Baseline characteristics of participants in the Kerala Diabetes Prevention Program: a cluster randomized controlled trial of lifestyle intervention in Asian Indians.

AIMS: To describe the baseline characteristics of participants in the Kerala Diabetes Prevention Program. METHODS: The Kerala Diabetes Prevention Program is a cluster randomized controlled trial of lifestyle intervention for prevention of Type 2 diabetes mellitus in India. Participants in the study were those aged 30-60 years who had an Indian Diabetes Risk Score ≥ 60 and who were without Type 2 diabetes on oral glucose tolerance test. Data on demographic, lifestyle, clinical and biochemical characteristics were collected using standardized tools. RESULTS: A total of 2586 individuals were screened with the Indian Diabetes Risk Score, of these 1529 people (59.1%) had a score ≥ 60, of whom 1209 (79.1%) underwent an oral glucose tolerance test. A total of 202 individuals (16.7%) had undiagnosed Type 2 diabetes and were excluded, and the remaining 1007 individuals were enrolled in the trial (control arm, n = 507; intervention arm, n = 500). The mean participant age was 46.0 ± 7.5 years, and 47.2% were women. The mean Indian Diabetes Risk Score was 67.1 ± 8.4. More than two-thirds (69.0%) had prediabetes and 31.0% had normal glucose tolerance. The prevalence of cardiometabolic risk factors was high, including current tobacco use (34.4% in men), current alcohol use (39.3% in men), no leisure time exercise (98.0%), no daily intake of fruit and vegetables (78.7%), family history of diabetes (47.9%), overweight or obesity (68.5%), hypertension (22.3%) and dyslipidemia (85.4%). CONCLUSIONS: The Kerala Diabetes Prevention Program recruited participants using a diabetes risk score. A large proportion of the participants had prediabetes and there were high rates of cardiometabolic risk factors. The trial will evaluate the effectiveness of lifestyle intervention in a population selected on the basis of a diabetes risk score.

Meeting American Diabetes Association diabetes management targets: trends in Mauritius.

AIMS: To examine the proportion of people with diabetes in the multi-ethnic country of Mauritius meeting American Diabetes Association targets in 2009 and 2015. METHODS: Data from independent population-based samples of 858 and 656 adults with diagnosed diabetes in 2009 and 2015, respectively, were analysed with regard to recommended American Diabetes Association targets for HbA1c , blood pressure and LDL cholesterol. RESULTS: In 2015 compared with 2009, the proportion of people achieving American Diabetes Association targets for glycaemic control in Mauritius was higher in women (P≤0.01) and in those with only a primary education level (P=0.07), but not in men or people with a higher level of education. Achievement of blood pressure <140/90 mmHg was higher in 2015 compared with 2009 (60% vs 42%) in people of South Asian ethnicity (P<0.001), but not in those of African ethnicity (P=0.16). The percentages of people with LDL cholesterol <2.59 mmol/l were 42.1% and 50.4%, in 2009 and 2015, respectively (P=0.27). Better control of HbA1c and blood pressure was observed in groups in which that control was poorest in 2009. The use of glucose-, blood pressure- and LDL cholesterol-lowering medication was higher in 2015 than in 2009. CONCLUSIONS: In certain subgroups, namely women, those with poorer education and those of South Asian ethnicity, whose target achievement was the poorest in 2009, control of glycaemia and blood pressure was better in 2015 as compared with 2009. While these findings are encouraging, further work is required to improve outcomes.

High consumption of pulses is associated with lower risk of abnormal glucose metabolism in women in Mauritius.

AIMS: To investigate if consumption of pulses was associated with a reduced risk of developing abnormal glucose metabolism, increases in body weight and increases in waist circumference in a multi-ethnic cohort in Mauritius. METHODS: Population-based surveys were performed in Mauritius in 1992 and in 1998. Pulse consumption was estimated from a food frequency questionnaire in 1992 and outcomes were measured in 1998. At both time points, anthropometry was undertaken and an oral glucose tolerance test was performed. RESULTS: Mauritian women with the highest consumption of pulses (highest tertile) had a reduced risk of developing abnormal glucose metabolism [odds ratio 0.52; 95% CI 0.27, 0.99) compared with those with the lowest consumption, and also after multivariable adjustments. In women, a high consumption of pulses was associated with a smaller increase in BMI. CONCLUSIONS: High consumption of pulses was associated with a reduced risk of abnormal glucose metabolism and a smaller increase in BMI in Mauritian women. Promotion of pulse consumption could be an important dietary intervention for the prevention of Type 2 diabetes and obesity in Mauritius and should be examined in other populations and in clinical trials.

Prevalence of diabetic retinopathy in Type 2 diabetes in developing and developed countries.

BACKGROUND: As the global prevalence of diabetes increases, so will the numbers of people with diabetic retinopathy. Our review aimed to provide a comprehensive picture of available studies of diabetic retinopathy and how prevalence varies around the developed and developing world. METHODS: A detailed literature search using PubMed was undertaken. The following search term was used: 'diabetic retinopathy AND prevalence'. The titles and abstracts of all publications identified by the search were reviewed and 492 studies were retrieved. Inclusion and exclusion criteria were applied. RESULTS: A total of 72 articles from 33 countries were included. There were only 26 population-based studies using fundus photography (12 in developing countries), of which only 16 (eight in developing countries) were published since 2000. Prevalence estimates varied from as low as 10% to as high as 61% in persons with known diabetes and from 1.5 to 31% in newly diagnosed diabetes. Across all the studies, the median (interquartile range) prevalence of any diabetic retinopathy in known diabetes was 27.9% (22-37%) and 10.5% (6-16%) in newly diagnosed diabetes. Prevalence of diabetic retinopathy was higher in developing countries. CONCLUSION: Significant gaps exist in that reliable population-based data from developing nations and indigenous populations in particular are lacking. Major differences in study characteristics and methodologies make comparisons very difficult. More research is required and study methodologies must be better standardized. This will provide important information for prevention and treatment strategies.

Current controversies in the use of haemoglobin A1c.

Haemoglobin A(1c) (HbA(1c)) has recently been adopted by the World Health Organization into its recommended criteria for diabetes diagnosis. Much debate continues regarding the relative benefits and potential disadvantages surrounding the use of HbA(1c) for this purpose. There is a lack of consensus as to whether this alteration to the definition of diabetes is a step forward or whether it could add further confusion and ambiguity to the debate on the method and criteria for the diagnosis of this globally important disease. This review provides a comprehensive overview of the current issues surrounding how HbA(1c) is measured and reported; and of the evidence for and against its use in diagnosis.

A bi-directional relationship between obesity and health-related quality of life: evidence from the longitudinal AusDiab study.

OBJECTIVE: To assess the prospective relationship between obesity and health-related quality of life, including a novel assessment of the impact of health-related quality of life on weight gain. DESIGN AND SETTING: Longitudinal, national, population-based Australian Diabetes, Obesity and Lifestyle (AusDiab) study, with surveys conducted in 1999/2000 and 2004/2005. PARTICIPANTS: A total of 5985 men and women aged ≥ 25 years at study entry. MAIN OUTCOME MEASURE(S): At both time points, height, weight and waist circumference were measured and self-report data on health-related quality of life from the SF-36 questionnaire were obtained. Cross-sectional and bi-directional, prospective associations between obesity categories and health-related quality of life were assessed. RESULTS: Higher body mass index (BMI) at baseline was associated with deterioration in health-related quality of life over 5 years for seven of the eight health-related quality of life domains in women (all P ≤ 0.01, with the exception of mental health, P>0.05), and six out of eight in men (all P<0.05, with the exception of role-emotional, P=0.055, and mental health, P>0.05). Each of the quality-of-life domains related to mental health as well as the mental component summary were inversely associated with BMI change (all P<0.0001 for women and P ≤ 0.01 for men), with the exception of vitality, which was significant in women only (P=0.008). For the physical domains, change in BMI was inversely associated with baseline general health in women only (P=0.023). CONCLUSIONS: Obesity was associated with a deterioration in health-related quality of life (including both physical and mental health domains) in this cohort of Australian adults followed over 5 years. Health-related quality of life was also a predictor of weight gain over 5 years, indicating a bi-directional association between obesity and health-related quality of life. The identification of those with poor health-related quality of life may be important in assessing the risk of future weight gain, and a focus on health-related quality of life may be beneficial in weight management strategies.

The Evaluation of Screening and Early Detection Strategies for Type 2 Diabetes and Impaired Glucose Tolerance (DETECT-2) update of the Finnish diabetes risk score for prediction of incident type 2 diabetes.

AIMS/HYPOTHESIS: The Finnish diabetes risk questionnaire is a widely used, simple tool for identification of those at risk for drug-treated type 2 diabetes. We updated the risk questionnaire by using clinically diagnosed and screen-detected type 2 diabetes instead of drug-treated diabetes as an endpoint and by considering additional predictors. METHODS: Data from 18,301 participants in studies of the Evaluation of Screening and Early Detection Strategies for Type 2 Diabetes and Impaired Glucose Tolerance (DETECT-2) project with baseline and follow-up information on oral glucose tolerance status were included. Incidence of type 2 diabetes within 5 years was used as the outcome variable. Improvement in discrimination and classification of the logistic regression model was assessed by the area under the receiver-operating characteristic (ROC) curve and by the net reclassification improvement. Internal validation was by bootstrapping techniques. RESULTS: Of the 18,301 participants, 844 developed type 2 diabetes in a period of 5 years (4.6%). The Finnish risk score had an area under the ROC curve of 0.742 (95% CI 0.726-0.758). Re-estimation of the regression coefficients improved the area under the ROC curve to 0.766 (95% CI 0.750-0.783). Additional items such as male sex, smoking and family history of diabetes (parent, sibling or both) improved the area under the ROC curve and net reclassification. Bootstrapping showed good internal validity. CONCLUSIONS/INTERPRETATION: The predictive value of the original Finnish risk questionnaire could be improved by adding information on sex, smoking and family history of diabetes. The DETECT-2 update of the Finnish diabetes risk questionnaire is an adequate and robust predictor for future screen-detected and clinically diagnosed type 2 diabetes in Europid populations.

Television viewing time and mortality: the Australian Diabetes, Obesity and Lifestyle Study (AusDiab).

BACKGROUND: Television viewing time, the predominant leisure-time sedentary behavior, is associated with biomarkers of cardiometabolic risk, but its relationship with mortality has not been studied. We examined the associations of prolonged television viewing time with all-cause, cardiovascular disease (CVD), cancer, and non-CVD/noncancer mortality in Australian adults. METHODS AND RESULTS: Television viewing time in relation to subsequent all-cause, CVD, and cancer mortality (median follow-up, 6.6 years) was examined among 8800 adults > or =25 years of age in the Australian Diabetes, Obesity and Lifestyle Study (AusDiab). During 58 087 person-years of follow-up, there were 284 deaths (87 CVD deaths, 125 cancer deaths). After adjustment for age, sex, waist circumference, and exercise, the hazard ratios for each 1-hour increment in television viewing time per day were 1.11 (95% confidence interval [CI], 1.03 to 1.20) for all-cause mortality, 1.18 (95% CI, 1.03 to 1.35) for CVD mortality, and 1.09 (95% CI, 0.96 to 1.23) for cancer mortality. Compared with a television viewing time of <2 h/d, the fully adjusted hazard ratios for all-cause mortality were 1.13 (95% CI, 0.87 to 1.36) for > or =2 to <4 h/d and 1.46 (95% CI, 1.04 to 2.05) for > or =4 h/d. For CVD mortality, corresponding hazard ratios were 1.19 (95% CI, 0.72 to 1.99) and 1.80 (95% CI, 1.00 to 3.25). The associations with both cancer mortality and non-CVD/noncancer mortality were not significant. CONCLUSIONS: Television viewing time was associated with increased risk of all-cause and CVD mortality. In addition to the promotion of exercise, chronic disease prevention strategies could focus on reducing sitting time, particularly prolonged television viewing.

Comparing incident diabetes as defined by fasting plasma glucose or by HbA(1c). The AusDiab, Inter99 and DESIR studies.

AIM: We examined the ability of fasting plasma glucose and HbA(1c) to predict 5-year incident diabetes for an Australian cohort and a Danish cohort and 6-year incident diabetes for a French cohort, as defined by the corresponding criteria. METHODS: We studied 6025 men and women from AusDiab (Australian), 4703 from Inter99 (Danish) and 3784 from DESIR (French), not treated for diabetes and with fasting plasma glucose < 7.0 mmol/l and HbA(1c) < 48 mmol/mol (6.5%) at inclusion. Diabetes was defined as fasting plasma glucose ≥ 7.0 mmol/l and/or treatment for diabetes or as HbA(1c) ≥ 48 mmol/mol (6.5%) and/or treatment for diabetes. RESULTS: For AusDiab, incident fasting plasma glucose-defined diabetes was more frequent than HbA(1c) -defined diabetes (P(McNemar)<0.0001), the reverse applied to Inter99 (P(McNemar) < 0.007) and for DESIR there was no difference (P(McNema)=0.17). Less than one third of the incident cases were detected by both criteria. Logistic regression models showed that baseline fasting plasma glucose and baseline HbA(1c) predicted incident diabetes defined by the corresponding criteria. The standardized odds ratios (95% confidence interval) for HbA(1c) were a little higher than for fasting plasma glucose, but not significantly so. They were respectively, 5.0 (4.1-6.1) and 4.1 (3.5-4.9) for AusDiab, 5.0 (3.6-6.8) and 4.8 (3.6-6.3) for Inter99, 4.8 (3.6-6.5) and 4.6 (3.6-5.9) for DESIR. CONCLUSIONS: Fasting plasma glucose and HbA(1c) are good predictors of incident diabetes defined by the corresponding criteria. Despite Diabetes Control and Complications Trial-alignment of the three HbA(1c) assays, there was a large difference in the HbA(1c) distributions between these studies, conducted some 10 years ago. Thus, it is difficult to compare absolute values of diabetes prevalence and incidence based on HbA(1c) measurements from that time.

Maximizing efficiency and cost-effectiveness of Type 2 diabetes screening: the AusDiab study.

AIMS: To evaluate how to most efficiently screen populations to detect people at high risk of incident Type 2 diabetes and those with prevalent, but undiagnosed, Type 2 diabetes. METHODS: Data from 5814 adults in the Australian Diabetes, Obesity and Lifestyle study were used to examine four different types of screening strategies. The strategies incorporated various combinations of cut-points of fasting plasma glucose, the non-invasive Australian Type 2 Diabetes Risk Assessment Tool (AUSDRISK1) and a modified version of the tool incorporating fasting plasma glucose (AUSDRISK2). Sensitivity, specificity, positive predictive value, screening costs per case of incident or prevalent undiagnosed diabetes identified and intervention costs per case of diabetes prevented or reverted were compared. RESULTS: Of the four strategies that maximized sensitivity and specificity, use of the non-invasive AUSDRISK1, followed by AUSDRISK2 in those found to be at increased risk on AUSDRISK1, had the highest sensitivity (80.3%; 95% confidence interval 76.6-84.1%), specificity (78.1%; 95% confidence interval 76.9-79.2%) and positive predictive value (22.3%; 95% confidence interval 20.2-24.4%) for identifying people with either prevalent undiagnosed diabetes or future incident diabetes. It required the fewest people (24.1%; 95% confidence interval 23.0-25.2%) to enter lifestyle modification programmes, and also had the lowest intervention costs and combined costs of running screening and intervention programmes per case of diabetes prevented or reverted. CONCLUSIONS: Using a self-assessed diabetes risk score as an initial screening step, followed by a second risk score incorporating fasting plasma glucose, would maximize efficiency of identifying people with undiagnosed Type 2 diabetes and those at high risk of future diabetes.

HOMA insulin sensitivity index and the risk of all-cause mortality and cardiovascular disease events in the general population: the Australian Diabetes, Obesity and Lifestyle Study (AusDiab) study.

AIMS/HYPOTHESIS: We assessed whether the relationships between insulin sensitivity and all-cause mortality as well as fatal or non-fatal cardiovascular disease (CVD) events are independent of elevated blood glucose, high blood pressure, dyslipidaemia and body composition in individuals without diagnosed diabetes. METHODS: Between 1999 and 2000, baseline fasting insulin, glucose and lipids, 2 h plasma glucose, HbA(1c), anthropometrics, blood pressure, medication use, smoking and history of CVD were collected from 8,533 adults aged >35 years from the population-based Australian Diabetes, Obesity and Lifestyle study. Insulin sensitivity was estimated by HOMA of insulin sensitivity (HOMA-%S). Deaths and fatal or non-fatal CVD events were ascertained through linkage to the National Death Index and medical records adjudication. RESULTS: After a median of 5.0 years there were 277 deaths and 225 CVD events. HOMA-%S was not associated with all-cause mortality. Compared with the most insulin-sensitive quintile, the combined fatal or non-fatal CVD HR (95% CI) for quintiles of decreasing HOMA-%S were 1.1 (0.6-1.9), 1.4 (0.9-2.3), 1.6 (1.0-2.5) and 2.0 (1.3-3.1), adjusting for age and sex. Smoking, CVD history, hypertension, lipid-lowering medication, total cholesterol and waist-to-hip ratio moderately attenuated this relationship. However, the association was rendered non-significant by adding HDL. Fasting plasma glucose, but not HOMA-%S significantly improved the prediction of CVD, beyond that seen with other risk factors. CONCLUSIONS/INTERPRETATION: In this cohort, HOMA-%S showed no association with all-cause mortality and only a modest association with CVD events, largely explained by its association with HDL. Fasting plasma glucose was a better predictor of CVD than HOMA-%S.

Health behaviours, socioeconomic status and diabetes incidence: the Australian Diabetes Obesity and Lifestyle Study (AusDiab).

AIMS/HYPOTHESIS: To identify the impact of socioeconomic status on incident impaired glucose metabolism and type 2 diabetes and to investigate the mediating role of health behaviours on this relationship using national, population-based data. METHODS: The Australian Diabetes Obesity and Lifestyle (AusDiab) Study is a national, population-based, longitudinal study of adults aged 25 years and above. A total sample of 4,405 people provided complete baseline (1999-2000) and 5 year follow-up (2004-2005) data relevant for these analyses. Fasting plasma glucose and 2 h plasma glucose were obtained from an OGTT, and demographic, socioeconomic and behavioural data were collected by interview and questionnaire. Multinomial logistic regression examined the role of socioeconomic position in the development of diabetes and mediation analyses tested the contribution of health behaviours in this relationship. RESULTS: Highest level of education was a stronger predictor of incident impaired glucose tolerance and type 2 diabetes (p = 0.002), compared with household income (p = 0.103), and occupational grade (p = 0.202). Education remained a significant independent predictor of diabetes in fully adjusted models. However, the relationship was attenuated by the health behaviours (smoking and physical activity). Mediation analyses indicated that these behaviours were partial mediators (explaining 27%) of the socioeconomic status-diabetes relationship. CONCLUSION/INTERPRETATION: Smoking and physical activity partly mediate the relationship between low education and type 2 diabetes. Identification of these modifiable behavioural mediators should facilitate the development of effective health promotion campaigns to target those at high risk of developing type 2 diabetes.

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.

Association between hyperglycaemia and fracture risk in non-diabetic middle-aged and older Australians: a national, population-based prospective study (AusDiab).

SUMMARY: The association between pre-diabetes and fracture risk remains unclear. In this large cohort of middle-aged and older Australian men and women without diabetes, elevated 2-h plasma glucose and pre-diabetes were associated with a reduced 5-year risk of low trauma and all fractures in women, independently of BMI, fasting insulin and other lifestyle factors. INTRODUCTION: We aimed to (1) examine associations between fasting and 2-h plasma glucose (FPG and 2-h PG), fasting insulin and risk of low trauma and all fractures in non-diabetic adults and (2) compare fracture risk between adults with pre-diabetes (impaired glucose tolerance or impaired fasting glucose) and those with normal glucose tolerance (NGT). METHODS: Six thousand two hundred fifty-five non-diabetic men and women aged ≥40 years with NGT (n = 4,855) and pre-diabetes (n = 1,400) were followed for 5 years in the AusDiab Study. Fractures were self-reported. RESULTS: Five hundred thirty-nine participants suffered at least one fracture (368 women, 171 men), of which the majority (318) occurred after a low-energy trauma (258 women, 60 men). In women, a 2-h PG ≥ 7.2 mmol/L (highest quartile) was associated with a decreased risk of low trauma and all fractures independent of age and BMI [OR (95% CI) for low trauma fractures, 0.59 (0.40-0.88)], but also fasting insulin, smoking, physical activity, history of fracture, dietary calcium and alcohol intake or menopausal status. There was no effect of 2-h PG on fracture risk in men [OR (95% CI), 1.39 (0.60-3.26)] or any relationship between fracture risk and quartiles of FPG or insulin in either sex. Compared to women with NGT, those with pre-diabetes had a reduced risk of fracture [OR (95% CI) for all fractures, 0.70 (0.52-0.95); for low trauma fractures, 0.75 (0.53-1.05)]. CONCLUSION: Elevated 2-h PG levels and pre-diabetes were inversely associated with low trauma and/or all fractures in non-diabetic women, independent of BMI and fasting insulin levels.

Does abnormal insulin action or insulin secretion explain the increase in prevalence of impaired glucose metabolism with age in populations of different ethnicities?

BACKGROUND: Age is associated with both impaired glucose and insulin metabolism. To what extent the age-related changes in insulin resistance (IR) and beta-cell function contribute to the increase in prevalence of impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) is less known, and this is investigated in this study. METHODS: This study included 6610 men and 7664 women of different ethnic groups aged 30-69 years. IR and beta-cell function were examined by the homeostasis model assessment of insulin resistance (HOMA-IR) and homeostasis model assessment of beta-cell function (HOMA-B). Odds ratios (ORs) and 95% confidence intervals (95% CIs) were estimated using logistic regression analysis adjusting for body mass index and study. RESULTS: In Chinese men, the ORs (95% CIs) for IFG were 2.69 (1.70, 4.26), 2.51 (1.49, 4.21) and 2.89 (1.68, 4.97), respectively, in age groups of 40-49, 50-59 and 60-69 years compared with 30-39 years (p < 0.001 for trend); the corresponding figures for IGT were 1.73 (1.25, 2.38), 2.54 (1.78, 3.63) and 3.57 (2.46, 5.19) (p < 0.001 for trend). Similar trends for IGT were observed also in Chinese women and other ethnic groups, but not for IFG in Mauritius Indian and Creole men. Adjustment for HOMA-IR and HOMA-B reduced the ORs in all age groups of all ethnicities for both IFG and IGT, but the risk gradient between age groups remained particularly for the IGT. CONCLUSIONS: The age-related increase in glucose intolerance may not be fully explained by the defect in HOMA-IR and HOMA-B. As HOMA-IR and HOMA-B are only surrogate measures of insulin sensitivity and insulin secretion, the results need to be further investigated.

Continuous relationships between non-diabetic hyperglycaemia and both cardiovascular disease and all-cause mortality: the Australian Diabetes, Obesity, and Lifestyle (AusDiab) study.

AIMS/HYPOTHESIS: Hyperglycaemia is a risk factor for cardiovascular disease (CVD) and all-cause mortality in individuals without diabetes. We investigated: (1) whether the risk of all-cause and CVD mortality extended continuously throughout the range of fasting plasma glucose (FPG), 2 h plasma glucose (2hPG) and HbA(1c) values; and (2) the ability of these measures to improve risk prediction for mortality. METHODS: Data on 10,026 people aged >or=25 years without diagnosed diabetes were obtained from the population-based Australian Diabetes, Obesity and Lifestyle study. Between 1999 and 2000, FPG, 2hPG and HbA(1c) were assessed and all-cause (332 deaths) and CVD (88 deaths) mortality were obtained after 7 years. RESULTS: Both 2hPG and HbA(1c) exhibited linear relationships with all-cause and CVD mortality, whereas FPG showed J-shaped relationships. The adjusted HR (95% CI) for all-cause mortality per SD increase was 1.2 (1.1-1.3) for 2hPG and 1.1 (1.0-1.2) for HbA(1c). The HR for FPG <5.1 mmol/l (per SD decrease) was 2.0 (1.3-3.0); for FPG >or=5.1 mmol/l (per SD increase) the HR was 1.1 (1.0-1.2). Corresponding HRs for CVD mortality were 1.2 (1.0-1.4), 1.2 (1.0-1.3), 4.0 (2.1-7.6) and 1.3 (1.1-1.4). The discriminative ability of each measure was similar; no measure substantially improved individual risk identification over traditional risk factors. CONCLUSIONS/INTERPRETATION: In individuals without diagnosed diabetes, 2hPG and FPG, but not HbA(1c) were significant predictors of all-cause mortality, whereas all measures were significant predictors of CVD mortality. However, these glucose measures did not substantially improve individual risk identification.

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.

Lifetime risk and projected population prevalence of diabetes.

AIMS/HYPOTHESIS: With incidence rates for diabetes increasing rapidly worldwide, estimates of the magnitude of the impact on population health are required. We aimed to estimate the lifetime risk of diabetes, the number of years lived free of, and the number of years lived with diabetes for the Australian adult population from the year 2000, and to project prevalence of diabetes to the year 2025. METHODS: Multi-state life-tables were constructed to simulate the progress of a cohort of 25-year-old Australians. National mortality rates were combined with incidence rates of diabetes and the RR of mortality in people with diabetes derived from the Australian Diabetes, Obesity and Lifestyle study (a national, population-based study of 11,247 adults aged >or=25 years). RESULTS: If the rates of mortality and diabetes incidence observed over the period 2000-2005 continue, 38.0% (95% uncertainty interval 36.6-38.9) of 25-year-olds would be expected to develop diabetes at some time throughout their life. On average, a 25-year-old Australian will live a further 56 years, 48 of these free of diabetes. On average, a 45-year-old person with diabetes can expect to live 6 years less than a person free of diabetes. The prevalence of diabetes is projected to rise from 7.6% in 2000 to 11.4% by 2025. CONCLUSIONS/INTERPRETATION: If we maintain current diabetes incidence rates, more than a third of individuals will develop diabetes within their lifetime and in Australia there will an additional 1 million cases of diabetes by the year 2025.

The metabolic syndrome as a tool for predicting future diabetes: the AusDiab study.

OBJECTIVE: To compare the ability of the metabolic syndrome (MetS), a diabetes prediction model (DPM), a noninvasive risk questionnaire and individual glucose measurements to predict future diabetes. DESIGN: Five-year longitudinal cohort study. Tools tested included MetS definitions [World Health Organization, International Diabetes Federation, ATPIII and European Group for the study of Insulin Resistance (EGIR)], the FINnish Diabetes RIsk SCore risk questionnaire, the DPM, fasting and 2-h post load plasma glucose. SETTING: Adult Australian population. SUBJECTS: A total of 5842 men and women without diabetes > or =25 years. Response 58%. A total of 224 incident cases of diabetes. RESULTS: In receiver operating characteristic curve analysis, the MetS was not a better predictor of incident diabetes than the DPM or measurement of glucose. The risk for diabetes among those with prediabetes but not MetS was almost triple that of those with MetS but not prediabetes (9.0% vs. 3.4%). Adjusted for component parts, the MetS was not a significant predictor of incident diabetes, except for EGIR in men [OR 2.1 (95% CI 1.2-3.7)]. CONCLUSIONS: A single fasting glucose measurement may be more effective and efficient than published definitions of the MetS or other risk constructs in predicting incident diabetes. Diagnosis of the MetS did not confer increased risk for incident diabetes independent of its individual components, with an exception for EGIR in men. Given these results, debate surrounding the public health utility of a MetS diagnosis, at least for identification of incident diabetes, is required.

Differences in height explain gender differences in the response to the oral glucose tolerance test- the AusDiab study.

AIM: To determine the extent of gender-related differences in the prevalence of glucose intolerance for the Australian population and whether body size may explain such differences. METHODS: Cross-sectional data were collected from a national cohort of 11 247 Australians aged > or = 25 years. Glucose tolerance status was assessed according to both fasting plasma glucose (FPG) and 2-h plasma glucose (2hPG) levels following a 75-g oral glucose tolerance test (OGTT). Anthropometric and glycated haemoglobin measurements were also made. RESULTS: Undiagnosed diabetes and non-diabetic glucose abnormalities were more prevalent among men than women when based only on the FPG results (diabetes: men 2.2%, women 1.6%, P = 0.02; impaired fasting glycaemia: men 12.3%, women 6.6%, P < 0.001). In contrast 16.0% of women and 13.0% of men had a 2hPG abnormality (either diabetes or impaired glucose tolerance, P = 0.14). Women had a mean FPG 0.3 mmol/l lower than men (P < 0.001), but 2hPG 0.3 mmol/l higher (P = 0.002) and FPG-2hPG increment 0.5 mmol/l greater (P < 0.001). The gender difference in mean 2hPG and FPG-2hPG increment disappeared following adjustment for height. For both genders, those in the shortest height quartile had 2hPG levels 0.5 mmol/l higher than the tallest quartile, but height showed almost no relationship with the FPG. CONCLUSIONS: Men and women had different glycaemic profiles; women had higher mean 2hPG levels, despite lower fasting levels. It appeared that the higher 2hPG levels for women related to lesser height and may be a consequence of using a fixed glucose load in the OGTT, irrespective of body size.