Gestational diabetes: utility of fasting plasma glucose as a screening test depends on the diagnostic criteria.

AIMS: To demonstrate the effect of diagnostic criteria, as defined by four international expert panels, on the usefulness of fasting plasma glucose (FPG) as a screening test for gestational diabetes mellitus (GDM). METHODS: We tested 4602 pregnant women using a 75-g oral glucose tolerance test (OGTT) for universal GDM screening. The area under the receiver operating characteristic curve (AUC) was used to determine the FPG performance to detect GDM by the criteria of the American Diabetes Association (ADA), the Australasian Diabetes in Pregnancy Society, the European Association for the Study of Diabetes, and the World Health Organization (WHO). RESULTS: By applying ADA, Australasian, European and WHO criteria, respectively, the FPG: (i) AUC (95% CI) was 0.882 (0.866-0.897), 0.830 (0.809-0.852), 0.808 (0.791-0.825) and 0.690 (0.670-0.710); (ii) independently could 'rule-in' GDM (with 100% specificity) in 74 (10.9%), 620 (53.5%), 252 (45.3%) and 74 (7.6%) women; (iii) independently could 'rule-out' GDM in an additional 2864 (62.2%), 928 (20.2%), 1510 (32.8%) and 1171 (25.4%) women, at FPG thresholds (with 85% sensitivity); (iv) false-positive rate (FPR) was 29.4, 75.5, 63.8 and 71.2%, at these thresholds. CONCLUSIONS: The value of the FPG as a screening test for GDM is highly dependent on the diagnostic criteria. The performance is excellent with the ADA criteria. With the other criteria, the high FPR (poor specificity) would limit its utility as a screening test. Regardless of the criteria used, initial testing by FPG can significantly decrease the number of cumbersome OGTTs needed for the diagnosis of GDM.     

Fasting plasma glucose as a screening test for gestational diabetes in a multi-ethnic, high-risk population.

AIMS: Screening every pregnant woman for gestational diabetes mellitus (GDM), as widely recommended for high-incidence populations, strains the healthcare system excessively. This study investigated the value of fasting plasma glucose (FPG) as an alternative to the more cumbersome oral glucose tolerance test (OGTT). METHODS: One thousand six hundred and forty-four pregnant women in a multi-ethnic, high-risk population were evaluated by the FPG as a screening test among two principal subgroups, i.e. women (n = 1276) at risk for GDM on clinical grounds and those women (n = 368) with a positive post 50-g, 1-h plasma glucose challenge test (GCT). Two threshold values for FPG 'ruled in or ruled out' a GDM diagnosis, which was confirmed by the 3-h, 100-g OGTT, using Carpenter's modified criteria as the 'gold standard'. RESULTS: In the women with a positive clinical history, at an optimal cut-off value of FPG < 4.4 mmol/l to rule out GDM; a sensitivity of 94.7% was achieved, 21 (1.6%) women being false negatives. Using a FPG > or = 5.3 mmol/l to rule in GDM; the specificity was 94.0% with 53 (4.2%) women being classified as false positives. FPG would have eliminated need for the OGTT in 50.9% pregnant women (misclassification rate 5.8%). In the positive GCT group, using similar cut-offs for FPG, a sensitivity of 96.6% and specificity of 90.8% was achieved with a potential to avoid 51.6% OGTTs (misclassification rate 7.3%). The positive predictive value of the GCT was 31.8% compared to 80.2% for FPG at 5.3 mmol/l. CONCLUSIONS: While previously neglected as a screening test for GDM, in selected high-risk populations the FPG offers a potentially simple, practical algorithm to screen for GDM by being cost-effective and patient friendly. A wider application should be explored.     

A postnatal fasting plasma glucose is useful in determining which women with gestational diabetes should undergo a postnatal oral glucose tolerance test.

AIMS: It is recommended that women with gestational diabetes (GDM) should have a 6-week postnatal oral glucose tolerance test (OGTT). As this test may be unpleasant, time-consuming and has resource implications, we evaluated whether the 6-week postnatal fasting glucose could be used to determine which women should undergo an OGTT. METHODS: All women with GDM, diagnosed according to the World Health Organization criteria, who were delivered at the Princess Anne Hospital, Southampton between May 2000 and May 2002, were recommended to have an OGTT. The results of the fasting plasma glucose concentration were assessed in relation to the 2-h glucose value. RESULTS: One-hundred and fifty-two women with GDM were delivered. Thirty (19.7%) women refused an OGTT or failed to attend. In the 122 OGTTs, three (2.4%; 95% confidence interval 0.8, 7) women had diabetes, three had impaired glucose tolerance and four had impaired fasting glycaemia. No woman with a normal test had fasting glucose of > or =6.0 mmol/l. Fasting glucose was correlated with the 2-h glucose (r=0.62, P<0.0001). Only 10 (8.1%) of the OGTTs would have been performed if only women with fasting glucose of > or =6.0 mmol/l underwent the test. The sensitivity and specificity of this approach for the diagnosis of postnatal diabetes is 100% and 94%, respectively. Linear regression methods indicate that it would miss fewer than three in 10 000 cases. CONCLUSIONS: In our population, a 6-week postnatal fasting plasma glucose is useful in determining which women with gestational diabetes should undergo an OGTT. Consequently we now perform OGTT only in women whose postnatal fasting plasma glucose is > or =6.0 mmol/l.     

Screening for diabetes mellitus--a two-step approach in individuals with impaired fasting glucose improves detection of those at risk of complications.

AIMS: To compare the new American Diabetes Association (ADA) fasting plasma glucose (FPG) criteria to the 1985 World Health Organization (WHO) 2-h post glucose (2hPG) criteria when used for screening of those with no prior history of diabetes mellitus. METHODS: The study included 3,407 subjects without a history of diabetes in whom both FPG and 2hPG were available from the 1992 Singapore National Health Survey. The agreement (kappa) between FPG and 2hPG for the diagnosis of DM was assessed. The optimal cut-off of FPG for the detection of individuals with 2hPG > or = 11.1 mmol/l was determined by receiver-operating characteristics analysis. RESULTS: The prevalence of diabetes diagnosed by FPG alone was 7.3% compared to 8.4% diagnosed by 2hPG. The prevalence of impaired fasting glucose was 8.0%. FPG and 2hPG showed moderate agreement (kappa = 0.646, 95% confidence interval 0.584-0.708). Age, ethnic group and obesity did not affect the degree of agreement. Of those with 2hPG > or = 11.1 mmol/l, 40.8% had FPG in the non-diabetic range while 24.8% of those with FG > or = 7.0 mmol/l had 2hPG in the non-diabetic range. The optimal FPG for the detection of 2hPG > or =11.1 mmol/l was 6.1 mmol/l. Oral glucose tolerance tests (OGTT) in those with 6.0 mmol/ < FPG < 7.0 mmol/l resulted in the diagnosis of diabetes in 90.7% of individuals at risk of microvascular complications. CONCLUSIONS: FPG provides a simple screening test for diabetes, which shows moderate agreement with the 2hPG. A two-step strategy of OGTT in those with impaired fasting glucose improves the detection of at-risk individuals. However, diabetes should not be diagnosed on a single test. The test should be repeated on another day if an individual tests positive for diabetes.     

Impaired fasting glucose and risk of diabetes in Taiwan: follow-up over 3 years

The purpose of this paper was to examine the relationship between fasting glucose levels and development of diabetes among residents of Penghu, Taiwan. From July 1995 to June 1996, a population-based cohort study was conducted among residents aged ≥40 years on the island of Penghu, Taiwan. Of the 1601 surveyed, 1306 (81.6%) did not have diabetes. Six hundred of these 1306 persons were re-examined 3 years later. Participants with fasting plasma glucose (FPG) concentration <110 mg/dl (<6.1 mmol/l) were classified as normoglycemic, those with a glucose concentration of 110–126 mg/dl (6.1–7.0 mmol/l) had impaired fasting glucose (IFG), and those with a fasting glucose concentration of ≥126 mg/dl (7.0 mmol/l) were considered to have diabetes. During the 3-year follow-up, 4.3% of the total population (1.4% per year, 95% CI 0.9–1.9%) developed diabetes. Of those with IFG at baseline, 9.6% (3.2% per year, 95% CI 1.8–5.0%) progressed to diabetes, but only 2.5% (0.8% per year, 95% CI 0.4–1.2%) of normoglycemic people did so. The multivariate-adjusted odds ratio of developing diabetes was 4.4 (95% CI 1.9–10.6) for persons with IFG compared with those who were normoglycemic at baseline. Other significant predictors of progression to diabetes were higher waist–hip ratio (WHR), triglyceride and apolipoprotein B (apo B) levels. In this Asian Chinese population, IFG is a strong predictor of diabetes. The high rate of conversion from IFG to diabetes, combined with the previously observed high IFG prevalence, suggests future high prevalence rates of diabetes in Taiwan.     

Can a screening programme for diabetes be applied to another population?

AIMS: To compare the performance of a Danish diabetes screening protocol in populations from Denmark and Australia. METHODS: The populations used were the Inter99 population from Denmark and the AusDiab population from Australia. The Inter99 study included 6270 individuals aged 30-60 years, randomly selected from Copenhagen County. The AusDiab study included 7079 individuals also aged 30-60 years, randomly selected from throughout Australia. In both studies, all individuals without known diabetes underwent an oral glucose tolerance test (OGTT). Screening using a Danish risk score as an initial step was followed by measurement of fasting plasma glucose (FPG). RESULTS: The characteristics of the study populations showed some differences in risk profile, with more individuals in the AusDiab study being obese, whilst in the Danish cohort, mean blood pressure was higher, less people took anti-hypertensive medication and there was a higher prevalence of screen-detected diabetes. Comparing the Australian and Danish populations, overall performance of the screening protocol was similar-area under area receiver operator characteristic (ROC) curve 0.75 vs. 0.77, sensitivity 71 vs. 76% and positive predictive value (PPV) 6 vs. 9%. Small but statistically significant differences were observed in specificity (70 vs. 66%; P < 0.001) and percentage of the population requiring further testing (31 vs. 36%; P < 0.001). Combining the risk score with FPG > or = 6.1 mmol/l showed a similar pattern. Again, specificity was slightly but significantly higher in the Australian population (95 vs. 93%; P < 0.001) and percentage of the population requiring further testing was lower (5 vs. 8%; P < 0.001). CONCLUSIONS: The Danish risk score performed well when applied to a geographically different Caucasian population and is a suitable tool for detecting people at high risk of undiagnosed diabetes.     

Waist circumference and impaired fasting glucose screening in a Mediterranean population

We evaluate the merits of routine waist circumference measurements for screening of impaired fasting glucose (IFG). Waist circumference and body mass index showed a strong association with the risk of IFG. The present data indicate the need for routine anthropometric measurements in clinical practice screening for IFG.     

Fatty liver index predicts incident diabetes in a Japanese general population with and without impaired fasting glucose

Aim

Fatty liver is associated with the development of diabetes. However, to our knowledge, no study has examined the relationship between the fatty liver index (FLI), calculated scores of hepatic steatosis, and the development of diabetes among individuals without impaired fasting glucose (IFG). We aimed to examine whether FLI predicts the development of diabetes in individuals with and without IFG in a Japanese general population.

Methods

We selected 1498 men and 2941 women who participated in Specific Health Checkups in Japan. We divided all participants into six groups according to tertiles of FLI (low, moderate, and high) and the presence or absence of IFG, by sex. We calculated hazard ratios for incident diabetes for each group using a Cox proportional hazard model, adjusting for potential confounders.

Results

During a mean follow‐up period of 3.0 years, 176 cases of diabetes in men and 320 cases in women were identified. Compared with the low FLI group without IFG, the high FLI group without IFG was significantly associated with incident diabetes in both men (hazard ratio, 1.90; 95% confidence interval, 1.08–3.36) and women (hazard ratio, 1.72; 95% confidence interval, 1.18–2.51). All IFG groups were significantly associated with incident diabetes regardless of FLI levels.

Conclusions

Our results showed that FLI is associated with the development of diabetes regardless of sex and the presence or absence of IFG, and that it may be a useful predictor of future risk of incident diabetes even in individuals without IFG.

     

糖代谢异常和糖尿病患者血浆纤维蛋白原的观察

目的探讨血浆纤维蛋白原在糖代谢异常和糖尿病患者中的变化。方法对155例糖尿病、糖代谢异常患者和正常对照者进行血浆纤维蛋白原、空腹血糖、总胆固醇、三酰甘油、高密度脂蛋白胆固醇、尿素氮和血肌酐检测。结果糖尿病、糖代谢异常和正常对照组之间纤维蛋白原和三酰甘油在各组之间比较差异有统计学意义(P<0.01或P<0.05);纤维蛋白原的多因素linear regression分析发现空腹血糖、三酰甘油是纤维蛋白原的相关因子(P<0.05)。结论糖尿病和糖代谢异常患者血浆纤维蛋白原升高,而且纤维蛋白原与空腹血糖水平相关。因此,血浆纤维蛋白原升高可能参与糖尿病患者心脑血管疾病的形成。     

Marginal association of fasting blood glucose with the risk of cystic fibrosis-related diabetes

ObjectivesCystic fibrosis-related diabetes (CFRD) may be diagnosed by fasting blood glucose ≥ 7.0 mmol/L and/or glucose ≥ 11.1 mmol/L following oral glucose tolerance test (OGTT). We compared the role of fasting and stimulated glucose for diagnosis of CFRD.MethodsWe performed a cross-sectional review of the prevalence of fasting glycemic abnormalities and Kaplan-Meier survival analysis of risk of progression to CFRD according to baseline fasting glucose in the prospective Montreal Cystic Fibrosis Cohort.ResultsIsolated fasting hyperglycemia was detected in only 8% of participants at study onset. Eighty percent of subjects had isolated post-challenge hyperglycemia on their first OGTT meeting criteria for CFRD. Kaplan Meier survival analysis demonstrated that impaired fasting glucose (IFG) alone is not a risk factor for CFRD. Subjects with combined IFG and impaired glucose tolerance at baseline (IGT) had the highest risk of progression to CFRD.ConclusionPost-prandial elevations in blood glucose are more common at diagnosis of CFRD. While IGT is a significant risk factor for CFRD, IFG alone is uncommon and does not increase the risk of CFRD. Patients with both IGT and IFG have the highest risk of CFRD.     

Progression from impaired fasting glucose and impaired glucose tolerance to diabetes in a high-risk screening programme in general practice: the ADDITION Study,Denmark

AIMS/HYPOTHESIS: To estimate the 1-year progression rates from both IFG and IGT to diabetes in individuals identified in a pragmatic diabetes screening programme in general practice (the ADDITION Study, Denmark [Anglo-Danish-Dutch Study of Intensive Treatment in People with Screen-Detected Diabetes in Primary Care]). METHODS: Persons aged 40-69 years were screened for type 2 diabetes based on a high-risk, stepwise strategy. At baseline, anthropometric measurements, blood samples and questionnaire data were collected. A total of 1,160 persons had IFG or IGT at baseline: 811 (70%) accepted re-examination after 1 year. Glucose tolerance classification was based on the 1999 WHO definition. At follow-up, diabetes was based on one diabetic glucose value of fasting blood glucose or 2-h blood glucose. RESULTS: At baseline, 308 persons had IFG and 503 had IGT. The incidence of diabetes was 17.6 and 18.8 per 100 person-years in the two groups, respectively. CONCLUSIONS/INTERPRETATION: IFG and IGT identified in general practice during a stepwise, high-risk screening programme for type 2 diabetes have high 1-year progression rates to diabetes. Consequently, intensive follow-up and intervention strategies are recommended for these high-risk individuals.     

Impaired fasting glucose and impaired glucose tolerance in urban population in India.

AIMS: To study prevalence of impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) in urban Indians and their demographic and anthropometric characteristics. METHODS: Data on capillary blood glucose (OGTT), anthropometric and demography details were available in 10 025 subjects (M : F 4711 : 5314) aged > or = 20 years. Glucose tolerance was categorized as normal, isolated IFG, isolated IGT, IFG + IGT and diabetes using the fasting and 2-h blood glucose (2hBG; 75-g glucose load) values. Subjects with known diabetes were excluded. RESULTS: Age-standardized prevalences of IFG, IGT and newly detected diabetes were 8.7%, 8.1% and 13.9%, respectively. IFG was more prevalent in women (9.8%) than in men (7.4%) (chi2 = 13.62, P = 0.0002), while the gender differences in IGT (men 8.4%, women 7.9%) and diabetes (men 13.3%, women 14.3%) were not significant. Body mass index and waist circumference were higher in glucose-intolerant groups than in normal glucose tolerance (NGT). Prevalence of diabetes, IGT and IFG + IGT increased with age. Among the IFG, 4% had diabetes and 27.1% had IGT using 2hBG criteria. In IFG, the fasting and 2hBG values were not correlated. CONCLUSIONS: Prevalences of IFG and IGT were similar in urban Indians and an overlap occurred in only less than half of these subjects. IFG was more common in women. Subjects with IFG were older and had more adverse anthropometric characteristics in comparison with NGT. IFG did not show an increasing trend with age.     

Normal fasting plasma glucose and risk of prediabetes and type 2 diabetes: the Isfahan Diabetes Prevention Study

AIM: To determine the association of fasting plasma glucose (FPG) level within normal range and the risk of prediabetes and type 2 diabetes in an Iranian population. METHODS: A total of 806 first-degree relatives (FDRs) of patients with type 2 diabetes who had FPG levels less than 5.6 mmol/l (100 mg/dl) in 2003 to 2005, and who did not have diabetes or impaired fasting glucose (IFG), were followed through 2010 for the occurrence of prediabetes or type 2 diabetes. At baseline and through follow-ups, participants underwent a standard 75 g 2-hour oral glucose tolerance test (OGTT). RESULTS: The incidence of type 2 diabetes, impaired glucose tolerance (IGT), and IFG was 9.6 (95% confidence interval (CI): 6.8-12.4), 28.7 (23.8-33.6), and 33.0 (27.7-38.2) per 1,000 person-years based on 4,489 person-years of follow-up, respectively. FPG was associated with the incidence of diabetes, IGT, and IFG. The multivariate-adjusted hazard ratios (95% CI) for diabetes, IGT, and IFG were 1.36 (1.01-1.84), 1.45 (1.10-1.91) and 1.31 (1.00-1.71), for the highest quintile of FPG compared with the lowest quintile, respectively. CONCLUSIONS: An increase in FPG in the normal range is associated with an increase in the incidence of IGT, IFG, and type 2 diabetes. These results prove FPG in the normal range to be useful in identifying apparently healthy FDRs of patients with type 2 diabetes at risk of developing prediabetes and diabetes.     

Comparison of the fasting and the 2-h glucose criteria for diabetes in different Asian cohorts

Aims/hypothesis. The American Diabetes Association recommended that only a single fasting plasma glucose of greater than or equal to 7.0 mmol/l should be used for diagnosing diabetes in epidemiological studies and did not recommend using a 2-h oral glucose tolerance test. We evaluated the effect of diagnostic changes on the prevalence of diabetes and on the choice of subjects diagnosed with diabetes. Methods. Existing epidemiological data collected from Asian people between 30 and 89 years of age, was re-analysed separately in 11 population-based studies (n = 17 666), 6 pre-selected hyperglycaemic cohorts (n = 12 221) and one suspected diabetic cohort (n = 8 382). Results. Among the 11 population-based studies, the new fasting glucose criteria resulted in an overall reduction of 1.8 % in the prevalence of diabetes, which ranged from a reduction of 4.8 % to an increase of 1.7 % in the different studies. Of 1215 subjects diagnosed with diabetes by either criteria, only 449 met both criteria, a concordance of 37 %. More than half of the diabetic subjects had isolated post-challenge hyperglycaemia and three quarters of the subjects with impaired glucose tolerance, according to the 2-h glucose criteria, were normal according to the fasting glucose criteria. Subjects diagnosed as diabetic based only on the 2-h glucose criteria were, on average, older than those with diabetes according to the fasting criteria. Conclusion/interpretation. The fasting and the 2-h glucose criteria diagnose different groups of subjects. It would therefore be inappropriate to use the fasting glucose criteria alone for screening diabetes in Asian populations. [Diabetologia (2000) 43: 1470–1475] Received: 2 June 2000 and in revised form: 27 July 2000