subjects and to alter the expression of several key adipose tissue genes (PPAR gamma, lipoprotein lipase (LPL), hormone-sensitive lipase (HSL) and uncoupling protein 2 (UCP-2)). Forty-four healthy subjects were randomly assigned to consume daily either a CLA-supplemented yoghurt-like product or a placebo yoghurt for 98 d. There were no significant effects of CLA supplementation on body weight, fat mass or free fat mass. Basal energy expenditure expressed as kg free fat mass increased significantly in the CLA group (123.3 (SEM 2.5) kJ/kg free fat mass per d on day 98 v. 118.7 (SEM 2.3) kJ/kg free fat mass per d on day 0, P = 0.03). PPAR gamma mRNA gene expression increased significantly with CLA supplementation (53 (SEM 20) %, P < 0.01) and a significant reduction in mRNA levels of HSL was observed ( - 42 (SEM 7) %, P = 0.01). The levels of UCP-2 and LPL mRNA were not affected. The present results suggest that a 98 d supplementation diet with a 50 : 50 mixture of the two CLA isomers cis-9, trans-11 and trans-10, cis-12 in a dairy product was unable to alter body composition, although a significant increase in the RMR has been induced. Moreover, changes in mRNA PPAR gamma and HSL in adipose tissue were recorded.

Beneficial effects of a 5-week low-glycaemic index regimen on weight control and cardiovascular risk factors in overweight non-diabetic subjects.

The glycaemic index (GI) has been developed in order to classify food according to the postprandial glycaemic response. This parameter is of interest, especially for people prone to glucose intolerance; however, the effects of a low-GI (LGI) diet on body weight, carbohydrate and lipid metabolism remain controversial. We studied the effects of either a LGI or high-GI (HGI) diet on weight control and cardiovascular risk factors in overweight, non-diabetic subjects. The study was a randomized 5-week intervention trial. The thirty-eight subjects (BMI 27.3 (sem 0.2) kg/m2) followed an intervention diet in which usual starch was replaced ad libitum with either LGI or HGI starch. Mean body weight decrease was significant in the LGI group ( - 1.1 (sEM 0.3) kg, P = 0.004) and was significantly greater than in the HGI group ( - 0.3 (sEM 0.2) kg, P = 0.04 between groups). Hunger sensation scales showed a trend towards a decrease in hunger sensation before lunch and dinner in the LGI group when compared with the HGI group (P = 0.09). No significant increase in insulin sensitivity was noticed. The LGI diet also decreased total cholesterol by 9.6 % (P < 0.001), LDL-cholesterol by 8.6 % (P = 0.01) and both LDL-:HDL-cholesterol ratio (10.1 %, P = 0.003) and total:HDL-cholesterol ratio (8.5 %, P = 0.001) while no significant changes were observed in the HGI group. Lowering the GI of daily meals with simple dietary recommendations results in increased weight loss and improved lipid profile and is relatively easy to implement with few constraints. These potential benefits of consuming a LGI diet can be useful to develop practical dietetic advice.

A controlled study of consumption of beta-glucan-enriched soups for 2 months by type 2 diabetic free-living subjects.

Type 2 diabetes is associated with a higher cardiovascular risk and there has been a growing interest in using dietary intervention to improve lipid profile and glucose control. The present work aims at analysing the effects of the enrichment of a normal diet with beta-glucan (3.5 g/d) in free-living type 2 diabetic subjects for 2 months, using a palatable soup. This trial was a parallel, placebo-controlled, double-blinded randomised study performed in fifty-three type 2 diabetic subjects. During a 3-week run-in period, subjects daily consumed a ready meal control soup (without beta-glucan). For the following 8 weeks, subjects were randomly assigned to consume daily either a control soup or a beta-glucan soup. Changes in lipid profile (total cholesterol (TC), HDL- and LDL-cholesterol (HDLc and LDLc), apo B and TAG) and in glucose control (HbA1c and fasting glucose) were measured. There was no significant alteration in lipid profile in the two groups (TC, HDLc, LDLc and apo B). TAG decreased significantly in the beta-glucan group compared with the control group ( - 0.12 (SD 0.38) v. 0.12 (SD 0.44) mmol/l, P = 0.03). HbA1c and fasting glucose were not reduced in any group. A single daily ingestion of 3.5 g beta-glucan, as required by official dietary recommendations, for 8 weeks did not change the lipid profile and HbA1c in type 2 diabetic subjects. To improve the metabolic profile of type 2 diabetic subjects in the long term, the quantity, the food vectors and the tolerability of beta-glucan products may be re-evaluated.

Modulation of the postprandial phase by β-glucan in overweight subjects: effects on glucose and insulin kinetics.

Decreasing the postprandial glucose response is potentially of major importance to public health when low-glycemic index or high-fibre content foods are associated with a decreased risk of diabetes. We investigated in overweight subjects the effect of adding beta-glucan (BG) to a polenta (Pol) meal on postprandial metabolism and glucose bioavailability using stable isotopes. In this single-blind, randomized, crossover trial, 12 subjects ate two meals containing Pol with (Pol + BG) or without (Pol) 5 g BG. Concentrations of glucose, insulin, C-peptide, nonesterified fatty acids, triacylglycerol, total and exogenous glucose kinetics were assessed for 6 h postprandially. The kinetics of total and exogenous glucose importantly differed between the meals, but not the quantity of total and exogenous glucose appearing in plasma. Less total and exogenous glucose appeared during the first 120 min after the Pol + BG meal; the phenomenon was then reversed (both p < 0.0001). After 120 min, glucose and insulin responses declined, but remained higher after the Pol + BG meal (p < 0.05) in parallel to the inhibition of lipolysis. The endogenous glucose production (EGP) was significantly more inhibited after the Pol + BG meal. The addition of BG slowed the appearance of glucose in plasma, resulting in longer-lasting insulin secretion which exerted a prolonged inhibition of EGP and lipolysis.

The SOS-framework (systems of sedentary behaviours) : an international transdisciplinary consensus framework for the study of determinants, research priorities and policy on sedentary behaviour across the life course: A DEDIPAC-study

Ecological models are currently the most used approaches to classify and conceptualise determinants of sedentary behaviour, but these approaches are limited in their ability to capture the complexity of and interplay between determinants. The aim of the project described here was to develop a transdisciplinary dynamic framework, grounded in a system-based approach, for research on determinants of sedentary behaviour across the life span and intervention and policy planning and evaluation. A comprehensive concept mapping approach was used to develop the Systems Of Sedentary behaviours (SOS) framework, involving four main phases: (1) preparation, (2) generation of statements, (3) structuring (sorting and ranking), and (4) analysis and interpretation. The first two phases were undertaken between December 2013 and February 2015 by the DEDIPAC KH team (DEterminants of DIet and Physical Activity Knowledge Hub). The last two phases were completed during a two-day consensus meeting in June 2015. During the first phase, 550 factors regarding sedentary behaviour were listed across three age groups (i.e., youths, adults and older adults), which were reduced to a final list of 190 life course factors in phase 2 used during the consensus meeting. In total, 69 international delegates, seven invited experts and one concept mapping consultant attended the consensus meeting. The final framework obtained during that meeting consisted of six clusters of determinants: Physical Health and Wellbeing (71 % consensus), Social and Cultural Context (59 % consensus), Built and Natural Environment (65 % consensus), Psychology and Behaviour (80 % consensus), Politics and Economics (78 % consensus), and Institutional and Home Settings (78 % consensus). Conducting studies on Institutional Settings was ranked as the first research priority. The view that this framework captures a system-based map of determinants of sedentary behaviour was expressed by 89 % of the participants. Through an international transdisciplinary consensus process, the SOS framework was developed for the determinants of sedentary behaviour through the life course. Investigating the influence of Institutional and Home Settings was deemed to be the most important area of research to focus on at present and potentially the most modifiable. The SOS framework can be used as an important tool to prioritise future research and to develop policies to reduce sedentary time.

Changes in Both Global Diet Quality and Physical Activity Level Synergistically Reduce Visceral Adiposity in Men with Features of Metabolic Syndrome

With regard to the beneficial impact of lifestyle interventions on weight and abdominal obesity management, our objective was to identify which components of a lifestyle-intervention program [physical activity (PA), energy and macronutrient intake, diet quality] had an influence on visceral adipose tissue (VAT) loss. The present lifestyle intervention targeted a daily energy deficit (500 kcal), coupled with a PA program (160 min/wk). From the 144 participants initially recruited, 93 viscerally obese men (age: 49 ± 1 y; waist circumference: 108 ± 9 cm; plasma triglyceride concentration: 2.46 ± 0.09 mmol/L) who completed a 3-d dietary journal both at baseline and after 1 y of intervention and a daily PA journal for 1 y were considered in the present analyses. Body composition and fat distribution were assessed by using dual-energy X-ray absorptiometry and computed tomography. After 1 y, abdominally obese men significantly improved their diet quality, as assessed by the Dietary Approaches to Stop Hypertension (DASH)-derived diet quality (DQ) score (P < 0.0001). Improved DQ and higher levels of PA were both independently and significantly associated with reductions in body weight, fat mass, VAT, and thigh muscle fat content, beyond reported energy intake or diet macronutrient composition. When stratified according to the level of PA and DQ [PA- (low PA), DQ- (low DQ), PA+ (high PA), DQ+ (high DQ)], the PA+/DQ+ group showed reductions in VAT that were 20% greater than in the PA-/DQ+ group, 28% greater than in the PA+/DQ- group, and 50% (P < 0.05) greater than in the PA-/DQ- group. Our results highlight the strong contribution of DQ beyond macronutrient and energy content to changes in body composition and suggest that synergistic changes in both DQ and PA levels optimally reduce VAT in men with features of metabolic syndrome.

Improvement in insulin sensitivity following a 1-year lifestyle intervention program in viscerally obese men: contribution of abdominal adiposity

The objectives of the study were to quantify the effect of a 1-year healthy eating-physical activity/exercise lifestyle modification program on insulin sensitivity in viscerally obese men classified according to their glucose tolerance status and to evaluate the respective contributions of changes in body fat distribution vs changes in cardiorespiratory fitness (CRF) to the improvements in indices of plasma glucose/insulin homeostasis. Abdominally obese, dyslipidemic men (waist circumference ≥90 cm, triglycerides ≥1.69 mmol/L, and/or high-density lipoprotein cholesterol <1.03 mmol/L) were recruited. The 1-year intervention/evaluation was completed by 104 men. Body weight, composition, and fat distribution were assessed by dual-energy x-ray absorptiometry/computed tomography. Cardiorespiratory fitness and cardiometabolic risk profile were measured. After 1 year, insulin sensitivity improved in association with decreases in both visceral (VAT) and subcutaneous adiposity (SAT) as well as with the improvement in CRF, regardless of baseline glucose tolerance. Further analyses were performed according to changes in glucose tolerance status: improvement (group I, n = 39), no change (group N, n = 50), or worsening (group W, n = 15) after 1 year. Groups I and N improved their insulin sensitivity and their CRF, whereas group W did not, while losing less VAT than groups I and N. Multiple regressions showed that reduction in VAT was associated with an improvement in homeostasis model assessment of insulin resistance, whereas reduction in SAT was rather associated with improvement of the insulin sensitivity index of Matsuda. Changes in CRF were not independently associated with changes in indices of plasma glucose/insulin homeostasis. A 1-year lifestyle intervention improved plasma glucose/insulin homeostasis in viscerally obese men, including those with normal glucose tolerance status at baseline. Changes in SAT and VAT but not in CRF appeared to mediate these improvements.

A life course examination of the physical environmental determinants of physical activity behaviour: A “Determinants of Diet and Physical Activity” (DEDIPAC) umbrella systematic literature review

Background Participation in regular physical activity is associated with a multitude of health benefits across the life course. However, many people fail to meet PA recommendations. Despite a plethora of studies, the evidence regarding the environmental (physical) determinants of physical activity remains inconclusive. Objective To identify the physical environmental determinants that influence PA across the life course. Methods An online systematic literature search was conducted using MEDLINE, ISI Web of Science, Scopus and SPORTDiscus. The search was limited to studies published in English (January 2004 to April 2016). Only systematic literature reviews (SLRs) and meta-analyses (MAs) of observational studies, that investigated the association between physical determinants and physical activity outcomes, were eligible for inclusion. The extracted data were assessed on the importance of determinants, strength of evidence and methodological quality. Results The literature search identified 28 SLRs and 3 MAs on 67 physical environmental characteristics potentially related to physical activity that were eligible for inclusion. Among preschool children, a positive association was reported between availability of backyard space and outdoor toys/equipment in the home and overall physical activity. The availability of physical activity programs and equipment within schools, and neighbourhood features such as pedestrian and cyclist safety structure were positively associated with physical activity in children and adolescents. Negative street characteristics, for example, lack of sidewalks and streetlights, were negatively associated with physical activity in adults. Inconsistent associations were reported for the majority of reviewed determinants in adults. Conclusion This umbrella SLR provided a comprehensive overview of the physical environment determinants of physical activity across the life course and has highlighted, particularly amongst youth, a number of key determinants that may be associated with overall physical activity. Given the limited evidence drawn mostly from cross-sectional studies, longitudinal studies are needed to further explore these associations. Registration PROSPERO CRD42015010616