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

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.

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.

Hyperglycaemia after glucose loading is a major predictor of preclinical atherosclerosis in nondiabetic subjects

OBJECTIVE

Carotid intima-media thickness (IMT) has proved to be an independent marker of preclinical atherosclerosis. The aim of this study was to determine whether carotid IMT is associated with the plasma glucose concentration in the fasting state, after loading with oral glucose, or with the insulin sensitivity index (ISI) in nondiabetic subjects with different levels of glucose intolerance and insulin resistance.

DESIGN

Cross-sectional study.

PATIENTS

A total of 160 nondiabetic subjects (147 from our obesity-overweight clinic and 13 healthy normal subjects) were included in the present study, among them 33 had normal glucose tolerance (NGT), 13 had impaired fasting glucose (IFG), 80 had impaired glucose tolerance (IGT) and 34 had both IFG and IGT.

MEASUREMENTS

Carotid IMT was assessed in the common carotid artery by a high-resolution B-mode ultrasound system. Plasma glucose was measured after fasting and at 30 min, 1, 2 and 3 h after a standard 75-g load of glucose. The ISI was calculated from the frequent sampling intravenous glucose tolerance test (FSIGT). Results The IMT values in the NGT group were lower than those in the IFG, IGT and IFG + IGT groups (P < 0.03). No statistical difference in IMT values was found among the latter three groups. Univariate correlation analyses showed that the IMT was positively associated with age, plasma glucose concentrations 1 and 2 h after glucose loading, and serum concentration of low density lipoprotein (LDL) cholesterol (r=0.39, 0.22, 0.25 and 0.18, respectively, P<0.05). Multiple regression analysis showed that only age, plasma glucose concentration 2 h after glucose loading, and LDL cholesterol appeared to be significant correlates of the IMT (P<0.0001), whereas the ISI was not.

CONCLUSIONS

In nondiabetic subjects with various degrees of glucose intolerance, there was a significant increase in IMT in those with IFG and IGT. Significant determinants of IMT, an indicator of preclinical atherosclerosis, include hyperglycaemia 2 h after a glucose load, age and LDL cholesterol, whereas fasting glucose concentration and the ISI were not significantly associated with IMT.

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.

Correlation of the dysmetabolic risk factors with different anthropometric measurements

Metabolic syndrome is a common disorder in Taiwan. For this study 431 subjects were randomly selected from visitors to the Department of Health Management. Blood pressure, blood glucose, lipid, uric acid levels and anthropometric measurements with immunoreactive insulin (IRI) and leptin levels were all correlated. We randomly selected 431 subjects who visited the Department of Health Management. Whole body three-dimensional (3-D) laser scanner scans were employed for the anthropometric measurements. The metabolic index (MI) was designed using anthropometric parameters. Of the 431 subjects, 50% had displayed a body mass index (BMI) equal to or exceeding 25 kg/m2. Pearson correlation coefficient and multiple regression analysis revealed that MI constituted another index for correlating metabolic parameters by comparing MI with BMI and waist circumference to hip circumference ratio (WHR). Most data related to metabolic syndrome showed statistically significant differences between high and low IRI groups, comprising uric acid, total cholesterol, fasting plasma glucose, triglyceride, LDL, Chol/HDL ratio, and LDL/HDL ratio. Both IRI and leptin revealed statistical association with BMI, WHR, waist cross section area to hip cross section area ratio (WHAR), and MI in the study. Hypercholesterolemia appeared in 14.6% of the subjects. Elevated low-density lipoprotein (> or = 130 mg/dL) affected 36.9% of the subjects. In conclusion, MI calculated from 3-D body scanner correlated with many important metabolic risk factors and associated with clinical disorders like DM, hyperlipidemia, hyperuricemia and hypertension.

Application of three-dimensional body scanner: observation of prevalence of metabolic syndrome

BACKGROUND AND AIMS

This retrospective cross-sectional study correlates blood pressure, blood glucose, lipid and uric acid levels with anthropometric measurements.

METHODS

A total of 3975 visitors to the Department of Health Management were randomly selected to participate in this cross-sectional study. Whole body three-dimensional (3-D) laser scans were used to obtain anthropometric measurements. A health index (HI) was also designed based on anthropometric parameters. Subjects were defined as having metabolic syndrome when three of the following criteria were met: obesity (BMI of at least 30 kg/m(2); or a WHR of over 0.9 for males and 0.85 for females); triglyceride of at least 150 mg/dl; high-density lipoprotein (HDL)-cholesterol below 35 mg/dl for males and 39 mg/dl for females; fasting sugar levels of at least 110 mg/dl and hypertension.

RESULTS

Of 3975 subjects, 341 (8.6%) met the criteria for diabetes mellitus (DM); of these, 32.8% were diagnosed with hypertension. This proportion exceeded 18% of the subjects had normal glucose levels. Of the 3975 subjects, 658 (16.6%) met the criteria for metabolic syndrome. Proportionally, more male subjects than female subjects were diagnosed with metabolic syndrome (18.5% vs 14.7%). Of these, central obesity, elevated triglyceride and low HDL-cholesterol were the main factors in men, while fasting glucose, hypertension and central obesity were the main factors in women. This investigation found that larger proportions of subjects with impaired glucose tolerance (41.1%) and DM (64.2%) than of subjects with normal glucose subjects, suffered from metabolic syndrome (9.5%).

CONCLUSIONS

3-D body scanning is useful in correlating pertinent factors with metabolic syndrome, these factors include central obesity, hyperglycemia, dyslipidemia, hyperuricemia and hypertension.

Association between indices of obesity and fasting hyperglycemia in Taiwan

OBJECTIVE

To examine the association of body mass index (BMI), waist-hip ratio (WHR), and waist circumference (WC) with fasting hyperglycemia after adjustment for age, cigarette smoking, and alcohol use.

DESIGN

A cross-sectional survey was conducted among individuals visiting four health-screening centers across Taiwan.

SUBJECTS

A total of 61 568 subjects (28 734 men and 32 834 women) between 25 and 64 years of age were included. Fasting hyperglycemia was defined as fasting plasma glucose > or =6.1 mmol/l or current diagnosis and use of insulin or hypoglycemic agent.

RESULTS

Fasting hyperglycemia was found in 11.0% of men and 8.3% of women. The factors significantly associated with fasting hyperglycemia in men were age, BMI, WHR, and heavy drinking, while for women these factors were age, educational level, BMI, WHR, and heavy smoking. For men, increased risk of fasting hyperglycemia started from age 30 to 34 years, BMI > or =25 kg/m2, and WHR > or =0.82. For women, increased risk of fasting hyperglycemia started from age 35 to 39 years, BMI > or =24 kg/m2, and WHR > or =0.74. WC lost its significance as a predictor of fasting hyperglycemia when WHR included in the model.

CONCLUSION

This study found that central obesity and general obesity were both independently associated with increased risk of fasting hyperglycemia in Taiwanese. The relationship between fasting hyperglycemia and central fat accumulation (WHR) begins to appear at levels that would not be regarded as representing obesity in Western populations, suggesting the need to redefine cutoffs for central obesity in this population.

Glucose intolerance in Chinese patients with chronic hepatitis C

AIM: To investigate the prevalence and the risk factors of glucose intolerance in Chinese patients with chronic hepatitis C and to evaluate the relationship between interferon (IFN) treatment and glucose intolerance in these patients.

METHODS: Prospective cross-sectional study was done to evaluate the prevalence of glucose intolerance in Chinese patients with chronic hepatitis C virus (HCV) infection from the outpatient clinic of Department of Family Medicine, Taipei Veterans General Hospital. Chronic hepatitis C was defined as persistent presence of anti-HCV and persistent elevation of liver transaminase for at least 1.5 folds for at least 6 months. Moreover, patients were further categorized into normal fasting glucose and glucose intolerance (diabetes mellitus (DM) and impaired fasting glucose) according to the diagnostic criteria of American Diabetic Association.

RESULTS: Totally, 359 Chinese patients with chronic hepatitis C were enrolled (212 males and 147 females, mean age = 58.1 ± 13.0 years). One hundred and twenty-three patients (34.3%) had received various forms of IFN treatment. One hundred and twenty-five patients (34.6%) had glucose intolerance, including 99 patients (27.6%) with DM and 26 patients (7.0%) with impaired fasting glucose. In comparison with those with normal fasting glucose levels, patients with chronic hepatitis C with glucose intolerance were significantly older, had a significantly higher body mass index, and they were more likely to suffer from obesity, to have family history of diabetes and to have had previous IFN treatment. Stepwise multivariate logistic regression revealed significantly that age 57 years, obesity, previous history of IFN treatment and the presence of family history of diabetes were independent risk factors associated with the presence of glucose intolerance in chronic hepatitis C patients.

CONCLUSION: In conclusion, 34.6% of Chinese patients with chronic hepatitis C had glucose intolerance. Chronic hepatitis C patients who were older in age, obese, had previous IFN treatment history and had family history of diabetes were prone to develop glucose intolerance. To our knowledge, this is the first population-based report to confirm that interferon treatment to be an independent risk factor to develop glucose intolerance.

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.

Comparison of three-dimensional anthropometric body surface scanning to waist-hip ratio and body mass index in correlation with metabolic risk factors

In this study, we used a three-dimensional (3D) body scanner to evaluate subjects with central obesity. These measurements were correlated with blood pressure, blood glucose, lipid, and uric acid levels. We randomly selected 1,204 subjects who visited the Department of Health Management at Chang Gung Medical Center in Linkou. The health index (HI) was calculated as HI = (body weight x 2 x waist profile area)/[body height(2) x (breast profile area + hip profile area)]. Among the 1,204 subjects, body mass index (BMI) equal to or greater than 30 kg/m(2) was found in 8.3% of the subjects. Pearson correlation coefficient studies revealed that HI was a better index for correlating metabolic parameters than BMI and waist-to-hips girth ratio. Of the 1,204 subjects, 9.5% (114) had diabetes mellitus, according to American Diabetes Association criteria. The percentages of men and women with total cholesterol greater than or equal to 245 mg/dL were almost the same (11.0% vs. 11.1%). Elevated low-density lipoprotein (> or =130 mg/dL) was found in 36.9% (444) of subjects. In conclusion, HI as determined by 3D scanning, is another method to predict these metabolic abnormalities. Further prospective long-term follow-up study is needed to determine the relationships of 3D body scanning data and HI to blood pressure, blood glucose, lipid, and uric acid levels.

[Significant incidence of type 2 diabetes on high-risk Spanish population. The IGT Study (2)]

BACKGROUND

Our purpose was to estimate the incidence of type 2 diabetes among a high risk population with or without impaired glucose tolerance (IGT), analysing the progression to diabetes.

PATIENTS AND METHOD

Multicenter cohort study on high risk individuals without diabetes (WHO-85 criteria) in primary health care. Subjects underwent an oral glucose tolerance test measuring fasting plasma glucose (FPG) and plasma glucose at 2 hours (2hPG). Mean follow-up was 37.2 months (4.3-69.7). Phenotypic features, diagnostic variation, diabetes incidence and predictive factors (multivariate analysis and Cox proportional hazards model) were assessed.

RESULTS

We included 243 individuals (148 females), aged 59.7 (10) years, with FPG < 7.8 mM and 2hPG < 11.1 mM. 137 IGT subjects (56.4%) and 106 (43.6%) normal glucose tolerance (NGT) subjects with a similar risk factor impact were evaluated. After the study was closed, 63 (25.9%) subjects developed diabetes: 43 (31.4%) with baseline IGT and 20 (18.9%) with NGT. Overall diabetes incidence increased over time but not proportionally. Mean annual incidence was 9.2% and it dropped to 4.6% when FPG was used as the unique diagnosis criterion (ADA-97). Male under 65 years with both overweight and IGT reported the highest incidence. HbA1c, FPG and 2hPG were independent predictors. Increased HDL cholesterol showed a protective effect on diabetes incidence. The IGT diagnosis interval was a much better predictor [OR = 2.06 (1.56-2.72)] of diabetes development than the impaired FPG diagnosis interval [OR = 1.37 (0.93-2.04)].

CONCLUSIONS

FPG predicted but undervalued diabetes incidence in high risk population. The IGT (2hPG) diagnosis interval predicted diabetes development better than the impaired fasting plasma glucose diagnosis interval. Increased diabetes incidence in high risk Spanish population, particularly with regard to IGT, means that primary preventive resources should be increased.

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.

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.