Progression to type 2 diabetes among high-risk groups in Kin-Chen, Kinmen. Exploring the natural history of type 2 diabetes

Association of risk factors with type 2 diabetes: A systematic review

Diabetes is the leading cause of severe health complications and one of the top 10 causes of death worldwide. To date, diabetes has no cure, and therefore, it is necessary to take precautionary measures to avoid its occurrence. The main aim of this systematic review is to identify the majority of the risk factors for the incidence/prevalence of type 2 diabetes mellitus on one hand, and to give a critical analysis of the cohort/cross-sectional studies which examine the impact of the association of risk factors on diabetes. Consequently, we provide insights on risk factors whose interactions are major players in developing diabetes. We conclude with recommendations to allied health professionals, individuals and government institutions to support better diagnosis and prognosis of the disease.

Uric acid and risk of new-onset metabolic syndrome, impaired fasting glucose and diabetes mellitus in a general Italian population: data from the Pressioni Arteriose Monitorate E Loro Associazioni study

BACKGROUND

Although several data suggest that serum uric acid (SUA) predicts future development of metabolic abnormalities, the evidence is not conclusive in Mediterranean populations.

METHODS

A total of 3200 individuals were randomly selected from the residents of Monza (North Italy) to be representative of its general population for sex and age (25-74 years). The participation rate was 64%. At baseline and 10 years later, we measured waist circumference, office blood pressure, fasting blood glucose, serum triglycerides, serum HDL cholesterol and SUA.

RESULTS

The analysis was carried out in individuals without metabolic syndrome at baseline (N = 1192) when looking for incidence of metabolic syndrome, without impaired fasting glucose (IFG) at baseline (N = 1320) when looking for incidence of IFG and without diabetes mellitus at baseline (N = 1352) when looking for incidence of diabetes mellitus. Adjusting for confounders, a 1-SD increase of baseline SUA was not associated with and increased risk of new-onset metabolic syndrome, but with new-onset IFG [relative risk (RR) = 1.26, confidence interval (CI) 1.06-1.5, P = 0.01]. It was associated with a 29% increased risk of new-onset diabetes mellitus, that was more than twice in the highest as compared with the lowest quartile of baseline SUA (RR = 1.29, CI 0.98-1.7, P = 0.07, and RR = 2.16, CI 0.95-4.88, P = 0.07). Focusing the analysis on the individuals with age above the median value, SUA increase was significantly associated with an increased risk of new-onset metabolic syndrome, IFG and diabetes mellitus.

CONCLUSION

SUA increase is associated with an increased risk of developing IFG and, in the population fraction with age above the median value, also metabolic syndrome and diabetes mellitus.

First Report on Association of Hyperuricemia with Type 2 Diabetes in a Vietnamese Population

BACKGROUND

Uric acid is a powerful free-radical scavenger in humans, but hyperuricemia may induce insulin resistance and beta-cell dysfunction. The study aimed to evaluate the association between hyperuricemia and hyperglycemia, considering the confounding factors in a Vietnamese population.

METHODS

A population-based cross-sectional study recruited 1542 adults aged 50 to 70 years to collect data on socioeconomic status, lifestyle factors, and clinical patterns. Associations between hyperuricemia and hyperglycemia (isolated impaired fasting glucose (IFG), isolated impaired glucose tolerance (IGT), combined IFG-IGT, and type 2 diabetes (T2D)) were evaluated by multinomial logistic regression analysis in several models, adjusting for the confounding factors including socioeconomic status, lifestyle factors, and clinical measures.

RESULTS

Uric acid values were much higher in IFG, IFG-IGT, and T2D groups compared to those in the normal glucose tolerance (NGT) group. The significant association of hyperuricemia with IFG, IFG-IGT, and T2D was found in the model unadjusted and remained consistently in several models adjusted for socioeconomic status, lifestyle factors, and clinical patterns. In the final model, the consistent hyperglycemia risk was found in total sample (OR = 2.23 for IFG, OR = 2.29 for IFG-IGT, and 1.75 for T2D, P ≤ 0.006) and in women (OR = 2.90 for IFG, OR = 3.96 for IFG-IGT, and OR = 2.49 for T2D, P < 0.001) but not in men.

CONCLUSIONS

It is the first report in Vietnamese population suggesting the significant association of hyperuricemia with IFG, IFG-IGT, and T2D; and the predominant association was found in women than in men, taken into account the confounding factors.

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.

Incident Type 2 diabetes and the effect of early regression to normoglycaemia in a population with impaired glucose regulation

AIMS

To report contemporary regression rates from impaired glucose regulation to normal glucose tolerance, identify modifiable factors associated with early regression, and establish whether it affects subsequent diabetes risk in a population-based cohort.

METHODS

Participants with impaired glucose regulation (impaired fasting glucose and/or impaired glucose tolerance on a 75-g oral glucose tolerance test) at baseline in the UK-based ADDITION-Leicester study had annual Type 2 diabetes re-screens for 5 years or until diabetes diagnosis. Logistic regression models investigated modifiable risk factors for regression to normal glucose tolerance at 1 year (n = 817). Cox regression models estimated subsequent diabetes risk (n = 630).

RESULTS

At 1 year, 54% of participants had regressed to normal glucose tolerance, and 6% had progressed to diabetes. Regression to normal glucose tolerance was associated with weight loss of 0.1-3% [adjusted odds ratio 1.81 (95% CI 1.08, 3.03) compared with maintaining or gaining weight] and a waist circumference reduction of > 3 cm [adjusted odds ratio 1.78 (95% CI 1.03, 3.06) compared with maintaining or increasing waist circumference]. Those with normal glucose tolerance at 1 year subsequently had lower diabetes risk than those who remained with impaired glucose regulation [adjusted hazard ratio 0.19 (95% CI 0.10, 0.37)].

CONCLUSIONS

Early regression to normal glucose tolerance was associated with reduced diabetes incidence, and might be induced by small reductions in weight or waist circumference. If confirmed in experimental research, this could be a clear and achievable target for individuals diagnosed with impaired glucose regulation.

THE DIABETES EPIDEMIC IN CHINA: AN INTEGRATED REVIEW OF NATIONAL SURVEYS

OBJECTIVE

To review trends in the prevalence and incidence of diabetes mellitus (DM) and related risk factors in China.

METHODS

We searched the literature using PubMed, China Knowledge Resource Integrated Database, and China Wanfang Digital Database for large epidemiologic studies and national surveys.

RESULTS

During the past 30 years (1980-2010), 7 national diabetes mellitus surveys were conducted in China mainland, indicating that the prevalence of DM has increased 17-fold, from 0.67 to 11.6% of the population. The prevalence of impaired glucose regulation (IGR, including impaired fasting glucose and impaired glucose tolerance) also increased, from 2.09 in 1994 to 27.2% in 2010. There was no national representative study of the incidence of diabetes to date; the reported incidence of type 2 diabetes during past 25 years in several cohort studies varied (2.7 to 15.8 per 1,000 person-years). Potential risk factors which could have contributed to the increasing prevalence and incidence of DM and IGR in the Chinese population include social and economic development, urbanization, dietary pattern, and Westernized lifestyle. Further, genetic studies have suggested that unique inheritable risk factors in the Chinese population may increase the risk for DM when compared to Caucasians.

CONCLUSION

DM and IGR have become epidemic in China. Public health strategies should focus on modifying lifestyle and dietary factors, particularly among those with a susceptible genetic background.

ABBREVIATIONS

BMI = body mass index DM = diabetes mellitus FBG = fasting blood glucose GWAS = genome-wide association study IGR = impaired glucose regulation IGT = impaired glucose tolerance OGTT = oral glucose tolerance test T2D = type 2 diabetes WC = waist circumference WHR = waist-hip ratio.

Prevalence and characteristics of non-obese diabetes in Japanese men and women: the Yuport Medical Checkup Center Study

BACKGROUND

This study examined the prevalence and characteristics of type 2 diabetes in non-obese subjects to compare their cardiometabolic markers to those without diabetes.

METHODS

Data were used from 17,098 men and 17,199 women from a voluntary health checkup program between 1998 and 2006 conducted in Japan. The prevalence of diabetes (fasting plasma glucose ≥ 7.0 mmol/L, hemoglobin A1c ≥ 6.5%, or known diabetes) was calculated in each subgroup of body mass index (group 1, <22; group 2, 22-25; group 3, 25-27.5; and group 4, ≥ 27.5). The effect of diabetes and obesity on risk of an abnormal level of cardiometabolic marker was evaluated with a logistic regression model.

RESULTS

In men, the prevalence of diabetes was 9.5% in total, 6.4%, 9.4%, 11.3% and 16.2% in group 1 through 4, respectively. In women, it accounted for 4.3% in total, 2.4%, 4.5%, 8.7% and 12.3% per group, respectively. Non-obese diabetic subjects (in group 1 and 2) accounted for 60.8% and 62.0% of all the diabetic subjects in men and women, respectively. Non-obese population accounted for 71.2% and 83.6% of all men and women, respectively. Levels of cardiometabolic markers were higher in diabetic subjects than in non-diabetic subjects in each subgroup. Diabetes was associated with each abnormal level of cardiometabolic marker independent of obesity.

CONCLUSION

Over 60% of the diabetic subjects in this Japanese population were not obese. Non-obese diabetes is not widely addressed and should be considered for increased public attention. The elevated levels of cardiometabolic markers may contribute to an increased risk of cardiovascular disease in non-obese diabetes.

Progression from impaired fasting glucose to type 2 diabetes mellitus among Chinese subjects with and without hypertension in a primary care setting

BACKGROUND

The progression from impaired fasting glucose (IFG) to type 2 diabetes mellitus (T2DM) in Chinese subjects, with and without hypertension, in a primary care setting was unknown.

METHODS

The present retrospective multicenter 5-year (2002-2007) cohort study was performed on IFG subjects attending 23 general outpatient clinics who were identified by their elevated fasting blood glucose laboratory results. Development of T2DM was determined by physician diagnosis of T2DM or starting of oral antidiabetic drugs within 5 years. The relationship between the time of T2DM diagnosis and subject characteristics was assessed by adjusted hazard ratios (aHR) from Cox hazards model.

RESULTS

Of the 9161 IFG subjects, 4080 (45%) were men and 5081 (55%) were women. There were 1998 subjects who developed T2DM. The 5-year cumulative incidence was 0.218, whereas the overall annual incidence rate was 5.981/100 person-years. Subjects were more likely to develop T2DM if they were hypertensive (aHR = 1.44; 95% confidence interval [CI] 1.28-1.62; P < 0.001), aged <60 years (aHR = 1.36, 95% CI 1.24-1.49; P < 0.001), female (aHR = 1.18, 95% CI 1.08-1.29; P < 0.001), and had higher fasting glucose levels (6.39 ± 0.49 vs 6.24 ± 0.43 mmol/L in the group that developed T2DM vs the group without T2DM, respectively; aHR = 2.01, 95% CI 1.83-2.20; P < 0.001).

CONCLUSION

Overall, more than one-fifth of IFG subjects in the primary care setting developed T2DM within 5 years. Health care professionals can target interventions to patients with risk factors for disease progression.

Serum uric acid levels and incidence of impaired fasting glucose and type 2 diabetes mellitus: a meta-analysis of cohort studies

AIMS

A meta-analysis of cohort studies was conducted to assess the association between serum uric acid (SUA) levels and incidence of impaired fasting glucose (IFG) and type 2 diabetes mellitus (T2DM).

METHODS

A comprehensive search was conducted to identify eligible studies. The fixed or random effect pooled measure was selected based on between-study heterogeneity. Dose-response relationship was assessed by restricted cubic spline model and multivariate random-effect meta-regression.

RESULTS

Twelve studies with fifteen results were included involving 6340 cases and 62,834 participants. The pooled multivariate-adjusted relative risk (RR) (95%CI) of IFG and T2DM for the highest vs. lowest level of SUA was 1.54 (1.41-1.68), I(2)=42.2%. The association was consistent and significant across subgroup analysis. A nonlinear relationship was found of SUA levels with incidence of IFG and T2DM (P<0.01), and the multivariate-adjusted RRs (95%CI) of IFG and T2DM were 1.02 (0.95-1.10), 1.04 (0.94-1.15), 1.10 (0.99-1.22), 1.25 (1.16-1.35), 1.43 (1.31-1.55), 1.50 (1.38-1.63) and 1.49 (1.34-1.67) for 2.5, 3.5, 4.5, 5.5, 6.5, 7.5 and 8.5mg/dl of SUA. The RR (95%CI) of T2DM for the highest vs. lowest level of SUA was 1.67 (1.51-1.86), and a nonlinear relationship was also found between SUA levels and incidence of T2DM.

CONCLUSIONS

SUA levels are positively associated with incidence of IFG and T2DM, and the association might be nonlinear.

Do non-glycaemic markers add value to plasma glucose and hemoglobin a1c in predicting diabetes? Yuport health checkup center study

BACKGROUND

Many markers have been indicated as predictors of type 2 diabetes. However, the question of whether or not non-glycaemic (blood) biomarkers and non-blood biomarkers have a predictive additive utility when combined with glycaemic (blood) biomarkers is unknown. The study aim is to assess this additive utility in a large Japanese population.

METHODS

We used data from a retrospective cohort study conducted from 1998 to 2002 for the baseline and 2002 to 2006 for follow-up, inclusive of 5,142 men (mean age of 51.9 years) and 4,847 women (54.1 years) at baseline. The cumulative incidence of diabetes [defined either as a fasting plasma glucose (FPG) ≥7.00 mmol/l or as clinically diagnosed diabetes] was measured. In addition to glycaemic biomarkers [FPG and hemoglobin A1c (HbA1c)], we examined the clinical usefulness of adding non-glycaemic biomarkers and non-blood biomarkers, using sensitivity and specificity, and the area under the curve (AUC) of the receiver operating characteristics.

RESULTS

The AUCs to predict diabetes were 0.874 and 0.924 for FPG, 0.793 and 0.822 for HbA1c, in men and women, respectively. Glycaemic biomarkers were the best and second-best for diabetes prediction among the markers. All non-glycaemic markers (except uric acid in men and creatinine in both sexes) predicted diabetes. Among these biomarkers, the highest AUC in the single-marker analysis was 0.656 for alanine aminotransferase (ALT) in men and 0.740 for body mass index in women. The AUC of the combined markers of FPG and HbA1c was 0.895 in men and 0.938 in women, which were marginally increased to 0.904 and 0.940 when adding ALT, respectively.

CONCLUSIONS

AUC increments were marginal when adding non-glycaemic biomarkers and non-blood biomarkers to the classic model based on FPG and HbA1c. For the prediction of diabetes, FPG and HbA1c are sufficient and the other markers may not be needed in clinical practice.

Persistent fasting hyperglycaemia is more predictive of type 2 diabetes than transient fasting hyperglycaemia

AIMS

We investigated the value of persistent fasting hyperglycaemia as assessed by repeated elevated fasting plasma glucose in predicting the progression to diabetes.

METHODS

A retrospective cohort study was conducted from 1998 to 2006 inclusive among 7929 persons (37,742 person-years), with a mean age of 53.0 years at baseline. The cumulative incidence of diabetes was measured. A baseline and follow-up fasting plasma glucose were categorized as normal fasting glucose (< 5.56 mmol/l), or impaired fasting glucose (5.56-6.94 mmol/l).

RESULTS

The cumulative incidence and incidence density of diabetes were 3.5% (275 cases) and 7.3 per 1000 person-years over a mean follow-up period of 4.8 years. The cumulative incidence of diabetes among subjects with impaired fasting glucose at both previous examinations (persistent impaired fasting glucose) was 30.4% (222/1518) compared with 0.6% (15/5063) of those with normal fasting glucose at both baseline and initial follow-up. The hazard ratios to develop diabetes, adjusted for possible confounders, was 37.10 (95% CI, 21.6-63.7) for persistent impaired fasting glucose versus persistent normal fasting glucose. Persistent impaired fasting glucose predicted diabetes at 80.7% (222/275) sensitivity and 83.1% (6358/7654) specificity, whereas first baseline impaired fasting glucose only predicted diabetes at 86.9% (239/275) sensitivity and 74.9% (5730/7654) specificity. The model using both previous fasting plasma glucose levels had a greater AUROC (area under receiver operating characteristic) than that using first baseline fasting plasma glucose only (0.92 vs. 0.88; P < 0.001).

CONCLUSIONS

Repeated measurements of fasting plasma glucose better predicts incidence of diabetes than a single test. In particular, persistent fasting hyperglycaemia adds more substantial precision to the prediction of future diabetes than transient impaired fasting glucose. This combination is cost efficient and may be practical for early detection of high-risk individuals.

Impact of hypertension, overall obesity and abdominal obesity on diabetes incidence in Shanghai residents with different glucose levels

The impact of hypertension, overall obesity and abdominal obesity, individually or collectively, on diabetes incidence over a period of 5 years in residents with different glucose levels is diverse, with abdominal obesity having an impact in both non-diabetic hyperglycaemia and normal groups.

Glucose metabolism among residents in Shanghai: natural outcome of a 5-year follow-up study

BACKGROUND

Previous studies have shown that Type 2 diabetes mellitus (T2DM) is usually preceded by a condition known as pre-diabetes. However, few studies evaluate the rate of each status of impaired glucose regulation progressed to T2DM and its related metabolic disorders impacting the development.

AIM

To investigate the natural outcome of glucose metabolism among Shanghai adult residents during a 5-yr period, and estimate the metabolic characteristics related with the conversion of glucose tolerance.

SUBJECTS AND METHODS

A cross-sectional survey with multiple- stage and random sampling was conducted among 1869 adult residents from Shanghai Pudong New District in 2002. In 2007, 1042 non-diabetic subjects were successfully followed up. All the participants completed a questionnaire and underwent anthropometric measurements and a 75-g oral glucose tolerance test.

RESULTS

The incidence of diabetes was higher in isolated impaired glucose tolerance (i- IGT), isolated impaired fasting glucose (i-IFG), and combined fasting and post-prandial hyperglycemia (IFG/IGT) group when compared to that in normal glucose tolerance group, as relative ratios with 95% confidence intervals of 9.2 (5.5- 15.2), 7.5 (3.6-15.7), and 13.2 (5.8-30.2), respectively. Subjects who had 2 or more metabolic disorders had a 2-3-fold higher incidence than those with less than 1 metabolic disorder (all p<0.001).

CONCLUSIONS

People with pre-diabetes are at increased risk of diabetes, suggesting the need for frequent screening in theloe people with several metabolic disorders.

Metabolic syndrome frequency in inflammatory bowel diseases

BACKGROUND/AIM

Metabolic syndrome (MetS) is a clinical condition characterized by central obesity, elevated triglycerides, low-high density lipoproteins, impaired fasting glucose, and hypertension. There is insufficient data on the prevalence of MetS in patients with inflammatory bowel disease (IBD). This study sought to determine the prevalence of MetS in a Turkish cohort of patients with IBD and the association between insulin resistance (IR) and the MetS parameters, in this population.

PATIENTS AND METHODS

A total of 177 patients over 18 years of age (62 with Crohn's disease (CD) and 115 with ulcerative colitis (UC)) were enrolled in the study. The presence of at least three criteria of the International Diabetes Federation (IDF) was accepted for the diagnosis of MetS. The Homeostasis Model Assessment (HOMA) was used to determine IR. HOMA values < 1 were considered normal and values > 2.5 indicated a high probability of IR.

RESULTS

MetS frequency was higher in patients n=34 (29.5%) with UC than in patients n=11 (17.7%) with CD (P < 0.01). MetS was detected in 12 of the 117 patients (10.3%) with IBD, under 45 years of age, and in 33 of 60 patients (55%) over 45 years of age. HOMA value in n=31 patients (27%) with UC was > 2.5. Body mass index, insulin (P < 0.001), waist circumference, fasting plasma glucose, leukocyte count (P < 0.01), triglycerides, C-reactive protein, and uric acid values (P < 0.05) were significantly higher in UC patients with IR than those without IR.

CONCLUSION

Frequent occurrence of MS with increasing age in IBD, particularly in UC, showed the importance of early diagnosis and treatment of cardiovascular disease risk factors in the long-term follow-up of these diseases.

Normalization of glucose intolerance in first-degree relatives of patients with type 2 diabetes

AIMS

The aim of this study was to estimate the conversion rate to normal glucose tolerance (NGT) from a state of abnormal glucose metabolism and to identify characteristics predicting the conversion rate in first-degree relatives (FDRs) of patients with type 2 diabetes with glucose intolerance.

METHODS

A total of 2368 (614 men and 1754 women) FDRs of consecutive patients with type 2 diabetes aged 20-70 years in 2003-2005 were followed through 2007. Glucose tolerance classification was based on the criteria of the American Diabetes Association base on standard 75 g 2-h oral glucose tolerance test. The study group consisted of 370 participants with glucose intolerance at baseline.

RESULTS

The conversion rates to normal glucose tolerance from impaired glucose tolerance (IGT) and impaired fasting glucose (IFG) were 16.2% (95% confidence interval (CI) 13.30, 19.10) and 10.9% (95% CI: 5.7, 16.1) per year after an average of 2 years, respectively. Lower baseline fasting plasma glucose (HR 1.02, 95% CI: 1.01, 1.04) and 2-h (HR 1.02, 95% CI: 1.01, 1.04) glucose predicted conversion to NGT, as did changes in body mass index (BMI), waist circumference (WC), and lipids.

CONCLUSIONS

This is the first estimate of conversion rate and predictors from IFG and IGT to NGT in FDRs of people with type 2 diabetes in Iran. Lower baseline fasting, 2-h plasma glucose and changes in BMI, WC, and lipids predicted reversal to NGT at 24 months follow-up.

Metabolic syndrome, aging, physical inactivity, and incidence of type 2 diabetes in general African population

The first objective of this study was to determine the baseline prevalence of metabolic syndrome and its individual components using the NCEP-R/ATPIII criteria, IDF criteria for Europe, and IDF criteria for Africa: waist circumference of at least 94 cm for men and women. The second objective was to investigate the incidence and the determinants of type 2 diabetes in a prospective cohort of 807 non-diabetic Central Africans aged >or= 40 years from December 2004 to September 2008. During 3,156 person-years of median follow up, there were 93 type 2 diabetes cases (11.5%), corresponding to an incidence of 29 (95% CI 15-43) per 1,000 person-years. The independent predictors of incident type 2 diabetes were age >or= 45 years, physical inactivity, non-diabetic hyperglycaemia and metabolic syndrome regardless of criteria used. In conclusion, urgent prevention strategies are needed to curb the type 2 diabetes epidemic in Africa.

Association between serum uric acid and development of type 2 diabetes

OBJECTIVE

To systematically evaluate the association between serum uric acid (SUA) level and subsequent development of type 2 diabetes.

RESEARCH DESIGN AND METHODS

We searched Medline (31 March from 1966 to 2009) and Embase (31 March from 1980 to 2009) for observational cohort studies examining the association between SUA and the risk of type 2 diabetes by manual literature search. Relative risks (RRs) for each 1 mg/dl increase in SUA were pooled by using a random-effects model. The studies included were stratified into subgroups representing different study characteristics, and meta-regression analyses were performed to investigate the effect of these characteristics on the association between SUA level and type 2 diabetes risk.

RESULTS

The search yielded 11 cohort studies (42,834 participants) that reported 3,305 incident cases of type 2 diabetes during follow-up periods ranging from 2.0 to 13.5 years. The pooled RR of a 1 mg/dl increase in SUA was 1.17 (95% CI 1.09-1.25). Study results were consistently significant (i.e., >1) across characteristics of participants and study design. Publication bias was both visually and statistically suggested (P = 0.03 for Egger's test, 0.06). Adjustment for publication bias attenuated the pooled RR per mg/dl increase in SUA (RR 1.11 [95% CI 1.03-1.20]), but the association remained statistically significant (P = 0.009).

CONCLUSIONS

The current meta-analysis suggests that SUA level is positively associated with the development of type 2 diabetes regardless of various study characteristics. Further research should attempt to determine whether it is effective to utilize SUA level as a predictor of type 2 diabetes for its primary prevention.

Factors determining normalization of glucose intolerance in middle-aged Swedish men and women: a 8-10-year follow-up

AIMS

To examine factors in middle-aged Swedish men and women predicting the conversion from a state of abnormal glucose regulation to normal glucose tolerance (NGT) after 8-10 years.

METHODS

At baseline 3128 men and 4821 women, aged 35-56 years, without previously diagnosed diabetes underwent an oral glucose tolerance test and completed a questionnaire. At follow-up, 2383 men and 3329 women were re-examined. The study group consisted of 156 men and 124 women with impaired fasting glucose (IFG), impaired glucose tolerance (IGT), or both at baseline.

RESULTS

The rate of reversal to NGT from IFG or IGT was similar regardless of gender. In participants having IFG or IGT, reversal to NGT was predicted by low fasting and 2-h insulin, homeostasis model assessment of insulin resistance and of pancreatic beta cell function, body mass index and waist circumference without differences between gender and baseline glucose tolerance group. Low 2-h glucose, however, predicted reversal to NGT in men with IFG at baseline, but not in men with IGT at baseline, or in women with either IFG or IGT at baseline. Men reverting to NGT had higher coffee consumption and women had higher baseline leisure-time physical activity. In multiple logistic regression, including all participants, low fasting and 2-h glucose remained independent predictors of reverting to NGT.

CONCLUSIONS

Factors predicting reversal to NGT were measures correlated with low insulin resistance, but also lower insulin secretion, perhaps indicating a lower pancreatic beta cell workload in those who reverted. In men, but not in women, low 2-h glucose was of predictive value.

Community-based study on summer-winter difference in insulin resistance in Kin-Chen, Kinmen, Taiwan

BACKGROUND

The aim of this community-based study was to explore the summer-winter difference in insulin resistance in Kin-Chen, Kinmen.

METHODS

A total of 2,412 residents aged 40 and over was enrolled in a mass survey in Kin-Chen, Kinmen, by the Yang-Ming Crusade, a volunteer organization of well-trained medical students from National Yang-Ming University. All participants were investigated in winter (first phase, January and February, before Chinese New Year) and summer (secondary phase, July and August) in 2002. Structured questionnaires, demographic and physical data, lifestyle, and blood chemistry parameters were collected.

RESULTS

Higher levels of fasting insulin, HOMA-insulin resistance and triglycerides, but lower levels of high-density lipoprotein cholesterol were found in summer than in winter. The prevalence of metabolic syndrome was higher in summer than in winter, with differences of 7.7% in both genders (p = 0.0092 in men, p = 0.0037 in women). Body mass index (BMI), age and physical activity were significantly correlated with metabolic syndrome. After controlling for BMI and other risk profiles, summer was independently and positively associated with fasting insulin and insulin resistance regardless of metabolic syndrome.

CONCLUSION

Fasting insulin, insulin resistance and prevalence of metabolic syndrome were higher in summer than in winter. BMI and season were 2 major determinants of the variation in fasting insulin. The contextual impacts of seasonal variation in shaping metabolic syndrome or insulin resistance in populations need to be reemphasized.

Fasting plasma glucose and HbA1c as risk factors for Type 2 diabetes

AIMS

We examined the value of combining fasting plasma glucose (FPG) and glycated haemoglobin (HbA(1c)) as a predictor of diabetes, using the new American Diabetes Association (ADA) criteria of FPG and lower cut-off point of HbA(1c).

METHODS

A retrospective cohort study was conducted from 1998 to 2006, inclusive, in 10 042 persons (55 884 person-years), with a mean age of 53.0 years at baseline. The cumulative incidence of diabetes (defined either as an FPG > or = 7.0 mmol/l or as clinically diagnosed diabetes) was measured.

RESULTS

The cumulative incidence and incidence density of diabetes were 3.7% (368 cases) and 6.6/1000 person-years over a mean follow-up period of 5.5 years. The cumulative incidence of diabetes in subjects with impaired fasting glucose (IFG) and HbA(1c) 5.5-6.4% was 24.8% (172/694 persons) compared with 0.4% (25/6698 persons), 2.5% (15/605 persons), 7.6% (156/2045 persons) in those with normal fasting glucose (NFG) and HbA(1c) < 5.5%, NFG and HbA(1c) 5.5-6.4% and IFG and HbA(1c) < 5.5%, respectively. The hazard ratio for diabetes, adjusted for possible confounders, was 7.4 (95% confidence interval, 4.70 to 11.74) for those with NFG and HbA(1c) 5.5-6.4%, 14.4 (11.93 to 27.79) for those with IFG and HbA(1c) < 5.5% and 38.4 (24.63 to 59.88) for those with IFG and HbA(1c) 5.5-6.4%.

CONCLUSIONS

The combination of FPG and HbA(1c) identifies individuals who are at risk of progression to Type 2 diabetes at the new ADA criteria of FPG and a lower cut-off point of HbA(1c) than previous studies.

Glucose metabolism disorder in obese children assessed by continuous glucose monitoring system

BACKGROUND

Continuous glucose monitoring system (CGMS) can measure glucose levels at 5-minute intervals over a few days, and may be used to detect hypoglycemia, guide insulin therapy, and control glucose levels. This study was undertaken to assess the glucose metabolism disorder by CGMS in obese children.

METHODS

Eighty-four obese children were studied. Interstitial fluid (ISF) glucose levels were measured by CGMS for 24 hours covering the time for oral glucose tolerance test (OGTT). Impaired glucose tolerance (IGT), impaired fasting glucose (IFG), type 2 diabetic mellitus (T2DM) and hypoglycemia were assessed by CGMS.

RESULTS

Five children failed to complete CGMS test. The glucose levels in ISF measured by CGMS were highly correlated with those in capillary samples (r=0.775, P<0.001). However, the correlation between ISF and capillary glucose levels was lower during the first hour than that in the later time period (r=0.722 vs r=0.830), and the ISF glucose levels in 69.62% of children were higher than baseline levels in the initial 1-3 hours. In 79 obese children who finished the CGMS, 2 children had IFG, 2 had IGT, 3 had IFG + IGT, and 2 had T2DM. Nocturnal hypoglycemia was noted during the overnight fasting in 11 children (13.92%).

CONCLUSIONS

Our data suggest that glucose metabolism disorder including hyperglycemia and hypoglycemia is very common in obese children. Further studies are required to improve the precision of the CGMS in children.

Annual incidence and relative risk of diabetes in people with various categories of dysglycemia: a systematic overview and meta-analysis of prospective studies

BACKGROUND

Several estimates of the risk of progression to diabetes in people with impaired fasting glucose (IFG) or impaired glucose tolerance (IGT) have been reported.

OBJECTIVE

To provide an estimate of the risk of progression to diabetes and regression to normoglycemia in these populations.

DESIGN

Systematic overview and meta-analysis of prospective cohort studies published from 1979 until 2004.

SETTING

Global cohort studies.

PATIENTS

People with IFG or IGT detected by a screening oral glucose tolerance test.

MEASUREMENTS

Fasting and post-load plasma glucose levels.

RESULTS

The absolute annual incidence of diabetes in individuals with various categories of IFG or IGT varied from 5 to 10%. Compared to normoglycemic people the meta-analyzed relative risk and 95% confidence interval for diabetes was: 6.35 (4.87-7.82) in people with IGT; 5.52 (3.13-7.91) in people with isolated IGT; 4.66 (2.47-6.85) in people with IFG; 7.54 (4.63-10.45) in people with isolated IFG; and 12.13 (4.27-20.00) in people with both IFG and IGT. People with IGT were 0.33 times as likely to be normoglycemic after 1 year compared to people with normal glucose tolerance (95% CI 0.23-0.43).

LIMITATIONS

Studies that used differing criteria for IFG and IGT were included, and participants were classified on the basis of only one test.

CONCLUSION

IFG and IGT are associated with similar, high relative risk for incident diabetes. The combined abnormality of IFG plus IGT is associated with the highest relative risk.

Predicting the 20-year diabetes incidence rate

BACKGROUND

The long-range prediction from clinical variables of the onset of diabetes is important to patients and clinicians. Our objective was to evaluate the efficacy of various glucose-related clinical measurements in predicting the 20-year risk of developing type 2 diabetes (T2DM) in an elderly population.

METHODS

In a prospective study, 672 men and women aged 59-92 years, who were not diabetic in 1980 and were part of a nationwide longitudinal randomized study, were followed-up in 2000-2003. Fasting glucose, 1- and 2-h post-oral glucose tolerance and insulin were measured in 1980 and 2000-2003.

RESULTS

A group of 174 (25.9%) survivors had progressed to diabetes during the 20-year follow-up. Fasting glucose values were a good predictor for diabetes. With the 100 mg/dL cut-off of impaired fasting glucose (IFG), a 2-4-times higher predictive sensitivity followed the dramatic increase in IFG prevalence compared to the 110 mg/dL cut-off, but at a cost of reduced specificity and positive predictive value (PPV). By receiver operating curve (ROC) analysis, a 1-h post-load glucose was similar to 2 h and fasting glucose in prediction of the 20-year incidence of diabetes, and classifying correctly the 77, 74 and 73% of the group, respectively. In adjusted logistic regressions, 2.28, 1.78 and 1.69-folds increased the 20-year risk, and were associated with each SD increment of the respective glucose values (p < 0.001).

CONCLUSIONS

Although the best population-based strategy for the diagnosis of T2DM would be the combination of fasting glucose followed by post-load glucose, for the purposes of long-term prediction of T2DM risk, fasting glucose is sufficient.

The combination of fasting plasma glucose and glycosylated hemoglobin predicts type 2 diabetes in Japanese workers

OBJECTIVES

We examined the usefulness of the combined use of fasting plasma glucose (FPG) and hemoglobin Alc (HbA1c) levels to predict the progression of diabetes in a Japanese population.

METHODS

A retrospective cohort study was conducted from 1995 to 2002 among 449 non-diabetic Japanese workers, ages 23-65, in whom baseline FPG levels and HbA1c were measured. Subjects were classified into six groups according to their baseline FPG level: low normal fasting glucose (NFG) (<5.55 mmol/l); high NFG (5.55-6.09 mmol/l); or impaired fasting glucose (IFG) (6.10-6.99 mmol/l), in combination with baseline HbA1c level: low HbA1c (<5.8%) and high HbA1c (> or =5.8%). The cumulative incidence of diabetes in 2002, as defined by the 1997 American Diabetes Association (ADA) diagnostic criteria, was compared between groups.

RESULTS

The overall cumulative incidence of diabetes was 3.8% (17/449). The cumulative incidence of diabetes was 0.6% (2/339) in those with low NFG/normal HbA1c; 0% (0/24) with low NFG/high HbA1c; 6.4% (3/47) with high NFG/normal HbA1c; 23.1% (3/13) with high NFG/high HbA1c; 17.6% (3/17) with IFG/normal HbA1c; and 66.7% (9/17) with IFG/high HbA1c. The odds ratios for diabetes, adjusted for age, sex, body mass index (BMI) and family history of diabetes, were 5.3 (95% CI, 3.0-9.3) and 3.0 (1.7-5.3), per 0.56 mmol/l increase in FPG and 0.5% increase in HbA1c, respectively.

CONCLUSIONS

The combined use of FPG and HbA1c levels predicts the progression to diabetes in individuals with no apparent risk. In particular, the combination is recommended for individuals with a FPG > or =5.55 mmol/l.

Predictors of incident diabetes, metabolic syndrome in middle-aged adults: a 10-year follow-up study from Kinmen, Taiwan

AIMS/HYPOTHESIS

The aim of this prospective study was to assess a population-based cohort for the predictors of incident diabetes and metabolic syndrome, which is most likely to lead to cardiovascular disease.

METHODS

We compared the baseline individual components of metabolic syndrome, adopted from the NCEP ATP III for Asians, in 3629 subjects who developed diabetes, metabolic syndrome, or diabetes and metabolic syndrome to those who remained free of diabetes and metabolic syndrome for 10 years.

RESULTS

The incidence rate of diabetes was 7.8% (9.8% in men and 6.3% in women, respectively), and metabolic syndrome was 24.2% (23.4% in men and 24.7% women, respectively). Eighty-five men and 99 women developed diabetes and metabolic syndrome, which yielded incidence rates of 5.7% in men and 4.7% in women. After adjustment for related covariable factors, each component of metabolic syndrome in women, higher triglyceride and greater waist circumference in men, independently predicted future incident diabetes and metabolic syndrome as compared with those who remained free of diabetes and metabolic syndrome.

CONCLUSIONS/INTERPRETATION

These findings suggest that several components of metabolic syndrome independently precede the development of diabetes and metabolic syndrome. Further intervention studies are required to demonstrate the benefits of intervention with all aspects in decreasing the incidence of diabetes and metabolic syndrome in the general population.

Prevalence of type 2 diabetes mellitus of Chinese populations in Mainland China, Hong Kong, and Taiwan

This article reviews and describes trends and differences in prevalence of type 2 diabetes mellitus of Chinese populations in Mainland China, Hong Kong and Taiwan based on literatures published in the MEDLINE Advanced database (January 1966-October 2005) in both Chinese and English languages. Chinese populations in Hong Kong and Taiwan have significant higher prevalence rates of diabetes than their Mainland counterparts, with odds ratios 1.5 (95% confidence intervals: 1.4, 1.7) and 2.0 (95% confidence intervals: 1.8, 2.2), respectively in 1995-2003 adjusted for age and diagnostic criteria. Using stratified diagnostic criteria; the odds ratios in Hong Kong and Taiwan were consistently higher than Mainland China for the periods of 1985-1994 and 1995-2003. A large proportion, i.e. 68.6% (95% confidence intervals: 67.4%, 69.7%) of diabetic patients remains undiagnosed in Mainland China as compared to 52.6% (95% confidence intervals: 49.8%, 55.5%) undiagnosed in Hong Kong and Taiwan. The prevalence rates of diabetes and impaired glucose tolerance of the Chinese populations rise in older age groups. In tandem with economic development and change toward lifestyle that is lack of physical activity and rich in high-fat diet, prevalence of diabetes of the Chinese populations are on the rise. If the undiagnosed individuals left uncontrolled, they are subject to higher risks of developing diabetes and its complications. These will increase the burdens of diabetes medically and financially.

Elevated fasting triglycerides predict impaired glucose tolerance in adolescents at risk for type 2 diabetes

OBJECTIVE

The aim of this study was to evaluate whether fasting laboratory values can predict impaired glucose tolerance (IGT) in adolescents who are at risk for developing type 2 diabetes mellitus (T2DM).

HYPOTHESIS

Elevated fasting triglycerides, a marker for worsening insulin resistance, predict risk for IGT.

DESIGN

Following a fast of at least 9 h, laboratory measures, body mass index (BMI), and demographic information were obtained. The subjects then underwent a 75-g oral glucose challenge with a 2-h postchallenge glucose determination.

SUBJECTS

Eighty-four adolescents aged 12-20 yr with at least two risk factors for developing T2DM (obesity, family history of T2DM, or acanthosis nigricans) and with either a fasting insulin level > or =25 microU/mL or a homeostasis model assessment of insulin resistance (HOMA-IR) > or =3.5 were recruited for the study.

RESULTS

Ten subjects (12%) had IGT [2-h glucose > or =140 mg/dL (7.77 mmol/L)], and 10 subjects (12%) had impaired fasting glucose [IFG; fasting glucose > or =100 mg/dL (5.55 mmol/L)]. However, only three (30%) subjects with IGT had IFG, though all subjects with IGT had a fasting triglyceride level > or =150 mg/dL (1.70 mmol/L). Of those subjects with elevated triglycerides, 29% had IGT. As a screening test to predict risk for IGT, elevated triglycerides >150 mg/dL had a sensitivity of 100% and a specificity of 68%. The positive predictive value was 29%, and the negative predictive value was 100%.

CONCLUSIONS

Screening with fasting glucose alone would have missed 70% of subjects with IGT in this population of insulin-resistant adolescents. However, a fasting triglyceride level > or =150 mg/dL was strongly associated with IGT and may help to identify at-risk adolescents who should undergo formal glucose tolerance testing.

Hyperuricemia and Associated Diseases

After introduction of urate-lowering therapy, asympotomatic hyperuricemia was treated with allopurinol or uricosuric agents in the belief that hyperuricemia and/or gout caused chronic kidney disease. Epidemiologic studies in the 1970s, however, failed to confirm the view that hyperuricemia and gout were independent risk factors for chronic kidney disease. As a result, urate-lowering pharmacotherapy is generally not recommended at the present time in the management of asymptomatic hyperuricemia even though recent epidemiological, experimental, and clinical studies have prompted reexamination of a causal role for hyperuricemia (with or without gout) in chronic kidney disease as well as other important disorders including cardiovascular disease, hypertension, and metabolic syndrome. The issue of such a role remains unresolved and this article reviews the current status of the relationship between hyperuricemia and associated disorders.

Retinal vessel diameters and risk of impaired fasting glucose or diabetes: the Rotterdam study

The association between a smaller retinal arteriolar-to-venular ratio (AVR) and incident diabetes may be due to arteriolar narrowing, venular dilatation, or both. We investigated associations between baseline vessel diameters and incident impaired fasting glucose or diabetes in a population-based cohort (aged > or =55 years). Baseline retinal vessel diameters (1990-1993) were measured on digitized images of 2,309 subjects with a normal glucose tolerance test (postload glucose <7.8 mmol/l). At follow-up (1997-1999), impaired fasting glucose was defined as 6.1-7.0 mmol/l and diabetes as > or =7.0 mmol/l and/or antidiabetic medication use. Odds ratios (ORs) per SD increase in venular diameters were 1.13 (95% CI 1.00-1.29) for impaired fasting glucose and 1.09 (0.90-1.33) for diabetes. ORs per SD decrease in arteriolar diameters were 1.12 (0.98-1.27) and 1.08 (0.89-1.31) and per SD decrease in AVR were 1.29 (1.13-1.46) and 1.19 (0.98-1.45). After adjustment for cardiovascular risk factors, the associations were unaltered for venules and disappeared for arterioles. After stratification on age, associations between venular dilatation and impaired fasting glucose (1.23 [1.02-1.47]) or diabetes (1.18 [0.89-1.56]) were mainly present in participants aged <70 years. In conclusion, in our study, the risk of impaired fasting glucose and diabetes with AVR was explained by venular dilatation rather than arteriolar narrowing, warranting more focus on the causes of this dilatation.

Persistent impaired glucose tolerance, insulin resistance, and β-cell dysfunction were independent predictors of type 2 diabetes

BACKGROUND AND OBJECTIVE

To compare clinical profiles and risk of diabetes between subjects with transient (trIGT) and persistent (pIGT) impaired glucose tolerance in Taiwan.

STUDY DESIGN AND SETTING

In the pIGT group, IGT was diagnosed in two consecutive periods (1992-1994 and 1995-1996); in the trIGT group, the diagnosis was IGT at the baseline but normal glucose tolerance in the second period. The normal group was defined by fasting plasma glucose < 6.1 mmol/L and 2-hour post-load plasma glucose < 7.8 mmol/L in both periods. All three groups were considered eligible subjects for further follow up (1998-1999).

RESULTS

Among 298 nondiabetic subjects at baseline, there were 29 new cases of diabetes diagnosed according to 1999 WHO criteria in 1,614.3 person-years of follow-up (1.79%/year; 95% CI = 1.14-2.44%/year). Among subjects with normal, trIGT, or pIGT, the incidence rates were 0.73%/year (8/1,093.0; 95% CI = 0.22-1.24%/year), 2.57%/year (7/272.2; 95% CI = 0.67-4.47%/year), and 5.62%/year (14/249.1; 95% CI = 2.68-8.56%/year), respectively.

CONCLUSION

The group with trIGT had abnormal glucose tolerance and beta-cell dysfunction, which may represent an earlier stage than the group with pIGT in development of type 2 diabetes. Moreover, pIGT, insulin resistance, and beta-cell dysfunction played independent roles in the deterioration from IGT to diabetes.

Predictors of changes in glucose tolerance status in obese youth

OBJECTIVE

Type 2 diabetes in obese youth is an emerging problem. The metabolic and anthropometric predictors of change in glucose tolerance status in obese youth are unknown.

RESEARCH DESIGN AND METHODS

A total of 117 obese children and adolescents were studied by performing an oral glucose tolerance test (OGTT) at baseline and after approximately 2 years. Data from both OGTTs and changes in weight were examined to identify youth at highest risk for developing diabetes and the factors that have the strongest impact on glucose tolerance.

RESULTS

Eighty-four subjects had normal glucose tolerance (NGT) and 33 impaired glucose tolerance (IGT) at baseline. Eight subjects (all of whom had IGT at baseline) developed type 2 diabetes, whereas 15 subjects with IGT reverted to NGT. In this cohort, severe obesity, impaired glucose tolerance, and African-American background emerged as the best predictors of developing type 2 diabetes, whereas fasting glucose, insulin, and C-peptide were nonpredictive. Changes in insulin sensitivity, strongly related to weight change, had a significant impact on the 2-h glucose level on the follow-up study.

CONCLUSIONS

Severely obese children and adolescents with IGT, particularly of African-American descent, are at very high risk for developing type 2 diabetes over a short period of time. Parameters derived from an OGTT and not fasting samples can serve as predictors of changes in glucose tolerance.

A reduced-fat diet and aerobic exercise in Japanese Americans with impaired glucose tolerance decreases intra-abdominal fat and improves insulin sensitivity but not beta-cell function

Lifestyle modification reduces the risk of developing type 2 diabetes and may have its effect through improving insulin sensitivity, beta-cell function, or both. To determine whether diet and exercise improve insulin sensitivity and/or beta-cell function and to evaluate these effects over time, we quantified insulin sensitivity and the acute insulin response to glucose (AIRg) in 62 Japanese Americans (age 56.5 +/- 1.3 years; mean +/- SE) with impaired glucose tolerance (IGT) who were randomized to the American Heart Association (AHA) Step 2 diet plus endurance exercise (n = 30) versus the AHA Step 1 diet plus stretching (n = 32) for 24 months. beta-Cell function (disposition index [DI]) was calculated as S(i) x AIRg, where S(i) is the insulin sensitivity index. The incremental area under the curve for glucose (incAUCg) was calculated from a 75-g oral glucose tolerance test. Intra-abdominal fat (IAF) and subcutaneous fat (SCF) areas were measured by computed tomography. At 24 months, the Step 2/endurance group had lower weight (63.1 +/- 2.4 vs. 71.3 +/- 2.9 kg; P = 0.004) and IAF (75.0 +/- 7.9 vs. 112.7 +/- 10.4 cm(2); P = 0.03) and SCF (196.5 +/- 18.0 vs. 227.7 +/- 19.9 cm(2); P < 0.001) areas, greater S(i) (4.7 +/- 0.5 vs. 3.3 +/- 0.3 x 10(-5) min . pmol(-1) . l(-1); P = 0.01), and a trend toward lower AIRg (294.9 +/- 50.0 vs. 305.4 +/- 30.0 pmol/l; P = 0.06) and incAUCg (8,217.3 +/- 350.7 vs. 8,902.0 +/- 367.2 mg . dl(-1) . 2 h(-1); P = 0.08) compared with the Step 1/stretching group after adjusting for baseline values. There was no difference in the DI (P = 0.7) between the groups. S(i) was associated with changes in weight (r = -0.426, P = 0.001) and IAF (r = -0.395, P = 0.003) and SCF (r = -0.341, P = 0.01) areas. Thus, the lifestyle modifications decreased weight and central adiposity and improved insulin sensitivity in Japanese Americans with IGT. However, such changes did not improve beta-cell function, suggesting that this degree of lifestyle modifications may be limited in preventing type 2 diabetes over the long term.

High incidence of type 2 diabetes and increasing conversion rates from impaired fasting glucose and impaired glucose tolerance to diabetes in Mauritius

OBJECTIVE

To describe the incidence of different stages of glucose intolerance in a population from Mauritius followed over 11 years. RESEARCH DESIGN, METHODS AND SUBJECTS: Population-based surveys were undertaken in the multi-ethnic nation of Mauritius in 1987, 1992 and 1998 with 5083, 6616 and 6291 participants, respectively. Questionnaires, anthropometric measurements, and a 2-h 75-g oral glucose tolerance test were included. Three cohorts aged between 25 and 79 years with classifiable glucose tolerance data were identified; 3680 between 1987 and 1992, 4178 between 1992 and 1998, and 2631 between 1987 and 1998. Glucose tolerance was classified according to WHO 1999 criteria.

RESULTS

The incidence rate of type 2 diabetes was higher between 1992 and 1998 than between 1987 and 1992. In men, the incidence was similar between cohorts (24.5 and 25.4 per 1000 person-years) whereas the incidence increased in women (23.3 and 16.4 per 1000 person-years). The incidence of diabetes peaked in the 45-54 year age group and then plateaued or fell. The incidences of impaired glucose tolerance (IGT) and impaired fasting glucose (IFG) decreased in both men and women. Of normoglycaemic subjects at baseline, more women than men developed IGT and more men than women developed IFG. Of those labelled as IFG in 1987, 38% developed diabetes after 11 years. The corresponding figure for IGT was 46%.

CONCLUSIONS

In this study, we report changes in incidence rates of glucose intolerance over a 11-year period. In particular, differences between men and women were observed. The increased incidence of IGT in women compared with men, and increased incidence of IFG in men compared with women was consistent with, and explains the sex biases seen in the prevalences of these states.

The Singapore impaired glucose tolerance follow-up study: does the ticking clock go backward as well as forward?

OBJECTIVE

To 1). document the change in glucose tolerance for subjects with normal glucose tolerance (NGT) and impaired glucose tolerance (IGT) over time, 2). identify baseline factors associated with worsening of glucose tolerance, and 3). determine whether cardiovascular disease (CVD) risk factors associated with IGT improved in tandem with glucose tolerance.

RESEARCH DESIGN

Subjects with IGT and NGT (matched for age, sex, and ethnic group) were identified from a cross-sectional survey conducted in 1992. Subjects with IGT (297) and NGT (298) (65.0%) were reexamined in 2000. Glucose tolerance (assessed by 75-g oral glucose tolerance test), anthropometric data, serum lipids, blood pressure, and insulin resistance were determined at baseline and at the follow-up examination.

RESULTS

For NGT subjects, 14.0% progressed to IGT and 4.3% to diabetes over 8 years. For IGT subjects, 41.4% reverted to NGT, 23.0% remained impaired glucose tolerant, and 35.1% developed diabetes. Obesity, hypertriglyceridemia, higher blood pressure, increased insulin resistance, and lower HDL cholesterol at baseline were associated with worsening of glucose tolerance in both IGT and NGT subjects. Those with IGT who reverted to NGT remained more obese and had higher blood pressure than those with NGT in both 1992 and 2000. However, serum triglyceride, HDL cholesterol, and insulin resistance values in 2000 became indistinguishable from those of subjects who maintained NGT throughout the study period.

CONCLUSIONS

Some, but not all, CVD risk factors associated with IGT and with the risk of future diabetes normalize when glucose tolerance normalizes. Continued surveillance and treatment in subjects with IGT, even after they revert to NGT, may be important in the prevention of CVD.

Relative role of insulin resistance and beta-cell dysfunction in the progression to type 2 diabetes--The Kinmen Study

This study compared the relative role of insulin resistance and beta-cell dysfunction (both assessed using the HOMA method) with glucose intolerance conditions in the progression to type 2 diabetes among a high risk group of subjects with fasting plasma glucose (FPG) 5.6-7.0 mmol/l in Kinmen, Taiwan. Data were collected during a continuing prospective study (1998-99) of a group of Taiwanese subjects at high-risk of developing type 2 diabetes who had fasting hyperglycemia (5.6-7.0 mmol/l) and exhibited 2-h postload glucose concentrations <11.1 mmol/l from 1992-94 to 1995-96. Among 644 non-diabetic subjects at baseline, 79.8% (514/644) had at least one follow-up examination. There were 107 new cases of diabetes diagnosed by 1999 WHO criteria in 2918.7 person-years of follow-up. The incidence rate was 3.67%/year (107/2918.7). After adjustment for other possible associative variables, including gender, age, BMI, waist circumference, insulin resistance, and beta-cell dysfunction, Cox's hazard model showed that those individuals with isolated IFG (impaired fasting glucose) and those individuals with isolated IGT (2-h glucose impairment) exhibited similar risk of developing diabetes. Those individuals with isolated IFG and isolated IGT showed a comparable impairment of basal or hepatic insulin sensitivity, but those individuals with isolated IFG had a greater beta-cell dysfunction by the HOMA method.

High incidence of Type 2 diabetes mellitus in South African Indians: a 10-year follow-up study

AIMS

Previous cross-sectional studies have established that South African Indians have a high prevalence of Type 2 diabetes mellitus. A prospective community study was undertaken to determine the incidence of Type 2 diabetes and the risk factors associated with its development in a cohort of South African Indians who had been studied 10 years previously.

METHODS

This is a report on 563 subjects who participated both at baseline and at the 10-year follow-up study. In the baseline study, 2479 subjects (> 15 years) were studied; using 1985 World Health Organization criteria for glucose tolerance based on 75 g oral glucose tolerance tests (OGTT), the crude prevalence of diabetes mellitus (Diabetes) was 9.8% and of impaired glucose tolerance (IGT) 5.8% (age and sex-adjusted prevalence 13% and 6.9%, respectively).

RESULTS

At the 10-year follow-up study, 563 of the subjects who could be traced consented to a repeat OGTT; of these, 91 (16.2%) were classified as Diabetes and 41 (7.3%) as IGT. Of the subjects who did not have diabetes at baseline (n = 517), 49 (9.5%) progressed to diabetes (PTD) and 40 (7.7%) had IGT. The crude cumulative incidence of diabetes was 9.5% (rate of progression 0.95% per annum; incidence density 9.5/1000 person years) with an age and sex-adjusted cumulative incidence of 8.3% (rate of progression 0.95% per annum; incidence density 8.3/1000 person years). Examination of risk factors predictive of subsequent diabetes development was undertaken by analysis of baseline (year 0) variables in the 517 subjects who did not have diabetes at baseline. In multivariate analysis using a logistic regression model, the significant predictive risk factors for future diabetes included 2-h post load plasma glucose (2 PG) (P < 0.0001, odds ratio (OR) 1.7, 95% confidence interval (CI) 1.4-2.1), body mass index (BMI) (P < 0.006, OR 1.1, 95% CI 1.0-1.3) and obesity (P < 0.01, OR 4.6, 95% CI 1.4-14.7).

CONCLUSIONS

This long-term study has shown that in South African Indians there is a high incidence of Type 2 diabetes, and in this population significant predictors include higher baseline blood glucose, BMI and obesity.

[Epidemiology of diabetes and its non-coronary complications]

Diabetes mellitus is among the diseases with great impact on health and society, not only for its high prevalence but also for its chronic complications and high mortality. The most precise method to investigate the prevalence of diabetes is by oral glucose tolerance testing. In Spain, the prevalence of diabetes in the 30-65 year-old population is estimated to be 6.5% among 30-to-65- year old, and 10.3% among the 30-to-89 year-old population. The ratio of known to unknown diabetes ranges from 1:3 to 2:3. The incidence of diabetes mellitus type 2 in Spain is 8/1000 persons per year, and the incidence of type 1 is 11 to 12 cases per 100,000 persons per year. The prevalence of chronic complications varies according to type of diabetes, time since onset and degree of metabolic control: neuropathy 25%, retinopathy 32% and nephropathy 23%. Diabetes is one of the most important causes of death in Spain, occupying third place for women and seventh for men.

Progression from IGT to type 2 diabetes mellitus: the central role of impaired early insulin secretion

Impaired glucose tolerance (IGT) is characterized by plasma glucose responses to an oral glucose challenge that are above normal but not at the level defining diabetes. IGT is a common condition that greatly increases risk for the subsequent development of type 2 diabetes. Individuals with IGT manifest abnormalities in both insulin action and early insulin secretion similar to those seen in patients with type 2 diabetes. These abnormalities not only precede diabetes, they predict it as well. Furthermore, the progression from IGT to diabetes is characterized by a dramatic decline in early insulin secretion. It is now evident that early insulin secretion plays an important role in the rapid and efficient suppression of endogenous glucose production following a meal. Loss of early insulin secretion initially leads to postprandial hyperglycemia which, as the disease progresses, worsens to clinical hyperglycemia. Obesity and a high fat diet may contribute to the development of both insulin resistance and insulin secretory dysfunction in susceptible individuals. Strategies that improve insulin resistance and enhance early insulin secretion may prevent the progression from IGT to diabetes. Already, there is substantial evidence the weight loss and exercise may reduce the risk of developing diabetes by up to 58%. Other trials using pharmacologic agents to decrease insulin resistance and increase early insulin secretion are underway. Prevention remains the best hope for a long-term solutions to the worldwide epidemic of diabetes.

Comparison of metabolic risk profiles between subjects with fasting and 2-hour plasma glucose impairment: The Kinmen Study

A two-step screening strategy was used to compare the metabolic risk profiles between subjects from Kinmen, Taiwan, who had fasting and 2-hr plasma glucose impairment and were considered at high risk of diabetes due to a fasting plasma glucose (FPG) between 5.6 and 7.8 mmol/l at the baseline screening. 1855 subjects without a previous diagnosis of diabetes who had an FPG of 5.6-7.8 mmol/l at the first step of screening were invited to undergo an Oral Glucose Tolerance Test (OGTT) for the second step of screening, and 1456 of these subjects (774 males and 682 females) completed the OGTT. Subjects who completed the OGTT were classified into normal, isolated impaired fasting glucose (isolated IFG), isolated impaired glucose tolerance (isolated IGT), both IFG and IGT, or undiagnosed diabetes groups. Sex-specific, age-adjusted mean values of metabolic risk profiles for various categories of glucose intolerance were calculated. The results for IFG and IGT agreed in only 20.8% of subjects. The clinical features of subjects with IGT (2-hr glucose impairment) were associated with cardiovascular risk profiles, while those subjects with isolated IFG (fasting glucose impairment only) were not. If the definition of IFG alone had been used for glucose intolerance screening, about 66.6% of subjects with IGT (i.e., isolated IGT with 2-hr glucose impairment and a normal fasting state) who had cardiovascular risk profiles would have been undetected.

Central obesity predicts the worsening of glycemia in southern Chinese

AIMS

The association between obesity and type 2 diabetes has been found to be consistent across different ethnic populations. Our aim was to study the contribution of obesity to the development of type 2 diabetes in a non-obese Chinese population with a high prevalence of diabetes (9.8% in 1995-1996).

METHODS

Six-hundred and forty-four non-diabetic subjects were recruited from the Hong Kong Cardiovascular Risk Factor Prevalence Study (1995-1996). This was a community-based population study which involved the use of a 75 g oral glucose tolerance test and 1985 World Health Organization diagnostic criteria. Their glycemic status was reassessed at 2 y.

RESULTS

In subjects with impaired glucose tolerance (n=322), the annual progression rate to diabetes (4.8%; 95% CI 2.5-7.1%), was 8-fold that in control subjects (0.6%; 95% CI 0.0-1.4%; P<0.001). Baseline waist-hip ratio (WHR; OR per unit increase=1.05; 95% CI 1.02-1.07, P=0.0003) and post-load 2 h plasma glucose (OR per unit increase=2.02; 95% CI 1.76-2.34, P<0.0001) were significantly associated with glycemic status at 2 y in stepwise polytomous logistic regression analysis. Subjects with high baseline waist circumference or WHR (> or =median) were more likely to have worsening of glucose tolerance at 2 y than those with low waist circumference (<median; conversion to diabetes, OR 3.8, P=0.001) or WHR (<median; conversion to diabetes, OR 2.8, P=0.019).

CONCLUSION

Abdominal obesity, readily assessed by the measurement of WHR or waist circumference, was for the first time shown prospectively to be independently associated with the deterioration of glucose tolerance in a Chinese population.

Epidemiology of type 2 diabetes in Taiwan

In the face of the growing worldwide prevalence of type 2 diabetes, effective methods of preventing further increases in prevalence are needed. In this paper, we review the community-based epidemiologic studies of diabetes in Taiwan published during the last decade, and look at the effectiveness of a two-stage screening protocol for identifying subjects at risk for progression to type 2 diabetes. The results of these studies indicate that the age-adjusted prevalence rate of undiagnosed diabetes in Taiwan is stable, at around 4.0%, while the annual incidence rate is about 1.8%. The results of several studies strongly suggest that a two-step screening strategy, in which only subjects with a fasting plasma glucose level of 5.6-7.8 mmol/l receive the oral glucose tolerance test, may be an effective means of identifying diabetics and persons at high risk for progression to type 2 diabetes and, ultimately, slowing the increase in the prevalence of this disease.

The impact of years since menopause on the development of impaired glucose tolerance

This is a community-based population survey carried out by the Yang-Ming Crusade to investigate the impact of years since menopause on the development of glucose intolerance in post-menopausal women. A total of 5412 women were screened with fasting plasma glucose. Those with fasting plasma glucose levels between 5.5 and 7.8 mM were given an oral glucose tolerance test. Among the 5412 women screened, 2039 (37.7%) were post-menopausal with a median age at menopause of 49 years. Pre-menopausal women showed impaired glucose tolerance (IGT) and diabetes mellitus (DM) prevalences of 3.7% and 3.1% respectively, whereas the corresponding figures for post-menopausal women were 8.4% and 17.6%, respectively. Comparing DM versus normal glucose tolerance (NGT) and IGT versus NGT as dependent variables in logistic regression analysis, menopause status was significantly associated with DM and IGT. In post-menopausal women, after maintaining body mass index, waist-hip ratio, systolic blood pressure, diastolic blood pressure, family history of DM, age at menopause, cholesterol, high density lipoprotein cholesterol and triglycerides as controls, years since menopause was the only significant factor associated with IGT (OR = 1.05, 95%CI 1.01-1.08) and years since menopause was not associated with DM. Further analysis indicated years since menopause (OR = 1.06, 95%CI, 1.01-1.11) was the only factor significantly associated with IGT for women whose age at menopause was greater than 49 years. Our study indicates that in subjects who have not undergone hormone replacement therapy and whose age at menopause is greater than 49 years, an increase in years since menopause confers a negative influence on glucose tolerance and increases the risk of IGT by 6% for each year after menopause.

The incidence of type 2 diabetes mellitus in Taiwan

Currently, diabetes mellitus is the fifth leading cause of death in Taiwan. The trends of diabetes mortality is increasing steadily. Epidemiologic studies also showed increasing prevalence of diabetes mellitus over the past few decades. The incidence of diabetes mellitus in Taiwan has only been studied in recent 10 years. The areas that have been included as study areas for diabetes incidence are Kin-Chen (Kinmen), Chu-Dung, Pu-Tzu, Pu-Li and Pu-Tai. The reported incidence rates ranged from 1.0 to 4.0% per year for people with varying degrees of baseline plasma glucose levels not reaching the diagnosis of diabetes mellitus according to the criteria of the World Health Organization. Age, baseline glucose level, and obesity are important predictors for the development of diabetes mellitus. In the Pu-Tai study, which was aimed at following a group of people who had been living in the hyperendemic villages of blackfoot disease and had been exposed to arsenic from drinking artesian well water, the incidence of diabetes mellitus was calculated to be 27.4 per 1000 person years. The incidence of diabetes mellitus in these arseniasis-hyperendemic villages correlated with age, body mass index and cumulative arsenic exposure.

Community-based epidemiological study of glucose tolerance in Kin-Chen, Kinmen: support for a new intermediate classification

In this population-based survey, we investigated the prevalence of varying degrees of glucose tolerance among residents of Kin-Chen, Kinmen, as well as the association of glucose tolerance status with potential risk factors for type 2 diabetes and cardiovascular disease (CVD). We focused particularly on subjects with normal 2-h postload glucose level (<7.8 mmol/l) but persistent fasting hyperglycemia (PFH) (5.6-7.8 mmol/l), to examine whether PFH represents an intermediate state between normal glucose tolerance (NGT) and impaired glucose tolerance (IGT). The target population comprised 6346 residents aged 30 years and older. A total of 4354 subjects could be classified into categories of NGT, PFH, IGT, new diabetes, and known diabetes according to medical history, fasting plasma glucose levels, and the results of a 75-g oral glucose tolerance test (OGTT). The potential cardiovascular risk factors assessed included age, obesity (general and central), systolic blood pressure, and fasting levels of insulin, C-peptide, triglyceride, cholesterol, and high-density lipoprotein cholesterol (HDL-C). The age-standardized prevalences of PFH, IGT, new diabetes, and known diabetes were 2.9%, 3.5%, 4.0%, and 3.0%, respectively. Among nondiabetic subjects, the cardiovascular risk factor profiles worsened with decreasing glucose tolerance, with most values differing significantly among the NGT, PFH, and IGT groups. Subjects with PFH, who would be classified as having NGT according to conventional WHO criteria, had physical and biochemical features between those of the NGT and IGT groups. These findings support our previous observation that PFH may be a transition state between NGT and IGT in the progression toward type 2 diabetes.

Comparison of the results between two diagnostic criteria by ADA and WHO among subjects with FPG 5.6-7.8 mmol/l in Kin-Hu and Kin-Chen, Kinmen, 1991-94

The objective of this study was to compare the results between two diagnostic criteria by ADA (1997) and WHO (1985) among those with fasting plasma glucose (FPG) level 5.6-7.8 mmol/l from a community-based survey in Kin-Hu and Kin-Chen, Kinmen conducted in 1991-94. According to official household registry, 10,797 residents aged over 30 were eligible for screening. 7580 had completed FPG screening and 1855 with FPG 5.6-7.8 mmol/l were invited to receive a 75-g oral glucose tolerance test (OGTT). 78.5% (1456/1855) had completed OGTT. The prevalence of impaired fasting glucose (IFG, by ADA) was 15.7%; the prevalence of impaired glucose tolerance (IGT, by WHO) was 22.7%; the prevalence of undiagnosed diabetes was 7.4% by ADA criteria and 10.9% by WHO criteria. It should be noticed that, among subjects with FPG 5.6-7.8 mmol/l, 50.3% of individuals with undiagnosed diabetes and 67.6% of individuals with IGT by WHO criteria would be missed by ADA criteria. Based on the above findings, the two-step screening strategy using FPG as the first line screening and OGTT for high-risk group (FPG 5.6-7.8 mmol/l) only was recommended in epidemiological study and case finding in consideration of feasibility and validity.

Comparison of ADA and WHO screening methods for diabetes mellitus in obese patients. American Diabetes Association

AIMS

To compare the performance of fasting glycaemia (FG) and oral glucose tolerance testing (OGTT) in screening for diabetes mellitus in obese patients.

METHODS

A consecutive series of 528 (445 female, 83 male) obese (body mass index > 30 kg/m2) outpatients, aged 45.2 +/- 14.3 years, was studied with FG and OGTT. The association of categories of glucose tolerance (diabetes and impaired glucose tolerance (IGT)) and fasting glycaemia (diabetes and impaired fasting glucose (IFG)) with hypertension and hyperlipidaemia were also assessed.

RESULTS

Prevalence of diabetes and IGT were 20.1 and 22.9%, respectively. FG (> 7 mmol/l) had a sensitivity of 56.7%. Using FG > 6.1 mmol/l, and OGTT in those above the threshold, the sensitivity for diabetes would have been 89.6%, with a positive predictive value of 59.0%, but 68.8% of cases of IGT would not have been detected. Patients with impaired fasting glucose (FG of 6.1-7.0 mmol/l) showed lower insulin sensitivity and impaired beta cell function, and a weaker association to hypertriglyceridaemia, when compared to IGT.

CONCLUSION

FG > 7.0 mmol/l does not show a sufficient sensitivity for the screening of diabetes in obese patients. FG > 6. mmol/l has a satisfactory sensitivity for diabetes, but not for IGT. IFG has different pathophysiological features than IGT and cannot be assumed to have the same prognostic value of IGT.

Correlation of fasting serum C-peptide and insulin with markers of metabolic syndrome-X in a homogenous Chinese population with normal glucose tolerance

We surveyed 1447 men and 1800 women aged 30 years (mean 46.7 years) with normal glucose tolerance in Kin-Chen, Kinmen. Correlations of fasting serum insulin and C-peptide with various clinical and biochemical parameters were analyzed by multiple linear regression analysis. Women had significantly higher levels of insulin than men (98+/-43 vs. 91+/-43 pM, p<0.0001), yet they also had a more favorable cardiovascular risk profile. Insulin was positively associated with the female sex, height, body mass index, waist-to-hip ratio, serum triglyceride, total cholesterol, uric acid, and fasting plasma glucose, and was negatively associated with age, smoking, and high-density lipoprotein cholesterol. Independent correlates for C-peptide were similar to those of insulin, except for the addition of mean blood pressure and the exclusion of age and total cholesterol. Significant interaction of sex-body mass index (coefficient = -0.0051, p = 0.0232) was detected for C-peptide only. In conclusion, both fasting serum insulin and C-peptide are quantitatively associated with cardiovascular risk factors in this homogeneous Chinese population with normal glucose tolerance. The female sex is independently associated with higher insulin and C-peptide levels, and the strength of the positive association between the female sex and C-peptide reduces when the body mass index increases.