Relative role of major risk factors for Type 2 diabetes development in the historical cohort of the Brisighella Heart Study: an 8-year follow-up

Development of type 2 diabetes mellitus in people with intermediate hyperglycaemia

BACKGROUND

Intermediate hyperglycaemia (IH) is characterised by one or more measurements of elevated blood glucose concentrations, such as impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and elevated glycosylated haemoglobin A1c (HbA1c). These levels are higher than normal but below the diagnostic threshold for type 2 diabetes mellitus (T2DM). The reduced threshold of 5.6 mmol/L (100 mg/dL) fasting plasma glucose (FPG) for defining IFG, introduced by the American Diabetes Association (ADA) in 2003, substantially increased the prevalence of IFG. Likewise, the lowering of the HbA1c threshold from 6.0% to 5.7% by the ADA in 2010 could potentially have significant medical, public health and socioeconomic impacts.

OBJECTIVES

To assess the overall prognosis of people with IH for developing T2DM, regression from IH to normoglycaemia and the difference in T2DM incidence in people with IH versus people with normoglycaemia.

SEARCH METHODS

We searched MEDLINE, Embase, ClincialTrials.gov and the International Clinical Trials Registry Platform (ICTRP) Search Portal up to December 2016 and updated the MEDLINE search in February 2018. We used several complementary search methods in addition to a Boolean search based on analytical text mining.

SELECTION CRITERIA

We included prospective cohort studies investigating the development of T2DM in people with IH. We used standard definitions of IH as described by the ADA or World Health Organization (WHO). We excluded intervention trials and studies on cohorts with additional comorbidities at baseline, studies with missing data on the transition from IH to T2DM, and studies where T2DM incidence was evaluated by documents or self-report only.

DATA COLLECTION AND ANALYSIS

One review author extracted study characteristics, and a second author checked the extracted data. We used a tailored version of the Quality In Prognosis Studies (QUIPS) tool for assessing risk of bias. We pooled incidence and incidence rate ratios (IRR) using a random-effects model to account for between-study heterogeneity. To meta-analyse incidence data, we used a method for pooling proportions. For hazard ratios (HR) and odds ratios (OR) of IH versus normoglycaemia, reported with 95% confidence intervals (CI), we obtained standard errors from these CIs and performed random-effects meta-analyses using the generic inverse-variance method. We used multivariable HRs and the model with the greatest number of covariates. We evaluated the certainty of the evidence with an adapted version of the GRADE framework.

MAIN RESULTS

We included 103 prospective cohort studies. The studies mainly defined IH by IFG5.6 (FPG mmol/L 5.6 to 6.9 mmol/L or 100 mg/dL to 125 mg/dL), IFG6.1 (FPG 6.1 mmol/L to 6.9 mmol/L or 110 mg/dL to 125 mg/dL), IGT (plasma glucose 7.8 mmol/L to 11.1 mmol/L or 140 mg/dL to 199 mg/dL two hours after a 75 g glucose load on the oral glucose tolerance test, combined IFG and IGT (IFG/IGT), and elevated HbA1c (HbA1c5.7: HbA1c 5.7% to 6.4% or 39 mmol/mol to 46 mmol/mol; HbA1c6.0: HbA1c 6.0% to 6.4% or 42 mmol/mol to 46 mmol/mol). The follow-up period ranged from 1 to 24 years. Ninety-three studies evaluated the overall prognosis of people with IH measured by cumulative T2DM incidence, and 52 studies evaluated glycaemic status as a prognostic factor for T2DM by comparing a cohort with IH to a cohort with normoglycaemia. Participants were of Australian, European or North American origin in 41 studies; Latin American in 7; Asian or Middle Eastern in 50; and Islanders or American Indians in 5. Six studies included children and/or adolescents.Cumulative incidence of T2DM associated with IFG5.6, IFG6.1, IGT and the combination of IFG/IGT increased with length of follow-up. Cumulative incidence was highest with IFG/IGT, followed by IGT, IFG6.1 and IFG5.6. Limited data showed a higher T2DM incidence associated with HbA1c6.0 compared to HbA1c5.7. We rated the evidence for overall prognosis as of moderate certainty because of imprecision (wide CIs in most studies). In the 47 studies reporting restitution of normoglycaemia, regression ranged from 33% to 59% within one to five years follow-up, and from 17% to 42% for 6 to 11 years of follow-up (moderate-certainty evidence).Studies evaluating the prognostic effect of IH versus normoglycaemia reported different effect measures (HRs, IRRs and ORs). Overall, the effect measures all indicated an elevated risk of T2DM at 1 to 24 years of follow-up. Taking into account the long-term follow-up of cohort studies, estimation of HRs for time-dependent events like T2DM incidence appeared most reliable. The pooled HR and the number of studies and participants for different IH definitions as compared to normoglycaemia were: IFG5.6: HR 4.32 (95% CI 2.61 to 7.12), 8 studies, 9017 participants; IFG6.1: HR 5.47 (95% CI 3.50 to 8.54), 9 studies, 2818 participants; IGT: HR 3.61 (95% CI 2.31 to 5.64), 5 studies, 4010 participants; IFG and IGT: HR 6.90 (95% CI 4.15 to 11.45), 5 studies, 1038 participants; HbA1c5.7: HR 5.55 (95% CI 2.77 to 11.12), 4 studies, 5223 participants; HbA1c6.0: HR 10.10 (95% CI 3.59 to 28.43), 6 studies, 4532 participants. In subgroup analyses, there was no clear pattern of differences between geographic regions. We downgraded the evidence for the prognostic effect of IH versus normoglycaemia to low-certainty evidence due to study limitations because many studies did not adequately adjust for confounders. Imprecision and inconsistency required further downgrading due to wide 95% CIs and wide 95% prediction intervals (sometimes ranging from negative to positive prognostic factor to outcome associations), respectively.This evidence is up to date as of 26 February 2018.

AUTHORS' CONCLUSIONS

Overall prognosis of people with IH worsened over time. T2DM cumulative incidence generally increased over the course of follow-up but varied with IH definition. Regression from IH to normoglycaemia decreased over time but was observed even after 11 years of follow-up. The risk of developing T2DM when comparing IH with normoglycaemia at baseline varied by IH definition. Taking into consideration the uncertainty of the available evidence, as well as the fluctuating stages of normoglycaemia, IH and T2DM, which may transition from one stage to another in both directions even after years of follow-up, practitioners should be careful about the potential implications of any active intervention for people 'diagnosed' with IH.

Different type 2 diabetes risk assessments predict dissimilar numbers at 'high risk': a retrospective analysis of diabetes risk-assessment tools

BACKGROUND

Use of a validated risk-assessment tool to identify individuals at high risk of developing type 2 diabetes is currently recommended. It is under-reported, however, whether a different risk tool alters the predicted risk of an individual.

AIM

This study explored any differences between commonly used validated risk-assessment tools for type 2 diabetes.

DESIGN AND SETTING

Cross-sectional analysis of individuals who participated in a workplace-based risk assessment in Carmarthenshire, South Wales.

METHOD

Retrospective analysis of 676 individuals (389 females and 287 males) who participated in a workplace-based diabetes risk-assessment initiative. Ten-year risk of type 2 diabetes was predicted using the validated QDiabetes(®), Leicester Risk Assessment (LRA), FINDRISC, and Cambridge Risk Score (CRS) algorithms.

RESULTS

Differences between the risk-assessment tools were apparent following retrospective analysis of individuals. CRS categorised the highest proportion (13.6%) of individuals at 'high risk' followed by FINDRISC (6.6%), QDiabetes (6.1%), and, finally, the LRA was the most conservative risk tool (3.1%). Following further analysis by sex, over one-quarter of males were categorised at high risk using CRS (25.4%), whereas a greater percentage of females were categorised as high risk using FINDRISC (7.8%).

CONCLUSION

The adoption of a different valid risk-assessment tool can alter the predicted risk of an individual and caution should be used to identify those individuals who really are at high risk of type 2 diabetes.

Long-term predictors of impaired fasting glucose and type 2 diabetes in subjects with family history of type 2 diabetes: a 12-years follow-up of the Brisighella Heart Study historical cohort

AIM

To identify and quantify the role of different risk factors in the long-term development of IFG and T2DM in a rural Italian population sample with family history of T2DM.

METHODS

We selected a sample of 1271 adult subjects from among those 1851 consecutively visited during four consecutive Brisighella Heart Study surveys (1996-2008), then selecting those ones with a family history of T2DM. Thus, we obtained a final sample including 545 subjects and for which a full clinical and ematochemistry data set was available.

RESULTS

The Cox-regression model better predicting the incident IFG and T2DM included age, gender, FPG, TG and SUA. The model best predicting the incident IFG status alone (without T2DM) is very similar to that predicting both IFG and T2DM, including the same predictors. Finally, the model best predicting T2DM (excluding IFG) simply includes FPG, BMI and ALT/AST ratio. Repeating the Cox-regression analysis using BMI as a covariate, TG appears to be also a significant predictor of T2DM (HR 1.018 95% CI 1.009-1.041, p=0.013).

CONCLUSION

In a sample of subjects with a family history of diabetes the best long-term predictors of IFG are age, gender, FPG, TG and SUA, while those of T2DM are FPG and BMI.

Population health needs assessment and healthcare services use in a 3 years follow-up on administrative and clinical data: results from the Brisighella Heart Study

INTRODUCTION

A large number of epidemiological trials clearly show the impact of the main cardiovascular disease risk factors in term of hospitalization and related cost, but relatively less frequently if this reflect the health needs of a given population.

AIM

To develop a model for the health needs-assessment that will be applied to verify if and how the prevalence of some classical risk factors for cardiovascular disease predicts mortality and hospitalisation episodes at 3 years, and if it could express the health need of that population. The long-life clinical record of 1,704 subjects, recruited during the 2004 Brisighella Heart Study survey, has been monitored. We defined the health profile of these subjects at 2004 (based on clinical history, smoking and dietary habits, physical activity, drug use, anthropometric data, blood pressure, and hematological data) and then sampled data relative to their hospitalisations, mortality, and general medical assistance.

RESULTS

Our results shows that age over 65 years (OR 4.08; 95 % CI 2.74-6.08), hypertension (OR 3.44; 95 % CI 2.36-5.01) and hypercholesterolemia (OR 1.33; 95 % CI 0.92-1.94) increase the probability to get hospitalised. Furthermore, the burden of care was defined and computed for our sample. Vascular and respiratory diseases [Burden of health care (Bc) = 24.5 and 36.5, respectively] are the most costly DRGs which means that the biggest part of our resources directed to cardiovascular patients were provided for these diagnoses.

CONCLUSION

The application of the proposed model could help policy makers and researchers in directing resources and workforce in the treatment of cardiovascular diseases.

ABCA1-dependent serum cholesterol efflux capacity inversely correlates with pulse wave velocity in healthy subjects

The capacity of HDL to induce cell cholesterol efflux is considered one of its main antiatherogenic properties. Little is known about the impact of such HDL function on vascular physiology. We investigated the relationship between ABCA1-dependent serum cholesterol efflux capacity (CEC), an HDL functionality indicator, and pulse wave velocity (PWV), an indicator of arterial stiffness. Serum of 167 healthy subjects was used to conduct CEC measurement, and carotid-femoral PWV was measured with a high-fidelity tonometer. J774 macrophages, labeled with [(3)H]cholesterol and stimulated to express ABCA1, were exposed to sera; the difference between cholesterol efflux from stimulated and unstimulated cells provided specific ABCA1-mediated CEC. PWV is inversely correlated with ABCA1-dependent CEC (r = -0.183; P = 0.018). Moreover, controlling for age, sex, body mass index, mean arterial pressure, serum LDL, HDL-cholesterol, and fasting plasma glucose, PWV displays a significant negative regression on ABCA1-dependent CEC (β = -0.204; 95% confidence interval, -0.371 to -0.037). The finding that ABCA1-dependent CEC, but not serum HDL cholesterol level (r = -0.002; P = 0.985), is a significant predictor of PWV in healthy subjects points to the relevance of HDL function in vascular physiology and arterial stiffness prevention.

Ultrasonography (US) and non-invasive diagnostic methods for non-alcoholic fatty liver disease (NAFLD) and early vascular damage. Possible application in a population study on the metabolic syndrome (MS)

Abdominal ultrasonography (US) represents the first-line imaging examination in chronic liver diseases; in most cases, US, laboratory findings and the clinical context are generally sufficient to guide the diagnosis. Thanks to the considerable diffusion of US, we have seen an increased diagnosis of NAFLD in recent years, although this condition is generally silent from a clinical point of view. We have to identify the metabolic syndrome in the general population and to promptly recognize NAFLD to prevent its development into non-alcoholic steatohepatitis, cirrhosis and hepatocellular carcinoma. Among the non-invasive diagnostic techniques for NAFLD and for early vascular damage, ultrasonography represents the method of choice. In fact, besides the traditional semiotics of fundamental US of the liver, new US techniques have recently been proposed (contrast enhancement US, acoustic structure characterization), with respect to serum biomarkers and Fibroscan, for the study of liver fibrosis. Similarly, also as concerns the US measurement of carotid intima-media thickness, new automated methods with sophisticated software and radio-frequency signal have recently been introduced. Finally, we report the preliminary results of a personal experience on liver and carotid US in the epidemiology of the metabolic syndrome.

Biomarker-calibrated dietary energy and protein intake associations with diabetes risk among postmenopausal women from the Women's Health Initiative

BACKGROUND

Self-report of dietary energy and protein intakes has been shown to be systematically and differentially underreported.

OBJECTIVE

We assessed and compared the association of diabetes among postmenopausal women with biomarker-calibrated and uncalibrated dietary energy and protein intakes from food-frequency questionnaires (FFQs).

DESIGN

The analyses were performed for 74,155 participants of various race-ethnicities from the Women's Health Initiative. Uncalibrated and calibrated energy and protein intakes from FFQs were assessed for associations with incident diabetes by using HR estimates based on Cox regression.

RESULTS

A 20% increment in uncalibrated energy consumption was associated with increased diabetes risk (HR) of 1.03 (95% CI: 1.01, 1.05), 2.41 (95% CI: 2.06, 2.82) with biomarker calibration, and 1.30 (95% CI: 0.96, 1.76) after adjustment for BMI. A 20% increment in uncalibrated protein (g/d) resulted in an HR of 1.05 (95% CI: 1.03, 1.07), 1.82 (95% CI: 1.56, 2.12) with calibration, and 1.16 (95% CI: 1.05, 1.28) with adjustment for BMI. A 20% increment in uncalibrated protein density (% of energy from protein) resulted in an HR of 1.13 (95% CI: 1.09, 1.17), 1.01 (95% CI: 0.75, 1.37) with calibration, and 1.19 (95% CI: 1.07, 1.32) with adjustment for BMI.

CONCLUSIONS

Higher protein and total energy intakes (calibrated) appear to be associated with a substantially increased diabetes risk that may be mediated by an increase in body mass over time. Diet-disease associations without correction of self-reported measurement error should be viewed with caution. This trial is registered at clinicaltrials.gov as NCT00000611.

A novel strategy in production of oligosaccharides in digestive tract: prevention of postprandial hyperglycemia and hyperinsulinemia

The aim of this study was to evaluate the effects of oral administration of transglucosidase (TG) on postprandial glucose concentrations in healthy subjects. A randomized placebo-controlled three-way crossover trial was separated by a washout period of more than 3 days. Twenty-one normal healthy volunteers, aged 30-61 years old (17 males and 4 females) were selected for this study. The subjects' health was assessed as normal by prestudy screening. All subjects received 3 types of test meals (3 rice balls: protein, 14.4 g; fat, 2.1 g; and carbohydrate, 111 g: total energy, 522 kcal) with 200 ml water in which 0 mg, 150 mg, or 300 mg of TG was dissolved. Blood samples for estimating plasma glucose and insulin concentrations were collected before and every 30 min after the experiment. As compared to no TG treatment, TG administration tended to prevent a postprandial increase in plasma glucose (p = 0.069: 150 mg of TG vs control) but there were no significant difference among three groups. With regard to the 17 subjects who were suggested to have impaired glucose tolerance, TG significantly decreased the postprandial blood glucose (p<0.05: 150 mg and 300 mg of TG vs control) and marginally decreased insulin concentrations (p = 0.099: 300 mg of TG vs control). These results suggest that TG may be useful for preventing the progression of type 2 diabetes mellitus.

Effects of metformin on body weight and body composition in obese insulin-resistant children: a randomized clinical trial

OBJECTIVE

Metformin can decrease adiposity and ameliorate obesity-related comorbid conditions, including abnormalities in glucose homeostasis in adolescents, but there are few data evaluating the efficacy of metformin among younger children. Our objective was to determine whether metformin treatment causes weight loss and improves obesity-related comorbidities in obese children, who are insulin-resistant.

RESEARCH DESIGN AND METHODS

This study was a randomized double-blind placebo-controlled trial consisting of 100 severely obese (mean BMI 34.6 ± 6.6 kg/m(2)) insulin-resistant children aged 6-12 years, randomized to 1,000 mg metformin (n = 53) or placebo (n = 47) twice daily for 6 months, followed by open-label metformin treatment for 6 months. All children and their parents participated in a monthly dietitian-administered weight-reduction program.

RESULTS

Eighty-five percent completed the 6-month randomized phase. Children prescribed metformin had significantly greater decreases in BMI (difference -1.09 kg/m(2), CI -1.87 to -0.31, P = 0.006), body weight (difference -3.38 kg, CI -5.2 to -1.57, P < 0.001), BMI Z score (difference between metformin and placebo groups -0.07, CI -0.12 to -0.01, P = 0.02), and fat mass (difference -1.40 kg, CI -2.74 to -0.06, P = 0.04). Fasting plasma glucose (P = 0.007) and homeostasis model assessment (HOMA) insulin resistance index (P = 0.006) also improved more in metformin-treated children than in placebo-treated children. Gastrointestinal symptoms were significantly more prevalent in metformin-treated children, which limited maximal tolerated dosage in 17%. During the 6-month open-label phase, children treated previously with placebo decreased their BMI Z score; those treated continuously with metformin did not significantly change BMI Z score further.

CONCLUSIONS

Metformin had modest but favorable effects on body weight, body composition, and glucose homeostasis in obese insulin-resistant children participating in a low-intensity weight-reduction program.

Risk factors for incident type 2 diabetes in individuals with a BMI of <27 kg/m2: the role of gamma-glutamyltransferase. Data from an Epidemiological Study on the Insulin Resistance Syndrome (DESIR)

AIMS/HYPOTHESIS

Risk factors for incident type 2 diabetes, in particular, hepatic markers, have rarely been studied in leaner individuals. We aimed to identify the metabolic and hepatic markers associated with incident diabetes in men and women with a BMI of <27 kg/m(2) and to compare them with those in individuals with a BMI of >or=27 kg/m(2).

METHODS

Risk factors for 9 year incident diabetes were compared in the French Data from an Epidemiological Study on the Insulin Resistance Syndrome (DESIR) cohort. Comparisons were made between the 2,947 participants with a BMI of <27 kg/m(2) and the 879 with a BMI of >or=27 kg/m(2).

RESULTS

There were 92 incident cases of diabetes in individuals with a BMI of <27 kg/m(2) and 111 in those with a BMI of >or=27 kg/m(2). Among those who were not markedly overweight, classical biological markers were associated with 9 year incident diabetes, glycaemia being the strongest predictor. gamma-Glutamyltransferase (GGT), either considered as a continuous variable or at levels >or=20 U/l, was associated with incident diabetes, with a stronger effect in the BMI <27 kg/m(2) group: OR 1.59 (95% CI 1.29-1.97, p < 0.001) in comparison with OR 1.07 (95% CI 0.82-1.38, p = 0.63) for those with a BMI of >or=27 kg/m(2) (results after adjustment for alcohol intake, alanine aminotransferase, waist circumference and the HOMA insulin resistance index).

CONCLUSIONS/INTERPRETATION

In individuals with a BMI of <27 kg/m(2), GGT was the strongest predictor of diabetes after fasting hyperglycaemia. This association with incident diabetes remained after adjustment for conventional markers of insulin resistance, suggesting potential interactions between GGT, enhanced hepatic neoglucogenesis and/or early alterations of insulin secretion.

Glucose indices, health behaviors, and incidence of diabetes in Australia: the Australian Diabetes, Obesity and Lifestyle Study

OBJECTIVE

This national, population-based study reports diabetes incidence based on oral glucose tolerance tests (OGTTs) and identifies risk factors for diabetes in Australians.

RESEARCH DESIGN AND METHODS

The Australian Diabetes, Obesity and Lifestyle Study followed-up 5,842 participants over 5 years. Normal glycemia, impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and diabetes were defined using World Health Organization criteria.

RESULTS

Age-standardized annual incidence of diabetes for men and women was 0.8% (95% CI 0.6-0.9) and 0.7% (0.5-0.8), respectively. The annual incidence was 0.2% (0.2-0.3), 2.6% (1.8-3.4), and 3.5% (2.9-4.2) among those with normal glycemia, IFG, and IGT, respectively, at baseline. Among those with IFG, the incidence was significantly higher in women (4.0 vs. 2.0%), while among those with IGT, it was significantly higher in men (4.4 vs. 2.9%). Using multivariate logistic regression, hypertension (odds ratio 1.64 [95% CI 1.17-2.28]), hypertriglyceridemia (1.46 [1.05-2.02]), log fasting plasma glucose (odds ratio per 1 SD 5.25 [95% CI 3.98-6.92]), waist circumference (1.26 [1.08-1.48]), smoking (1.70 [96% CI 1.11-2.63]), physical inactivity (1.56 [1.12-2.16]), family history of diabetes (1.82 [1.30-2.52]), and low education level (1.85 [1.04-3.31]) were associated with incident diabetes. In age- and sex-adjusted models, A1C was a predictor of diabetes in the whole population, in those with normal glycemia, and in those with IGT or IFG.

CONCLUSIONS

Diabetes incidence is 10-20 times greater in those with IGT or IFG than those with normal glycemia. Measures of glycemia, A1C, metabolic syndrome components, education level, smoking, and physical inactivity are risk factors for diabetes.

Metabolic and cardiovascular risk factors in subjects with impaired fasting glucose: the 100 versus 110 mg/dL threshold

BACKGROUND

In 2003, the American Diabetes Association (ADA) established a new cutoff for impaired fasting glucose (IFG) by reducing it from 110 to 100 mg/dL. This change was challenged as to its appropriateness. A few studies have examined the impact of the ADA(2003) threshold of IFG on metabolic and cardiovascular risk factors.

METHODS

We examined whether metabolic and cardiovascular risk factors, including inflammatory biomarkers, differ in subjects with the new ADA(2003) threshold of IFG (IGF100) as compared with subjects with the old ADA(1997) threshold of IFG (IFG110) in a cohort of 946 nondiabetic Italian Caucasians (fasting plasma glucose < 126 mg/dL).

RESULTS

As compared with normal fasting glucose (NFG), subjects with IFG100 and IFG110 had higher body mass index (BMI), waist circumference, total and low density lipoprotein (LDL) cholesterol, triglyceride, fasting and 2-h post-challenge plasma glucose, fasting insulin, systolic blood pressure, and lower levels of high density lipoprotein (HDL) and insulin-like growth factor I (IGF-I). In a logistic regression analysis with adjustment for age and gender, IFG110 was associated with higher risk of post-challenge glucose intolerance as compared with IFG100. As compared with IFG100, subjects with IFG110 have significantly lower levels of circulating IGF-I. As compared with NFG, IFG110, but not IFG100, showed a significant association with increased levels of inflammatory markers including white blood cell count (WBCC), and C-reactive protein (CRP). Both CRP and WBCC were correlated with 2-h plasma glucose but not with fasting plasma glucose (FPG).

CONCLUSIONS

The data show that IFG110 is associated with a worse metabolic and cardiovascular risk profile as compared with IFG100.

Predictive ability of fasting plasma glucose for a diabetic 2-h postload glucose value in oral glucose tolerance test: spectrum effect

The performance of diagnostic tests may vary according to patient characteristics. The aim of this study is to find out the factors, if any, that may affect the performance of fasting plasma glucose (FPG) to predict a diabetic 2-h postload glucose level (> or =200 mg/dl) in oral glucose tolerance test (OGTT). One hundred ninety-six patients with known risk factors for diabetes mellitus to whom OGTT was applied were included. Factors that may have an effect on the performance of FPG in prediction of a diabetic value in OGTT were determined by using logistic regression and likelihood ratios (LRs). The cutoff of FPG predicting a 2-h postload glucose of > or =200 mg/dl was calculated by receiver operating characteristic curve as 110 mg/dl (sensitivity, 76.7%; specificity, 75.9%). Waist-to-hip ratio (WHR) and body mass index (BMI) influenced sensitivity, whereas age, family history, and presence of hyperlipidemia affected specificity of FPG. Significant factors for positive LR were age and hyperlipidemia, whereas sex, smoking, hyperlipidemia, physical inactivity, WHR, and BMI influenced negative LR. Fasting plasma glucose performance as a diagnostic test can be affected by many factors that are clearly stated as risk factors for diabetes mellitus. These data emphasize how the interpretation of a diagnostic test varies as the patient characteristics vary; the criteria that we confidently rely on may not be that reliable, changing between just two different patients.

Epidemiological characteristics of diabetes mellitus and impaired glucose regulation in a Chinese adult population: the Shanghai Diabetes Studies, a cross-sectional 3-year follow-up study in Shanghai urban communities

AIMS/HYPOTHESIS

To estimate the prevalence and incidence of diabetes mellitus and impaired glucose regulation (IGR) in a Chinese population aged 20-94 years.

SUBJECTS AND METHODS

A group of 5,628 randomly selected adults, aged 20-94 years, living in the Huayang and Caoyang communities in Shanghai, China, were investigated between 1998 and 2001. During 2002-04, 2,666 subjects were followed up. All the participants underwent anthropometric measurements, blood biochemical analyses and a 75-g OGTT.

RESULTS

Based on the 2000 census data of China, the age-standardised prevalences were 6.87% for diabetes and 8.53% for IGR at baseline. More than two in five cases with diabetes were undiagnosed. The age-adjusted prevalence of diabetes and IGR increased with age. The age-adjusted prevalences of hypertension, dyslipidaemia and overweight in males were significantly higher (p < 0.001) than in females. The 3-year cumulative incidence rates of diabetes and IGR were 4.96 and 11.10%, respectively. The relative risk of developing diabetes was significantly higher in subjects with IGR than in subjects with NGT (p < 0.001).

CONCLUSIONS/INTERPRETATION

The prevalence and incidence rates for diabetes or IGR have increased dramatically over the last decades, especially in younger age groups. A large proportion of cases are undiagnosed. We strongly recommend that population-based diabetes screening programmes should be implemented and generalised for younger people.

The threshold for diagnosing impaired fasting glucose: a position statement by the European Diabetes Epidemiology Group

The category of IFG was introduced in the late 1990s to denote a state of non-diabetic hyperglycaemia defined by a fasting plasma glucose (FPG) concentration between 6.1 and 6.9 mmol/l. In 2003 the American Diabetes Association recommended that this diagnostic threshold be lowered to 5.6 mmol/l. The justification for lowering the threshold has been questioned. This simple change in cut-off value creates a pandemic of IFG, with a two- to five-fold increase in the prevalence of IFG across the world. Such a change in threshold has far-reaching public health implications. The European Diabetes Epidemiology Group (EDEG) has reviewed the evidence for this lower cut-off point for the definition of IFG and concludes that the previous definition should not be altered. EDEG further recommends that the value of all categorical definitions of non-diabetic hyperglycaemia should be reconsidered.