The prevalence of prediabetes,diabetes, and insulin resistance among urban obese children of south Andhra Pradesh in India

Obesity is increasing rapidly in developing countries undergoing rapid nutrition and lifestyle transition. Obesity and associated insulin resistance are considered the main risk factors for developing type 2 diabetes mellitus, regardless of genetic predisposition. The aim of this study is to analyze the prevalence of prediabetes (impaired fasting glycemia (IFG) and impaired glucose tolerance (IGT)), diabetes, and insulin resistance in obese children/adolescents. In this prospective study, a total of 224 obese children/adolescents were recruited. All patients underwent oral glucose tolerance test (OGTT) with blood samples at 0 and 2 h. Fasting insulin and lipid profiles were also estimated in each case. The prevalence of IFG, IGT, and type 2 DM in obese children was found to be 8.33 % (6/72), 9.72 % (7/72), and 1.38 % (1/72), respectively. Similarly, the prevalence of IFG, IGT, and type 2 DM in obese adolescents was found to be 9.86 % (15/152), 15.78 % (24/152), and 1.97 % (3/152), respectively. The prevalence of insulin resistance in obese children was 33.33 % (24/72) and adolescents was 47.36 (72/152). Also, 2-h plasma glucose (P = 0.014) was significantly elevated in the insulin-resistant group compared to the group without insulin resistance in obese children/adolescents. IGT and insulin resistance are highly prevalent in obese children/adolescents. Therefore, obese children/adolescents are more prone to prediabetes and type 2 DM is to be screened by OGTT.     

The utility of fasting glucose for detection of prediabetes

Treatment of prediabetes attenuates progression to type 2 diabetes mellitus. The American Diabetes Association (ADA) previously defined prediabetes as either impaired fasting glucose (IFG) = 6.1 to 6.9 mmol/L (110-125 mg/dL) and/or impaired glucose tolerance (IGT) (2-hour postload glucose of 7.8-11.0 mmol/L [140-199 mg/dL]). For practical reasons, fasting plasma glucose (FPG) is commonly used for diabetes screening. Recently, the ADA lowered the fasting glucose threshold value for IFG from 110 to 100 mg/dL. Our objective was to determine the utility of FPG alone for detecting prediabetes in African Americans. Oral glucose tolerance test (OGTT) data from a cohort of 304 young adult African American men and women were examined. We calculated prediabetes prevalence using the previous ADA criteria and examined the effect of lowering the IFG threshold value for IFG to 100 mg/dL. The prediabetes prevalence in this cohort using the previous ADA criteria was 20.4% (n = 62). Of the 62 cases, 8 had IFG, 45 had IGT, and 9 had IFG together with IGT. Fasting plasma glucose testing alone detected 17 (27.4%) prediabetic cases, whereas a complete OGTT detected 54 (87.1%). Lowering the IFG threshold value to FPG = 100 mg/dL identified 13 of the 45 IGT-only cases. However, this lower IFG threshold increased prediabetes prevalence in the overall cohort from 20.4% to 31.9%. In conclusion, in young adult African Americans, an ethnic group at high risk for developing diabetes, FPG testing alone may be inadequate for diagnosing prediabetes. Until alternative strategies are identified, an OGTT is presently the best method for detecting the prediabetic condition in these high-risk patients.     

Progression rates from HbA1c 6.0–6.4% and other prediabetes definitions to type 2 diabetes: a meta-analysis

Aims/hypothesis

Precise estimates of progression rates from ‘prediabetes’ to type 2 diabetes are needed to optimise prevention strategies for high-risk individuals. There is acceptance of prediabetes defined by impaired fasting glucose (IFG) and impaired glucose tolerance (IGT), but there is some controversy surrounding HbA_1c-defined prediabetes ranges, with some favouring 6.0–6.4% (42–46 mmol/mol). Comparing progression rates between groups might aid this issue, thus we aimed to accurately estimate progression rates to diabetes from different prediabetes categories.

Methods

Meta-analysis of prospective observational studies in which participants had prediabetes at baseline (ADA-defined IFG [5.6–6.9 mmol/l], WHO-defined IFG [6.1–6.9 mmol/l], IGT (7.8–11.0 mmol/l) or raised HbA_1c [6.0–6.4%/42–46 mmol/mol]) and were followed up for incident diabetes. Incidence rates were combined using Bayesian random effects models.

Results

Overall, 70 studies met the inclusion criteria. In the six studies that used raised HbA_1c, the pooled incidence rate (95% credible interval) of diabetes was 35.6 (15.1, 83.0) per 1,000 person-years. This rate was most similar to that for ADA-defined IFG (11 studies; 35.5 [26.6, 48.0]) and was non-significantly lower than WHO-defined IFG (34 studies; 47.4 [37.4, 59.8]), IGT (46 studies, 45.5 [37.8, 54.5]) and IFG plus IGT (15 studies, 70.4 [53.8, 89.7]). Similar results were seen when the data were analysed by the criteria used to diagnose diabetes.

Conclusions/interpretation

This study provides evidence that progression rates differ by prediabetes definition, which has implications for the planning and implementation of diabetes prevention programmes. HbA_1c 6.0–6.4% might identify people at a lower diabetes risk than other prediabetes definitions, but further research is needed.     

The study of diabetes prevalence and related risk factors in Fuyang,a Chinese county under rapid urbanization

The fast urbanization of China potentially affects development of diabetes. Fuyang is one of the typical cities being involved but its epidemiological characteristics of diabetes is not clear. In this study, 4131 adults in randomly selected families from all the townships and streets of Fuyang were investigated. This study showed that the standardized prevalence of diabetes was 8.10 % in Fuyang. The prevalence of prediabetes was 11.3 %. The prevalence of isolated impaired glucose tolerance (IGT) was 10.51 %. The prevalence of diabetes in urban areas was slightly higher than that of rural areas (14.3 % vs. 13.0 %). The prevalence of prediabetes in urban areas was also higher than that of rural areas (19.1 % vs. 15.6 %). Among all the patients diagnosed with diabetes, 46.02 % of them received treatment. Age, family history of diabetes, obesity, high level of triglyceride, and low-density lipoprotein were risk factors of 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.     

2008年成都地区40～79岁常住人群糖代谢异常患病率调查

目的 了解成都地区糖代谢异常的流行情况.方法 2008年4月至11月应用分层整群抽样方法,选取成都市3个大社区的40～79岁居民,给予口服葡萄糖耐量实验,进行问卷调查和体格检查.危险因素分析用非条件Logistic回归分析.结果 调查总人数为5205人,糖尿病患病率为18.0%(936/5205),其中既往有糖尿病史者为40.6%(380/936),未诊断的糖尿病患者为59.4%(556/936).空腹血糖受损、糖耐量受损和糖调节受损的患病率分别为2.5%(128/5205)、20.1%(1048/5205)和22.6%(1176/5205).空腹血糖受损、糖耐量受损、糖调节受损和糖尿病患病率性别间比较差异无统计学意义(X~2分别为2.156、1.689、0.320、0.115,均P＞0.05);糖耐量受损、糖调节受损和糖尿病的患病率随着年龄的增长而增加(X~2值分别为105.0、107.0、258.0,均P＜0.05);但空腹血糖受损的患病率与年龄无明显相关性(X~2=1.9,P＞0.05).而男性,城市人口,体质量、舒张压、甘油三酯和尿酸升高为糖调节受损的危险因素.腰围增大,甘油三酯、总胆固醇升高、高密度脂蛋白胆固醇降低为成都市40岁以上人群糖尿病的危险因素.结论 成都地区中老年人群糖代谢异常患病率高,有一半以上为新发糖尿病.糖调节受损和糖尿病的患病率均随年龄增长而增加.     

Family history of diabetes is associated with higher risk for prediabetes: a multicentre analysis from the German Center for Diabetes Research

Aims/hypothesis

Prediabetes is a collective term for different subphenotypes (impaired glucose tolerance [IGT] and/or impaired fasting glucose [IFG]) with different pathophysiologies. A positive family history for type 2 diabetes (FHD) is associated with increased risk for type 2 diabetes. We assumed that it would also associate with prediabetes, but wondered whether all subphenotypes are related to a positive family history.

Methods

In a study population of 8,106 non-diabetic individuals of European origin collected from four study centres (normal glucose tolerance, NGT n?=?5,482, IFG and/or IGT n?=?2,624), we analysed whether having at least one first degree relative with diabetes is associated with prediabetes. The analyses were performed using the same models in each population separately. Afterwards, a meta-analysis was performed.

Results

FHD was significantly associated with the risk for prediabetes (IFG and/or IGT, OR 1.40; 95% CI 1.27, 1.54). This association remained significant in multivariable logistic regression models including sex, age and BMI (OR 1.26; 95% CI 1.14, 1.40). When different prediabetic outcomes were considered separately, the association was found for isolated IFG (OR 1.37; 95% CI 1.20, 1.57), isolated IGT (OR 1.25; 95% CI 1.07, 1.46) as well as for the combination IFG+IGT (OR 1.64; 95% CI 1.40, 1.93). After stratification on BMI, association between FHD and prediabetes was seen only in non-obese individuals (BMI?<?30 kg/m²).

Conclusions/interpretation

We found that FHD is an important risk factor for prediabetes, especially for combined IGT and IFG. Its relevance seems to be more evident in the non-obese.     

Association of serum ferritin concentrations with prevalence of prediabetes,type 2 diabetes mellitus,and metabolic syndrome in a Chinese population from Sichuan

Body iron stores reflected by serum ferritin levels have been implicated in many chronic diseases. We investigated associations between serum ferritin concentrations and the risk of prediabetes, type 2 diabetes mellitus (T2DM), and metabolic syndrome (MetS) in a Chinese population. For a cross-sectional study, 3040 subjects were recruited from three communities in Sichuan. Subjects were grouped by prediabetes or T2DM status, or components of MetS. Subjects with prediabetes were classified as having impaired fasting glucose (IFG), impaired glucose tolerance (IGT), or both (IFG + IGT). The odds ratios, assessed by gender, for the associations between serum ferritin concentration and prediabetes, T2DM, and MetS were calculated using multivariate logistic regression. The prevalence of IGT, IFG + IGT, T2DM, and MetS in the highest quartile of ferritin concentrations was higher than those in the lowest quartile, in both genders. In women, the adjusted odds ratios of IGT, IFG + IGT, T2DM, and MetS were higher in the highest ferritin quartile than the lowest; in men, only that of IFG + IGT was higher. In both genders, high ferritin levels were associated with higher odds ratios of hypertriglyceridemia and hyperglycemia, components of MetS. IGT, IFG + IGT, T2DM, and MetS were more common in the highest ferritin quartile for both genders. Elevated ferritin concentrations were associated with an increased risk for IGT and IFG + IGT in prediabetes, T2DM, and MetS, especially in women.

     

Fasting, non-fasting glucose and HDL dysfunction in risk of pre-diabetes, diabetes, and coronary disease in non-diabetic adults

We determined in non-diabetic persons the risk of fasting and non-fasting glucose levels for pre-diabetes, diabetes, and coronary heart disease (CHD), including the roles of serum C-reactive protein (CRP) and HDL cholesterol, and delineated risk profiles of the pre-diabetic states. Over 7¼ years, 2,619 middle-aged Turkish adults free of diabetes and CHD were studied prospectively. Using different serum glucose categories including impaired fasting glucose (IFG, 6.1–6.97 mmol/L) and impaired glucose tolerance (IGT), outcomes were analyzed by Cox regression. IFG was identified at baseline in 112 and IGT in 33 participants. Metabolic syndrome components distinguished individuals with IFG from those with normoglycemia. Participants with IGT tended to differ from adults in normal postprandial glucose categories in regard to high levels of triglycerides, apoA-I, and CRP. Diabetes risk, adjusted for sex, age, waist circumference, CRP, and HDL cholesterol, commenced at a fasting 5.6–6.1 mmol/L threshold, was fourfold at levels 6.1–6.97 mmol/L. Optimal glucose values regarding CHD risk were 5.0–6.1 mmol/L. Fasting and postprandial glucose values were not related to CHD risk in men; IGT alone predicted risk in women (HR 3.74 [1.16;12.0]), independent of age, systolic blood pressure, non-HDL cholesterol, waist circumference, smoking status, and CRP. HDL cholesterol was unrelated to the development of IFG, IGT, and diabetes, while CRP elevation independently predicted the development of diabetes. IGT independently predicts CHD risk, especially in women. HDL dysfunction associated with low-grade inflammation is a co-determinant of pre-diabetic states and their progression to diabetes.     

Glucose tolerance in a rural population of Bangladesh

CONTEXT:

The prevalence of type 2 diabetes is increasing in the Bangladeshi population. However, there is little information available on the prevalence of glucose intolerance, ie, type 2 diabetes, impaired glucose tolerance, and impaired fasting glucose.

AIMS:

The main aim of this study is to determine the prevalence of different categories of glucose intolerance and their relationship with different anthropometric and demographic characteristics.

SETTINGS AND DESIGN:

This cross-sectional study was performed in a rural area of Bangladesh.

MATERIALS AND METHODS:

A random sample of 5000 persons aged ≥ 20 years was included in this study. Fasting blood glucose was measured in 3981 individuals and 2-h post-glucose blood glucose was measured in 3954 subjects after the known cases of diabetes (n = 27) were excluded. Height, weight, waist and hip circumference, and blood pressure were measured.

STATISTICAL ANALYSIS:

Pearson Chi-squared test and correlation test were used for analysis as appropriate.

RESULTS:

The prevalence of impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and diabetes (DM) were 1.3, 2.0, and 7.0%, respectively. IFG, IGT, and IFG + IGT were more prevalent in females. Age showed a significant positive relationship with increasing levels of glucose intolerance. Body mass index, waist circumference, and waist-to-hip ratio were higher in the glucose-intolerant group than in the normal glucose tolerance (NGT) group. There was a positive correlation between FBG and 2-h BG in NGT and DM subjects.

CONCLUSION:

The FBG value identified more people with glucose intolerance than the 2-h BG. These findings will help developing diabetes preventive strategy in rural populations.     

Prediabetes: diagnosis, evaluation of chronic complications, and treatment

Type 2 diabetes mellitus accounts for 90% of diabetes cases and is associated with macro- and microvascular complications of high morbidity and mortality. Individuals with increased risk for type 2 diabetes include those with impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and especially those with combined IFG and IGT. These individuals are part of a group known as prediabetes patients. Approximately 25% of individuals with prediabetes will develop type 2 diabetes in three to five years. Hyperglycemia, in the absence of diabetes, is also associated with increased risk of cardiovascular disease. Studies have shown that changes in lifestyle and drug interventions are effective in delaying or preventing type 2 diabetes in patients with prediabetes. Metformin is the drug of choice when medical treatment is warranted. IGT and IFG are associated with type 2 diabetes and, despite controversy, most studies reinforce the importance of these conditions in the development of micro- and macrovascular disease. Thus, therapeutic interventions in patients with prediabetes are important in primary prevention of type 2 diabetes and its chronic complications.     

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.     

Prediction of diabetes using ADA or WHO criteria in post-menopausal women: a 10-year follow-up study

Aims/hypothesis. To study the risk of women with impaired fasting glucose (IFG) as against impaired glucose tolerance (IGT) developing diabetes.¶Methods. Oral glucose tolerance tests (75 g) were done in 265 women selected at random at baseline (age 55–57 years) and at a 10-year follow-up. Of the women 42 had IFG/NGT (fasting glucose 6.1–6.9 mmol/l, 2-h glucose < 7.8 mmol/l), 66 IGT/NFG (2-h glucose 7.8–11.0 mmol/l, fasting glucose < 6.1 mmol/l), 30 IGT/IFG and 127 NFG/NGT.¶Results. The 10-year progression to diabetes was similar in IGT/NFG (12.1 %) and IFG/NGT groups (11.9 %, p = 0.97). In IGT/IFG, 20.0 % had developed diabetes, which was not significantly higher than in IFG/NGT and IGT/NFG (p = 0.53). In NFG/NGT at baseline, only 3.9 % had developed diabetes, which was lower than in the other groups (p = 0.023).¶Conclusion/interpretation. Fasting and 2-h glucose concentrations are equally good in predicting diabetes development over a 10-year period in Caucasian postmenopausal women. Because IGT is more common than IFG, measuring only fasting glucose concentrations would, however, result in missing a prediabetic stage in a large group of people at risk for diabetes and cardiovascular diseases. [Diabetologia (2000) 43: 1224–1228]     

Trend analysis of diabetic prevalence and incidence in a rural area of South Korea between 2003–2008

Aims/Introduction: This study determined the change in prevalence of diabetes and prediabetes over a period of 5 years in South Korea. The incidence of diabetes and prediabetes and risk factors associated with the development of diabetes were also investigated. Materials and Methods: The Dalseong population‐based cohort survey recruited 1806 subjects who were over 20‐years‐old in 2003. Five years later, 1287 of the original subjects were re‐evaluated and 187 new subjects were added to the study. All participants completed a questionnaire, were given a physical examination, and provided blood samples for analysis including 2 h oral glucose tolerances. Results: Age‐adjusted prevalence of diabetes rose from 6.7% in 2003 to 9.1% in 2008. The prevalence of prediabetes also increased from 18.5% in 2003 to 28.4% in 2008. The incidence rates of diabetes and prediabetes were 18.3 per 1000 person‐years and 55.4 per 1000 person‐years, respectively. The development of diabetes was associated with impaired fasting glucose (IFG) (odds ratio [OR] 5.661), impaired glucose tolerance (IGT) (OR: 6.013), age (OR 1.013), and waist‐to‐hip ratio (OR 1.513). After excluding the IFG and IGT, systolic blood pressure (OR 1.023), high‐sensitivity C‐reactive protein (hsCRP; OR 1.097), triglyceride (OR 1.002) and waist‐to‐hip ratio (OR 1.696) were statistically significant risk factors in a multivariate logistic regression analysis. Conclusions: A significant rise in the prevalence of diabetes and prediabetes was observed between 2003 and 2008. In addition, this study newly demonstrated that waist‐to‐hip ratio and hsCRP were associated with the development of diabetes after adjusting for several confounding factors. (J Diabetes Invest, doi: 10.1111/j.2040‐1124.2010.00045.x, 2010)     

Plasma glucose levels as predictors of diabetes: the Mexico City diabetes study

Aims/hypothesis  The value of diagnostic categories of glucose intolerance for predicting type 2 diabetes is much debated. We therefore sought to estimate relative and population-attributable risk of different definitions based on fasting (impaired fasting glucose [IFG]) or 2 h plasma glucose concentrations (impaired glucose tolerance [IGT]) and to describe the associated clinical phenotypes. Methods  We prospectively observed a population-based cohort of 1,963 non-diabetic participants (mean age 47 years), in whom an OGTT was performed at baseline and 7 years later. Results  IGT was fivefold more prevalent (13.5%) than IFG. In both categories, participants were older, heavier, hyperinsulinaemic, hyperproinsulinaemic and dyslipidaemic compared with participants with normal glucose tolerance. Relative risk of incident diabetes was similar for IFG and IGT categories (3.73 [95% CI: 2.18–6.39] and 4.01 [95% CI: 3.12–5.14], respectively), but the population-attributable risk was fivefold higher for IGT (29% [95% CI: 26–32]) than for IFG (6% [95% CI: 5–7]). Isolated IFG carried no increase in risk. Lowering the threshold to 5.6 mmol/l raised the population-attributable risk of IFG to 23% (95% CI: 20–25); its contribution to diabetes progression, however, was largely due to co-existent IGT. In multivariate analysis adjusting for sex, age, familial diabetes and BMI, fasting and 2 h glucose were independent predictors. Conclusions/interpretation  Fasting and 2 h glucose values are independent predictors of incident diabetes. Isolated IFG is not a high-risk condition; lowering the diagnostic threshold increases the population-attributable risk of IFG fourfold, but performing an OGTT captures additional diabetes progressors compared with the number identified by IFG.     

北京市昌平区10-18岁超重／肥胖人群空腹血糖受损的患病率调查

目的调查北京市昌平区10-18岁超重／肥胖人群空腹血糖受损（IF℃）的患病率。方法随机抽样获得样本3409名。体检并记录身高、体重、血压,计算BMI。BMI高于同年龄性别第85百分点者测定空腹血糖。FPG≥5．6mmol／L者做口服葡萄糖耐量试验（OGTT）。结果空腹血糖筛查发现81例IFG和1例2型糖尿病。超重／肥胖儿童青少年IFG患病率6．12％。OGTT结果显示,除1例2型糖尿病外未发现餐后血糖〉7．8mmol／L者。结论本地区10～18岁超重／肥胖人群IFG患病率较低。     

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.     

Fasting hyperglycaemia blunts the reversal of impaired glucose tolerance after exercise training in obese older adults

Aim: Lifestyle modification, consisting of exercise and weight loss, delays the progression from prediabetes to type 2 diabetes (T2D). However, no study has determined the efficacy of exercise training on glucose metabolism in the different prediabetes subtypes. Methods: Seventy‐six older (65.1 ± 0.6 years) obese adults with impaired fasting glucose (IFG; n = 12), impaired glucose tolerance (IGT; n = 9) and combined glucose intolerance (IFG + IGT = CGI; n = 22) were compared with normal glucose tolerant (NGT; n = 15) and T2D (n = 18) groups after 12 weeks of exercise training (60 min/day for 5 days/week at ～85% HR_max). An oral glucose tolerance test was used to assess glucose levels. Insulin sensitivity (IS; euglycaemic hyperinsulinaemic clamp at 40 mU/m²/min), β‐cell function (glucose‐stimulated insulin secretion corrected for IS), body composition (hydrostatic weighing/computed tomography scan) and cardiovascular fitness (treadmill VO₂max) were also assessed. Results: Exercise training reduced weight and increased cardiovascular fitness (p < 0.05). Exercise training lowered fasting glucose levels in IFG, CGI and T2D (p < 0.05) and 2‐h glucose levels in IGT, CGI and T2D (p < 0.05). However, 2‐h glucose levels were not normalized in adults with CGI compared with IGT (p < 0.05). β‐Cell function improved similarly across groups (p < 0.05). Although not statistically significant, IS increased approximately 40% in IFG and IGT, but only 17% in CGI. Conclusion: The magnitude of improvement in glucose metabolism after 12 weeks of exercise training is not uniform across the prediabetes subtypes. Given the high risk of progressing to T2D, adults with CGI may require more aggressive therapies to prevent diabetes.     

Exercise resistance across the prediabetes phenotypes: Impact on insulin sensitivity and substrate metabolism

Prediabetes is a heterogeneous term that encompasses different origins of insulin resistance and insulin secretion that contribute to distinct patterns of hyperglycemia. In fact, prediabetes is an umbrella term that characterizes individuals at high risk for developing type 2 diabetes (T2D) and/or cardiovascular disease (CVD). Based on current definitions there are at least 3 distinct phenotypes of prediabetes: impaired fasting glucose (IFG), impaired glucose tolerant (IGT), or the combination of both (IFG + IGT). Each phenotype is clinically relevant as they are uniquely recognized as having different levels of risk for progressing to T2D and CVD. Herein, we discuss the underlying pathophysiology that characterizes IFG, IGT and the combination, as well as examine how some of these phenotypes appear resistant to traditional exercise interventions. We propose that substrate metabolism differences between the prediabetes phenotypes may be a unifying mechanism that explains the inter-subject variation in response to exercise seen across obese, metabolic syndrome, pre-diabetic and T2D patients in the current literature. Ultimately, a better understanding of the pathophysiologic mechanisms that govern disturbances responsible for fasting vs. postprandial hyperglycemia and the combination of both is important for designing optimal and personalized exercise treatment strategies that treat and prevent hyperglycemia and CVD risk.     

Comparison of WHO and ADA criteria for diagnosis of glucose status in adults

The aim was to compare the 1997 American Diabetes Association (ADA) and 1985 and 1998 World Health Organisation (WHO) criteria for the diagnosis of diabetes and impaired glucose tolerance (IGT) by ethnicity and cardiovascular risk factors. We analysed the oral glucose tolerance tests carried out in a cross-sectional survey of 5816 New Zealand workers aged 22-78 years (4211 men, 1605 women) carried out between 1988 and 1990. Prevalence of diabetes was similar using ADA (3.1%) compared with the 1998 WHO criteria (3.0%). The overall prevalence rate of diabetes using the 1985 WHO criteria was only 1.5%. The prevalence rate of impaired fasting glucose (IFG) was the lowest in Europeans (7.3%) and highest in Asians (15.0%). The overall weighted kappa for agreement between the 1997 ADA and 1998 WHO criteria was moderate (0.59), but varied between ethnic groups. Cardiovascular disease (CVD) risk factors were approximately more adverse across groups with IFG, normal (ADA)/IGT (WHO), IFG/IGT and diabetes compared with normal subjects. Compared to those with IFG, participants with the normal (ADA)/IGT (WHO) criteria differed in fasting and 2-h glucose, diastolic blood pressure, and urinary albumin levels, and the proportions of males and number with hypertension, but had a significantly adverse pattern of CVD risk factors compared to those with normal glycaemia. The 1988 WHO criteria using the OGTT provides additional information for classifying various categories of glucose intolerance that is not captured using the 1997 ADA fasting glucose criteria alone.