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.     

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.     

Differences in insulin resistance and pancreatic B‐cell function in obese subjects with isolated impaired glucose tolerance and isolated impaired fasting glucose

Aims To investigate changes in insulin action and insulin secretion in obese subjects with different categories of impaired glucose regulation (IGR): impaired glucose tolerance (IGT), impaired fasting glucose (IFG), and combined IFG/IGT (CGI). Methods A total of 222 subjects underwent an oral glucose tolerance test and a frequently sampled intravenous glucose tolerance test (FSIGTT); 100 had normal glucose tolerance (subdivided into 32 lean NGT, 68 obese NGT), and 122 were obese with IGR (82 IGT, 14 IFG and 26 CGI). The insulin sensitivity index (S_I) was assessed by Bergman's minimal model method with FSIGTT; insulin secretion was determined by acute insulin response to glucose (AIRg). The disposition index (DI), the product of AIRg and S_I, was used to determine whether AIRg was adequate to compensate for insulin resistance. Results S_I was similar in NGT and IGR obese subgroups. AIRg was significantly increased in obese NGT as compared with lean NGT, significantly reduced in IGT, and further reduced in IFG and CGI subjects as compared with obese NGT subgroups. DI was reduced in NGT obese individuals. Within the obese IGR subgroups, IFG and CGI subjects had even lower DI value than IGT subjects. Conclusions Obese Chinese subjects with IGR have a similar degree of insulin resistance but differ in insulin secretion. Subjects with IFG and CGI have a more prominent deficiency in insulin secretion than subjects with IGT.     

红细胞体积分布宽度与糖代谢异常/糖耐量异常和糖尿病相关

目的探讨红细胞体积分布宽度（RDW）与2型糖尿病（T2DM）、空腹血糖受损／葡萄糖耐量异常（IFG／IGT）的相互关系。方法对152例在我院定期进行健康体检或治疗的患者,依据血糖情况分为3组,其中T2DM组42例,IFG／IGT组38例,正常对照（NGT）组72例,采取空腹血,采用全自动血液分析仪测定RDW、血红蛋白,多功能血生化自动分析仪测定血总胆固醇、三酰甘油、高密度脂蛋白胆固醇、低密度脂蛋白胆固醇、血肌酐、血尿素氮和空腹血糖,同时统计高血压、冠心病的发病率并分析其关系。结果RDW在T2DM组、IFG／IGT组和NGT组之间比较具有统计学差异,其中T2DM组和NGT组、IFG／IGT组比较,差异均有统计学意义（P〈0．05或P〈0．01）,IFG／IGT组与NGT组比较差异无统计学意义（P〉0．05）。多因素直线回归分析显示空腹血糖（P〈0．01）和高密度脂蛋白胆固醇（P〈0．05）是RDW的独立危险因子。结论T2DM患者RDW升高,RDW的变化与空腹血糖水平相关。     

Gender differences in the prevalence of impaired fasting glycaemia and impaired glucose tolerance in Mauritius. Does sex matter?

OBJECTIVE: To examine gender differences in the characteristics and prevalence of various categories of glucose tolerance in a population study in Mauritius. RESEARCH DESIGN AND METHODS: In 1998, a community-based cross-sectional survey was conducted in Mauritius. Categories of glucose metabolism were determined in 5388 adults, with an oral glucose tolerance test given to those who did not have previously diagnosed diabetes (n=4036). Other cardiovascular risk factors were assessed among those without known diabetes. RESULTS: For men and women the prevalence of diabetes (22.0 vs. 21.8%, respectively) and the prevalence of coexisting impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) (3.2 vs. 2.9%) were similar. However, men were twice as likely as women to have isolated IFG [5.1% (4.2-6.0) vs. 2.9% (2.3-3.5)], despite being younger, thinner and with lower plasma insulin but higher lipids. Conversely, the prevalence of isolated IGT was lower in men [9.0% (7.9-10.2) vs. 13.9% (12.6-15.1)]. Among non-diabetic individuals, fasting glucose was higher in men than women, whereas 2-h glucose was higher in women. In people without diabetes, women had significantly higher body mass index, beta cell function (HOMA-B), fasting and 2-h insulin than men and significantly lower waist-hip ratios, waist circumference, insulin sensitivity (HOMA-S) and triglycerides. CONCLUSION: In Mauritius, the distribution of impaired glucose metabolism differs by sex. The observation that IFG is more prevalent in men and IGT more prevalent in women raises important questions about their underlying aetiology and the ability of the current glucose thresholds to equally identify men and women at high-risk of developing diabetes. IFG should be seen as a complimentary category of abnormal glucose tolerance, rather than a replacement for IGT.     

Psychosocial factors are independent risk factors for the development of Type 2 diabetes in Japanese workers with impaired fasting glucose and/or impaired glucose tolerance1

Aims We prospectively studied Japanese workers with impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT) and analysed possible risk factors for diabetes, including psychosocial factors such as stress. Methods The participants were 128 male Japanese company employees (mean age, 49.3 ± 5.9 years) with IFG and/or IGT diagnosed by oral glucose tolerance test (OGTT). Participants were prospectively studied for 5 years with annual OGTTs. The Kaplan–Meier method and Cox's proportional hazard model were used to analyse the incidence of diabetes and the factors affecting glucose tolerance, including anthropometric, biochemical and social–psychological factors. Results Of 128 participants, 36 (28.1%) developed diabetes and 39 (30.5%) returned to normal glucose tolerance (NGT) during a mean follow‐up of 3.2 years. Independent risk factors for diabetes were night duty [hazard ratio (HR) = 5.48, P = 0.002], higher fasting plasma glucose (FPG) levels within 6.1–6.9 mmol/l (HR = 1.05, P = 0.031), stress (HR = 3.81, P = 0.037) and administrative position (HR = 12.70, P = 0.045), while independent factors associated with recovery were lower FPG levels (HR = 0.94, P = 0.017), being a white‐collar worker (HR = 0.34, P = 0.033), non‐smoking (HR = 0.31, P = 0.040) and lower serum alanine aminotransferase (ALT) levels (HR = 0.97, P = 0.042). Conclusions In addition to FPG levels at baseline, psychosocial factors (night duty, stress and administrative position) are risk factors for Type 2 diabetes, while being a white‐collar worker, a non‐smoker and lower serum ALT levels are factors associated with return to NGT in Japanese workers with IFG and/or IGT.     

老年空腹血糖受损62例进展研究

目的分析老年空腹血糖受损者(IFG)8年间进展情况。方法于2002年5～6月对我区离退休老干部中IFG行口服75g葡萄糖试验(OGTT),选取单纯空腹血糖受损者(I-IFG)62例,依据2003年美国糖尿病学会IFG诊断标准,将空腹血糖(FPG)为5.6～6.09mmol/L的受损者分为新增IFG组(A组),空腹血糖为6.1～6.99mmol/L的受损者分为原IFG组(B组),定期随访8年。结果基线时2组IFG者的血压、血脂、体质量指数(BMI)等临床指标差异均无统计学意义(P>0.05)。至随访结束时,A组进展为糖尿病(DM)的比率为20.59%,B组IFG进展为DM的比率为46.43%,是A组的2.25倍,差异有统计学意义(P<0.05);2组IFG逆转为糖耐量正常(NGT)、仍保持I-IFG以及进展为空腹血糖受损合并糖耐量受损(IFG/IGT)者的比率差异均无统计学意义(P>0.05)。全部IFG进展为DM的比率是32.25%,逆转为NGT的比率是14.52%,仍维持在I-IFG或IFG/IGT状态的比率是53.23%。结论 IFG诊断标准下调后,IFG患病率明显上升,但新增IFG进展为DM的风险明显低于原IFG。     

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.     

Incidence of Type 2 diabetes in England and its association with baseline impaired fasting glucose: the Ely study 1990-2000.

AIM: To determine the incidence of Type 2 diabetes and to examine the effect of different cut-points for impaired fasting glucose (IFG) on diabetes incidence. METHODS: Population-based longitudinal study (1990-2000) with clinical, anthropometric and biochemical measurements, including an oral glucose tolerance test (OGTT), in 1040 non-diabetic adults aged 40-69 years at baseline. Baseline glucose status was defined as normoglycaemia < 5.6, IFG-lower 5.6-6.0 and IFG-original 6.1-6.9 mmol/l. The all-IFG group included fasting glucose values of 5.6-6.9 mmol/l. RESULTS: The 10-year cumulative incidence of diabetes was 7.3 per 1000 person-years. Diabetes incidence was 2.4 [95% confidence interval (CI) 1.2, 4.8], 6.2 (4.0, 9.8) and 17.5 (12.5, 24.5) per 1000 person-years in those with normoglycaemia, IFG-lower and IFG-original, respectively. Compared with normoglycaemia, the age/sex-adjusted risk [hazard ratio (HR) and 95% CI] for incident diabetes was greatest in the IFG-original category (HR 6.9; 3.1, 15.2) and increased to a lesser degree in the IFG-lower (HR 2.5; 1.1, 5.7) and all-IFG categories (HR 4.1; 1.9, 8.7). When adjusted for confounding factors, the magnitude and direction of associations persisted, with HR 1.9, 4.4 and 2.9, for the categories IFG-lower, IFG-original and all-IFG, respectively. CONCLUSIONS: Diabetes incidence is more strongly related to IFG defined as fasting glucose between 6.1 and 6.9 mmol/l than to the lower category of 5.6-6.0 mmol/l, or entire range of 5.6-6.9 mmol/l. Future studies should examine the association of IFG with cardiovascular outcomes, but for diabetes risk our study supports the use of the IFG cut-point at 6.1 mmol/l.     

空腹血糖受损与糖耐量受损患者血管内皮功能的对比研究

目的:应用多普勒超声技术检测空腹血糖受损(IFG)与糖耐量受损(IGT)患者的血管内皮功能,探讨其对动脉粥样硬化的影响。方法:根据口服葡萄糖耐量试验(OGTT)结果,选择血糖正常(NGT)组25例,IFG组24例,IGT组22例,检测TC、TG、LDL-C、HDL-C、空腹血糖(FPG)、空腹胰岛素(FINS)、糖化血红蛋白(HbA1C)、高敏C反应蛋白(hs-CRP)及血管性血友病因子(vWF),OGTT后2h血糖(2hPG)及2h胰岛素(2hINS),以及肱动脉内皮依赖性舒张功能(EDD)。结果:IGT组vWF较IFG组、NGT组明显升高[(170.25±21.76)%∶(155.16±17.19)%、(135.46±15.52)%,P<0.05～0.01],肱动脉EDD较IFG组、NGT组明显降低[(4.86±0.94)%∶(5.47±0.90)%、(6.24±0.97)%,P<0.05～0.01];IFG组vWF较NGT组明显升高[(155.16±17.19)%∶(135.46±15.52)%,P<0.05],肱动脉EDD较NGT组明显降低[(5.47±0.90)%∶(6.24±0.97)%,P<0.05]。多因素逐步回归分析显示,EDD与2hPG、LDL-C明显负相关(r分别为-0.73、-0.59,P<0.05)。结论:IGT较IFG对血管内皮功能危害更大,加强IGT防治对延缓动脉粥样硬化更为重要。     

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.

     

空腹血糖受损患者糖耐量异常及影响因素分析

目的了解空腹血糖受损(IFG)患者糖耐量异常(IGT)情况及其影响因素。方法纳入空腹血糖为5.6~6.1 mmol/L的IFG患者337例,检测患者口服75克葡萄糖后2小时血糖等资料,分析患者IGT情况及其影响因素。结果纳入的337例IFG患者中46.6%(157/337)伴有IGT。口服葡萄糖耐量异常和正常组超重和肥胖率分别为75.0%和63.1%(P0.05);口服葡萄糖耐量异常组甘油三酯水平显著高于正常组,高密度脂蛋白胆固醇水平低于正常组,均有统计学差异(P0.05)。多因素Logistic回归分析结果显示,年龄、体重指数、甘油三酯水平是IFG患者葡萄糖耐量异常的影响因素,相对危险分别为:1.06(95%CI:1.03~1.08);1.11(95%CI:1.05~119);1.58(95%CI:1.23~2.09)。进一步对体重正常者发生糖耐量异常的影响因素进行分析,除年龄外,甘油三酯水平是空腹血糖受损患者糖耐量异常的影响因素,相对危险为2.10(95%CI:1.29~3.43)。结论空腹血糖受损患者约半数伴有糖耐量异常,体重指数和甘油三酯水平是空腹血糖受损患者糖耐量异常的影响因素。     

空腹血糖异常、糖耐量减低患者血清胰岛素水平的变化及其意义

目的 观察空腹血糖异常(IFG)、糖耐量减低(IGT)患者血清胰岛素水平的变化。方法 对50例空腹血糖和糖耐量正常者(NGT)、40例IFC和80例IGT患者行口服葡萄糖耐量试验(0GTT)，用氧化酶法检测血糖，用放免法测定血清空腹及餐后2小时胰岛素。结果 IFG、IGT组空腹血糖、空腹胰岛素水平及胰岛素敏感指数较NGT组明显升高(P＜0.05或P＜0．01)，IFG组胰岛素敏感指数与IGT组比较无显著性差异(P＞0．05)。结论 在IFG、IGT状态下已经存在胰岛素抵抗，而且在程度上两者间并没有显著性差异，应早期干预治疗。     

Random Plasma Glucose in Serendipitous Screening for Glucose Intolerance: Screening for Impaired Glucose Tolerance Study 2

Background With positive results from diabetes prevention studies, there is interest in convenient ways to incorporate screening for glucose intolerance into routine care and to limit the need for fasting diagnostic tests. Objective The aim of this study is to determine whether random plasma glucose (RPG) could be used to screen for glucose intolerance. Design This is a cross-sectional study. Participants The participants of this study include a voluntary sample of 990 adults not known to have diabetes. Measurements RPG was measured, and each subject had a 75-g oral glucose tolerance test several weeks later. Glucose intolerance targets included diabetes, impaired glucose tolerance (IGT), and impaired fasting glucose₁₁₀ (IFG₁₁₀; fasting glucose, 110–125 mg/dl, and 2 h glucose < 140 mg/dl). Screening performance was measured by area under receiver operating characteristic curves (AROC). Results Mean age was 48 years, and body mass index (BMI) was 30.4 kg/m²; 66% were women, and 52% were black; 5.1% had previously unrecognized diabetes, and 24.0% had any “high-risk” glucose intolerance (diabetes or IGT or IFG₁₁₀). The AROC was 0.80 (95% CI 0.74–0.86) for RPG to identify diabetes and 0.72 (0.68–0.75) to identify any glucose intolerance, both highly significant (p < 0.001). Screening performance was generally consistent at different times of the day, regardless of meal status, and across a range of risk factors such as age, BMI, high density lipoprotein cholesterol, triglycerides, and blood pressure. Conclusions RPG values should be considered by health care providers to be an opportunistic initial screening test and used to prompt further evaluation of patients at risk of glucose intolerance. Such “serendipitous screening” could help to identify unrecognized diabetes and prediabetes.     

Prevalence of undiagnosed Type 2 diabetes and impaired fasting glucose in older British men and women.

AIM: To estimate the prevalence of undiagnosed diabetes and impaired fasting glucose in older British men and women, using the 1999 World Health Organization (WHO) thresholds based on fasting glucose measurements. METHODS: Participants in the British Regional Heart Study and the British Women's Heart and Health Study were selected from one socially representative general practice in 24 British towns. Included in this analysis were 3736 men and 3642 women aged 60-79 years (predominantly white), who provided a single fasting blood sample at a clinical examination between 1998 and 2001, and who had no previous diagnosis of diabetes. RESULTS: Two hundred and eleven men (5.7%) and 190 women (5.2%) had a fasting blood glucose level consistent with the WHO threshold for a diagnosis of diabetes (> or = 7.0 mmol/l), whilst a further 667 men (17.9%) and 642 women (17.6%) had impaired fasting glucose levels (6.1 < or = 7 mmol/l). When analyses were restricted to subjects who had fasted for at least 8 h, and whose blood sample was taken before 12.00 h, the predicted prevalence of undiagnosed diabetes (based on two separate measurements) was 6.7% in men and 6.0% in women. The predicted prevalence of impaired fasting glucose (based on two separate measurements) was approximately 20% in both sexes. CONCLUSIONS: More than one-fifth of older white British men and women have either undiagnosed diabetes or impaired fasting glucose according to new WHO criteria. Strategies for the primary and secondary prevention of Type 2 diabetes among older individuals are urgently needed.     

The prevalence of retinopathy in impaired glucose tolerance and recent‐onset diabetes in the Diabetes Prevention Program

Aims Retinopathy is considered the complication most closely associated with and characteristic of diabetes mellitus. Hyperglycaemia below levels diagnostic of diabetes, so called pre‐diabetes, is associated with a low prevalence of ‘diabetic’ retinopathy. However, few longitudinal studies of non‐diabetic populations have performed repeated measures of glycaemia and screened for retinopathy to determine its occurrence in the non‐diabetic population and the onset of retinopathy in new‐onset diabetic patients. We determined the prevalence of retinopathy characteristically seen in diabetes in persons with impaired glucose tolerance and in patients with new‐onset diabetes of known duration in the Diabetes Prevention Program (DPP) cohort. Methods The DPP recruited persons with elevated fasting glucose (5.3–6.9 mmol/l) and impaired glucose tolerance, and no history of diagnosed diabetes, other than gestational diabetes not persisting after pregnancy. Seven‐field, stereoscopic fundus photography was completed a mean of 3.1 years after the development of diabetes in 594 of 878 participants who had developed diabetes during the DPP, and in a random sample of 302 participants who remained non‐diabetic. Results Retinopathy consistent with diabetic retinopathy was detected in 12.6 and 7.9% of the diabetic and non‐diabetic participants, respectively (P = 0.03, comparing prevalence in the two groups). Systolic blood pressure and HbA_1c were higher at baseline in the diabetic participants who had retinopathy compared with the diabetic participants without retinopathy. Conclusions Retinopathy characteristic of diabetes is present in persons with elevated fasting glucose and impaired glucose tolerance and no known history of diabetes. The prevalence of retinopathy is significantly higher in persons who develop diabetes, even within 3 years of diagnosis.