Ethnic differences in cardiac structure and function assessed by MRI in healthy South Asian and White European people: A UK Biobank Study.

BACKGROUND: Echocardiographic studies indicate South Asian people have smaller ventricular volumes, lower mass and more concentric remodelling than White European people, but there are no data using cardiac MRI (CMR). We aimed to compare CMR quantified cardiac structure and function in White European and South Asian people. METHODS: Healthy White European and South Asian participants in the UK Biobank Imaging CMR sub-study were identified by excluding those with a history of cardiovascular disease, hypertension, obesity or diabetes. Ethnic groups were matched by age and sex. Cardiac volumes, mass and feature tracking strain were compared. RESULTS: 121 matched pairs (77 male/44 female, mean age 58 ± 8 years) of South Asian and White European participants were included. South Asian males and females had smaller absolute but not indexed left ventricular (LV) volumes, and smaller absolute and indexed right ventricular volumes, with lower absolute and indexed LV mass and lower LV mass:volume than White European participants. Although there were no differences in ventricular or atrial ejection fractions, LV global longitudinal strain was higher in South Asian females than White European females but not males, and global circumferential strain was higher in both male and South Asian females than White European females. Peak early diastolic strain rates were higher in South Asian versus White European males, but not different between South Asian and White European females. CONCLUSIONS: Contrary to echocardiographic studies, South Asian participants in the UK Biobank study had less concentric remodelling and higher global circumferential strain than White European subjects. These findings emphasise the importance of sex- and ethnic- specific normal ranges for cardiac volumes and function.

Response to a low-energy meal replacement plan on glycometabolic profile and reverse cardiac remodelling in type 2 diabetes: a comparison between South Asians and White Europeans.

Background: South Asians (SA) constitute a quarter of the global population and are disproportionally affected by both type 2 diabetes (T2D) and heart failure. There remains limited data of the acceptability and efficacy of low-energy meal replacement plans to induce remission of T2D in SA. Objectives: The objective of this exploratory secondary analysis of the DIASTOLIC study was to determine if there was a differential uptake, glycometabolic and cardiovascular response to a low-energy meal replacement plan (MRP) between SA and White European (WE) people with T2D. Methods: Obese adults with T2D without symptomatic cardiovascular disease were allocated a low-energy (~810 kcal/day) MRP as part of the DIASTOLIC study (NCT02590822). Comprehensive multiparametric cardiovascular magnetic resonance imaging, echocardiography, cardiopulmonary exercise testing and metabolic profiling were undertaken at baseline and 12 weeks. A comparison of change at 12 weeks between groups with baseline adjustment was undertaken. Results: Fifteen WE and 12 SAs were allocated the MRP. All WE participants completed the MRP versus 8/12 (66%) SAs. The degree of concentric left ventricular remodelling was similar between ethnicities. Despite similar weight loss and reduction in liver fat percentage, SA had a lower reduction in Homeostatic Model Assessment for Insulin Resistance [-5.7 (95% CI: -7.3, -4.2) versus -8.6 (-9.7, -7.6), p = 0.005] and visceral adiposity compared to WE [-0.43% (-0.61, -0.25) versus -0.80% (-0.91, -0.68), p = 0.002]. Exercise capacity increased in WE with no change observed in SA. There was a trend towards more reverse remodelling in WE compared to SAs. Conclusions: Compliance to the MRP was lower in SA versus WE. Overall, those completing the MRP saw improvements in weight, body composition and indices of glycaemic control irrespective of ethnicity. Whilst improvements in VAT and insulin resistance appear to be dampened in SA versus WE, given the small sample, larger studies are required to confirm or challenge this potential ethnic disparity. Trail registration: NCT02590822.

Evaluation and refinement of the PRESTARt tool for identifying 12-14 year olds at high lifetime risk of developing type 2 diabetes compared to a clinicians assessment of risk: a cross-sectional study.

BACKGROUND: Traditionally Type 2 Diabetes Mellitus (T2DM) was associated with older age, but is now being increasingly diagnosed in younger populations due to the increasing prevalence of obesity and inactivity. We aimed to evaluate whether a tool developed for community use to identify adolescents at high lifetime risk of developing T2DM agreed with a risk assessment conducted by a clinician using data collected from five European countries. We also assessed whether the tool could be simplified. METHODS: To evaluate the tool we collected data from 636 adolescents aged 12-14 years from five European countries. Each participant's data were then assessed by two clinicians independently, who judged each participant to be at either low or high risk of developing T2DM in their lifetime. This was used as the gold standard to which the tool was evaluated and refined. RESULTS: The refined tool categorised adolescents at high risk if they were overweight/obese and had at least one other risk factor (High waist circumference, family history of diabetes, parental obesity, not breast fed, high sugar intake, high screen time, low physical activity and low fruit and vegetable intake). Of those found to be at high risk by the clinicians, 93% were also deemed high risk by the tool. The specificity shows that 67% of those deemed at low risk by the clinicians were also found to be a low risk by the tool. CONCLUSIONS: We have evaluated a tool for identifying adolescents with risk factors associated with the development of T2DM in the future. Future work to externally validate the tool using prospective data including T2DM incidence is required.

Rationale, design and study protocol of the randomised controlled trial: Diabetes Interventional Assessment of Slimming or Training tO Lessen Inconspicuous Cardiovascular Dysfunction (the DIASTOLIC study).

INTRODUCTION: Despite their young age and relatively short duration of disease, younger adults with type 2 diabetes (T2D) already have diastolic dysfunction and may be at risk of incipient heart failure. Whether weight loss or exercise training improve cardiac dysfunction in people with T2D remains to be established. METHODS AND ANALYSIS: Prospective, randomised, open-label, blind endpoint trial. The primary aim of the study is to determine if diastolic function can be improved by either a meal replacement plan or a supervised exercise programme, compared with guideline-directed care. A total of 90 obese participants with T2D (aged 18-65 years), diabetes duration <12 years and not on insulin treatment will be randomised to either guideline-directed clinical care with lifestyle coaching, a low-energy meal replacement diet (average ≈810 kcal/day) or a supervised exercise programme for 12 weeks. Participants undergo glycometabolic profiling, cardiopulmonary exercise testing, echocardiography and MRI scanning to assesses cardiac structure and function and dual-energy X-ray absorptiometry scanning for body composition. Key secondary aims are to assess the effects of the interventions on glycaemic control and insulin resistance, exercise capacity, blood pressure, changes in body composition and association of favourable cardiac remodelling with improvements in weight loss, exercise capacity and glycometabolic control. ETHICS AND DISSEMINATION: The study has full ethical approval, and data collection was completed in August 2018. The study results will be submitted for publication within 6 months of completion. TRIAL REGISTRATION NUMBER: NCT02590822; Pre-results.