COVID-19 and metabolic disease: mechanisms and clinical management

Up to 50% of the people who have died from COVID-19 had metabolic and vascular disorders. Notably, there are many direct links between COVID-19 and the metabolic and endocrine systems. Thus, not only are patients with metabolic dysfunction (eg, obesity, hypertension, non-alcoholic fatty liver disease, and diabetes) at an increased risk of developing severe COVID-19 but also infection with SARS-CoV-2 might lead to new-onset diabetes or aggravation of pre-existing metabolic disorders. In this Review, we provide an update on the mechanisms of how metabolic and endocrine disorders might predispose patients to develop severe COVID-19. Additionally, we update the practical recommendations and management of patients with COVID-19 and post-pandemic. Furthermore, we summarise new treatment options for patients with both COVID-19 and diabetes, and highlight current challenges in clinical management.

Diagnosing type 2 diabetes using Hemoglobin A1c: a systematic review and meta-analysis of the diagnostic cutpoint based on microvascular complications

AIMS

Diabetic microvascular complications of retinopathy, nephropathy and neuropathy may occur at hemoglobin A1c levels (HbA1c) below the 6.5% (48 mmol/mol) diagnostic threshold. Our objective was to assess the validity of the HbA1c diagnostic cutpoint of 6.5% based upon published evidence of the prevalence of retinopathy, nephropathy and neuropathy as markers of diabetes.

METHODS

Data Sources PubMed, Embase, Cochrane, Scopus and CINAHL from 1990-March 2019, grey literature sources. Study Selection All studies reported after 1990 (to ensure standardized HbA1c values) where HbA1c levels were presented in relation to prevalence of retinopathy, nephropathy or neuropathy in subjects not known to have diabetes. Data Extraction Studies were screened independently, data abstracted, and risk of bias appraised. Data Synthesis Data were synthesized using HbA1c categories of < 6.0% (< 42 mmol/mol), 6.0-6.4% (42-47 mmol/mol) and ≥ 6.5% (≥ 48 mmol/mol). Random-effects meta-analyses were conducted for retinopathy, nephropathy and neuropathy prevalence stratified by HbA1c categories. Random-effects multivariable meta-regression was conducted to identify predictors of retinopathy prevalence and sources of between-study heterogeneity.

RESULTS

Pooled mean prevalence was: 4.0%(95% CI: 3.2-5.0%) for retinopathy, 10.5% (95% CI: 4.0-19.5%) for nephropathy, 2.5% (95% CI: 1.1-4.3%) for neuropathy. Mean prevalence when stratified for HbA1c < 6.0%, 6.0-6.4% and ≥ 6.5% was: retinopathy: 3.4% (95% CI: 1.8-5.4%), 2.3% (95% CI: 1.6-3.2%) and 7.8%(95% CI: 5.7-10.3%); nephropathy: 7.1% (95% CI: 1.7-15.9%), 9.6% (95% CI: 0.8-26.4%) and 17.1% (95% CI: 1.0-46.9%); neuropathy: 2.1% (95% CI: 0.0-6.8%), 3.4% (95% CI: 0.0-11.6%) and 2.8% (95% CI: 0.0-12.8%). Multivariable meta-regression showed HbA1c ≥ 6.5% (OR: 4.05; 95% CI: 1.92-8.57%), age > 55 (OR: 3.23; 95% CI 1.81-5.77), and African-American race (OR: 10.73; 95% CI: 4.34-26.55), to be associated with higher retinopathy prevalence. Marked heterogeneity in prevalence estimates was found across all meta-analyses (Cochran's Q-statistic p < 0.0001).

CONCLUSIONS

The prevalence of nephropathy and moderate retinopathy was increased in subjects with HbA1c values ≥ 6.5% confirming the high specificity of this value for diagnosing T2DM; however, at HbA1c < 6.5% retinopathy increased at age > 55 years and, most strikingly, in African-Americans, suggesting there may be excess microvascular complication prevalence (particularly nephropathy) in individuals below the diabetes diagnostic threshold.

Experience of point-of-care HbA1c testing in the English National Health Service Diabetes Prevention Programme: an observational study

INTRODUCTION

To report the observations of point-of-care (POC) glycated hemoglobin (HbA1c) testing in people with non-diabetic hyperglycemia (NDH; HbA1c 42-47 mmol/mol (6.0%-6.4%)), applied in community settings, within the English National Health Service Diabetes Prevention Programme (NHS DPP).

RESEARCH DESIGN AND METHODS

A service evaluation assessing prospectively collected national service-level data from the NHS DPP, using data from the first referral received in June 2016-October 2018. Individuals were referred to the NHS DPP with a laboratory-measured HbA1c in the NDH range and had a repeat HbA1c measured at first attendance of the program using one of three POC devices: DCA Vantage, Afinion or A1C Now+. Differences between the referral and POC HbA1c and the SD of the POC HbA1c were calculated. The factors associated with the difference in HbA1c and the association between POC HbA1c result and subsequent attendance of the NHS DPP were also evaluated.

RESULTS

Data from 73 703 participants demonstrated a significant mean difference between the referral and POC HbA1c of -2.48 mmol/mol (-0.23%) (t=157, p<0.001) with significant differences in the mean difference between devices (F(2, 73 700)=738, p<0.001). The SD of POC HbA1c was 4.46 mmol/mol (0.41%) with significant differences in SDs between devices (F(2, 73 700)=1542, p<0.001). Participants who were older, from more deprived areas and from Asian, black and mixed ethnic groups were associated with smaller HbA1c differences. Normoglycemic POC HbA1c versus NDH POC HbA1c values were associated with lower subsequent attendance at behavioral interventions (58% vs 67%, p<0.001).

CONCLUSION

POC HbA1c testing in community settings was associated with significantly lower HbA1c values when compared with laboratory-measured referrals. Acknowledging effects of regression to the mean, we found that these differences were also associated with POC method, location, individual patient factors and time between measurements. Compared with POC HbA1c values in the NDH range, normoglycemic POC HbA1c values were associated with lower subsequent intervention attendance.

Black African men with early type 2 diabetes have similar muscle, liver and adipose tissue insulin sensitivity to white European men despite lower visceral fat

AIMS/HYPOTHESIS

Type 2 diabetes is more prevalent in black African than white European populations although, paradoxically, black African individuals present with lower levels of visceral fat, which has a known association with insulin resistance. Insulin resistance occurs at a tissue-specific level; however, no study has simultaneously compared whole body, skeletal muscle, hepatic and adipose tissue insulin sensitivity between black and white men. We hypothesised that, in those with early type 2 diabetes, black (West) African men (BAM) have greater hepatic and adipose tissue insulin sensitivity, compared with white European men (WEM), because of their reduced visceral fat.

METHODS

Eighteen BAM and 15 WEM with type 2 diabetes underwent a two-stage hyperinsulinaemic-euglycaemic clamp with stable glucose and glycerol isotope tracers to assess tissue-specific insulin sensitivity and a magnetic resonance imaging scan to assess body composition.

RESULTS

We found no ethnic differences in whole body, skeletal muscle, hepatic or adipose tissue insulin sensitivity between BAM and WEM. This finding occurred in the presence of lower visceral fat in BAM (3.72 vs 5.68 kg [mean difference -1.96, 95% CI -3.30, 0.62]; p = 0.01). There was an association between skeletal muscle and adipose tissue insulin sensitivity in WEM that was not present in BAM (r = 0.78, p < 0.01 vs r = 0.25 p = 0.37).

CONCLUSIONS/INTERPRETATION

Our data suggest that in type 2 diabetes there are no ethnic differences in whole body, skeletal muscle, hepatic and adipose tissue insulin sensitivity between black and white men, despite differences in visceral adipose tissue, and that impaired lipolysis may not be contributing to skeletal muscle insulin resistance in men of black African ethnicity.

Associations Between Pancreatic Lipids and β-Cell Function in Black African and White European Men With Type 2 Diabetes

CONTEXT

Intrapancreatic lipid (IPL) has been linked to β-cell dysfunction. Black populations disproportionately develop type 2 diabetes (T2D) and show distinctions in β-cell function compared with white populations.

OBJECTIVE

We quantified IPL in white European (WE) and black West African (BWA) men with early T2D and investigated the relationships between IPL and β-cell insulin secretory function (ISF).

DESIGN, SETTING, AND PARTICIPANTS

We performed a cross-sectional assessment of 18 WE and 19 BWA middle-age men with early T2D as part of the South London Diabetes and Ethnicity Phenotyping study.

MAIN OUTCOME MEASURES

The participants underwent Dixon MRI to determine IPL in the pancreatic head, body, and tail and subcutaneous and visceral adipose tissue volumes. Modeled first- and second-phase ISFs were comprehensively determined using C-peptide measurements during a 3-hour meal tolerance test and a 2-hour hyperglycemic clamp test.

RESULTS

The WE men had greater mean IPL levels compared with BWA men (P = 0.029), mainly owing to greater IPL levels in the pancreatic head (P = 0.009). The mean IPL level was inversely associated with orally stimulated first-phase ISF in WE but not BWA men (WE, r = -0.554, P = 0.026; BWA, r = -0.183, P = 0.468). No association was found with orally stimulated second-phase ISF in either WE or BWA men. No associations were found between the mean IPL level and intravenously stimulated ISF.

CONCLUSIONS

The IPL levels were lower in BWA than WE men with early T2D, and the lack of inverse association with first-phase ISF in BWA men indicates that IPL might be a less important determinant of the development of T2D in BWA than in WE men.

Association between type 2 diabetes mellitus and disability: What is the contribution of diabetes risk factors and diabetes complications?

BACKGROUND

The aim of this study was to evaluate the association between type 2 diabetes and disability in Mauritius and to assess the extent to which the effect of diabetes is explained by diabetes risk factors and concomitant complications.

METHODS

Data from a national survey in the multiethnic nation of Mauritius, which comprises South Asians and African Creoles, were analyzed. Disability was measured using the Katz activities of daily living questionnaire in participants aged >50 years.

RESULTS

Among 3692 participants, 487 (13.2%) had some level of disability. Diabetes was associated with significantly higher risk of disability (odds ratio [OR] 1.67; 95% confidence interval [CI] 1.34-2.08). After adjusting for demographic, behavioral, and metabolic factors, as well as comorbidities, disability was significantly associated with diabetes among African Creoles (OR 2.03; 95% CI 1.16-3.56), but not South Asians (OR 1.27; 95% CI 0.98-1.66). Obesity explained much of the association between diabetes and disability (excess percentage of risk: 26.3% in South Asians and 12.1% in African Creoles). Obesity, history of cardiovascular disease (CVD), asthma-like symptoms, and depression together explained 46.5% and 29.0% of the excess risk in South Asians and African Creoles, respectively.

CONCLUSIONS

Diabetes is associated with a 67% increased risk of disability. Diabetes risk factors and comorbidities explain more of the association between diabetes and disability among South Asians than Africans. Obesity and history of CVD explained the largest percentage of the relationship between diabetes and disability, indicating that weight and CVD management may be helpful in controlling disability related to diabetes.

Ethnic differences in insulin secretory function between black African and white European men with early type 2 diabetes

AIM

To test the hypothesis that men of black (West) African ethnicity (black African men [BAM]) with early type 2 diabetes (T2D) would have greater insulin secretory deficits compared with white European men (WEM), following prediabetic hypersecretion.

METHODS

In 19 BAM and 15 WEM, matched for age, body mass index and duration of diabetes, we assessed and modelled insulin secretory responses to hyperglycaemia stimulated intravenously (hyperglycaemic clamp) and orally (meal tolerance test).

RESULTS

With similar post-challenge glucose responses, BAM had lower second-phase C-peptide responses to intravenous glucose (BAM 70.6 vs WEM 115.1 nmol/L/min [ratio of geometric mean 0.55, 95% confidence interval {CI} 0.37, 0.83]; P = .006) and to oral glucose (BAM 65.4 vs WEM 88.5 nmol/L/min [mean difference -23.2, 95% CI -40.0, -6.3]; P = .009). Peripheral insulin response in BAM to oral glucose was preserved (BAM 47.4 vs WEM 59.4 nmol/L/min [ratio of geometric mean 0.89, 95% CI 0.59, 1.35]; P = .566), with relative reductions in insulin clearance (BAM 506.2 vs WEM 630.1 mL/m² BSA/min [mean difference -123.9, 95% CI -270.5, 22.6]; P = .095), associated with enhanced incretin responses (gastric inhibitory polypeptide incremental area under the curve: BAM 46.8 vs WEM 33.9 μg/L/min [mean difference 12.9, 95% CI 2.1, 23.7]; P = .021).

CONCLUSIONS

In early T2D, BAM had significantly lower insulin secretory responses to intravenous and oral stimulation than WEM. Lower insulin clearance, potentially driven by increased incretin responses, may act to preserve peripheral insulin concentrations. Tailoring early management strategies to reflect distinct ethnic-specific pathophysiology may improve outcomes in this high-risk population.

Fasting plasma glucose and variation in cardiometabolic risk factors in people with high-risk HbA1c-defined prediabetes: A cross-sectional multiethnic study

AIMS

Variation in cardiometabolic risk in prediabetes and any impacts of ethnicity on such variation have been little studied. In an ethnically diverse dataset, selected according to a high-risk HbA1c-based definition of prediabetes, we have investigated relationships between glycaemia and cardiometabolic risk factors and the influence of ethnicity on these relationships.

METHODS

We undertook a cross-sectional analysis of baseline data from a diabetes prevention study in the UK and a chronic care clinic in Thailand, selected for people without diabetes (fasting plasma glucose <7.0 mmol/l) with HbA1c 6.0-6.4% (42-47 mmol/mol). Thai (n=158) and UK White (n=600), South Asian (n=112), Black (n=70) and other/mixed (n=103) groups were distinguished and measurements included fasting plasma glucose (FPG), blood pressure (BP), lipids and insulin resistance-related risk factors (IRFs).

RESULTS

Independently of individual characteristics including ethnicity, only systolic BP was weakly associated with FPG (beta coefficient 1.76 (95%CI 0.10-3.42), p 0.03) and only LDL-c with IFG (FPG 5.6 to <7) (adjusted -0.14 (-0.27, -0.003) p 0.04). There were no significant independent associations with cardiometabolic risk factors when categories of impaired fasting glucose (FPG ≥ 6.1 to <7.0 mmol/L) were considered. Relative to White, South Asian ethnicity was independently associated with lower systolic and diastolic BP, Black with lower triglycerides, cholesterol/HDL-c ratio and having 2 or more IRFs, and Thai with lower cholesterol/HDL-c ratio and all three non-white ethnicities with lower total and LDL cholesterol.

CONCLUSION

In high-risk HbA1c-defined prediabetes additional measurement of FPG will add little to evaluation of cardiometabolic risk. Additionally, UK Whites tend to have the most adverse cardiometabolic profile of any ethnic group.

Metabolic Surgery in the Treatment Algorithm for Type 2 Diabetes: A Joint Statement by International Diabetes Organizations

BACKGROUND

Despite growing evidence that bariatric/metabolic surgery powerfully improves type 2 diabetes (T2D), existing diabetes treatment algorithms do not include surgical options.

AIM

The 2nd Diabetes Surgery Summit (DSS-II), an international consensus conference, was convened in collaboration with leading diabetes organizations to develop global guidelines to inform clinicians and policymakers about benefits and limitations of metabolic surgery for T2D.

METHODS

A multidisciplinary group of 48 international clinicians/scholars (75% nonsurgeons), including representatives of leading diabetes organizations, participated in DSS-II. After evidence appraisal (MEDLINE [1 January 2005-30 September 2015]), three rounds of Delphi-like questionnaires were used to measure consensus for 32 data-based conclusions. These drafts were presented at the combined DSS-II and 3rd World Congress on Interventional Therapies for Type 2 Diabetes (London, U.K., 28-30 September 2015), where they were open to public comment by other professionals and amended face-to-face by the Expert Committee.

RESULTS

Given its role in metabolic regulation, the gastrointestinal tract constitutes a meaningful target to manage T2D. Numerous randomized clinical trials, albeit mostly short/midterm, demonstrate that metabolic surgery achieves excellent glycemic control and reduces cardiovascular risk factors. On the basis of such evidence, metabolic surgery should be recommended to treat T2D in patients with class III obesity (BMI≥40 kg/m(2)) and in those with class II obesity (BMI 35.0-39.9 kg/m(2)) when hyperglycemia is inadequately controlled by lifestyle and optimal medical therapy. Surgery should also be considered for patients with T2D and BMI 30.0-34.9 kg/m(2) if hyperglycemia is inadequately controlled despite optimal treatment with either oral or injectable medications. These BMI thresholds should be reduced by 2.5 kg/m(2) for Asian patients.

CONCLUSIONS

Although additional studies are needed to further demonstrate long-term benefits, there is sufficient clinical and mechanistic evidence to support inclusion of metabolic surgery among antidiabetes interventions for people with T2D and obesity. To date, the DSS-II guidelines have been formally endorsed by 45 worldwide medical and scientific societies. Health care regulators should introduce appropriate reimbursement policies.

Metabolic Surgery in the Treatment Algorithm for Type 2 Diabetes: a Joint Statement by International Diabetes Organizations

BACKGROUND

Despite growing evidence that bariatric/metabolic surgery powerfully improves type 2 diabetes (T2D), existing diabetes treatment algorithms do not include surgical options.

AIM

The 2nd Diabetes Surgery Summit (DSS-II), an international consensus conference, was convened in collaboration with leading diabetes organizations to develop global guidelines to inform clinicians and policymakers about benefits and limitations of metabolic surgery for T2D.

METHODS

A multidisciplinary group of 48 international clinicians/scholars (75% nonsurgeons), including representatives of leading diabetes organizations, participated in DSS-II. After evidence appraisal (MEDLINE [1 January 2005-30 September 2015]), three rounds of Delphi-like questionnaires were used to measure consensus for 32 data-based conclusions. These drafts were presented at the combined DSS-II and 3rd World Congress on Interventional Therapies for Type 2 Diabetes (London, U.K., 28-30 September 2015), where they were open to public comment by other professionals and amended face-to-face by the Expert Committee.

RESULTS

Given its role in metabolic regulation, the gastrointestinal tract constitutes a meaningful target to manage T2D. Numerous randomized clinical trials, albeit mostly short/midterm, demonstrate that metabolic surgery achieves excellent glycemic control and reduces cardiovascular risk factors. On the basis of such evidence, metabolic surgery should be recommended to treat T2D in patients with class III obesity (BMI ≥40 kg/m²) and in those with class II obesity (BMI 35.0-39.9 kg/m²) when hyperglycemia is inadequately controlled by lifestyle and optimal medical therapy. Surgery should also be considered for patients with T2D and BMI 30.0-34.9 kg/m² if hyperglycemia is inadequately controlled despite optimal treatment with either oral or injectable medications. These BMI thresholds should be reduced by 2.5 kg/m² for Asian patients.

CONCLUSIONS

Although additional studies are needed to further demonstrate long-term benefits, there is sufficient clinical and mechanistic evidence to support inclusion of metabolic surgery among antidiabetes interventions for people with T2D and obesity. To date, the DSS-II guidelines have been formally endorsed by 45 worldwide medical and scientific societies. Health care regulators should introduce appropriate reimbursement policies.

Metabolic Surgery in the Treatment Algorithm for Type 2 Diabetes: A Joint Statement by International Diabetes Organizations

BACKGROUND

Despite growing evidence that bariatric/metabolic surgery powerfully improves type 2 diabetes (T2D), existing diabetes treatment algorithms do not include surgical options.

AIM

The 2nd Diabetes Surgery Summit (DSS-II), an international consensus conference, was convened in collaboration with leading diabetes organizations to develop global guidelines to inform clinicians and policymakers about benefits and limitations of metabolic surgery for T2D.

METHODS

A multidisciplinary group of 48 international clinicians/scholars (75% nonsurgeons), including representatives of leading diabetes organizations, participated in DSS-II. After evidence appraisal (MEDLINE [1 January 2005-30 September 2015]), three rounds of Delphi-like questionnaires were used to measure consensus for 32 data-based conclusions. These drafts were presented at the combined DSS-II and 3rd World Congress on Interventional Therapies for Type 2 Diabetes (London, U.K., 28-30 September 2015), where they were open to public comment by other professionals and amended face-to-face by the Expert Committee.

RESULTS

Given its role in metabolic regulation, the gastrointestinal tract constitutes a meaningful target to manage T2D. Numerous randomized clinical trials, albeit mostly short/midterm, demonstrate that metabolic surgery achieves excellent glycemic control and reduces cardiovascular risk factors. On the basis of such evidence, metabolic surgery should be recommended to treat T2D in patients with class III obesity (BMI ≥40 kg/m(2)) and in those with class II obesity (BMI 35.0-39.9 kg/m(2)) when hyperglycemia is inadequately controlled by lifestyle and optimal medical therapy. Surgery should also be considered for patients with T2D and BMI 30.0-34.9 kg/m(2) if hyperglycemia is inadequately controlled despite optimal treatment with either oral or injectable medications. These BMI thresholds should be reduced by 2.5 kg/m(2) for Asian patients.

CONCLUSIONS

Although additional studies are needed to further demonstrate long-term benefits, there is sufficient clinical and mechanistic evidence to support inclusion of metabolic surgery among antidiabetes interventions for people with T2D and obesity. To date, the DSS-II guidelines have been formally endorsed by 45 worldwide medical and scientific societies. Health care regulators should introduce appropriate reimbursement policies.

Epidemiology of Diabetes-Status of a Pandemic and Issues Around Metabolic Surgery

The number of people with diabetes worldwide has more than doubled during the past 20 years. One of the most worrying features of this rapid increase is the emergence of type 2 diabetes in children, adolescents, and young adults. Although the role of traditional risk factors for type 2 diabetes, such as genetic, lifestyle, and behavioral risk factors, has been given attention, recent research has focused on identifying the contributions of epigenetic mechanisms and the effect of the intrauterine environment. Epidemiological data predict an inexorable and unsustainable increase in global health expenditure attributable to diabetes, so disease prevention should be given high priority. An integrated approach is needed to prevent type 2 diabetes and must recognize its heterogeneity. Future research needs to be directed at improved understanding of the potential role of determinants, such as the maternal environment and other early life factors, as well as changing trends in global demography, to help shape disease prevention programs. Equally important is a better understanding of the role of metabolic surgery in helping to address the management both of persons with type 2 diabetes and of those persons in the community who are at higher risk for type 2 diabetes, particularly in emerging nations where the diabetes epidemic is in full flight.

Barriers to the delivery of diabetes care in the Middle East and South Africa: a survey of 1,082 practising physicians in five countries

AIMS

Developing countries face a high and growing burden of type 2 diabetes. We surveyed physicians in a diverse range of countries in the Middle East and Africa (Egypt, Kingdom of Saudi Arabia, United Arab Emirates, South Africa and Lebanon) with regard to their perceptions of barriers to type 2 diabetes care identified as potentially important in the literature and by the authors.

METHODS

One thousand and eighty-two physicians completed a questionnaire developed by the authors.

RESULTS

Most physicians enrolled in the study employed guideline-driven care; 80-100% of physicians prescribed metformin (with lifestyle intervention, where there are no contraindications) for newly diagnosed type 2 diabetes, with lifestyle intervention alone used where metformin was not prescribed. Sulfonylureas were prescribed widely, consistent with the poor economic status of many patients. About one quarter of physicians were not undertaking any form of continuing medical education, and relatively low proportions of practices had their own diabetes educators, dieticians or diabetic foot specialists. Physicians identified the deficiencies of their patients (unhealthy lifestyles, lack of education and poor diet) as the most important barriers to optimal diabetes care. Low-treatment compliance was not ranked highly. Access to physicians did not appear to be a problem, as most patients were seen multiple times per year.

CONCLUSIONS

Physicians in the Middle East and South Africa identified limitations relating to their patients as the main barrier to delivering care for diabetes, without giving high priority to issues relating to processes of care delivery. Further study would be needed to ascertain whether these findings reflect an unduly physician-centred view of their practice. More effective provision of services relating to the prevention of complications and improved lifestyles may be needed.

Glucose-independent ethnic differences in HbA1c in people without known diabetes

OBJECTIVE

To determine whether glucose-independent differences in HbA1c exist between people of African, South Asian, and Chinese ethnicities.

RESEARCH DESIGN AND METHODS

Data from 6,701 people aged 19-78 years, without known diabetes, from Mauritius, and participating in the population-based Non-Communicable Disease Surveys of the main island and the island of Rodrigues were included. Participants were African (n = 1,219 from main island, n = 1,505 from Rodrigues), South Asian (n = 3,820), and Chinese (n = 157). Survey data included HbA1c, plasma glucose during oral glucose tolerance testing (OGTT), anthropometry, demographics, and medical and lifestyle history.

RESULTS

Mean HbA1c, after adjustment for fasting and 2-h plasma glucose and other factors known to influence HbA1c, was higher in Africans from Rodrigues (6.1%) than in South Asians (5.7%, P < 0.001), Chinese (5.7%, P < 0.001), or Africans from the main island of Mauritius (5.7%, P < 0.001). The age-standardized prevalence of diabetes among Africans from Rodrigues differed substantially depending on the diagnostic criteria used [OGTT 7.9% (95% CI 5.8-10.0); HbA1c 17.3% (15.3-19.2)]. Changing diagnostic criteria resulted in no significant change in the prevalence of diabetes within the other ethnic groups.

CONCLUSIONS

People of African ethnicity from Rodrigues have higher HbA1c than those of South Asian or African ethnicity from the main island of Mauritius for reasons not explained by plasma glucose during an OGTT or traditional factors known to affect glycemia. Further research should be directed at determining the mechanism behind this disparity and its relevance to clinical outcomes.

The publication of Diabetes UK position statements and care recommendations; a virtual issue

Diabetes UK is the charity that cares for, connects with and campaigns on behalf of all people affected by and at risk of diabetes. Founded in 1934 by the novelist H. G. Wells and Dr R. D. Lawrence, the charity has always combined the expertise of lay and professional members to achieve its mission to improve the lives of people with diabetes and to work towards a future without diabetes.

All-cause cancer mortality over 15 years in multi-ethnic Mauritius: the impact of diabetes and intermediate forms of glucose tolerance

There are accumulating data describing the association between diabetes and cancer mortality from Westernised populations. There are no data describing the relationship between diabetes and cancer mortality in African or South Asian populations from developing countries. We explored the relationship of abnormal glucose tolerance and diabetes on cancer mortality risk in a large, multi-ethnic cohort from the developing nation of Mauritius. Population-based surveys were undertaken in 1987, 1992 and 1998. The 9559 participants comprised 66% of South Asian (Indian), 27% of African (Creole), and 7% of Chinese descent. Cox's proportional hazards model with time varying covariates was used to obtain hazard ratios (HRs) and 95% confidence intervals (95% CI) for risk of cancer mortality, after adjustment for confounding factors. In men, but not women, cancer mortality risk increased with rising 2h-PG levels with HR for the top versus bottom quintile of 2.77 (95%CI: 1.28 to 5.98). South Asian men with known diabetes had a significantly greater risk of cancer mortality than those with normal glucose tolerance (NGT) HR: 2.74 (95%CI: 1.00-7.56). Overall, impaired glucose tolerance was associated with an elevated risk of cancer mortality compared to NGT (HR: 1.47, 95% CI: 0.98-2.19), though this was not significant. We have shown that the association between abnormal glucose tolerance and cancer extends to those of African and South Asian descent. These results highlight the importance of understanding this relationship in a global context to direct future health policy given the rapid increase in type 2 diabetes, especially in developing nations.

Associations of infant nutrition with insulin resistance measures in early adulthood: evidence from the Barry-Caerphilly Growth (BCG) study

Background

Previous studies suggest that over-nutrition in early infancy may programme long-term susceptibility to insulin resistance.

Objective

To assess the association of breast milk and quantity of infant formula and cows' milk intake during infancy with insulin resistance measures in early adulthood.

Design

Long-term follow-up of the Barry Caerphilly Growth cohort, into which mothers and their offspring had originally been randomly assigned, between 1972–1974, to receive milk supplementation or not. Participants were the offspring, aged 23–27 years at follow-up (n = 679). Breastfeeding and formula/cows' milk intake was recorded prospectively by nurses. The main outcomes were insulin sensitivity (ISI₀) and insulin secretion (CIR₃₀).

Results

573 (84%) individuals had valid glucose and insulin results and complete covariate information. There was little evidence of associations of breastfeeding versus any formula/cows' milk feeding or of increasing quartiles of formula/cows' milk consumption during infancy (<3 months) with any outcome measure in young adulthood. In fully adjusted models, the differences in outcomes between breastfeeding versus formula/cows' milk feeding at 3 months were: fasting glucose (−0.07 mmol/l; 95% CI: −0.19, 0.05); fasting insulin (8.0%; −8.7, 27.6); ISI₀ (−6.1%; −11.3, 12.1) and CIR₃₀ (3.8%; −19.0, 32.8). There was also little evidence that increasing intakes of formula/cows' milk at 3 months were associated with fasting glucose (increase per quartile of formula/cows' milk intake = 0.00 mmol/l; −0.03, 0.03); fasting insulin (0.8%; −3.2, 5.1); ISI ₀ (−0.9%; −5.1, 3.5) and CIR₃₀ (−2.6%; −8.4, 3.6).

Conclusions

We found no evidence that increasing consumption of formula/cows' milk in early infancy was associated with insulin resistance in young adulthood.

Explaining the increase of diabetes prevalence and plasma glucose in Mauritius

OBJECTIVE

Secular trends in the epidemiology of diabetes are best described by studying the same population over time, but few such studies exist. Using surveys from Mauritius in 1987 and 2009, we examined 1) the change in the prevalence of diabetes, 2) the extent to which changes in traditional diabetes risk factors explained the increase, and 3) the change in the distribution of plasma glucose levels over time.

RESEARCH DESIGN AND METHODS

Independent population-based surveys were undertaken in Mauritius in 1987 and 2009 using similar methodology in adults aged 20-74 years. Physical measurements and fasting blood samples were taken, and an oral glucose tolerance test was performed at both surveys.

RESULTS

The age-standardized prevalence of diabetes in 2009 was 22.3% (95% CI 20.0-24.6) among men and 20.2% (18.3-22.3) among women, representing an increase since 1987 of 64 and 62% among men and women, respectively. Concurrent changes in the distribution of age, ethnicity, waist circumference, BMI, physical activity, smoking, family history of diabetes, and hypertension explained more of the increase in the prevalence of diabetes in men than in women. Increases in plasma glucose (especially fasting glucose) were seen across the population but were greater at the upper levels.

CONCLUSIONS

In Mauritius, there has been a marked increase in diabetes prevalence over 22 years. This mainly results from changes in traditional risk factors, leading to population-wide increases in plasma glucose levels. Interventions to control this escalation of diabetes should focus on population-wide strategies.

Cut-points for waist circumference in Europids and South Asians

There is little strong evidence that currently recommended higher waist circumference cut-points for Europids compared with South Asians are associated with similar risk for type 2 diabetes. This study was designed to provide such evidence. Longitudinal studies over 5 years were conducted among 5,515 Europid and 2,214 ethnically South Asian participants. Age-standardized diabetes incidence at different levels of waist circumference and incidence difference relative to a reference value were calculated. The Youden Index was used to determine waist circumference cut-points. At currently recommended cut-points, estimated annual diabetes incidence for a 50-year-old Europid was <0.6% for both sexes, and for a 50-year-old South Asian, 5.8% for men and 2.1% for women. Annual diabetes incidence of 1% was observed for a 50 year old at a waist circumference 35-40 cm greater in Europid compared to South Asian men and women. Incidence difference between recommended cut-points and a reference value (80 cm in men, 70 cm in women) was 0.3 and 4.4% per year for Europid and South Asian men, and 0.2 and 0.8% per year for Europid and South Asian women, respectively. Waist circumference cut-points chosen using the Youden Index were shown to be dependent on obesity levels in the population. The much higher observed risk of diabetes in South Asians compared to Europids at the respective recommended waist circumference cut-points suggests that differences between them should be greater. Approaches that use the Youden Index to select waist circumference cut-points are inappropriate and should not be used for this purpose.

Mortality, all-cause and cardiovascular disease, over 15 years in multiethnic mauritius: impact of diabetes and intermediate forms of glucose tolerance

OBJECTIVE

Little information is available on the impact of abnormal glucose tolerance on mortality in South Asian and African populations in the developing world. We explored this issue in a large, multiethnic cohort from the developing nation of Mauritius.

RESEARCH DESIGN AND METHODS

Population-based surveys were undertaken in 1987, 1992, and 1998. The 9,559 participants (20-82 years old) comprised 66% South Asian (Indian), 27% Creole (African), and 7% Chinese descent. Mortality was ascertained in 2007.

RESULTS

Over a median 15.1-year follow-up, 1,557 participants died. Compared with those with normal glucose tolerance, the all-cause mortality hazard ratios (HR) for known diabetes, newly diagnosed diabetes, and impaired glucose tolerance were 3.35 (95% CI 2.77-4.04), 2.11 (1.73-2.57), and 1.53 (1.26-1.87) in South Asians and 2.14 (1.65-2.79), 1.41 (1.06-1.88), and 1.08 (0.83-1.40) in Africans, respectively. Those with impaired fasting glucose were not at increased risk in either ethnicity. In the Chinese, only those with known diabetes were at increased risk of mortality with HR 3.68 (1.87-7.25).

CONCLUSIONS

This is the first study in a developing country of the impact of glucose intolerance on mortality in an African population, and one of the first studies of a South Asian population. It shows that the impact on mortality in these populations in Mauritius is comparable to that seen in developed countries. These results are important in a global context for future health policy in light of the impact of the rapid increase in prevalence of diabetes, especially in developing nations.

Early emergence of ethnic differences in type 2 diabetes precursors in the UK: the Child Heart and Health Study in England (CHASE Study)

BACKGROUND

Adults of South Asian origin living in the United Kingdom have high risks of type 2 diabetes and central obesity; raised circulating insulin, triglyceride, and C-reactive protein concentrations; and low HDL-cholesterol when compared with white Europeans. Adults of African-Caribbean origin living in the UK have smaller increases in type 2 diabetes risk, raised circulating insulin and HDL-cholesterol, and low triglyceride and C-reactive protein concentrations. We examined whether corresponding ethnic differences were apparent in childhood.

METHODS AND FINDINGS

We performed a cross-sectional survey of 4,796 children aged 9-10 y in three UK cities who had anthropometric measurements (68% response) and provided blood samples (58% response); ethnicity was based on parental definition. In age-adjusted comparisons with white Europeans (n = 1,153), South Asian children (n = 1,306) had higher glycated haemoglobin (HbA1c) (% difference: 2.1, 95% CI 1.6 to 2.7), fasting insulin (% difference 30.0, 95% CI 23.4 to 36.9), triglyceride (% difference 12.9, 95% CI 9.4 to 16.5), and C-reactive protein (% difference 43.3, 95% CI 28.6 to 59.7), and lower HDL-cholesterol (% difference -2.9, 95% CI -4.5 to -1.3). Higher adiposity levels among South Asians (based on skinfolds and bioimpedance) did not account for these patterns. Black African-Caribbean children (n = 1,215) had higher levels of HbA1c, insulin, and C-reactive protein than white Europeans, though the ethnic differences were not as marked as in South Asians. Black African-Caribbean children had higher HDL-cholesterol and lower triglyceride levels than white Europeans; adiposity markers were not increased.

CONCLUSIONS

Ethnic differences in type 2 diabetes precursors, mostly following adult patterns, are apparent in UK children in the first decade. Some key determinants operate before adult life and may provide scope for early prevention.

The metabolic syndrome: useful concept or clinical tool? Report of a WHO Expert Consultation

This article presents the conclusions of a WHO Expert Consultation that evaluated the utility of the 'metabolic syndrome' concept in relation to four key areas: pathophysiology, epidemiology, clinical work and public health. The metabolic syndrome is a concept that focuses attention on complex multifactorial health problems. While it may be considered useful as an educational concept, it has limited practical utility as a diagnostic or management tool. Further efforts to redefine it are inappropriate in the light of current knowledge and understanding, and there is limited utility in epidemiological studies in which different definitions of the metabolic syndrome are compared. Metabolic syndrome is a pre-morbid condition rather than a clinical diagnosis, and should thus exclude individuals with established diabetes or known cardiovascular disease (CVD). Future research should focus on: (1) further elucidation of common metabolic pathways underlying the development of diabetes and CVD, including those clustering within the metabolic syndrome; (2) early-life determinants of metabolic risk; (3) developing and evaluating context-specific strategies for identifying and reducing CVD and diabetes risk, based on available resources; and (4) developing and evaluating population-based prevention strategies.

Higher leptin levels in Asian Indians than Creoles and Europids: a potential explanation for increased metabolic risk

BACKGROUND AND PURPOSE

Leptin predicts cardiovascular diseases and type 2 diabetes, diseases to which Asian Indians are highly susceptible. As a risk marker, leptin's intra-individual and seasonal stability is unstudied and only small studies have compared leptin levels in Asian Indians with other populations. The aim of this study was to explore ethnicity related differences in leptin levels and its intra-individual and seasonal stability.

METHODS

Leptin and anthropometric data from the northern Sweden MONICA (3513 Europids) and the Mauritius Non-communicable Disease (2480 Asian Indians and Creoles) studies were used. In both studies men and women, 25- to 74-year old, participated in both an initial population survey and a follow-up after 5-13 years. For the analysis of seasonal leptin variation, a subset of 1780 participants, 30- to 60-year old, in the Västerbotten Intervention Project was used.

RESULTS

Asian Indian men and women had higher levels of leptin, leptin per body mass index (BMI) unit (leptin/BMI) or per cm in waist circumference (WC; leptin/waist) than Creoles and Europids when adjusted for BMI (all P<0.0005) or WC (all P<0.005). In men, Creoles had higher leptin, leptin/BMI and leptin/waist than Europids when adjusted for BMI or WC (all P<0.0005). In women, Creoles had higher leptin/BMI and leptin/waist than Europids only when adjusted for WC (P<0.0005). Asian Indian ethnicity in both sexes, and Creole ethnicity in men, was independently associated with high leptin levels. The intra-class correlation for leptin was similar (0.6-0.7), independently of sex, ethnicity or follow-up time. No seasonal variation in leptin levels was seen.

CONCLUSION

Asian Indians have higher levels of leptin, leptin/BMI and leptin/waist than Creoles and Europids. Leptin has a high intra-individual stability and seasonal leptin variation does not appear to explain the ethnic differences observed here.

Optimising the medical management of hyperglycaemia in type 2 diabetes in the Middle East: pivotal role of metformin

AIMS

Increases in the prevalence of type 2 diabetes will likely be greater in the Middle East and other developing countries than in most other regions during the coming two decades, placing a heavy burden on regional healthcare resources.

METHODOLOGY

Medline search, examination of data from major epidemiological studies in the Middle Eastern countries.

RESULTS

The aetiology and pathophysiology of diabetes appears comparable in Middle Eastern and other populations. Lifestyle intervention is key to the management of diabetes in all type 2 diabetes patients, who should be encouraged strongly to diet and exercise. The options for pharmacologic therapy in the management of diabetes have increased recently, particularly the number of potential antidiabetic combinations. Metformin appears to be used less frequently to initiate antidiabetic therapy in the Middle East than in other countries. Available clinical evidence, supported by current guidelines, strongly favours the initiation of antidiabetic therapy with metformin in Middle Eastern type 2 diabetes patients, where no contraindications exist. This is due to its equivalent or greater efficacy relative to other oral antidiabetic treatments, its proven tolerability and safety profiles, its weight neutrality, the lack of clinically significant hypoglycaemia, the demonstration of cardiovascular protection for metformin relative to diet in the UK Prospective Diabetes Study and in observational studies, and its low cost. Additional treatments should be added to metformin and lifestyle intervention as diabetes progresses, until patients are receiving an intensive insulin regimen with or without additional oral agents.

CONCLUSIONS

The current evidence base strongly favours the initiation of antidiabetic therapy with metformin, where no contraindications exist. However, metformin may be under-prescribed in the Middle East.

Harmonizing the Metabolic Syndrome

A cluster of risk factors for cardiovascular disease and type 2 diabetes mellitus, which occur together more often than by chance alone, have become known as the metabolic syndrome. The risk factors include raised blood pressure, dyslipidemia (raised triglycerides and lowered high-density lipoprotein cholesterol), raised fasting glucose, and central obesity. Various diagnostic criteria have been proposed by different organizations over the past decade. Most recently, these have come from the International Diabetes Federation and the American Heart Association/National Heart, Lung, and Blood Institute. The main difference concerns the measure for central obesity, with this being an obligatory component in the International Diabetes Federation definition, lower than in the American Heart Association/National Heart, Lung, and Blood Institute criteria, and ethnic specific. The present article represents the outcome of a meeting between several major organizations in an attempt to unify criteria. It was agreed that there should not be an obligatory component, but that waist measurement would continue to be a useful preliminary screening tool. Three abnormal findings out of 5 would qualify a person for the metabolic syndrome. A single set of cut points would be used for all components except waist circumference, for which further work is required. In the interim, national or regional cut points for waist circumference can be used.

The metabolic syndrome: in need of a global mission statement

AIMS

The value of clinical definitions of the metabolic syndrome has been questioned, with confusion surrounding their intended use and purpose. Our aim was to construct a mission statement that outlines the value of the metabolic syndrome in clinical and public health settings.

METHODS

Case studies have been used to demonstrate three key points.

RESULTS

We argue here for recognition of obesity as being a crucial element within the metabolic syndrome but perhaps even more important before its development. We also contend that the concept does indeed have a role as a risk prediction tool, and that it could provide a useful metric for the scale and progress of the looming global epidemic of diabetes and cardiovascular disease.

CONCLUSIONS

Through appreciation of its purpose, and recognition of both its limitations and those attributes that make it unique and valuable, we believe we have demonstrated here that the metabolic syndrome deserves its place in the global toolbox of diabetes and CVD prevention.

Hyperglycemia and stroke mortality: comparison between fasting and 2-h glucose criteria

OBJECTIVE

We investigated stroke mortality in individuals in different categories of glycemia and compared hazard ratios (HRs) corresponding to a 1-SD increase in 2-h plasma glucose and fasting plasma glucose (FPG) criteria.

RESEARCH DESIGN AND METHODS

We examined data from 2-h 75-g oral glucose tolerance tests taken from 13 European cohorts comprising 11,844 (55%) men and 9,862 (45%) women who were followed up for a median of 10.5 years. A multivariate adjusted Cox proportional hazards model was used to estimate HRs for stroke mortality.

RESULTS

In men and women without a prior history of diabetes, multivariate adjusted HRs for stroke mortality corresponding to a 1-SD increase in FPG were 1.02 (95% CI 0.83-1.25) and 1.52 (1.22-1.88) and those in 2-h plasma glucose 1.21 (1.06-1.38) and 1.31 (1.06-1.61), respectively. Addition of 2-h plasma glucose to the model with FPG significantly improved prediction of stroke mortality in men (chi2 = 10.12; P = 0.001) but not in women (chi2 = 0.01; P = 0.94), whereas addition of FPG to 2-h plasma glucose improved stroke mortality in women (chi2 = 4.08; P = 0.04) but not in men (chi2 = 3.29; P = 0.07).

CONCLUSIONS

Diabetes defined by either FPG or 2-h plasma glucose increases the risk of stroke mortality. In individuals without a history of diabetes, elevated 2-h postchallenge glucose is a better predictor than elevated fasting glucose in men, whereas the latter is better than the former in women.

BMI compared with central obesity indicators as a predictor of diabetes incidence in Mauritius

The aim of the study was to compare BMI with waist circumference (WC), waist-to-hip ratio (WHR), and waist-to-stature ratio (WSR) as a predictor of diabetes incidence. A total of 1,841 men and 2,104 women of Mauritian Indian and Mauritian Creole ethnicity, aged 25-74 years, free of diabetes, hypertension, cardiovascular disease, and gout were seen at baseline in 1987 or 1992, and follow-up in 1992 and/or 1998. At all time points, participants underwent a 2 h 75 g oral glucose tolerance test. Hazard ratios for diabetes incidence were estimated applying an interval-censored survival analysis using age as timescale. Six hundred and twenty-eight individuals developed diabetes during the follow-up period. Multivariable adjusted hazard ratios for diabetes incidence corresponding to a 1 s.d. increase in baseline BMI, WC, WHR, and WSR for Mauritian Indians were 1.49 (1.31-1.71), 1.58 (1.38-1.81), 1.54 (1.37-1.72), and 1.61 (1.41-1.84) in men and 1.33 (1.17-1.51), 1.35 (1.19-1.53), 1.39 (1.24-1.55), and 1.38 (1.21-1.57) in women, respectively; and for Mauritian Creoles they were 1.86 (1.51-2.30), 2.07 (1.68-2.56), 1.92 (1.62-2.26), and 2.17 (1.76-2.69) in men and 1.29 (1.06-1.55), 1.27 (1.04-1.55), 1.24 (1.04-1.48), and 1.27 (1.04-1.55) in women. Paired homogeneity tests showed that there was no difference between BMI and each of the central obesity indicators (all P > 0.05). The relation of BMI with the development of diabetes was as strong as that for indicators of central obesity in this study population.

Central obesity as a precursor to the metabolic syndrome in the AusDiab study and Mauritius

Evidence from epidemiologic studies that central obesity precedes future metabolic change and does not occur concurrently with the appearance of the blood pressure, glucose, and lipid abnormalities that characterize the metabolic syndrome (MetS) has been lacking. Longitudinal surveys were conducted in Mauritius in 1987, 1992, and 1998, and in Australia in 2000 and 2005 (AusDiab). This analysis included men and women (aged > or = 25 years) in three cohorts: AusDiab 2000-2005 (n = 5,039), Mauritius 1987-1992 (n = 2,849), and Mauritius 1987-1998 (n = 1,999). MetS components included waist circumference, systolic blood pressure, fasting and 2-h postload plasma glucose, high-density lipoprotein (HDL) cholesterol, triglycerides, and homeostasis model assessment of insulin sensitivity (HOMA-S) (representing insulin sensitivity). Linear regression was used to determine which baseline components predicted deterioration in other MetS components over 5 years in AusDiab and 5 and 11 years in Mauritius, adjusted for age, sex, and ethnic group. Baseline waist circumference predicted deterioration (P < 0.01) in four of the other six MetS variables tested in AusDiab, five of six in Mauritius 1987-1992, and four of six in Mauritius 1987-1998. In contrast, an increase in waist circumference between baseline and follow-up was only predicted by insulin sensitivity (HOMA-S) at baseline, and only in one of the three cohorts. These results suggest that central obesity plays a central role in the development of the MetS and appears to precede the appearance of the other MetS components.

Blood lipid levels in relation to glucose status in European men and women without a prior history of diabetes: the DECODE Study

OBJECTIVE

Dyslipidaemia is present not only in diabetic but also in prediabetic subjects. The purpose of this study is to investigate the relationship between lipid and glucose levels in a large European population without a prior history of diabetes.

RESEARCH DESIGN AND METHODS

Data from the population-based studies of 8960 men and 10,516 women aged 35-74 years representing 15 cohorts in 8 European countries were jointly analyzed. Multivariate adjusted linear regression analyses with standardized coefficients (beta) were performed to estimate the relationship between lipid and plasma glucose.

RESULTS

In subjects without a prior history of diabetes, positive relationships were shown between fasting plasma glucose (FPG) and total cholesterol (TC) (beta=0.06 and 0.03, respectively for men and women, p<0.01), triglycerides (TG) (beta=0.14 and 0.12, p<0.001), non-high-density lipoprotein cholesterol (non-HDL-C) (beta=0.06 and 0.03, p<0.01) and TC to HDL ratio (beta=0.06 and 0.05, p<0.001) but a negative trend between FPG and HDL-C (beta=-0.02, p>0.05 in men and beta=-0.03, p<0.05 in women). The relationship between lipid and 2-h plasma glucose (2hPG) followed a similar pattern as that for FPG, except that TC was not increased and HDL-C was reduced in both sexes in subjects with impaired glucose tolerance (IGT).

CONCLUSIONS

For cardiovascular prevention, the different lipid patterns between impaired fasting glucose (IFG) and IGT may deserve further attention to evaluate the combined risks of dyslipidaemia and elevated glucose levels below the diagnostic threshold of diabetes.

Sleep-disordered breathing and type 2 diabetes: a report from the International Diabetes Federation Taskforce on Epidemiology and Prevention

Sleep-disordered breathing (SDB) has been associated with insulin resistance and glucose intolerance, and is frequently found in people with type 2 diabetes. SDB not only causes poor sleep quality and daytime sleepiness, but has clinical consequences, including hypertension and increased risk of cardiovascular disease. In addition to supporting the need for further research into the links between SDB and diabetes, the International Diabetes Federation Taskforce on Epidemiology and Prevention strongly recommends that health professionals working in both type 2 diabetes and SDB adopt clinical practices to ensure that a patient presenting with one condition is considered for the other.

Ethnic and sex differences in circulating endotoxin levels: A novel marker of atherosclerotic and cardiovascular risk in a British multi-ethnic population

BACKGROUND

Circulating endotoxin levels are associated with atherosclerosis. Moreover, ethnic differences in pro-inflammatory markers may be associated with ethnic differences in atherosclerotic and cardiovascular (CVD) and coronary heart disease (CHD) risk.

OBJECTIVE AND METHODS

To investigate ethnic differences in circulating plasma endotoxin levels, its soluble receptor (sCD14), and high-sensitivity CRP (hs-CRP). 192 individuals, aged 40-59 years (61 white (30 women), 68 of African origin (33 women) and 63 South Asians (33 women)), free from coronary heart disease (CHD), stroke, CVD and diabetes were randomly selected from the UK 'Wandsworth Heart and Stroke Study'.

RESULTS

Age-adjusted endotoxin levels were lower in women than in men (p=0.002) and were highest in South Asians (13.3EU/mL [95% CI 12.0-14.7]) and lowest in individuals of African origin (10.1EU/mL [9.1-11.1]) than in whites (p for linear trend <0.001). Endotoxin levels were positively associated with waist, waist-hip ratio, total cholesterol, serum triglycerides and serum insulin levels and negatively associated with serum HDL-cholesterol. Serum hs-CRP and plasma sCD14 varied by ethnic group (p<0.001) but was not associated with endotoxin.

CONCLUSIONS

This study is the first to indicate a graded increase in endotoxin levels from black Africans to whites to South Asians, which is consistent with the ethnic difference in CHD risk. Whilst these findings support the concept that the innate immune system (IIS) may contribute significantly to the metabolic component underlying the development of CVD and CHD risk, further studies are required to see whether endotoxin levels are causally related to the development of CHD.

Partnering with governments and other institutions: driving change in diabetes care

The human and material cost of type 2 diabetes is a cause of increasing concern for health professionals, representative organisations and governments worldwide. The scale of morbidity and mortality has led the United Nations to issue a resolution on diabetes, calling for national policies for prevention, treatment and care. There is clearly an urgent need for a concerted response from all interested parties at the community, national and international level to work towards the goals of the resolution and create effective, sustainable treatment models, care systems and prevention strategies. Action requires both a 'bottom-up' approach of public awareness campaigns and pressure from healthcare professionals, coupled with a 'top-down' drive for change, via partnerships with governments, third sector (non-governmental) organisations and other institutions. In this review, we examine how existing collaborative initiatives serve as examples for those seeking to implement change in health policy and practice in the quest to alleviate the health and economic burden of diabetes. Efforts are underway to provide continuous and comprehensive care models for those who already have type 2 diabetes; in some cases, national plans extend to prevention strategies in attempts to improve overall public health. In the spirit of partnership, collaborations with governments that incorporate sustainability, long-term goals and a holistic approach continue to be a driving force for change. It is now critical to maintain this momentum and use the growing body of compelling evidence to educate, inform and deliver a long-term, lasting impact on patient and public health worldwide.

The metabolic syndrome as a predictor of incident diabetes mellitus in Mauritius

AIMS

To assess the utility of the metabolic syndrome (MetS) and a Diabetes Predicting Model as predictors of incident diabetes.

METHODS

A longitudinal survey was conducted in Mauritius in 1987 (n = 4972; response 80%) and 1992 (n = 3685; follow-up 74.2%). Diabetes status was retrospectively determined using 1999 World Health Organization (WHO) criteria. MetS was determined according to four definitions and sensitivity, positive predictive value (PPV), specificity and the association with incident diabetes before and after adjustment for MetS components calculated.

RESULTS

Of the 3198 at risk, 297 (9.2%) developed diabetes between 1987 and 1992. The WHO MetS definition had the highest prevalence (20.3%), sensitivity (42.1%) and PPV (26.8%) for prediction of incident diabetes, the strongest association with incident diabetes after adjustment for age and sex [odds ratio 4.6 (3.5-6.0)] and was the only definition to show a significant association after adjustment for its component parts (in men only). The low prevalence and sensitivity of the International Diabetes Federation (IDF) and ATPIII MetS definitions resulted from waist circumference cut-points that were high for this population, particularly in men, and both were not superior to a diabetes predicting model on receiver operating characteristic analysis.

CONCLUSIONS

Of the MetS definitions tested, the WHO definition best identifies those who go on to develop diabetes, but is not often used in clinical practice. If cut-points or measures of obesity appropriate for this population were used, the IDF and ATPIII MetS definitions could be recommended as useful tools for prediction of diabetes, given their relative simplicity.

Waist circumference cut-off points for identification of abdominal obesity among the tunisian adult population

AIMS

Waist circumference (WC) is a convenient measure of abdominal adipose tissue. It itself is a cardiovascular disease (CVD) and diabetes-risk factor and is strongly linked to other CVD risk factors. There are, however, ethnic differences in the relationship of WC to the other risk factors. The aim of this study was to determine the optimal cut-off points of WC and body mass index (BMI) at which cardiovascular risk factors can be identified with maximum sensitivity and specificity in a representative sample of the Tunisian adult population and to investigate any correlation between WC and BMI.

METHODS

We used a sample of the Tunisian National Nutrition Survey, a cross-sectional population-based survey, conducted in 1996 on a large nationally representative sample, which included 3435 adults (1244 men and 2191 women) of 20 years or older. WC, BMI, blood pressure and fasting blood measurements (plasma glucose, total cholesterol, triglycerides) were recorded. Receiver operating characteristic (ROC) curve analysis was used to identify optimal cut-off values of WC and BMI to identify with maximum sensitivity and specificity the detection of high blood pressure, hyperglycaemia, high blood cholesterol and hypertriglyceridaemia.

RESULTS

ROC curve analysis suggested WC cut-off points of 85 cm in men and 85 cm in women for the optimum detection of high blood pressure, diabetes and dyslipidaemia. The optimum BMI cut-off points for predicting cardiovascular risk factors were 24 kg/m(2) in men and 27 kg/m(2) in women. The cut-off points recommended for the Caucasian population differ from those appropriate for the Tunisian population. The data show a continuous increase in odds ratios of each cardiovascular risk factor, with increasing level of WC and BMI. WC exceeding 85 cm in men and 79 cm in women correctly identified subjects with a BMI of >/=25 kg/m(2), sensitivity of >90% and specificity of >83%.

CONCLUSIONS

Based on the ROC analysis, we suggest a WC of 85 cm for both men and women as appropriate cut-off points to identify central obesity for the purposes of CVD and diabetes-risk detection among Tunisians. WCs of 85 cm in men and 79 cm in women were the most sensitive and specific to identify most subjects with a BMI >/=25 kg/m(2).

Screening and diagnosis of prediabetes: where are we headed?

It is currently estimated that more than 300 million people have impaired glucose tolerance (IGT), putting them at increased risk for type 2 diabetes mellitus (T2DM) and its adverse consequences. In addition, many others are at risk on the basis of a family history of T2DM, obesity, dyslipidaemia and hypertension. Screening for risk should include both blood glucose testing in high-risk populations and prescreening (e.g. by questionnaire, waist circumference measurement) to identify high-risk individuals in overall low-risk populations; these individuals should then undergo glucose testing. Fasting plasma glucose measurement cannot diagnose IGT; the preferred definite test for diagnosis is oral glucose tolerance testing.

Glucose-potassium-insulin infusions in the management of post-stroke hyperglycaemia: the UK Glucose Insulin in Stroke Trial (GIST-UK)

BACKGROUND

Hyperglycaemia after acute stroke is a common finding that has been associated with an increased risk of death. We sought to determine whether treatment with glucose-potassium-insulin (GKI) infusions to maintain euglycaemia immediately after the acute event reduces death at 90 days.

METHODS

Patients presenting within 24 h of stroke onset and with admission plasma glucose concentration between 6.0-17.0 mmol/L were randomly assigned to receive variable-dose-insulin GKI (intervention) or saline (control) as a continuous intravenous infusion for 24 h. The purpose of GKI infusion was to maintain capillary glucose at 4-7 mmol/L, with no glucose intervention in the control group. The primary outcome was death at 90 days, and the secondary endpoint was avoidance of death or severe disability at 90 days. Additional planned analyses were done to determine any differences in residual disability or neurological and functional recovery. The trial was powered to detect a mortality difference of 6% (sample size 2355), with 83% power, at the 5% two-sided significance level. This study is registered as an International Standard Randomised Controlled Trial (number ISRCTN 31118803)

FINDINGS

The trial was stopped due to slow enrolment after 933 patients were recruited. For the intention-to-treat data, there was no significant reduction in mortality at 90 days (GKI vs control: odds ratio 1.14, 95% CI 0.86-1.51, p=0.37). There were no significant differences for secondary outcomes. In the GKI group, overall mean plasma glucose and mean systolic blood pressure were significantly lower than in the control group (mean difference in glucose 0.57 mmol/L, p<0.001; mean difference in blood pressure 9.0 mmHg, p<0.0001).

INTERPRETATION

GKI infusions significantly reduced plasma glucose concentrations and blood pressure. Treatment within the trial protocol was not associated with significant clinical benefit, although the study was underpowered and alternative results cannot be excluded.

International Diabetes Federation: a consensus on Type 2 diabetes prevention

AIMS

Early intervention and avoidance or delay of progression to Type 2 diabetes is of enormous benefit to patients in terms of increasing life expectancy and quality of life, and potentially in economic terms for society and health-care payers. To address the growing impact of Type 2 diabetes the International Diabetes Federation (IDF) Taskforce on Prevention and Epidemiology convened a consensus workshop in 2006. The primary goal of the workshop and this document was the prevention of Type 2 diabetes in both the developed and developing world. A second aim was to reduce the risk of cardiovascular disease in people who are identified as being at a higher risk of Type 2 diabetes. The IDF plan for prevention of Type 2 diabetes is based on controlling modifiable risk factors and can be divided into two target groups: People at high risk of developing Type 2 diabetes. The entire population.

CONCLUSIONS

In planning national measures for the prevention of Type 2 diabetes, both groups should be targeted simultaneously with lifestyle modification the primary goal through a stepwise approach. In addition, it is important that all activities are tailored to the specific local situation. Further information on the prevention of diabetes can be found on the IDF website: http://www.idf.org/prevention.

Leptin predicts the development of diabetes in Mauritian men, but not women: a population–based study

OBJECTIVE

To determine if levels of the adipocyte-derived hormone, leptin, predict the development of type 2 diabetes.

METHODS

Population-based surveys were undertaken in the multiethnic nation of Mauritius in 1987, 1992 and 1998. Questionnaires, anthropometric measurements, and a 2-h 75-g oral glucose tolerance test were included. A cohort of 2330 participants who were free of diabetes, aged 25-79 years in 1987, and who were followed-up in 1992 and 1998 was studied. Serum leptin was measured in baseline samples. Glucose tolerance was classified according to WHO (World Health Organization) 1999 criteria.

RESULTS

In total, 456 subjects developed diabetes over 11 years with similar incidences in all ethnic groups (P=0.2). Baseline leptin correlated positively with anthropometric measurements, fasting and postload insulin and homeostasis model assessment indices (all P<0.001), and inversely with subsequent weight increase. Participants with incident diabetes had higher serum levels of leptin at baseline than those remaining nondiabetic (P<0.001). After adjustment for confounders, high leptin levels and high leptin/body mass index ratio were independently associated with incident diabetes over 11 years in men (odds ratio for top versus bottom quartile of leptin 2.18; 95% CI: 1.09-4.35), but not in women.

CONCLUSION

We conclude that high leptin levels are associated with the future development of diabetes, and the association is independent of other factors in men, but not in women.

Chronic non-communicable diseases

Chronic non-communicable diseases (NCD) account for almost 60% of global mortality, and 80% of deaths from NCD occur in low- and middle-income countries. One quarter of these deaths--almost 9 million in 2005--are in men and women aged <60 years. Taken together, NCD represent globally the single largest cause of mortality in people of working age, and their incidences in younger adults are substantially higher in the poor countries of the world than in the rich. The major causes of NCD-attributable mortality are cardiovascular disease (30% of total global mortality), cancers (13%), chronic respiratory disease (7%) and diabetes (2%). These conditions share a small number of behavioural risk factors, which include a diet high in saturated fat and low in fresh fruit and vegetables, physical inactivity, tobacco smoking, and alcohol excess. In low- and middle-income countries such risk factors tend to be concentrated in urban areas and their prevalences are increasing as a result of rapid urbanization and the increasing globalisation of the food, tobacco and alcohol industries. Because NCD have a major impact on men and women of working age and their elderly dependents, they result in lost income, lost opportunities for investment, and overall lower levels of economic development. Reductions in the incidences of many NCD and their complications are, however, already possible. Up to 80% of all cases of cardiovascular disease or type-2 diabetes and 40% of all cases of cancer, for example, are probably preventable based on current knowledge. In addition, highly cost-effective measures exist for the prevention of some of the complications of established cardiovascular disease and diabetes. Achieving these gains will require a broad range of integrated, population-based interventions as well as measures focused on the individuals at high risk. At present, the international-assistance community provides scant resources for the control of NCD in poor countries, partly, at least, because NCD continue to be wrongly perceived as predominantly diseases of the better off. As urbanization continues apace and populations age, investment in the prevention and control of NCD in low-and middle-income countries can no longer be ignored.