Associations between air pollutants and blood pressure in an ethnically diverse cohort of adolescents in London, England.

Longitudinal evidence on the association between air pollution and blood pressure (BP) in adolescence is scarce. We explored this association in an ethnically diverse cohort of schoolchildren. Sex-stratified, linear random-effects modelling was used to examine how modelled residential exposure to annual average nitrogen dioxide (NO2), particulate matter (PM2.5, PM10) and ozone (O3), measures in µg/m3, associated with blood pressure. Estimates were based on 3,284 adolescents; 80% from ethnic minority groups, recruited from 51 schools, and followed up from 11-13 to 14-16 years old. Ethnic minorities were exposed to higher modelled annual average concentrations of pollution at residential postcode level than their White UK peers. A two-pollutant model (NO2 & PM2.5), adjusted for ethnicity, age, anthropometry, and pubertal status, highlighted associations with systolic, but not diastolic BP. A µg/m3 increase in NO2 was associated with a 0.30 mmHg (95% CI 0.18 to 0.40) decrease in systolic BP for girls and 0.19 mmHg (95% CI 0.07 to 0.31) decrease in systolic BP for boys. In contrast, a 1 µg/m3 increase in PM2.5 was associated with 1.34 mmHg (95% CI 0.85 to 1.82) increase in systolic BP for girls and 0.57 mmHg (95% CI 0.04 to 1.03) increase in systolic BP for boys. Associations did not vary by ethnicity, body size or socio-economic advantage. Associations were robust to adjustments for noise levels and lung function at 11-13 years. In summary, higher ambient levels of NO2 were associated with lower and PM2.5 with higher systolic BP across adolescence, with stronger associations for girls.

Air pollution and trajectories of adolescent conduct problems: the roles of ethnicity and racism; evidence from the DASH longitudinal study.

PURPOSE: No known UK empirical research has investigated prospective associations between ambient air pollutants and conduct problems in adolescence. Ethnic minority children are disproportionately exposed to structural factors that could moderate any observed relationships. This prospective study examined whether exposure to PM2.5 and NO2 concentrations is associated with conduct problems in adolescence, and whether racism or ethnicity moderate such associations. METHODS: Longitudinal associations between annual mean estimated PM2.5 and NO2 concentrations at the residential address and trajectories of conduct problems, and the potential influence of racism and ethnicity were examined school-based sample of 4775 participants (2002-2003 to 2005-2006) in London, using growth curve models. RESULTS: Overall, in the fully adjusted model, exposure to lower concentrations of PM2.5 and NO2 was associated with a decrease in conduct problems during adolescence, while exposure to higher concentrations was associated with a flattened trajectory of conduct symptoms. Racism amplified the effect of PM2.5 (ß = 0.05 (95% CI 0.01 to 0.10, p < 0.01)) on adolescent trajectories of conduct problems over time. At higher concentrations of PM2.5, there was a divergence of trajectories of adolescent conduct problems between ethnic minority groups, with White British and Black Caribbean adolescents experiencing an increase in conduct problems over time. CONCLUSION: These findings suggest that the intersections between air pollution, ethnicity, and racism are important influences on the development of conduct problems in adolescence.

Longitudinal changes in vascular function parameters in pregnant women with chronic hypertension and association with adverse outcome: a cohort study.

OBJECTIVES: Raised vascular function measures are associated with adverse maternal and perinatal outcomes in low-risk pregnancy. This study aimed to evaluate the association between longitudinal vascular function parameters and adverse outcome in pregnant women with chronic hypertension, and to assess whether these measures vary according to baseline parameters such as black ethnicity. METHODS: This was a nested cohort study of women with chronic hypertension and a singleton pregnancy recruited to the PANDA (Pregnancy And chronic hypertension: NifeDipine vs lAbetalol as antihypertensive treatment) study at one of three UK maternity units. Women had serial pulse-wave analyses performed using the Arteriograph®, while in a sitting position, from 12 weeks' gestation onwards. Statistical analysis was performed using random-effects logistic regression models. Longitudinal vascular parameters were compared between women who developed superimposed pre-eclampsia (SPE) and those who did not, between women who delivered a small-for-gestational-age (SGA) infant (birth weight < 10th centile) and those who delivered an infant with birth weight ≥ 10th centile and between women of black ethnicity and those of non-black ethnicity. RESULTS: The cohort included 97 women with chronic hypertension and a singleton pregnancy, of whom 90% (n = 87) were randomized to antihypertensive treatment and 57% (n = 55) were of black ethnicity, with up to six (mean, three) longitudinal vascular function assessments. SPE was diagnosed in 18% (n = 17) of women and 30% (n = 29) of infants were SGA. In women who developed subsequent SPE, compared with those who did not, mean brachial systolic blood pressure (SBP) (148 mmHg vs 139 mmHg; P = 0.002), mean diastolic blood pressure (DBP) (87 mmHg vs 82 mmHg; P = 0.01), mean central aortic pressure (139 mmHg vs 128 mmHg; P = 0.001) and mean augmentation index (AIx-75) (29% vs 22%; P = 0.01) were significantly higher across gestation. In women who delivered a SGA infant compared to those who delivered an infant with birth weight ≥ 10th centile, mean brachial SBP (146 mmHg vs 138 mmHg; P = 0.001), mean DBP (86 mmHg vs 82 mmHg; P = 0.01), mean central aortic pressure (137 mmHg vs 127 mmHg; P < 0.0001) and mean pulse-wave velocity (9.1 m/s vs 8.5 m/s; P = 0.02) were higher across gestation. No longitudinal differences were found in vascular function parameters in women of black ethnicity compared with those of non-black ethnicity. CONCLUSION: There were persistent differences in vascular function parameters and brachial blood pressure throughout pregnancy in women with chronic hypertension who later developed adverse maternal or perinatal outcome. Further investigation into the possible clinical use of these findings is warranted. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Haemostatic factors, lipoproteins and long-term mortality in a multi-ethnic population of Gujarati, African-Caribbean and European origin.

OBJECTIVES: To examine the relations between haemostatic factors and lipoproteins with mortality in British Europeans, African-Caribbeans (AfC) and Gujarati Indians. METHODS: A prospective cohort study of 331 subjects (40-79 years), followed-up over 26 years for mortality. Apolipoprotein-A1 (Apo-A1), apolipoprotein-B (Apo-B), factor VII coagulant activity (FVIIc), fibrinogen and von Willebrand Factor (vWF) were measured at baseline in 118 Europeans, 100 AfC and 113 Gujaratis. Aortic pulse wave velocity (aPWV) was measured in 174 participants. RESULTS: 147 (44.4%) subjects died during a median of 24 years follow-up with 69 cardiovascular deaths. Women at baseline had higher, and AfC males the lowest FVIIc and Apo-A1 levels. Baseline age-sex and ethnicity adjusted FVIIc levels were higher in those who died (131.0 vs. 117.4%; P = 0.048). In similarly adjusted partial correlations, Apo-A1 was inversely related to arterial stiffness (ρ = -0.23, P = 0.04). Over the 26 years follow-up, participants below the median (i.e. with lower concentration) of FVIIc, Fibrinogen, Apo-B and vWF had better survival rates than those with higher concentrations; those with higher concentrations of Apo-A1 had better survival. In Cox multivariable regression analyses including sex, ethnicity and aPWV, independently increased risk of all-cause mortality came only from SBP (per 5 mmHg); P = 0.011), age (per year); P < 0.0001 and FVIIc at 7% (per 10-unit; HR 1.07 (1.02, 1.12); P = 0.008. Separately, Apo-A1 (HR 0.12 (0.02, 0.75; P = 0.029) was independently associated with a very significant 88% reduction in all-cause mortality. CONCLUSIONS: Despite a relatively small sample size, long-term follow-up suggests an independent effect of the prothrombotic state (via FVIIc) and apo-A1 (a constituent of HDL) on mortality.

Localized micro- and nano-scale remodelling in the diabetic aorta.

Diabetes is strongly associated with cardiovascular disease, but the mechanisms, structural and biomechanical consequences of aberrant blood vessel remodelling remain poorly defined. Using an experimental (streptozotocin, STZ) rat model of diabetes, we hypothesized that diabetes enhances extracellular protease activity in the aorta and induces morphological, compositional and localized micromechanical tissue remodelling. We found that the medial aortic layer underwent significant thickening in diabetic animals but without significant changes in collagen or elastin (abundance). Scanning acoustic microscopy demonstrated that such tissue remodelling was associated with a significant decrease in acoustic wave speed (an indicator of reduced material stiffness) in the inter-lamellar spaces of the vessel wall. This index of decreased stiffness was also linked to increased extracellular protease activity (assessed by semi-quantitative in situ gelatin zymography). Such a proteolytically active environment may affect the macromolecular structure of long-lived extracellular matrix molecules. To test this hypothesis, we also characterized the effects of diabetes on the ultrastructure of an important elastic fibre component: the fibrillin microfibril. Using size exclusion chromatography and atomic force microscopy, we isolated and imaged microfibrils from both healthy and diabetic aortas. Microfibrils derived from diabetic tissues were fragmented, morphologically disrupted and weakened (as assessed following molecular combing). These structural and functional abnormalities were not replicated by in vitro glycation. Our data suggest that proteolysis may be a key driver of localized mechanical change in the inter-lamellar space of diabetic rat aortas and that structural proteins (such as fibrillin microfbrils) may be biomarkers of diabetes induced damage.

Expert consensus document on the measurement of aortic stiffness in daily practice using carotid-femoral pulse wave velocity.

Stiffness of elastic arteries like the aorta predicts cardiovascular risk. By directly reflecting arterial stiffness, having the best predictive value for cardiovascular outcome and the ease of its measurement, carotid-femoral pulse wave velocity is now considered the gold standard for arterial stiffness assessment in daily practice. Many different measurement procedures have been proposed. Therefore, standardization of its measurement is urgently needed, particularly regarding the distance measurement. This consensus document advises on the measurement procedures in general and provides arguments for the use of 80% of the direct carotid-femoral distance as the most accurate distance estimate. It also advises the use of 10 m/s as new cut-off value for carotid-femoral pulse wave velocity.

Changes in arterial stiffness but not carotid intimal thickness in acromegaly.

CONTEXT: Acromegaly increases cardiovascular morbidity. We tested the hypothesis that increased arterial stiffness together with left ventricular hypertrophy may be a contributory factor. PATIENTS AND DESIGN: Fifty-six patients (40 males, 54 ± 13 yr; 25 active disease, 31 in remission) and 46 healthy controls (30 males, 52 ± 13 yr) underwent measurements of aortic pulse wave velocity (PWV), carotid Doppler (IMT), echocardiography, and cardiovascular risk factors. RESULTS: Mean serum IGF-I was 323 ± 286 ng/ml (sd score 1.8 ± 1.9) in all patients. Age, body mass index, diastolic blood pressure (BP), and lipid levels were similar comparing patients and controls. Systolic BP (130.8 ± 19.9 vs. 122 ± 14 mm Hg controls, P < 0.01) and PWV (11.7 ± 3.8 vs. 9.7 ± 2.8 m/sec, 95% confidence interval -3.4 to -0.7, P <0.01) were higher in patients than controls. Regression analysis revealed age, presence of acromegaly, systolic BP, and body mass index, inversely, as significantly and independently associated with PWV. No difference in carotid IMT was seen (0.8 ± 0.2 patients vs. 0.7 ± 0.2 mm controls, P = 0.5) or between active/controlled disease. In the subset of participants with echocardiography (n = 32), left ventricular mass was higher by a mean of 38.2 g (95% confidence interval -80.9 to +4.6, P = 0.08). CONCLUSION: In summary, patients with acromegaly had independently and significantly increased aortic PWV as evidence of arterial stiffening but unaltered carotid IMT compared with controls, also influenced by age and systolic BP. Premature cardiovascular disease in patients with acromegaly is likely related to pressure-related arterial and left ventricular stiffening rather than atherosclerotic disease.

Protection Against Nephropathy in Diabetes with Atorvastatin (PANDA): a randomized double-blind placebo-controlled trial of high- vs. low-dose atorvastatin(1).

AIMS: To compare the renal effects of low- vs. high-dose atorvastatin in patients with Type 2 diabetes mellitus and optimally managed early renal disease. METHODS: We compared the 2-year progression of nephropathy in a double-blind randomized controlled trial of atorvastatin 80 mg/day (n = 60) vs. 10 mg/day (n = 59) in patients with Type 2 diabetes with microalbuminuria or proteinuria [mean (sd): age 64 years (10 years); HbA(1c) 7.7% (1.3%), 61 mmol/mol (10 mmol/mol); blood pressure 131/73 mmHg; renin-angiotensin system blocker use > 80%; dual blockade > 67%] recruited from diabetes clinics in Greater Manchester. RESULTS: Over (mean) 2.1 years of follow-up, the Modification of Diet in Renal Disease estimated glomerular filtration rate declined by 3 ml min(-1) 1.73 m(-2) in the combined group. The mean (95% CI) between-group difference during follow-up was not significant [2.2 ml min(-1) 1.73 m(-2) (-1.1 to 5.4 ml min(-1) 1.73: m(-2) ), P = 0.20] after adjusting for baseline differences in renal function; positive difference favours 80 mg dose. Similarly, there was no significant difference in creatinine clearance by Cockcroft and Gault [2.5 ml/min (-2.4 to 7.3 ml/min), P = 0.32]; serum creatinine/24-h urine collections [4.0 ml/min (-4.8 to 12.7 ml/min), P = 0.38]; cystatin C (P = 0.69); or 24-h urine protein or albumin excretion (P = 0.92; P = 0.93). We recorded no significant between-group differences in deaths or adverse events. CONCLUSIONS: In patients with Type 2 diabetes with early renal disease, we found no statistical difference in renal function between those taking high- or low-dose atorvastatin over 2 years. We cannot exclude a beneficial effect of < 1.6 ml min(-1) 1.73 m(-2) year(-1) on Modification of Diet in Renal Disease estimated glomerular filtration rate, or if blood pressure management or if renin-angiotensin system blocker use had not been optimized.

[Management of high blood pressure in children and adolescents: Recommendations of the European Society of hypertension]. / Manejo de la hipertensión arterial en niños y adolescentes: recomendaciones de la Sociedad Europea de Hipertensión.

Hypertension in children and adolescents has been gaining ground in cardiovascular medicine, mainly due to the advances made in several areas of pathophysiological and clinical research. These guidelines arose from the consensus reached by specialists in the detection and control of hypertension in children and adolescents. Furthermore, these guidelines are a compendium of scientific data and the extensive clinical experience it contains represents the most complete information that doctors, nurses and families should take into account when making decisions. These guidelines, which stress the importance of hypertension in children and adolescents, and its contribution to the current epidemic of cardiovascular disease, should act as a stimulus for governments to develop a global effort for the early detection and suitable treatment of high pressure in children and adolescents. J Hypertens 27:1719-1742 Q 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins.

Manejo de la hipertensión arterial en niños y adolescentes: recomendaciones de la Sociedad Europea de Hipertensión / Management of high blood pressure in children and adolescents: Recommendations of the European Society of hypertension

La hipertensión en niños y adolescentes ha ido ganando terreno en la medicina cardiovascular, gracias a los avances producidos en distintas áreas de la investigación fisiopatológica y clínica. Estas guías nacen del consenso al que han llegado los especialistas en la detección y control de la hipertensión en niños y adolescentes. Por otra parte, dichas guías son un compendio de los datos científicos y la extensa experiencia clínica con la que se cuenta, y constituyen la información clínica más completa que los médicos, enfermeras y familiares deberían tener en cuenta a la hora de tomar decisiones. Estas guías, que hacen hincapié en la importancia de la hipertensión en niños y adolescentes, así como en el papel que desempeña en la actual epidemia de enfermedades cardiovasculares, deberían constituir un estímulo para que los gobiernos desarrollaran un esfuerzo global para una detección precoz y un tratamiento adecuado de la hipertensión arterial en niños y adolescentes. J Hypertens 27:1719-1742 Q 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins(AU)

Hypertension in children and adolescents has been gaining ground in cardiovascular medicine, mainly due to the advances made in several areas of pathophysiological and clinical research. These guidelines arose from the consensus reached by specialists in the detection and control of hypertension in children and adolescents. Furthermore, these guidelines are a compendium of scientific data and the extensive clinical experience it contains represents the most complete information that doctors, nurses and families should take into account when making decisions. These guidelines, which stress the importance of hypertension in children and adolescents, and its contribution to the current epidemic of cardiovascular disease, should act as a stimulus for governments to develop a global effort for the early detection and suitable treatment of high pressure in children and adolescents. J Hypertens 27:1719-1742 Q 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins(AU)

Triglycerides and small dense low density lipoprotein in the discrimination of coronary heart disease risk in South Asian populations.

INTRODUCTION: Coronary heart disease (CHD) is exceptionally prevalent amongst globally dispersed migrant groups originating from the Indian subcontinent, but the contribution of dyslipidaemia to their increased risk remains poorly defined. METHODS: Fasting lipids and lipoproteins, apolipoproteins (Apo), low density lipoprotein (LDL) diameter and oxidised LDL were measured amongst rural Indians in India (n=294) and their migrant contemporaries in the UK (n=242). The performance of qualitative and quantitative measures of lipid metabolism were compared in the discrimination of WHO defined metabolic risk and raised Framingham CHD risk scores (>15%) using Receiver Operating Characteristic (ROC) curves. RESULTS: LDL diameter was correlated with triglycerides (R(2)=0.12, P<0.001) and with high density lipoprotein (HDL) cholesterol levels (R(2)=0.15, P<0.001) in both groups. Migrants had less small dense LDL (95% CI: 12.5-14.2%) vs. rural Indians (15.7-17.2, P<0.05). On ROC analysis, triglycerides were the only consistent discriminators of metabolic and CHD risk scores (all P< or =0.001). Apo B was also a strong indicator of raised CHD risk scores. Irrespective of site, individuals with raised triglycerides also had higher total cholesterol and Apo B, denser LDL, lower HDL and more oxidised LDL (all P< or =0.01). DISCUSSION: Fasting triglycerides reflect both qualitative and quantitative aspects of lipid metabolism, and are a comprehensive discriminator of CHD risk in this South Asian population.

Effects of blood pressure lowering and intensive glucose control on the incidence and progression of retinopathy in patients with type 2 diabetes mellitus: a randomised controlled trial.

AIMS/HYPOTHESIS: The aim of the present study was to investigate the effect of blood pressure lowering and intensive glucose control on the incidence and progression of retinopathy in type 2 diabetic patients. METHODS: The Action in Diabetes and Vascular Disease: Preterax and Diamicron MR Controlled Evaluation (ADVANCE) Retinal Measurements study, a substudy of ADVANCE, is a randomised (using a central, computer-based procedure) controlled 2 x 2 factorial trial comprising a double-blind comparison of blood pressure lowering with perindopril-indapamide vs placebo, and an open comparison of standard vs intensive glucose control targeting a HbA(1c) of < or = 6.5% in 1,602 diabetic patients from ADVANCE centres with access to retinal cameras conducted from 2001 to 2008. At baseline and the final visit, seven-field stereoscopic retinal photographs were taken and graded by blinded readers (gradeable baseline and final photographs from 1,241 patients). Progression of > or =2 steps in the Early Treatment of Diabetic Retinopathy Study classification (using the eye with worst grading) was the primary outcome. RESULTS: Retinopathy progressed in 59 (4.8%) patients and developed in 128 (10.3%) patients over 4.1 years. Fewer patients on blood pressure-lowering treatment (n = 623) experienced incidence or progression of retinopathy compared with patients on placebo (n = 618), but the difference was not significant (OR 0.78; 95% CI 0.57-1.06; p = 0.12). Blood pressure-lowering treatment reduced the occurrence of macular oedema (OR 0.50; 95% CI 0.29-0.88; p = 0.016) and arteriovenous nicking compared with placebo (OR 0.60; 95% CI 0.38-0.94; p = 0.025). Compared with standard glucose control (n = 611), intensive glucose control (n = 630) did not reduce (p = 0.27) the incidence and progression of retinopathy (OR 0.84; 95% CI 0.61-1.15). Lower, borderline significant risks of microaneurysms, hard exudates and macular oedema were observed with intensive glucose control, adjusted for baseline retinal haemorrhages. These effects of the two treatments were independent and additive. Adverse events in the ADVANCE study are reported elsewhere. CONCLUSIONS/INTERPRETATION: Blood pressure lowering or intensive glucose control did not significantly reduce the incidence and progression of retinopathy, although consistent trends towards a benefit were observed, with significant reductions in some lesions observed with both interventions. TRIAL REGISTRATION: ClinicalTrials.gov ID no. NCT00145925. FUNDING: Grants from Servier and the National Health and Medical Research Council of Australia.

Inflammatory markers and growth in South Asian and European origin infants in Britain: the Manchester Children's Growth and Vascular Health Study.

OBJECTIVE: Given the high risk of cardiovascular disease in South Asians and the importance of inflammation in coronary heart disease we tested the hypothesis that circulating C-reactive protein (CRP) and interleukin 6 (IL-6) would be higher in healthy British born infants of South Asian origin than in infants of European origin in the first 2 years of life. STUDY DESIGN AND SETTING: Infants of South Asian (n=74) and European (n=129) origin were followed prospectively from birth. Anthropometry and fasting CRP and IL-6 concentrations were measured at one or more of 3, 6, 12 and 24 months of age. RESULTS: South Asian infants had a significantly lower circulating CRP compared with European infants (beta=0.63, 95% CI 0.41-0.98 mg/l, P=0.040). There was no significant change in CRP from birth to 2 years in either ethnic group so that neither infant weight nor weight gain were associated with CRP during follow-up. IL-6 concentrations were low or undetectable during follow-up in all participants. CONCLUSION: In our cohort, South Asian origin infants had significantly lower markers of inflammation compared with European infants. Infant growth to age 2 years was not associated with CRP or IL-6. Inflammatory markers are not useful indices of CVD risk at this age, with such markers not being elevated as expected in South Asian infants. The timing of the rise of such markers to the levels found in adult South Asian populations needs longer prospective study.

Migration is associated with lower total, but not free testosterone levels in South Asian men.

OBJECTIVE: Serum testosterone measurement is an integral part of the endocrine assessment of men. Little is known about its variation in relation to migration. We examined within a South Asian group the effect of migration to the UK on androgen levels. DESIGN: Circulating testosterone and SHBG concentrations were measured in 97 Gujarati men resident in India and in 79 men from the same villages of origin living in Birmingham, UK. Free testosterone was calculated by Vermeulen's method. Insulin sensitivity (HOMA-S) was determined from paired fasting plasma intact insulin and glucose values. RESULTS: Circulating testosterone was significantly lower in UK Gujarati men (17.2 nmol/l [15.7-18.7]) vs. Indian Gujarati men (21.7 [20.0-23.5]) (P = 0.0002) (age-adjusted median [95% CI]). There was no difference by migration status in circulating free testosterone. Sex hormone binding globulin (SHBG) levels were lower in UK migrants (16.8 nmol/l [15.5-18.1]) than in nonmigrants (21.9 nmol/l [20.5-23.3]) (P < 0.0001). Testosterone level correlated positively with insulin sensitivity (HOMA-S) (rho 0.16, P = 0.04). In multivariate analysis, total testosterone was independently and positively associated with logSHBG (normalized beta (beta) = 0.29, P = 0.002) and independently and negatively with waist circumference (beta = -0.19, P = 0.04), in a model also including height, age, migration status, leptin and fasting insulin. CONCLUSION: Lower circulating testosterone in UK Gujarati men and its association with markers of insulin sensitivity suggest a profound influence of body composition change with migration on testosterone levels. The lower SHBG in this group restores parity in free testosterone. Account should be taken of SHBG in interpreting testosterone levels in men, as well as in women.

Dietary advice for treatment of type 2 diabetes mellitus in adults.

BACKGROUND: While initial dietary management immediately after formal diagnosis is an 'accepted' cornerstone of treatment of type 2 diabetes mellitus, a formal and systematic overview of its efficacy and method of delivery is not currently available. OBJECTIVES: To assess the effects of type and frequency of different types of dietary advice for adults with type 2 diabetes. SEARCH STRATEGY: We carried out a comprehensive search of The Cochrane Library, MEDLINE, EMBASE, CINAHL, AMED, bibliographies and contacted relevant experts. SELECTION CRITERIA: All randomised controlled trials, of six months or longer, in which dietary advice was the main intervention. DATA COLLECTION AND ANALYSIS: The lead investigator performed all data extraction and quality scoring with duplication being carried out by one of the other six investigators independently with discrepancies resolved by discussion and consensus. Authors were contacted for missing data. MAIN RESULTS: Thirty-six articles reporting a total of eighteen trials following 1467 participants were included. Dietary approaches assessed in this review were low-fat/high-carbohydrate diets, high-fat/low-carbohydrate diets, low-calorie (1000 kcal per day) and very-low-calorie (500 kcal per day) diets and modified fat diets. Two trials compared the American Diabetes Association exchange diet with a standard reduced fat diet and five studies assessed low-fat diets versus moderate fat or low-carbohydrate diets. Two studies assessed the effect of a very-low-calorie diet versus a low-calorie diet. Six studies compared dietary advice with dietary advice plus exercise and three other studies assessed dietary advice versus dietary advice plus behavioural approaches. The studies all measured weight and measures of glycaemic control although not all studies reported these in the articles published. Other outcomes which were measured in these studies included mortality, blood pressure, serum cholesterol (including LDL and HDL cholesterol), serum triglycerides, maximal exercise capacity and compliance. The results suggest that adoption of regular exercise is a good way to promote better glycaemic control in type 2 diabetic patients, however all of these studies were at high risk of bias. AUTHORS' CONCLUSIONS: There are no high quality data on the efficacy of the dietary treatment of type 2 diabetes, however the data available indicate that the adoption of exercise appears to improve glycated haemoglobin at six and twelve months in people with type 2 diabetes. There is an urgent need for well-designed studies which examine a range of interventions, at various points during follow-up, although there is a promising study currently underway.

Change in pancreatic B-cell function (HOMA-B) varies in different populations with similar genetic backgrounds but different environments.

OBJECTIVE: To determine whether pancreatic B-cell function varies in different populations with similar genetic backgrounds but different environments. RESEARCH DESIGN/METHODS: We compared a specific migrant Gujarati community in the UK (n = 205) with people still resident in the same villages of origin in Gujarat, India (n = 246). Pancreatic B-cell function (HOMA-B) was determined and the influence of age, migration and other factors was explored. RESULTS: As anticipated, there was an age-related decline in log(HOMA-B) in both groups. However, the age-related fall in log(HOMA-B) was more pronounced in the UK than in Gujarat (normalized beta-0.29 vs. -0.14, P for difference = 0.03). The decline of HOMA-B with age persisted after adjustment for body mass index (UK beta = -0.31; Gujarat beta = -0.16, P = 0.015, P < 0.001). There was no significant change in insulin sensitivity (HOMA-S) with age at either site, although insulin sensitivity was lower in the UK. Fasting non-estrified fatty acid (NEFA) levels rose with age in the UK but not in Gujarat (P = 0.003 for difference in gradients). In multiple linear regression analysis, lower log(HOMA-B) was independently associated with higher fasting log(NEFA) levels; normalized beta = -0.24, P < 0.001, age; beta = -0.16, P = 0.005, higher log(insulin-like growth factor binding protein-1); beta = -0.19, P = 0.007 and lower body mass index; beta = 0.26, P = 0.001. This model accounted for 25% of the variability in HOMA-B. CONCLUSIONS: HOMA-B as a measure of B-cell function declines more rapidly with age in the migrant UK group than in Gujarat. This may be a direct consequence of chronically higher NEFA exposure in the UK group.