Ethnic differences in cross-sectional associations between impaired glucose regulation, identified by oral glucose tolerance test or HbA1c values, and cardiovascular disease in a cohort of European and South Asian origin.

AIMS: We contrasted impaired glucose regulation (prediabetes) prevalence, defined according to oral glucose tolerance test or HbA1c values, and studied cross-sectional associations between prediabetes and subclinical/clinical cardiovascular disease (CVD) in a cohort of European and South Asian origin. METHODS: For 682 European and 520 South Asian men and women, aged 58-85 years, glycaemic status was determined by oral glucose tolerance test or HbA1c thresholds. Questionnaires, record review, coronary artery calcification scores and cerebral magnetic resonance imaging established clinical plus subclinical coronary heart and cerebrovascular disease. RESULTS: Prediabetes was more prevalent in South Asian participants when defined by HbA1c rather than by oral glucose tolerance test criteria. Accounting for age, sex, smoking, systolic blood pressure, triglycerides and waist-hip ratio, prediabetes was associated with coronary heart disease and cerebrovascular disease in European participants, most obviously when defined by HbA1c rather than by oral glucose tolerance test [odds ratios for HbA1c -defined prediabetes 1.60 (95% CI 1.07, 2.39) for coronary heart disease and 1.57 (95% CI 1.00, 2.51) for cerebrovascular disease]. By contrast, non-significant associations were present between oral glucose tolerance test-defined prediabetes only and coronary heart disease [odds ratio 1.41 (95% CI 0.84, 2.36)] and HbA1c -defined prediabetes only and cerebrovascular disease [odds ratio 1.39 (95% CI 0.69, 2.78)] in South Asian participants. Prediabetes defined by HbA1c or oral glucose tolerance test criteria was associated with cardiovascular disease (defined as coronary heart and/or cerebrovascular disease) in Europeans [odds ratio 1.95 (95% CI 1.31, 2.91) for HbA1c prediabetes criteria] but not in South Asian participants [odds ratio 1.00 (95% CI 0.62, 2.66); ethnicity interaction P = 0.04]. CONCLUSIONS: Prediabetes appeared to be less associated with cardiovascular disease in the South Asian than in the European group. These findings have implications for screening, and early cardiovascular prevention strategies in South Asian populations.

Depressive symptoms are doubled in older British South Asian and Black Caribbean people compared with Europeans: associations with excess co-morbidity and socioeconomic disadvantage.

BACKGROUND: Despite elevated risk profiles for depression among South Asian and Black Caribbean people in the UK, prevalences of late-life depressive symptoms across the UK's three major ethnic groups have not been well characterized. METHOD: Data were collected at baseline and 20-year follow-up from 632 European, 476 South Asian and 181 Black Caribbean men and women (aged 58-88 years), of a community-based cohort study from north-west London. The 10-item Geriatric Depression Scale was interviewer-administered during a clinic visit (depressive symptoms defined as a score of ⩾4 out of 10), with clinical data (adiposity, diabetes, cardiovascular disease, cognitive function) also collected. Sociodemographic, psychosocial, behavioural, disability, and medical history information was obtained by questionnaire. RESULTS: Prevalence of depressive symptoms varied by ethnic group, affecting 9.7% of White European, 15.5% of South Asian, and 17.7% of Black Caribbean participants. Compared with White Europeans, South Asian and Black Caribbean participants were significantly more likely to have depressive symptoms (odds ratio 1.79, 95% confidence interval 1.24-2.58 and 1.80, 1.11-2.92, respectively). Adjustment for co-morbidities had most effect on the excess South Asian odds, and adjustment for socioeconomic position had most effect on the elevated Black Caribbean odds. CONCLUSIONS: Higher prevalence of depressive symptoms observed among South Asian people were attenuated after adjustment for physical health, whereas the Black Caribbean increased prevalence was most explained by socioeconomic disadvantage. It is important to understand the reasons for these ethnic differences to identify opportunities for interventions to address inequalities.

Ethnicity-specific obesity cut-points in the development of Type 2 diabetes - a prospective study including three ethnic groups in the United Kingdom.

AIMS: Conventional definitions of obesity, e.g. body mass index (BMI) ≥ 30 kg/m² or waist circumference cut-points of 102 cm (men) and 88 cm (women), may underestimate metabolic risk in non-Europeans. We prospectively identified equivalent ethnicity-specific obesity cut-points for the estimation of diabetes risk in British South Asians, African-Caribbeans and Europeans. METHODS: We studied a population-based cohort from London, UK (1356 Europeans, 842 South Asians, 335 African-Caribbeans) who were aged 40-69 years at baseline (1988-1991), when they underwent anthropometry, fasting and post-load (75 g oral glucose tolerance test) blood tests. Incident Type 2 diabetes was identified from primary care records, participant recall and/or follow-up biochemistry. Ethnicity-specific obesity cut-points in association with diabetes incidence were estimated using negative binomial regression. RESULTS: Diabetes incidence rates (per 1000 person years) at a median follow-up of 19 years were 20.8 (95% CI: 18.4, 23.6) and 12.0 (8.3, 17.2) in South Asian men and women, 16.5 (12.7, 21.4) and 17.5 (13.0, 23.7) in African-Caribbean men and women, and 7.4 (6.3, 8.7), and 7.2 (5.3, 9.8) in European men and women. For incidence rates equivalent to those at a BMI of 30 kg/m² in European men and women, age- and sex-adjusted cut-points were: South Asians, 25.2 (23.4, 26.6) kg/m²; and African-Caribbeans, 27.2 (25.2, 28.6) kg/m². For South Asian and African-Caribbean men, respectively, waist circumference cut-points of 90.4 (85.0, 94.5) and 90.6 (85.0, 94.5) cm were equivalent to a value of 102 cm in European men. Waist circumference cut-points of 84.0 (74.0, 90.0) cm in South Asian women and 81.2 (71.4, 87.4) cm in African-Caribbean women were equivalent to a value of 88 cm in European women. CONCLUSIONS: In prospective analyses, British South Asians and African-Caribbeans had equivalent diabetes incidence rates at substantially lower obesity levels than the conventional European cut-points.

Impaired post-ischaemic microvascular hyperaemia in Indian Asians is unexplained by diabetes or other cardiovascular risk factors.

OBJECTIVE: People of Indian Asian descent have an increased risk of cardiovascular disease (CVD) that cannot be explained by diabetes and other established CVD risk factors. We investigated if microcirculatory function was impaired in a population-based sample of people of Indian Asian descent compared with Europeans in the UK and whether any differences could be accounted for by diabetes or other CVD risk factors. RESEARCH DESIGN AND METHODS: Cutaneous microvascular function was assessed using laser Doppler fluximetry in response to heating to 42 °C (maximum hyperaemia) and 3 min arterial occlusion (post occlusive reactive hyperaemia: PORH) in 148 Indian Asians and 147 Europeans. Blood pressure, anthropometry and fasting bloods were also measured. RESULTS: Maximum hyperaemia and minimum resistance did not differ significantly by ethnicity. Resting flux and PORH were lower in Indian Asians and time to peak of PORH was prolonged. Diabetes was associated with reduced maximum hyperaemia and PORH. Adjustment for diabetes accounted for differences in resting flux and time to peak but not differences in PORH (Europeans = 45.0 (40.3, 50.1)au, Indian Asians = 35.6 (31.9, 39.7)au, mean (95% confidence interval); p = 0.008 after adjustment). Differences in conventional CVD risk factors did not account for interethnic differences in microvascular responses. CONCLUSIONS: People of Indian Asian descent have impaired post-occlusive reactive hyperaemia unexplained by diabetes, dysglycaemia or other CVD risk factors. Abnormal microvascular function in response to ischaemia could represent a novel mechanism contributing to the elevated risk of CVD in Indian Asians.

Ethnic differences in retinal microvascular structure.

AIMS/HYPOTHESIS: People of African origin have increased risk of stroke and retinal microvascular disease compared with populations of European origin. We compared quantitative measures of retinal microvasculature in British white Europeans and African Caribbeans. METHODS: Population-based study of 215 (45% male) British African-Caribbean migrants and 323 (48% male) white Europeans aged 40-69 years. Digitised retinal images were analysed using a validated semi-automated system. RESULTS: Arteriolar optimality deviation, an indicator of endothelial dysfunction, was greater in African Caribbeans (age- and sex-adjusted means [95% CIs]: 0.06 [0.05-0.06] vs 0.04 [0.04-0.05], p = 0.004); this was unexplained by conventional risk factors. Arteriolar diameters were narrower in African Caribbeans (age- and sex-adjusted means [95% CIs]: 18.4 [18.1-18.6] vs 17.9 [17.6-18.2], p = 0.011). These ethnic differences in diameters were attenuated on adjustment for systolic BP (SBP) (adjusted means: 18.2 vs 18.1, p = 0.31). However, there was a significant interaction (p = 0.011) between diabetes and SBP, such that SBP was strongly associated with arteriolar diameter in people without diabetes, but not in those with diabetes (adjusted beta-coefficients for SBP: Europeans: -0.42, p = 0.002 vs 0.17, p = 0.69, African Caribbeans: -0.35, p = 0.023 vs 0.01, p = 0.96). Other measures of retinal vasculature did not differ by ethnicity. CONCLUSIONS/INTERPRETATION: British African Caribbeans appear to have poorer retinal arteriolar endothelial function than white Europeans. Higher BPs explained the narrower arterioles in African Caribbeans; however, patterns of association between arteriolar narrowing and BP suggest the possibility that cerebral autoregulation and/or remodelling might be adversely affected by diabetes in both ethnic groups.

Cardiovascular disease mortality in relation to childhood and adulthood socioeconomic markers in British South Asian men.

OBJECTIVE: To study the effects of childhood and adulthood socioeconomic position (SEP) including length of education on rates of cardiovascular disease (CVD) mortality in British South Asians. DESIGN: Cross-sectional study with ongoing mortality follow-up. SETTING: West London Borough of Ealing, population-based study. PATIENTS: 1400 South Asian men (52% Punjabi Sikh origin) aged 40-69, first studied 1988-1990 and followed for mortality to October 2006. MAIN OUTCOME MEASURES: Deaths due to cardiovascular disease. RESULTS: 143 men have died from CVD. Men in non-manual adult occupations were less likely to die from CVD than those in unskilled manual occupations (age-adjusted hazard ratio (HR) 0.55 (95% CI 0.35 to 0.88)). Men with 11+ years of education had reduced risk compared with those with <11 years of education (HR 0.66 (95% CI 0.47 to 0.94)). Men who had both non-manual occupations and 11+ years of education were less likely to die from CVD (15 deaths, 282 men; HR 0.39, 95% CI 0.21 to 0.73) than those who were most socially disadvantaged during childhood and adulthood (27 deaths, 187 men). These associations remained after adjustment for other markers of SEP, lifestyle and conventional risk factors. Similar, but weaker, associations were observed when paternal occupation defined childhood SEP. CONCLUSIONS: Years of education, and to a lesser extent paternal occupation, as markers of childhood SEP, had cumulative effects with adulthood socioeconomic circumstances on risk of CVD death; these cumulative effects were strongest in men whose own occupation was non-manual and were unexplained by conventional risk factors measured in middle age.

Third-party prospective evaluation of patient outcomes after dynamic graciloplasty.

BACKGROUND: Dynamic graciloplasty (DGP) is a complex procedure designed to improve bowel function in patients with end-stage faecal incontinence. Outcomes of DGP were examined in comparison with stoma formation or continued medical management. METHODS: This third-party evaluation comprised a prospective case-comparison study of patient-based and clinical outcomes at a London hospital. Forty-nine patients who underwent DGP during 5 years from 1997 were compared with 87 patients with similar bowel disorders who did not undergo DGP. Outcome measures were quality of life (QoL), symptoms, anxiety and depression. RESULTS: At 2 years after surgery, bowel-related QoL and continence had improved by more than 20 per cent compared with the preoperative status for two-thirds of patients who had DGP (P < 0.001). Two-thirds were continent all or most of the time, although one-third experienced disordered bowel evacuation. Large deteriorations on the Nottingham Health Profile pain score occurred in 11 of 34 patients who had DGP, compared with seven of 57 patients in comparison groups (P = 0.027). Patients in comparison groups experienced no significant changes in measured outcomes over the 2 years of follow-up. CONCLUSION: Although DGP is associated with a high level of morbidity, it deserves consideration as an alternative to life with severe and refractory faecal incontinence or stoma formation in people in whom conventional treatments have failed.

Do known risk factors explain the higher coronary heart disease mortality in South Asian compared with European men? Prospective follow-up of the Southall and Brent studies, UK.

AIMS/HYPOTHESIS: We examined prospectively whether measured risk factors can explain the higher CHD mortality in South Asians compared with Europeans. MATERIALS AND METHODS: Conventional CHD risk factors and those associated with insulin resistance were measured in 1,787 European and 1,420 South Asian men aged 40 to 69 years at baseline in the population-based Southall and Brent studies (London) between 1988 and 1990. Participants were followed up for mortality. RESULTS: By February 2006, there were 202 CHD deaths (108 Asian, 94 European). South Asian men had double the CHD mortality of European men in Cox regression analyses adjusted for age, smoking, and cholesterol (hazard ratio [HR] 2.14, 95% CI 1.56-2.94, p<0.001). Nearly half of all South Asian CHD deaths versus 13% of deaths among Europeans were among persons with diabetes. Asian men had greater CHD mortality than Europeans, both in the with- and the without-diabetes categories at baseline. CHD mortality remained significantly higher in South Asian men in multivariable models that adjusted for conventional risk factors and diabetes and/or impaired glucose regulation, features of insulin resistance, or the metabolic syndrome (HR 1.6-1.9). Accounting for co-morbidity and socio-economic status did not materially alter the findings. CONCLUSIONS/INTERPRETATION: These data confirm that South Asian men have significantly higher CHD mortality than their European counterparts, while indicating that neither conventional risk factors, nor insulin resistance parameters or metabolic syndrome criteria as currently defined can account for this excess risk. The contribution of unmeasured factors to the elevated vascular risk in South Asians should be addressed in future studies.

Outcomes of electrically stimulated gracilis neosphincter surgery.

OBJECTIVES: To examine patient quality of life (QoL) and long-term costs of electrically stimulated gracilis neosphincter surgery (ESGNS). DESIGN: Independently conducted prospective case-comparison study of patients at the Royal London Hospital (RLH), plus a cross-sectional study of outcomes of ESGNS performed at three other UK centres. PARTICIPANTS: Cases were patients who underwent ESGNS at the participating hospitals during a 5-year period from 1977. Comparisons were made with two groups of people with similar bowel disorders who did not undergo ESGNS. INTERVENTION: ESGNS is a procedure designed to improve bowel function for people living with severe faecal incontinence or stomas. It involves transposition of the gracilis muscle to form a neo-anal sphincter. The transposed muscle is electrically stimulated via an electronic pulse generator implanted beneath the skin of the abdomen. MAIN OUTCOME MEASURES: Clinical success and symptomatic outcomes of surgery. Generic, domain and condition specific measures of QoL. Comparative costs to the NHS of ESGNS and conventional alternatives. RESULTS: At 3 years after surgery approximately three-quarters of patients still had functioning neosphincters. At this stage, bowel-related QoL and continence improved by more than 20% for nearly two-thirds of RLH patients. However, ongoing bowel evacuation difficulties occurred in half of those with good continence outcomes. QoL improvements were maintained in the smaller group of RLH patients who had reached 4 and 5 years of follow-up, although at this stage the proportion with failed neosphincters had increased. The RLH findings were supported by those from the three other UK centres. No significant changes in QoL were observed in the comparison groups during the follow-up period. The mean cost of patient care at RLH, was 23,253 pounds. In the other three centres, the estimated mean cost of the intervention per patient was 11,731 pounds, reflecting fewer planned operations and repeat admissions. Costs of patient care for those with stomas who did not undergo ESGNS were estimated at 2125 pounds per patient-year and for those who remained with severe faecal incontinence, 442 pounds per patient-year. For patients with prior faecal incontinence, a decision to refer to ESGNS resulted in a cost-effectiveness ratio, estimated over 25 years of follow-up, of between 30,000 pounds and 40,000 pounds per quality-adjusted life-year (QALY) gained, depending on centre. The choice of stoma for these patients resulted in a slightly higher cost than ESGNS. For those with prior stoma, referral to ESGNS resulted in a cost-effectiveness ratio of between 5000 pounds and 15,000 pounds per QALY gained, depending on the centre. Cost-effectiveness ratios of around 30,000 pounds per QALY gained are generally regarded to be reasonably attractive in the UK NHS context. CONCLUSIONS: Although ESGNS is a major procedure associated with a high rate of long-term failure and bowel evacuation difficulty, it could be considered as an option at the extreme end of the treatment spectrum for refractory faecal incontinence. A strategy to refer patients for ESGNS would be regarded as cost-effective for patients already with stoma, whilst on the margin of cost-effectiveness for patients initially being managed conservatively.

Metabolic syndrome and coronary heart disease in South Asians, African-Caribbeans and white Europeans: a UK population-based cross-sectional study.

AIMS/HYPOTHESIS: The aim of this study was to study differences in the prevalence of the metabolic syndrome and its associations with prevalent CHD according to ethnicity and sex. METHODS: We performed a combined analysis of two population-based cross-sectional studies conducted between 1988 and 1991 that followed identical protocols. Participants (aged 40-69 years) comprised 2,346 Europeans (76% male), 1,711 South Asians (83% male) and 803 African-Caribbeans (57% male) resident in west London. Fasting blood, overnight urine collection, clinical and anthropometric measurements were performed. Clinical history or major ECG changes defined prevalent CHD. The metabolic syndrome was defined according to the criteria recommended by the World Health Organization (WHO) and the National Cholesterol Education Programme (NCEP). RESULTS: The prevalence of the metabolic syndrome was highest in South Asians (WHO, men 46%, women 31%; NCEP, men 29%, women 32%) and lowest in European women (WHO, 9%; NCEP, 14%). The prevalence of CHD was 10% in South Asian men, 9% in European men, 5-6% in African-Caribbeans and European women, and 2% in South Asian women. The metabolic syndrome was associated with prevalent CHD in European men [NCEP, odds ratio (OR)=1.6, 95% CI 1.2-2.4; WHO, OR=1.7, 95% CI 1.2-2.5] and South Asian men (NCEP, OR=2.1, 95% CI 1.5-3.1; WHO, OR=1.6, 95% CI 1.1-2.3). Associations with CHD were weaker in African-Caribbeans and were inconsistent among European women. CONCLUSIONS/INTERPRETATION: The current definitions of the metabolic syndrome give an inconsistent picture of cardiovascular disease risk when applied to different ethnic groups within the UK. Prospective studies are needed to validate workable ethnic-specific definitions.