Impaired fasting glucose or impaired glucose tolerance. What best predicts future diabetes in Mauritius?

Prevalence of Prediabetes and Related Modifiable Cardiovascular Risk Factors Among Employees of Ayder Comprehensive Specialized Hospital, Tigray, Northern Ethiopia

BACKGROUND

Prediabetes is considered an important risk factor for type 2 diabetes and related cardiovascular problems. However, evidence shows that both prediabetes and its associated cardiovascular risk factors could be mitigated through lifestyle modification. This study aims at determining the magnitude of prediabetes and related modifiable cardiovascular risk factors as an initial step towards undertaking such mitigation measures.

METHODS

A cross-sectional study was conducted on employees of a tertiary care hospital from March to June/2019. Socio-demographic data were collected using a self-administered questionnaire. Anthropometric and blood pressure measurements were performed following WHO guidelines. Biochemical parameters were assayed following standard operating procedures. Categorical variables are summarized using frequencies and percentages. Normality test was performed ahead of describing the numeric data and log transformations were carried out when appropriate. International Diabetes Federation (IDF) and American Diabetes Association (ADA) criteria were used to classify glycemic status. Likewise, IDF and revised National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) were employed for the diagnosis of metabolic syndrome.

RESULTS

In this study, we engaged a total of 265 employees. About 35.1% were males and 64.9% were females. The median age was 29 (9) years. About 5.7% and 18.1% had prediabetes based on IDF and ADA criteria, respectively. Equally, 3.4% had FBS levels that meet the criteria for overt diabetes on IDF and ADA. Besides, 55.1% had a metabolic risk as implied by the elevated waist-to-height ratio (WhtR), 24.2% had hypertriglyceridemia, 27.9% had above optimal LDL and 57% had low HDL. Overall, 17.9% and 21.9% of the participants had metabolic syndrome according to IDF and revised NCEP ATP III criteria, respectively.

CONCLUSION

The prevalence of prediabetes and metabolic syndrome observed in hospital employees is comparable with the general population.

A simulation model estimates lifetime health and economic outcomes of screening prediabetes using the 1-h plasma glucose

AIMS

The current method to diagnose impaired glucose tolerance (IGT) is based on the 2-h plasma glucose (2-hPG) value during a 75-g oral glucose tolerance test (OGTT). Robust evidence demonstrates that the 1-h post-load plasma glucose (1-hPG) ≥ 8.6 mmol/L in those with normal glucose tolerance is highly predictive of type 2 diabetes (T2D), micro and macrovascular complications and mortality. The aim of this study was to conduct a health economic analysis to estimate long-term cost-effectiveness of using the 1-hPG compared to the 2-hPG for screening and assessing the risk of diabetes over 35 years. The main outcome was cost per quality-adjusted life year (QALY) gained.

METHODS

A Monte Carlo-based Markov simulation model was developed to forecast long-term effects of two screening strategies with regards to clinical and cost-effectiveness outcomes. The base case model included 20,000 simulated patients over 35-years follow-up. Transition probabilities on disease progression, mortality, effects on preventive treatments and complications were retrieved from landmark diabetes studies. Direct medical costs were sourced from published literature and inflated to 2019 Euros.

RESULTS

In the lifetime analysis, the 1-hPG was projected to increase the number of years free from disease (2 years per patient); to delay the onset of T2D (1 year per patient); to reduce the incidence of T2D complications (0·6 RR-Relative Risk per patient) and to increase the QALY gained (0·58 per patient). Even if the 1-hPG diagnostic method resulted in higher initial costs associated with preventive treatment, long-term diabetes-related costs as well as complications costs were reduced leading to a lifetime saving of - 31225719.82€. The incremental cost-effectiveness ratio was - 8214.7€ per each QALY gained for the overall population.

CONCLUSIONS

Screening prediabetes with the 1-hPG is feasible and cost-effective resulting in reduced costs per QALY. Notwithstanding, the higher initial costs of testing with the 1-hPG compared to the 2-hPG due to incremental preventive intervention, long-term diabetes and complications costs were reduced projecting an overall cost saving of - 8214.7€ per each QALY gained.

Non-pharmacological interventions for the prevention of type 2 diabetes in low-income and middle-income countries: a systematic review of randomised controlled trials

OBJECTIVE

Diabetes poses serious health threats and economic burdens to patients, especially in low-income and middle-income countries (LMICs). This systematic review searches for non-pharmacological interventions for the prevention of type-2 diabetes mellitus (T2DM) among patients who are non-diabetic and pre-diabetic from LMICs.

SETTINGS

LMICs.

PARTICIPANTS

Adult population aged over 18 years without having diabetes.

PRIMARY AND SECONDARY OUTCOMES

Primary outcome is to measure the change in the incidence of T2DM. The secondary outcome is to measure changes in glycated haemoglobin (HbA1c) level, weight/body mass index (BMI), fasting glucose level and 2-hour glucose from baseline of the included randomised controlled trials.

METHODS

This review has been conducted following the standard systematic review guidelines. A total of six electronic databases including MEDLINE, Embase, the Cochrane Library, Web of Science, ClinicalTrials.gov and International Clinical Trials Registry Platform were searched in February 2021 using a comprehensive search strategy.Two sets of independent reviewers performed screening, risk of bias (ROB) assessment using the Cochrane ROB tool and data extraction. Narrative coalescence of selected articles was demonstrated using tables. No meta-analysis was performed due to the lack of homogenous intervention strategies and study settings.

RESULT

A total of five studies were included for the review with a combined population of 1734 from three countries. Three of the studies showed a significant reduction in T2DM incidence after the intervention of physical training and dietary modifications. Four of the studies also demonstrated a significant reduction of different secondary outcomes like weight, BMI, fasting and 2-hour plasma glucose and HbA1c. All the studies demonstrated a low ROB in most of the bias assessment domains with some unclear results in allocation concealments.

CONCLUSIONS

Emphasising non-pharmacological interventions for T2DM prevention can improve health outcomes and lessen the economic burdens, which will be of paramount importance in LMICs.

SYSTEMATIC REVIEW REGISTRATION NUMBER

CRD42020191507.

A Narrative Review of Human Clinical Trials on the Impact of Phenolic-Rich Plant Extracts on Prediabetes and Its Subgroups

Phenolic-rich plant extracts have been demonstrated to improve glycemic control in individuals with prediabetes. However, there is increasing evidence that people with prediabetes are not a homogeneous group but exhibit different glycemic profiles leading to the existence of prediabetes subgroups. Prediabetes subgroups have been identified as: isolated impaired fasting glucose (IFG), isolated impaired glucose tolerance (IGT), and combined impaired fasting glucose and glucose intolerance (IFG/IGT). The present review investigates human clinical trials examining the hypoglycemic potential of phenolic-rich plant extracts in prediabetes and prediabetes subgroups. Artemisia princeps Pampanini, soy (Glycine max (L.) Merrill) leaf and Citrus junos Tanaka peel have been demonstrated to improve fasting glycemia and thus may be more useful for individuals with IFG with increasing hepatic insulin resistance. In contrast, white mulberry (Morus alba Linn.) leaf, persimmon (Diospyros kaki) leaf and Acacia. Mearnsii bark were shown to improve postprandial glycemia and hence may be preferably beneficial for individuals with IGT with increasing muscle insulin resistance. Elaeis guineensis leaf was observed to improve both fasting and postprandial glycemic measures depending on the dose. Current evidence remains scarce regarding the impact of the plant extracts on glycemic control in prediabetes subgroups and therefore warrants further study.

Association between plasma irisin in pregnancy and postpartum glucose levels among Chinese women: A cohort study

AIMS/INTRODUCTION

The association between plasma irisin and glucose levels in the general population is controversial, and few studies have longitudinally detected this correlation. We aimed to examine whether irisin in pregnancy was associated with postpartum glucose levels among Chinese women and explore the modifiable factors.

MATERIALS AND METHODS

We carried out a prospective cohort study in Guangzhou, China, during 2017 and 2018, and 453 pregnant women (20-28 weeks) were enrolled. Plasma irisin levels in pregnancy were tested. At 6-8 weeks after delivery, 93 women with gestational diabetes mellitus (GDM) underwent a 75-g oral glucose tolerance test, and the other 360 women had a fasting blood glucose (FBG) test. Multivariable linear, quantile and logistic regressions were carried out.

RESULTS

The mean plasma irisin in mid-pregnancy was 13.73 ng/mL. We observed a significantly negative association between mid-pregnancy irisin and postpartum FBG (β: -0.056 ± 0.024). However, quantile regression showed the association was only significant in high percentiles of FBG levels (P50 to P95 ), and the magnitude showed an increasing trend. Higher baseline irisin was also associated with a lower risk of postpartum impaired fasting glucose (relative risk 0.563, 95% confidence interval 0.384-0.825). Furthermore, we found significant interactions between irisin and predominant breast-feeding on FBG and impaired fasting glucose (both Pinteraction  < 0.05). In women with GDM, baseline irisin was non-significantly associated with postpartum postprandial 2-h glucose levels (β: -0.305 ± 0.160, P = 0.061).

CONCLUSIONS

Plasma irisin levels in mid-pregnancy were negatively associated with FBG levels and impaired fasting glucose at 6-8 weeks postpartum among Chinese women, and stronger associations were observed in women with higher FBG values. Furthermore, breast-feeding might modify this relationship.

Prediabetes: how pathophysiology drives potential intervention on a subclinical disease with feared clinical consequences

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disorder whose rising incidence suggests the epidemic proportions of the disease. Impaired Fasting Glucose (IFG) and Impaired Glucose Tolerance (IGT) - alone or combined - represent two intermediate metabolic condition between Normal Glucose Tolerance (NGT) and overt T2DM. Several studies have demonstrated that insulin resistance and beta-cell impairment can be identified even in normoglycemic prediabetic individuals. Worsening of these two conditions may lead to progression of IGT and/or IFG status to overt diabetes. Starting from these assumptions, it seems logical to suppose that interventions aimed at improving metabolic conditions, even in prediabetes, could represent an effective target to halt transition from IGT/IFG to manifest T2DM. Starting from pathophysiological knowledge, in this review we evaluate two possible interventions (lifestyle modifications and pharmacological agents) eligible as prediabetes therapy since they have been demonstrated to improve insulin resistance and beta-cell impairment. Detecting high-risk people and treating them could represent an effective strategy to slow down progression to overt diabetes, normalize glucose tolerance, and even prevent micro- and macrovascular complications.

Predictive capability of fasting-state glucose and insulin measurements for abnormal glucose tolerance in women with polycystic ovary syndrome

Objective

The aim of the present study was to evaluate the predictive capability of fasting-state measurements of glucose and insulin levels alone for abnormal glucose tolerance in women with polycystic ovary syndrome (PCOS).

Methods

In total, 153 Korean women with PCOS were included in this study. The correlations between the 2-hour postload glucose (2-hr PG) level during the 75-g oral glucose tolerance test (OGTT) and other parameters were evaluated using Pearson correlation coefficients and linear regression analysis. The predictive accuracy of fasting glucose and insulin levels and other fasting-state indices for assessing insulin sensitivity derived from glucose and insulin levels for abnormal glucose tolerance was evaluated using receiver operating characteristic (ROC) curve analysis.

Results

Significant correlations were observed between the 2-hr PG level and most fasting-state parameters in women with PCOS. However, the area under the ROC curve values for each fasting-state parameter for predicting abnormal glucose tolerance were all between 0.5 and 0.7 in the study participants, which falls into the “less accurate” category for prediction.

Conclusion

Fasting-state measurements of glucose and insulin alone are not enough to predict abnormal glucose tolerance in women with PCOS. A standard OGTT is needed to screen for impaired glucose tolerance and type 2 diabetes mellitus in women with PCOS.

Diabetes and Cardiovascular Disease Risk Perception and Risk Indicators: a 5-Year Follow-up

BACKGROUND

Perceived disease risk may reflect actual risk indicators and/or motivation to change lifestyle. Yet, few longitudinal studies have assessed how perceived risk relates to risk indicators among different disease risk groups. We examined in a 5-year follow-up, whether perceived risks of diabetes and cardiovascular disease predicted physical activity, body mass index (BMI kg/m2), and blood glucose level, or the reverse. We examined further whether perceived risk, self-efficacy, and outcome beliefs together predicted changes in these risk indicators.

METHOD

Participants were high diabetes risk participants (N = 432) and low/moderate-risk participants (N = 477) from the national FINRISK 2002 study who were followed up in 2007. Both study phases included questionnaires and health examinations with individual feedback letters. Data were analyzed using gender- and age-adjusted structural equation models.

RESULTS

In cross-lagged autoregressive models, perceived risks were not found to predict 5-year changes in physical activity, BMI, or 2-h glucose. In contrast, higher BMI and 2-h glucose predicted 5-year increases in perceived risks (β-values 0.07-0.15, P-values < 0.001-0.138). These associations were similar among high- and low/moderate-risk samples. In further structural equation models, higher self-efficacy predicted increased physical activity among both samples (β-values 0.10-0.16, P-values 0.005-0.034). Higher outcome beliefs predicted lower BMI among the low/moderate-risk sample (β-values - 0.04 to - 0.05, P-values 0.008-0.011).

CONCLUSION

Perceived risk of chronic disease rather follows risk indicators than predicts long-term lifestyle changes. To promote sustained lifestyle changes, future intervention studies need to examine the best ways to combine risk feedback with efficient behavior change techniques.

Patterns of changes in fasting plasma glucose, hemoglobin A1c and the area under the curve during oral glucose tolerance tests in prediabetic subjects: results from a 16-year prospective cohort study among first-degree relatives of type 2 diabetic patients

AIM

This study aimed to identify the patterns of changes in glycemic indices over time in prediabetics and to classify these subjects as either having a high or low risk for developing diabetes in future.

METHODS

This prospective 16-year cohort study was conducted among 1228 prediabetic subjects. Three measurements including first visit, mean values during the follow-up period, and last visit from fasting plasma glucose (FPG), glycosylated hemoglobin (HbA1_C), and area under the curve during an oral glucose tolerance test (OGTT AUC) were used to evaluate the patterns of changes by using the latent Markov model (LMM).

RESULTS

The mean (standard deviation) age of subjects was 44.0 (6.8) years, and 73.6% of them were female. The LMM identified 2 latent states of subjects in terms of changes in FPG, HbA1c, OGTT AUC, and the combination of these glycemic measures: a low tendency to progress diabetes and a high tendency to progress diabetes with the latent state sizes (87, 13%), (94, 6%), (57, 43%), and (84, 16%), respectively. The LMM showed that the probability of transitioning from a low tendency to a high tendency to progress diabetes was higher than the probability of transitioning in the opposite direction.

CONCLUSION

Based on a long-term evaluation of patterns of changes in glycemic indices, we classified prediabetic subjects into 2 groups (high or low risk to progress diabetes states in future). Also, the method used enabled us to estimate the transition probabilities from low- to high-risk states and vice versa. Our results reemphasized the values of all 3 glycemic measures in clinical settings for identifying prediabetic people with a high risk of progressing diabetes and the need for more effective prevention strategies, which should be conducted as urgently in prediabetic life as high-risk subjects.

Clinical profiles of post-load glucose subgroups and their association with glycaemic traits over time: An IMI-DIRECT study

AIM

To examine the hypothesis that, based on their glucose curves during a seven-point oral glucose tolerance test, people at elevated type 2 diabetes risk can be divided into subgroups with different clinical profiles at baseline and different degrees of subsequent glycaemic deterioration.

METHODS

We included 2126 participants at elevated type 2 diabetes risk from the Diabetes Research on Patient Stratification (IMI-DIRECT) study. Latent class trajectory analysis was used to identify subgroups from a seven-point oral glucose tolerance test at baseline and follow-up. Linear models quantified the associations between the subgroups with glycaemic traits at baseline and 18 months.

RESULTS

At baseline, we identified four glucose curve subgroups, labelled in order of increasing peak levels as 1-4. Participants in Subgroups 2-4, were more likely to have higher insulin resistance (homeostatic model assessment) and a lower Matsuda index, than those in Subgroup 1. Overall, participants in Subgroups 3 and 4, had higher glycaemic trait values, with the exception of the Matsuda and insulinogenic indices. At 18 months, change in homeostatic model assessment of insulin resistance was higher in Subgroup 4 (β = 0.36, 95% CI 0.13-0.58), Subgroup 3 (β = 0.30; 95% CI 0.10-0.50) and Subgroup 2 (β = 0.18; 95% CI 0.04-0.32), compared to Subgroup 1. The same was observed for C-peptide and insulin. Five subgroups were identified at follow-up, and the majority of participants remained in the same subgroup or progressed to higher peak subgroups after 18 months.

CONCLUSIONS

Using data from a frequently sampled oral glucose tolerance test, glucose curve patterns associated with different clinical characteristics and different rates of subsequent glycaemic deterioration can be identified.

The role of the gut microbiome and its metabolites in metabolic diseases

It is well known that an unhealthy lifestyle is a major risk factor for metabolic diseases, while in recent years, accumulating evidence has demonstrated that the gut microbiome and its metabolites also play a crucial role in the onset and development of many metabolic diseases, including obesity, type 2 diabetes, nonalcoholic fatty liver disease, cardiovascular disease and so on. Numerous microorganisms dwell in the gastrointestinal tract, which is a key interface for energy acquisition and can metabolize dietary nutrients into many bioactive substances, thus acting as a link between the gut microbiome and its host. The gut microbiome is shaped by host genetics, immune responses and dietary factors. The metabolic and immune potential of the gut microbiome determines its significance in host health and diseases. Therefore, targeting the gut microbiome and relevant metabolic pathways would be effective therapeutic treatments for many metabolic diseases in the near future. This review will summarize information about the role of the gut microbiome in organism metabolism and the relationship between gut microbiome-derived metabolites and the pathogenesis of many metabolic diseases. Furthermore, recent advances in improving metabolic diseases by regulating the gut microbiome will be discussed.

Patterns of changes in serum lipid profiles in prediabetic subjects: results from a 16-year prospective cohort study among first-degree relatives of type 2 diabetic patients

Background

Lipid abnormality pervasively is associated with the risk of type 2 diabetes mellitus. To the best of our knowledge, there is no study that has examined the longitudinal changes in a wide range of serum lipid profiles in prediabetic subjects in association with the risk of developing type 2 diabetes mellitus in the future. This study aimed to identify the patterns of changes in lipid profiles over time in prediabetic patients and to classify these subjects in order to highlight which patients are at high risk for future diabetes.

Methods

This prospective 16-year (2003–2019) cohort study was conducted among 1228 prediabetic subjects. The study subjects were followed, and the changes in their lipid profiles, including triglycerides, cholesterol, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol, were evaluated. The latent Markov model was used for data analysis.

Results

The mean (standard deviation) age of subjects was 44.0 (6.8) years, and 73.6% of them were female. The latent Markov model identified two latent states of subjects in terms of changes in lipid profiles: a low tendency to progress diabetes / high tendency to progress diabetes (74, 26%). The latent Markov model showed that the transition probability from a “low tendency to progress diabetic” state to a “high tendency to progress diabetic” state was lower than the transition probability from “high tendency to progress diabetic” state to “low tendency to progress diabetic” state.

Conclusions

The present study showed that more than half of the first-degree relatives of T2DM had approximately normal lipid profiles and that these patients are more inclined to transition from a higher- to a lower-tendency diabetic state. These findings confirm the value of regular screening of first-degree relatives of T2DM. Moreover, preventive intervention strategies are recommended to reduce their risk of developing T2DM.

Factors associated with progression to pre-diabetes: a recurrent events analysis

AIMS

Pre-diabetes is a strong risk factor for type 2diabetes (T2D). The aim of this study was to explore factors associated with normal glucose maintenance and pre-diabetes prevention or delay.

METHODS

Data of 1016 first-degree relatives of T2D patients were retrieved from the Isfahan Diabetes Prevention Study (IDPS). Association of various variables including nutrients, serum tests and physical activity with the risk of pre-diabetes was assessed using recurrent events approach.

RESULTS

Cumulative incidence of diabetes was 8.17, 9.44, and 4.91% for total sample and individuals with and without pre-diabetes experience in the follow-up. Risk of progression to pre-diabetes was higher in women and older people (p < 0.01). Additionally, BMI and blood pressure had significant association with the risk (p < 0.01) and individuals with higher intake of fat were at higher risk (HR = 2.26; 95% CI 1.66-3.07 for high-intake and HR = 1.52; 95% CI 1.27-1.83 for medium-intake compared to low-intake group). Carbohydrates and protein intake were positively associated with the risk of pre-diabetes with HR = 8.63 per 49 g extra carbohydrates per day and HR = 1.32 per 6 g extra protein per day (p < 0.01). The association was also significant for triglyceride (TG) with 7% risk increase per 1 SD = 1.14 increase in TG level.

CONCLUSION

Despite frequent studies on lifestyle modification for pre-diabetes prevention, less information is available about the role of nutritional components. We observed direct effects for intake of macronutrients including fat, carbohydrates, and protein in first-degree relatives. Further research is warranted to assess these associations in general populations.

LEVEL OF EVIDENCE

Level III: Evidence obtained from a single-center cohort study.

Prevalence of type 2 diabetes mellitus compared between lean and overweight/obese patients with polycystic ovarian syndrome: a 5-year follow-up study

PURPOSE

To investigate the prevalence of type 2 diabetes mellitus (T2DM) at the 5-year follow-up after polycystic ovarian syndrome (PCOS) diagnosis compared between lean and overweight/obese groups.

METHODS

This retrospective cohort study included 400 prediabetes PCOS women who attended our clinic. Participants were divided into either the lean group (body mass index [BMI]: < 23 kg/m²) or the overweight/obese group (BMI: ≥ 23 kg/m²). Patient demographic, clinical characteristics, metabolic profiles, and laboratory values were collected and compared between groups at baseline and during follow-up for 5 years.

RESULTS

At the end of the follow-up, overweight/obese group had a higher risk for developing T2DM than lean group (11.5% vs. 0.5%, p < 0.001). Lean group had a lower incidence of hypertension (3% vs. 38.5%, p < 0.001) and dyslipidemia (35% vs. 53.5%, p < 0.001) than overweight/obese group. The factors found to be independently associated with increased risk for developing T2DM were BMI ≥ 23 kg/m² (odds ratio [OR]: 1.075, p = 0.047), non-use of oral combined contraceptive pills (OR: 0.312, p = 0.028), and impaired fasting glucose at baseline (OR: 38.167, p < 0.001).

CONCLUSIONS

Overweight/obese PCOS patients were found to be at significantly higher risk for developing T2DM than lean PCOS patients. Higher BMI, IFG at baseline, and non-use of oral contraceptive pills found to be independent predictors of T2DM in PCOS.

Predicting long-term type 2 diabetes with support vector machine using oral glucose tolerance test

Diabetes is a large healthcare burden worldwide. There is substantial evidence that lifestyle modifications and drug intervention can prevent diabetes, therefore, an early identification of high risk individuals is important to design targeted prevention strategies. In this paper, we present an automatic tool that uses machine learning techniques to predict the development of type 2 diabetes mellitus (T2DM). Data generated from an oral glucose tolerance test (OGTT) was used to develop a predictive model based on the support vector machine (SVM). We trained and validated the models using the OGTT and demographic data of 1,492 healthy individuals collected during the San Antonio Heart Study. This study collected plasma glucose and insulin concentrations before glucose intake and at three time-points thereafter (30, 60 and 120 min). Furthermore, personal information such as age, ethnicity and body-mass index was also a part of the data-set. Using 11 OGTT measurements, we have deduced 61 features, which are then assigned a rank and the top ten features are shortlisted using minimum redundancy maximum relevance feature selection algorithm. All possible combinations of the 10 best ranked features were used to generate SVM based prediction models. This research shows that an individual’s plasma glucose levels, and the information derived therefrom have the strongest predictive performance for the future development of T2DM. Significantly, insulin and demographic features do not provide additional performance improvement for diabetes prediction. The results of this work identify the parsimonious clinical data needed to be collected for an efficient prediction of T2DM. Our approach shows an average accuracy of 96.80% and a sensitivity of 80.09% obtained on a holdout set.

Endothelial dysfunction and intima media thickness are selectively related to the different carbohydrate disturbances across the glucose continuum

Aim: The aim of the present study was to investigate the prevalence of macrovascular complications across different carbohydrate disturbances. Patients and methods: In the study, we included 167 patients, divided them into three age and BMI matched groups - group 1 with obesity without carbohydrate disturbances (n = 66), group 2 with prediabetes (n = 68) and group 3 with newly diagnosed type 2 diabetes (n = 33). Endothelial function was evaluated using EndoPAT, intima media thickness (IMT) was measured on the common carotid artery and ankle-brachial index (ABI) was calculated. Results: The patients with T2D had significantly higher mean IMT than the other two groups. The best predictors of increased IMT were fasting blood glucose followed by age and SBP. ROC-analysis showed that blood glucose on 60 min of OGTT had a very good predictive value for endothelial dysfunction. Conclusions: Patients with newly diagnosed diabetes have increased IMT and a tendency towards higher ABI compared to normoglycemic and prediabetic subjects.

Paraoxonase-1 as a Regulator of Glucose and Lipid Homeostasis: Impact on the Onset and Progression of Metabolic Disorders

Metabolic disorders are characterized by an overall state of inflammation and oxidative stress, which highlight the importance of a functional antioxidant system and normal activity of some endogenous enzymes, namely paraoxonase-1 (PON1). PON1 is an antioxidant and anti-inflammatory glycoprotein from the paraoxonases family. It is mainly expressed in the liver and secreted to the bloodstream, where it binds to HDL. Although it was first discovered due to its ability to hydrolyze paraoxon, it is now known to have an antiatherogenic role. Recent studies have shown that PON1 plays a protective role in other diseases that are associated with inflammation and oxidative stress, such as Type 1 and Type 2 Diabetes Mellitus and Non-Alcoholic Fatty Liver Disease. The aim of this review is to elucidate the physiological role of PON1, as well as the impact of altered PON1 levels in metabolic disorders.

Differential clusters of modifiable risk factors for impaired fasting glucose versus impaired glucose tolerance in adults 50 years of age and older

Background

The aim of this study was to identify modifiable risk factors associated with isolated impaired fasting glucose (IFG), isolate impaired glucose tolerance (IGT), or combined IFG-IGT in men and women aged 50 years and older.

Methods

Cross-sectional analyses were performed in 703 men and women aged between 50 and 80 years old from NHANES (2007-2008). Outcome variables: IFG and IGT (ADA 2003), estimated body composition, cardiometabolic profile, and socio-demographic, dietary, and lifestyle factors.

Results

First, 235 had normal glucose tolerance (men = 38.3%, women = 61.7%), 243 had IFG (men = 61.7%, women = 38.3%), 67 had IGT (men = 40.3%, women = 59.7%) and 158 had both conditions (men = 57.0%, women = 43.0%). The only common determinant of both IFG and IGT was triglyceride levels. High total fat mass index (FMI) and high total fat-free mass index (FFMI) were independently associated with IFG; while high C-reactive protein (CRP) levels were independently associated with IGT. Finally, combined IFG-IGT was associated with inadequate fiber intake, high FMI, FFMI, and CRP levels.

Conclusions

Middle-age and older individuals presented different modifiable risk factors depending on whether they had IFG or IGT. IFG was associated with deteriorated body composition and lipids, whereas IGT was associated with deteriorated lipids and inflammatory factors. IFG-IGT, on the other hand, was associated with a larger number of risk factors, including worsen body composition, cardiometabolic and dietary factors. To prevent the transition to type 2 diabetes, specific clinical interventions targeting these risk factors should be considered.

Serum AGEs and sRAGE levels are not related to vascular complications in patients with prediabetes

BACKGROUND

While hyperglycemia has a key role in the pathogenesis of microvascular complications of diabetes, it is just one of the many factors contributing to macrovascular damage. The aim of the present study is to investigate the link between serum pentosidine and sRAGE levels and vascular complications in patients with prediabetes compared to normal glucose tolerance controls with obesity.

METHODS

In this study were included 76 patients with mean age 50.7 ± 10.7 years, divided into two age and BMI-matched groups - group 1 with obesity without glycemic disturbances (n = 38) and group 2 with obesity and prediabetes (n = 38).

RESULTS

There was no significant difference in pentosidine and sRAGE levels between patients with obesity and prediabetes. Patients with hypertension had lower levels of sRAGE compared to nonhypertensive subjects. sRAGE showed a weak negative correlation to blood glucose on 60th min of OGTT and HOMA index. There was no correlation between sRAGE and pentosidine levels and the markers of micro- and macrovascular complications. There was no difference in sRAGE and pentosidine levels between patients with and without endothelial dysfunction.

CONCLUSIONS

sRAGE and pentosidine levels are similar in patients with obesity with and without prediabetes and do not correlate to the markers of micro- and macrovascular complications.

11th Annual Symposium on Self-Monitoring of Blood Glucose: April 12-14, 2018, Oslo, Norway

A panel of international experts in the field of diabetes and diabetes technology met in Oslo, Norway, for the 11th Annual Symposium on Self-Monitoring of Blood Glucose. The goal of these meetings is to share current knowledge, facilitate new collaborations, and encourage further research projects that can improve the lives of people with diabetes. The 2018 meeting comprised a comprehensive scientific program and four keynote lectures.

Factors associated with regression from prediabetes to normal glucose tolerance in a Korean general population: A community-based 10-year prospective cohort study

AIM

A proportion of people with prediabetes convert back to normal glucose tolerance. We sought to determine the clinical variables associated with conversion from prediabetes to normal glucose tolerance, with a focus on insulin secretory capacity, insulin sensitivity and body composition.

METHODS

We followed 1731 people with prediabetes at baseline from the Korean Genome and Epidemiology Study every 2 years for 10 years. Oral glucose tolerance tests (OGTT) were performed, and muscle and fat mass were estimated using bioelectrical impedance analysis.

RESULTS

During 10 years of follow-up, 36% (623/1731) of people with prediabetes converted to normal glucose tolerance. Higher baseline fasting glucose, 2-h OGTT glucose and triglyceride levels were inversely associated with this conversion. Higher 60-min insulinogenic index (IGI₆₀ ) at baseline was independently associated with this conversion [HR per sd (95% CI) 1.09 (1.02-1.17); P = 0.01]. However, other indices reflecting insulin sensitivity, including the composite insulin sensitivity index, were not associated with this conversion. In addition, a higher baseline muscle to fat ratio was independently associated with conversion to normal glucose tolerance [HR per sd (95% CI) 1.15 (1.04-1.26); P = 0.005]. People with conversion to normal glucose tolerance showed a greater increase in the 60-min insulinogenic index and disposition index and a smaller decrease in the composite insulin sensitivity index compared with people without conversion during 10 years of follow-up (all p-values < 0.001).

CONCLUSION

A higher insulin secretory capacity at baseline and during follow-up and higher baseline muscle to fat ratio were independently associated with an improvement in glucose tolerance in Korean adults with prediabetes.

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.

Higher Fasting and Postprandial Free Fatty Acid Levels Are Associated With Higher Muscle Insulin Resistance and Lower Insulin Secretion in Young Non-Obese Women

Background

To assess the relationship of the shape of glucose concentration curve during a standardized meal test to serum free fatty acid (FFA) concentrations, insulin resistance and insulin secretion in young non-obese women.

Methods

Thirty-five young women had a standardized meal for breakfast with measurement of glucose, insulin and FFA concentrations at 0 (fasting), 30, 60 and 120 min; the areas under the concentration curves were calculated (AUCg, AUCi and AUCffa, respectively). Meal-induced insulin response (MIR) was calculated as the ratio between the incremental insulin and glucose concentrations during the first 30 min of meal tests. In two women (group A), post-breakfast glucose (PBG) returned to levels below fasting plasma glucose (FPG) at 30 min; in 15 and 11 women, PBG returned to levels below FPG at 60 and 120 min (groups B and C, respectively). In the remaining seven women (group D), PBG never fell below FPG.

Results

Despite no difference in fasting insulin and AUCi, fasting FFA, AUCg and AUCffa were the lowest in group A, increased linearly from group B to C and plateaued in group D, whereas MIR might be the highest in group A, decreased from group B to C and plateaued in group D.

Conclusion

Young women whose PBG returned to FPG more slowly had higher muscle insulin resistance and lower MIR associated with higher fasting and postprandial FFA levels compared with young women whose PBG returned to baseline more quickly.

Association of serum orosomucoid with 30-min plasma glucose and glucose excursion during oral glucose tolerance tests in non-obese young Japanese women

OBJECTIVE

Inflammatory markers are elevated in insulin resistance (IR) and diabetes. We tested whether serum orosomucoid (ORM) is associated with postload glucose, β-cell dysfunction and IR inferred from plasma insulin kinetics during a 75 g oral glucose tolerance test (OGTT).

RESEARCH DESIGN AND METHODS

75 g OGTTs were performed with multiple postload glucose and insulin measurements over a 30-120 min period in 168 non-obese Japanese women (aged 18-24 years). OGTT responses, serum adiponectin and high-sensitivity C reactive protein (hsCRP) were cross-sectionally analyzed by analysis of variance and then Bonferroni's multiple comparison procedure. Stepwise multivariate linear regression analyses were used to identify most important determinants of ORM.

RESULTS

Of 168 women, 161 had normal glucose tolerance. Postload glucose levels and the area under the glucose curve (AUCg) increased in a stepwise fashion from the first through the third ORM tertile. In contrast, there was no or modest, if any, association with fat mass index, trunk/leg fat ratio, adiponectin, hsCRP, postload insulinemia, the Matsuda index and homeostasis model assessment IR. In multivariable models, which incorporated the insulinogenic index, the Matsuda index and HOMA-IR, 30 min glucose (standardized β: 0.517) and AUCg (standardized β: 0.495) explained 92.8% of ORM variations.

CONCLUSIONS

Elevated circulating orosomucoid was associated with elevated 30 min glucose and glucose excursion in non-obese young Japanese women independently of adiposity, IR, insulin secretion, adiponectin and other investigated markers of inflammation. Although further research is needed, these results may suggest a clue to identify novel pathways that may have utility in monitoring dysglycemia within normal glucose tolerance.

Area under the curve during OGTT in first-degree relatives of diabetic patients as an efficient indicator of future risk of type 2 diabetes and prediabetes

OBJECTIVE

To establish whether the area under the curve of an OGTT has a predictive role in identifying prediabetic and diabetic subjects among first-degree relatives (FDR) of patients with diabetes mellitus type 2 (DM).

DESIGN, PATIENTS AND MEASUREMENTS

In a population-based cohort study, 766 FDR of diabetic patients with a normal glucose tolerance test (NGT) completed a 2-hour OGTT. They were followed up for 7 years and classified according to the American Diabetes Association criteria into: NGT, impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and DM. Relative risk (RR) and 95% confidence intervals (95%CI) were calculated based on logistic regression. Receiver operator characteristic (ROC) analysis along with AUC at different intervals and at time points during the OGTT was used to evaluate the risk of prediabetes and diabetes.

RESULTS

Twenty-three subjects (3%) developed type 2 DM, 118 (29.3%) IFG, 81 (11.5%) IGT and 544 (71%) subjects remained NGT. AUC and mean difference of glucose in all high-risk groups demonstrated significant differences in both intervals and time points when compared to the NGT group. The cut-off values during OGTT to predict prediabetes and diabetes was determined as blood glucose more than 7.2 and 7.8 mmol/L at 30 and 60 minutes, respectively. The time point 60 has the highest predictive role for the development of diabetes, alone, and improved the performance of a prediction model containing multiple important clinical risk factors.

CONCLUSION

The data suggest that the glycaemic response to an OGTT may predict the risk of development of diabetes in first-degree relatives of DM patients.

Evaluating FINDRISC as a screening tool for type 2 diabetes among overweight adults in the PREVIEW:NZ cohort

AIMS

This study aimed to evaluate the efficacy of a high (≥12) Finnish diabetes risk (FINDRISC) score in identifying undiagnosed prediabetes and type 2 diabetes (T2D) in an New Zealand population of overweight and obese individuals, across a variety of ethnic groups.

METHODS

We estimated the efficacy of elevated FINDRISC scores in predicting prediabetes and T2D in 424 overweight adults with no prior diagnosis recruited for the PREVention of diabetes through lifestyle Interventions in Europe and Worldwide (PREVIEW) study. All participants who completed the FINDRISC questionnaire during a pre-screening phase with a score of ≥12 were then screened using a 2h oral glucose tolerance test (2h-OGTT) to identify undiagnosed dysglycaemia.

RESULTS

Of the 424 participants, 65% (n=280) were pre-diabetic and 7% (n=32) had undiagnosed T2D. A higher FINDRISC score was significantly associated with prediabetes and T2D (P=0.02). There was a significant association between ethnicity and glycaemic status (normal vs prediabetes/T2D, P=0.02). Increasing the FINDRISC cut-off to ≥15 resulted in a non-significant increase in the proportion of participants correctly classified with dysglycaemia. ROC-AUC=0.6 with sensitivity=0.6026 (95% CI: 0.5459-0.6573) and specificity=0.5536 (95% CI: 0.4567-0.6476). Isolated impaired fasting glucose (IFG) was more efficient in predicting dysglycaemia than isolated impaired glucose tolerance (IGT).

CONCLUSIONS

The FINDRISC questionnaire is a useful and efficacious screening tool to identify unknown prediabetes and T2D in overweight New Zealanders, particularly in Maori individuals.

The 1h post glucose value best predicts future dysglycemia among normal glucose tolerance subjects

AIM

To analyse the OGTT glycemic parameters - fasting, 1h and 2h plasma glucose values singly and in various combinations; with respect to their prediction of future dysglycemia in subjects with normal glucose tolerance (NGT).

METHODS

Electronic medical records of individuals who underwent an OGTT between 1991 and 2016 at a tertiary diabetes centre were analysed. NGT subjects who had at least one more follow up OGTT (n=1356) were selected for the study. Regarding their prediction of future dysglycemia, the glycemic parameters-Fasting plasma glucose (FPG), 1h plasma glucose (1HrPG) and 2h plasma glucose (2HrPG) were analysed separately and also in different combinations. HbA1c and the combined use of HbA1c and FPG were also compared. Receiver operating characteristic (ROC) curve analysis was performed to assess the capability of various glycemic parameters to discriminate between NGT and dysglycemia. The WHO criteria were used to define dysglycemia as the presence of prediabetes (Impaired fasting glucose and/or Impaired glucose tolerance) or diabetes.

RESULTS

318(23.4%) developed prediabetes (median follow up 3.5years) and 134(10%) developed diabetes (median follow up 5.6years). The 1hrPG had a significantly higher AUC (0.684, 0.716) compared to FPG (0.560 and 0.593) and 2hrPG (0.644 and 0.618) for prediabetes and diabetes respectively. Adding the FPG or the 2hrPG to the 1HrPG did not significantly improve the AUC beyond 1HrPG alone. The 1HrPG also predicted diabetes better than HbA1c as well as the combined use of HbA1c and FPG.

CONCLUSION

The 1HrPG value during OGTT is a good predictor of future dysglycemia among NGT subjects.

Association of Alcohol Drinking Patterns With Presence of Impaired Fasting Glucose and Diabetes Mellitus Among South Korean Adults

Background

We aimed to investigate the association between alcohol drinking patterns and the presence of impaired fasting glucose (IFG) and diabetes mellitus (DM).

Methods

We used data from the Korean National Health and Nutrition Examination Survey, 2010–2014. The participants were aged ≥30 years and had no previous diagnosis of DM. High-risk drinking was defined as alcohol consumption of ≥7 glasses at a sitting for men, and ≥5 glasses for women. After adjusting for confounding factors, a polychotomous logistic regression analysis was performed to assess the association of drinking patterns with IFG and DM.

Results

For men, high-risk drinking was associated with higher odds ratios (ORs) of IFG (2–4/month, OR 1.51; 95% confidence interval [CI], 1.13–2.04; 2–3/week, OR 1.79; 95% CI, 1.38–2.33; and ≥4/week, OR 2.24; 95% CI, 1.65–3.03) and of DM (2–4/month, OR 2.12; 95% CI, 1.20–3.77; 2–3/week, OR 1.78; 95% CI, 1.05–3.03; and ≥4/week, OR 2.98; 95% CI, 1.72–5.17). For women, high-risk drinking was associated with higher risk of IFG (2–4/month, OR 1.51; 95% CI, 1.04–2.21; 2–3/week, OR 3.19; 95% CI, 2.20–4.64; and ≥4/week, OR 2.23; 95% CI, 1.23–4.06), but not of DM, compared with non-high-risk drinkers who consumed alcohol ≤1 day/month. Non-high-risk drinkers who consumed alcohol ≥4 days/week had higher ORs of DM in men, but lower ORs of DM in women compared with non-high risk drinkers who consumed alcohol ≤1 day/month.

Conclusions

Compared with non-high-risk alcohol drinking, even occasional high-risk alcohol drinking was associated with a higher risk of IFG in men and women, and DM in men. Nearly daily non-high-risk alcohol drinking was associated with a higher risk of DM in men and lower risk of DM in women.

Effects of medicinal food plants on impaired glucose tolerance: A systematic review of randomized controlled trials

BACKGROUND

The objective of this systematic review was to assess available scientific data on the efficacy and safety of medicinal food plants for the treatment of impaired glucose tolerance.

METHODS

We included randomized controlled trials (RCTs) with a minimum follow-up period of 6weeks. The diagnosis was determined by fasting plasma glucose values after two-hour oral glucose tolerance testing (OGTT). Two authors independently extracted data and evaluated bias. The Cochrane tool of risk of Bias Tool was used.

RESULTS

This review included ten trials. Most studies were highly biased as data were incomplete or reporting was selective. The two-hour fasting plasma glucose after the curcumin extract intervention showed statistical significance after 3, 6 and 9months: p<0.01. Also, glycosylated haemoglobin levels A1c (HbA1c) values after curcumin extract intervention showed statistical significance after 3, 6 and 9months: p<0.01. Insulin resistance (HOMA-IR) after curcumin extract intervention showed statistical significance after 6months and after 9months: p<0.05 and p<0.01.

CONCLUSIONS

Curcumin has shown the confident results to be effective for the treatment of impaired glucose tolerance. Fenugreek and flaxseed may also be effective, but due to low quality of these studies the results must be interpreted with caution.

Influence of estrogen-related receptor γ (ESRRG) rs1890552 A > G polymorphism on changes in fasting glucose and arterial stiffness

To determine the effects of the estrogen-related receptor γ (ESRRG) rs1890552 A > G polymorphism on dietary advice-mediated changes in fasting glucose and arterial stiffness, 374 subjects with normal fasting glucose (NFG; control group, no treatment) and 142 subjects with impaired fasting glucose (IFG group, dietary advice) were followed for 3.5 years. At follow-up, the GG subjects in the IFG group showed a significant reduction in fasting glucose, which was greater than in the AA subjects. A significant association was observed between ESRRG rs1890552 A > G polymorphism and changes in fasting glucose, brachial-ankle pulse wave velocity (ba-PWV), and 8-epi-prostaglandin F2α in the IFG subjects. At baseline, the GG subjects showed a higher ba-PWV than the AA subjects in the IFG group. At the 3.5-year follow-up, subjects with AA or AG showed significant increases in ba-PWV, whereas subjects with GG showed a decrease from baseline. This study suggests that the ESRRG rs1890552 A > G polymorphism may modulate interindividual differences in atrial stiffness, with a reduction in fasting glucose in response to dietary advice in subjects with IFG after a 3.5-year follow-up.

Biochemical and clinical relevance of alpha lipoic acid: antioxidant and anti-inflammatory activity, molecular pathways and therapeutic potential

BACKGROUND

The molecular nature of lipoic acid (LA) clarifies its capability of taking part to a variety of biochemical reactions where redox state is meaningful. The pivotal action of LA is the antioxidant activity due to its ability to scavenge and inactivate free radicals. Furthermore, LA has been shown to chelate toxic metals both directly and indirectly by its capability to enhance intracellular glutathione (GSH) levels. This last property is due to its ability to interact with GSH and recycle endogenous GSH. LA exhibits significant antioxidant activity protecting against oxidative damage in several diseases, including neurodegenerative disorders. Interestingly, LA is unique among natural antioxidants for its capability to satisfy a lot of requirements, making it a potentially highly effective therapeutic agent for many conditions related with oxidative damage. In particular, there are evidences showing that LA has therapeutic activity in lowering glucose levels in diabetic conditions. Similarly, LA supplementation has multiple beneficial effects on the regression of the mitochondrial function and on oxidative stress associated with several diseases and aging.

AIM

The aim of the present review is to describe the molecular mechanisms underlying the beneficial effects of LA under various experimental conditions and disease and how to exploit such effect for clinical purposes.

CONCLUSION

LA has pleiotropic effects in different pathways related with several diseases, its use as a potential therapeutic agent is very promising.

Post-Prandial Plasma Glucose Less Than or Equal to 70 mg/dL Is Not Uncommon in Young Japanese Women

BACKGROUND

Post-breakfast/post-challenge plasma glucose (PG) concentrations were studied less in young normal weight Japanese women. We addressed these issues.

METHODS

Two separate groups of female collegiate athletes and female untrained students underwent either a standardized meal test or a standard 75-g oral glucose tolerance test, but not both. Frequency of women whose post-breakfast/post-load PG fell to 70 mg/dL or lower (termed as low glycemia) was compared between athletes and non-athletes, who also underwent measurements of serum adipokines, markers of insulin resistance and inflammation and dual-energy X-ray absorptiometry. Insulin secretion, insulin sensitivity/resistance and serum adipokines were compared between women with and without post-breakfast low glycemia. The same comparison was done between women whose post-breakfast PG returned to levels below the fasting PG and women whose post-breakfast PG never fell below the fasting PG.

RESULTS

There was no difference between athletes and non-athletes in frequency of post-breakfast low glycemia (47% (8/17) and 44% (8/18)) and post-challenge low glycemia (24% (12/50) and 23% (27/118)). As compared to seven women whose post-breakfast PG never fell below the fasting PG, 28 women whose post-breakfast PG returned to levels below the fasting PG had higher meal-induced insulin responses (283 ± 366 vs. 89 ± 36 µU/mg, P = 0.014). However, two groups did not differ in body composition, markers of insulin resistance and serum adiponectin. No significant difference was also observed in any of these variables between women with and without post-breakfast low glycemia.

CONCLUSION

Post-prandial PG ≤ 70 mg/dL is not uncommon in young normal weight Japanese women and may not be a pathological condition. The underlying mechanisms for this finding need further exploration.

Increased Vascular Disease Mortality Risk in Prediabetic Korean Adults Is Mainly Attributable to Ischemic Stroke

Background and Purpose—

Prediabetes is a known risk factor for vascular diseases; however, its differential contribution to mortality risk from various vascular disease subtypes is not known.

Methods—

The subjects of the National Health Insurance Service in Korea (2002–2013) nationwide cohort were stratified into normal glucose tolerance (fasting glucose <100 mg/dL), impaired fasting glucose (IFG) stage 1 (100–109 mg/dL), IFG stage 2 (110–125 mg/dL), and diabetes mellitus groups based on the fasting glucose level. A Cox regression analysis with counting process formulation was used to assess the mortality risk for vascular disease and its subtypes—ischemic heart disease, ischemic stroke, and hemorrhagic stroke.

Results—

When adjusted for age, sex, and body mass index, IFG stage 2, but not stage 1, was associated with significantly higher all-cause mortality (hazard ratio [HR], 1.26; 95% confidence interval [CI], 1.18–1.34) and vascular disease mortality (HR, 1.27; 95% CI, 1.08–1.49) compared with normal glucose tolerance. Among the vascular disease subtypes, mortality from ischemic stroke was significantly higher (HR, 1.60; 95% CI, 1.18–2.18) in subjects with IFG stage 2 but not from ischemic heart disease and hemorrhagic stroke. The ischemic stroke mortality associated with IFG stage 2 remained significantly high when adjusted other modifiable vascular disease risk factors (HR, 1.51; 95% CI: 1.10–2.09) and medical treatments (HR, 1.75; 95% CI, 1.19–2.57).

Conclusions—

Higher IFG degree (fasting glucose, 110–125 mg/dL) was associated with increased all-cause and vascular disease mortality. The increased vascular disease mortality in IFG stage 2 was attributable to ischemic stroke, but not ischemic heart disease or hemorrhagic stroke in Korean adults.

Low-Level Environmental Lead Exposure and Dysglycemia in Adult Individuals: Results from the Canadian Health and Measure Survey 2007-2011

We aimed to evaluate the association of exposure to lead with glycated hemoglobin (HbA1c), fasting glucose levels (FGLs), and the likelihood for dysglycemia. We accessed data from Canada Health and Measures Survey. General linear models were used to estimate the association between blood lead concentrations (BPb) and both HbA1c and FGLs, while controlling for confounders. Multivariate logistic regression was used for assessing the relation between BPb and the likelihood for dysglycemia. FGLs in participants with moderate BPb (2.5-5.0 μg/dL) were 1.03 (95 % CI 1.00-1.06) times higher compared with participants with BPb < 2.5 μg/dL. Equivalent figures for those with BPb ≥ 5.0 μg/dL were 1.10 (95 % CI 1.01-1.20) times, relative to the lowest stratum. This association was attenuated using HbA1c to define dysglycemia. Lead exposure was associated with the likelihood for neither FGLs ≥ 1.10 g/L nor HbA1c ≥ 5.7 %. The association between lead exposure and dysglycemia, if any, is likely to be very modest, at least at the population level.

Impact of dietary fat composition on prediabetes: a 12-year follow-up study

Objective

Dietary fatty acid composition likely affects prediabetic conditions such as isolated impaired fasting glucose (IFG) or impaired glucose tolerance (IGT); however, this risk has not been evaluated in a large population nor has it been followed prospectively.

Design

Diet, physical activity, anthropometric, socio-economic and blood glucose data from the Atherosclerosis Risk in Communities (ARIC) study were obtained from BioLINCC. Cox proportional hazards regression models were used to evaluate associations of dietary SFA, MUFA, PUFA,n-3 fatty acid (FA) andn-6 FA intakes with incidence of one (isolated IFG) or two (IFG with IGT) prediabetic conditions at the end of 12-year follow-up.

Setting

Study volunteers were from counties in North Carolina, Mississippi, Minnesota and Maryland, USA.

Subjects

Data from 5288 volunteers who participated in the ARIC study were used for all analyses reported herein.

Results

The study population was 62% male and 84 % white, mean age 53·5 (sd5·7) years and mean BMI 26·2 (sd4·6) kg/m2. A moderately high intake of dietary MUFA (10–15 % of total daily energy) was associated with a 10 % reduced risk of isolated IFG incidence, while a high intake ofn-3 FA (>0·15 % of total daily energy) was associated with a 10 % increase in risk. Curiously, moderately high intake ofn-6 PUFA (4–5 % of total daily energy) was associated with a 12 % reduction in IFG and IGT incidence.

Conclusions

MUFA,n-3 andn-6 FA contribute differently to the development of isolated IFGv. IFG with IGT; and their mechanism may be more complex than originally proposed.

Metabolomics based markers predict type 2 diabetes in a 14-year follow-up study

BACKGROUND

The growing field of metabolomics has opened up new opportunities for prediction of type 2 diabetes (T2D) going beyond the classical biochemistry assays.

OBJECTIVES

We aimed to identify markers from different pathways which represent early metabolic changes and test their predictive performance for T2D, as compared to the performance of traditional risk factors (TRF).

METHODS

We analyzed 2776 participants from the Erasmus Rucphen Family study from which 1571 disease free individuals were followed up to 14-years. The targeted metabolomics measurements at baseline were performed by three different platforms using either nuclear magnetic resonance spectroscopy or mass spectrometry. We selected 24 T2D markers by using Least Absolute Shrinkage and Selection operator (LASSO) regression and tested their association to incidence of disease during follow-up.

RESULTS

The 24 markers i.e. high-density, low-density and very low-density lipoprotein sub-fractions, certain triglycerides, amino acids, and small intermediate compounds predicted future T2D with an area under the curve (AUC) of 0.81. The performance of the metabolic markers compared to glucose was significantly higher among the young (age < 50 years) (0.86 vs. 0.77, p-value <0.0001), the female (0.88 vs. 0.84, p-value =0.009), and the lean (BMI < 25 kg/m²) (0.85 vs. 0.80, p-value =0.003). The full model with fasting glucose, TRFs, and metabolic markers yielded the best prediction model (AUC = 0.89).

CONCLUSIONS

Our novel prediction model increases the long-term prediction performance in combination with classical measurements, brings a higher resolution over the complexity of the lipoprotein component, increasing the specificity for individuals in the low risk group.

Barriers and Facilitators to Healthy Lifestyle Changes in Minority Ethnic Populations in the UK: a Narrative Review

Minority ethnic populations experience a disproportionate burden of health inequalities compared with the rest of the population, including an increased risk of type 2 diabetes (T2DM). The purpose of this narrative review was to explore knowledge and attitudes around diabetes, physical activity and diet and identify barriers and facilitators to healthy lifestyle changes in minority ethnic populations in the UK. The narrative review focused on three key research topics in relation to barriers and facilitators to healthy lifestyle changes in minority adult ethnic populations: (i) knowledge and attitudes about diabetes risk; (ii) current behaviours and knowledge about physical activity and diet; and (iii) barriers and facilitators to living a healthier lifestyle. Nearly all of the studies that we identified reported on South Asian minority ethnic populations; we found very few studies on other minority ethnic populations. Among South Asian communities, there was generally a good understanding of diabetes and its associated risk factors. However, knowledge about the levels of physical activity required to gain health benefits was relatively poor and eating patterns varied. Barriers to healthy lifestyle changes identified included language barriers, prioritising work over physical activity to provide for the family, cultural barriers with regard to serving and eating traditional food, different perceptions of a healthy body weight and fear of racial harassment or abuse when exercising. Additional barriers for South Asian women included expectations to remain in the home, fear for personal safety, lack of same gender venues and concerns over the acceptability of wearing ‘western’ exercise clothing. Facilitators included concern that weight gain might compromise family/carer responsibilities, desire to be healthy, T2DM diagnosis and exercise classes held in ‘safe’ environments such as places of worship. Our findings suggest that South Asian communities are less likely to engage in physical activity than White populations and highlight the need for health promotion strategies to engage people in these communities. There is a gap in knowledge with regard to diabetes, physical activity, diet and barriers to healthy lifestyle changes among other ethnic minority populations in the UK; we recommend further research in this area.

Increased peroxiredoxin 4 levels in patients with prediabetes compared to normal glucose tolerance subjects

BACKGROUND

Peroxiredoxin 4 is a part of endogen antioxidant system and its levels are elevated in oxidative stress conditions. Its levels are positively associated with cardiovascular risk. The aim of this study was to compare serum peroxiredoxin 4 levels between obese subjects with prediabetes and with normal glucose tolerance.

METHODS

In this study, we included 80 patients with mean age 50·4 ± 10·6 years and divided them into two age and BMI-matched groups - group 1 with obesity without glycaemic disturbances (n = 41) and group 2 with obesity and prediabetes (n = 39). Oral glucose tolerance test with measurement of immunoreactive insulin was performed in all participants, and the levels of peroxiredoxin 4 were measured using ELISA method.

RESULTS

We found significantly higher levels of peroxiredoxin 4 in patients with prediabetes compared to controls (2851·2 ± 4576·6 pg/ml vs 1088·0 ± 753·3 pg/ml; P = 0·022). There was a mild but statistically significant correlation between peroxiredoxin 4 and weight (r = 0·232; P = 0·038), waist circumference (r = 0·239; P = 0·044), creatinine (r = 0·264; P = 0·019), liver enzymes (ASAT - r = 0·289; P = 0·019 and ALAT - r = 0·305; P = 0·07) and white blood cells count (r = 0·317; P = 0·005). There was no difference in peroxiredoxin 4 levels in patients with and without insulin resistance, as well as with and without metabolic syndrome (MetS), although the levels of peroxiredoxin 4 increased with the number of components of MetS.

CONCLUSIONS

The levels of peroxiredoxin 4 are higher in patients with prediabetes, but are similar in subjects with and without insulin resistance, which suggests that the main factor for its increased levels is hyperglycaemia and not insulin sensitivity state.

The Glucose Tolerance Test, But Not HbA 1c, Remains the Gold Standard in Identifying Unrecognized Diabetes Mellitus and Impaired Glucose Tolerance in Hypertensive Subjects

The objective of this study was to compare the value of the oral glucose tolerance test (GTT), glycated hemoglobin concentration (HbA1c), and fasting plasma glucose (FPG) for identifying unrecognized diabetes mellitus (DM) and impaired glucose tolerance (IGT) in hypertensive subjects. One hundred forty-four consecutive subjects who were not known to have DM and who were attending the Hypertension Clinic underwent 24-hour ambulatory blood pressure (BP) monitoring. A GTT and an HbA1c measurement were also carried out. Abnormal results from GTT were found in 94 patients (65%). Results from FPG were not different between those with DM and IGT but were significantly higher than in the euglycemic subjects. The FPG was between 110-125 mg/dL (6.1-6.9 mmol/L) in 31% (n=20) of patients with IGT and in 53% (n=16) of those with DM. With use of the previously published criteria to diagnose DM of FPG ≥103 mg/dL (5.7 mmol/L) and HbA1c ≥5.9%, 33% of our diabetic subjects and 75% of those with IGT would have been misclassified as euglycemic. The previously reported cut-off point for HbA1c of >6.1% to diagnose DM was present in 77% of our patients with DM and in 14% (n=9) of the patients with IGT. Multiple regression analysis showed that an abnormal result from GTT was independent of the level of clinical or ambulatory BP, nocturnal BP dip, cholesterol level, smoking history, race, or class of antihypertensive medication taken. FPG levels or HbA1c, or their combination, are not accurate enough to identify DM or IGT in patients attending a hospital Hypertension Clinic. A GTT may be required in these patients to reliably identify those with DM or IGT.

Machine learning to predict rapid progression of carotid atherosclerosis in patients with impaired glucose tolerance

Objectives

Prediabetes is a major epidemic and is associated with adverse cardio-cerebrovascular outcomes. Early identification of patients who will develop rapid progression of atherosclerosis could be beneficial for improved risk stratification. In this paper, we investigate important factors impacting the prediction, using several machine learning methods, of rapid progression of carotid intima-media thickness in impaired glucose tolerance (IGT) participants.

Methods

In the Actos Now for Prevention of Diabetes (ACT NOW) study, 382 participants with IGT underwent carotid intima-media thickness (CIMT) ultrasound evaluation at baseline and at 15–18 months, and were divided into rapid progressors (RP, n = 39, 58 ± 17.5 μM change) and non-rapid progressors (NRP, n = 343, 5.8 ± 20 μM change, p < 0.001 versus RP). To deal with complex multi-modal data consisting of demographic, clinical, and laboratory variables, we propose a general data-driven framework to investigate the ACT NOW dataset. In particular, we first employed a Fisher Score-based feature selection method to identify the most effective variables and then proposed a probabilistic Bayes-based learning method for the prediction. Comparison of the methods and factors was conducted using area under the receiver operating characteristic curve (AUC) analyses and Brier score.

Results

The experimental results show that the proposed learning methods performed well in identifying or predicting RP. Among the methods, the performance of Naïve Bayes was the best (AUC 0.797, Brier score 0.085) compared to multilayer perceptron (0.729, 0.086) and random forest (0.642, 0.10). The results also show that feature selection has a significant positive impact on the data prediction performance.

Conclusions

By dealing with multi-modal data, the proposed learning methods show effectiveness in predicting prediabetics at risk for rapid atherosclerosis progression. The proposed framework demonstrated utility in outcome prediction in a typical multidimensional clinical dataset with a relatively small number of subjects, extending the potential utility of machine learning approaches beyond extremely large-scale datasets.

Association between impaired fasting glycaemia in pediatric obesity and type 2 diabetes in young adulthood

Objectives:

In adults, impaired fasting glycemia (IFG) increases the risk for type 2 diabetes mellitus (T2DM). This study aimed to investigate to which extent children with obesity develop T2DM during early adulthood, and to determine whether IFG and elevated hemoglobin A1c (HbA1c) in obese children are risk markers for early development of T2DM.

Methods:

In this prospective cohort study, 1620 subjects from the Swedish Childhood Obesity Treatment Registry – BORIS who were ⩾18 years at follow-up and 8046 individuals in a population-based comparison group, matched on gender age and living area, were included. IFG was defined according to both ADA (cut-off 5.6 mmol l⁻¹) and WHO (6.1 mmol l⁻¹). Elevated HbA1c was defined according to ADA (cut-off 39 mmol l⁻¹). Main outcome was T2DM medication, as a proxy for T2DM. Data on medications were retrieved from a national registry.

Results:

The childhood obesity cohort were 24 times more likely to receive T2DM medications in early adulthood compared with the comparison group (95% confidence interval (CI): 12.52–46). WHO-defined IFG predicted future use of T2DM medication with an adjusted hazard ratio (HR) of 3.73 (95% CI: 1.87–7.45) compared with those who had fasting glucose levels <5.6 mmol l⁻¹. A fasting glucose level of 5.6–6.0 mmol l⁻¹, that is, the IFG-interval added by American Diabetes Association (ADA), did not increase the use of T2DM medication more than pediatric obesity itself, adjusted HR=1.72 (0.84–3.52). Elevated levels of HbA1c resulted in an adjusted HR=3.12 (1.50–6.52). More severe degree of obesity also increased the future T2DM risk.

CONCLUSION:

IFG according to WHO and elevated HbA1c (39–48 mmol l⁻¹), but not the additional fasting glucose interval added by ADA (5.6–6.0 mmol l⁻¹), can be considered as prediabetes in the obese pediatric population in Sweden.

Review: Pre-diabetes: clinical relevance and therapeutic approach

Type 2 diabetes mellitus is epidemic in most developed and many developing countries. The associated morbidity, mortality and high costs of care, make type 2 diabetes an important global public health challenge and target for prevention. Patients at high risk for type 2 diabetes can be diagnosed by fasting glucose levels or responses to an oral glucose tolerance test (OGTT). Such patients are also at increased risk for cardiovascular disease (CVD). Since obesity and physical inactivity are important risk factors for type 2 diabetes, lifestyle interventions, emphasising modest weight loss and increases in physical activity, should be recommended for most patients with pre-diabetes. Such interventions are safe and effective and also reduce risk factors for CVD. Several oral antidiabetic agents have been shown to be effective at delaying onset of type 2 diabetes. Thiazolidinediones (TZDs) reduced incident diabetes by ~60%, whilst metformin, acarbose and orlistat are only about half as effective as the TZDs. Pharmacological interventions may be appropriate for patients at particular risk for developing diabetes, but the benefits of treatment need to be balanced against the safety and tolerability of the intervention. If pharmacological treatment is warranted, metformin should be considered first because of its favourable overall safety, tolerability, efficacy, and cost profile.

Lifestyle interventions in preventing new type 2 diabetes in Asian populations

The aim of this study was to review current evidence on interventional studies aimed at the prevention of type 2 diabetes in Asian population with lifestyle interventions. Prevalence of type 2 diabetes sharply increased in most Asian countries during the last decades. This issue has now also relevant implication for Europe where different surveys are also consistently revealing an higher prevalence of type 2 diabetes and other and major CVD risk factors among subjects originating from Asian Countries than in the native population. Nutrition and lifestyle transition seem to play a role in disclosing the predisposition for the development of type 2 diabetes and great interest is now shown toward the possibility to intervene with lifestyle intervention on at risk populations. A meta-analysis of Randomized Controlled Trials showed that lifestyle interventions are highly effective also in the Asian population. All studies were, however, conducted with an individual approach based on the identification of high-risk individuals. When ethnic minority groups have to be addressed, an approach directed to the community rather than to the individual might, however, be more effective. This review reinforces the importance for policy-makers to consider the involvement of the whole community of minority immigrant groups with lifestyle intervention programs.

Effect of vitamin D supplementation on insulin resistance and glycaemic control in prediabetes: a systematic review and meta-analysis

AIMS

To evaluate the effect of vitamin D on insulin resistance and glycaemic control in prediabetes.

METHODS

A literature search was conducted of MEDLINE, the Cochrane Library, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Scopus, Web of Science and www.clinicaltrials.gov, together with a historical search through the reference lists of relevant articles until end of June 2014. Studies were included if they were randomized controlled trials of vitamin D or vitamin D analogues in prediabetes and if they reported homeostatic model assessment of insulin resistance or 2-h plasma glucose after oral glucose tolerance test. Treatment effect was estimated according to mean difference in the changes from baseline of homeostatic model assessment of insulin resistance, 2-h oral glucose tolerance test plasma glucose, fasting plasma glucose and HbA1c between vitamin D and control groups. Meta-analysis of eligible studies was performed.

RESULTS

A total of 10 randomized controlled trials were included. Vitamin D did not significantly improve homeostatic model assessment of insulin resistance and 2-h oral glucose tolerance test plasma glucose: the mean differences were -0.06 (95% CI -0.36 to 0.24) and -0.23 mmol/l (95% CI -0.65 to 0.19), respectively. Subgroup analysis suggested that vitamin D improved homeostatic model assessment of insulin resistance in a subgroup with baseline 25-hydroxyvitamin D ≥ 50 nmol/l [mean difference -0.59 (95% CI -1.14 to -0.04); P = 0.03] and improved 2-h oral glucose tolerance test plasma glucose in the subgroup with baseline 25-hydroxyvitamin D < 50 nmol/l [mean difference -0.68 mmol/l (95% CI -1.35 to -0.01); P = 0.05]. Vitamin D significantly reduced fasting plasma glucose and HbA1c levels. The mean differences were -0.10 mmol/l (95% CI -0.18 to -0.03), P = 0.006 and -1 mmol/mol (95% CI -2 to 0), P = 0.008, respectively.

CONCLUSIONS

No beneficial effect of vitamin D in improving insulin resistance was identified.

Predictive Value of Glucose Parameters Obtained From Oral Glucose Tolerance Tests in Identifying Individuals at High Risk for the Development of Diabetes in Korean Population

Previous studies suggest that the future risk for type 2 diabetes is not similar among subjects in the same glucose tolerance category. In this study, we aimed to evaluate simple intuitive indices to identify subjects at high risk for future diabetes development by using 0, 30, 120 minute glucose levels obtained during 75 g OGTTs from participants of a prospective community-based cohort in Korea.Among subjects enrolled at the Chungju Metabolic disease Cohort, those who performed an OGTT between 2007 and 2010 and repeated the test between 2011 and 2014 were recruited after excluding subjects with diabetes at baseline. Subjects were categorized according to their 30 minute glucose (G30) and the difference between 120 and 0 minute glucose (G(120-0)) levels with cutoffs of 9.75 and 2.50 mmol/L, respectively.Among 1126 subjects, 117 (10.39%) developed type 2 diabetes after 4 years. In diabetes nonconverters, increased insulin resistance was accompanied by compensatory insulin secretion, but this was not observed in converters during 4 years of follow-up. Subjects with G(120-0) ≥ 2.50 mmol/L or G30 ≥ 9.75 mmol/L demonstrated lower degrees of insulin secretion, higher degrees of insulin resistance, and ∼6-fold higher risk of developing future diabetes compared to their lower counterparts after adjustment for possible confounding factors. Moreover, subjects with high G(120-0) and high G30 demonstrated 22-fold higher risk for diabetes development compared to subjects with low G(120-0) and low G30.By using the G(120-0) and G30 values obtained during the OGTT, which are less complicated measurements than previously reported methods, we were able to select individuals at risk for future diabetes development. Further studies in different ethnicities are required to validate our results.

Insulin Secretory Defect and Insulin Resistance in Isolated Impaired Fasting Glucose and Isolated Impaired Glucose Tolerance

OBJECTIVE

To investigate the characteristics of isolated impaired glucose tolerance (IGT) and isolated impaired fasting glucose (IFG), we analyzed the factors responsible for elevation of 2-hour postchallenge plasma glucose (2 h PG) and fasting plasma glucose (FPG) levels.

METHODS

We investigated the relationship between 2 h PG and FPG levels who underwent 75 g OGTT in 5620 Japanese subjects at initial examination for medical check-up. We compared clinical characteristics between isolated IGT and isolated IFG and analyzed the relationships of 2 h PG and FPG with clinical characteristics, the indices of insulin secretory capacity, and insulin sensitivity.

RESULTS

In a comparison between isolated IGT and isolated IFG, insulinogenic index was lower in isolated IGT than that of isolated IFG (0.43 ± 0.34 versus 0.50 ± 0.47, resp.; p < 0.01). ISI composite was lower in isolated IFG than that of isolated IGT (6.87 ± 3.38 versus 7.98 ± 4.03, resp.; p < 0.0001). In isolated IGT group, insulinogenic index showed a significant correlation with 2 h PG (r = -0.245, p < 0.0001) and had the strongest correlation with 2 h PG (β = -0.290). In isolated IFG group, ISI composite showed a significant correlation with FPG (r = -0.162, p < 0.0001) and had the strongest correlation with FPG (β = -0.214).

CONCLUSIONS

We have elucidated that decreased early-phase insulin secretion is the most important factor responsible for elevation of 2 h PG levels in isolated IGT subjects, and decreased insulin sensitivity is the most important factor responsible for elevation of FPG levels in isolated IFG subjects.

Fasting and postprandial regulation of the intracellular localization of adiponectin and of adipokines secretion by dietary fat in rats

Background/Objective:

Dietary fat sources modulate fasting serum concentration of adipokines, particularly adiponectin. However, previous studies utilized obese animals in which adipose tissue function is severely altered. Thus, the present study aimed to assess the postprandial regulation of adipokine secretion in nonobese rats that consumed high-fat diet (HFD) composed of different types of fat for a short time.

Methods:

The rats were fed a control diet or a HFD containing coconut, safflower or soybean oil (rich in saturated fatty acid, monounsaturated fatty acid or polyunsaturated fatty acid, respectively) for 21 days. The serum concentrations of adiponectin, leptin, retinol, retinol-binding protein-4 (RBP-4), visfatin and resistin were determined at fasting and after refeeding. Adiponectin multimerization and intracellular localization, as well as the expression of endoplasmic reticulum (ER) chaperones and transcriptional regulators, were evaluated in epididymal white adipose tissue.

Results:

In HFD-fed rats, serum adiponectin was significantly decreased 30 min after refeeding. With coconut oil, all three multimeric forms were reduced; with safflower oil, only the high-molecular-weight (HMW) and medium-molecular-weight (MMW) forms were decreased; and with soybean oil, only the HMW form was diminished. These reductions were due not to modifications in mRNA abundance or adiponectin multimerization but rather to an increment in intracellular localization at the ER and plasma membrane. Thus, when rats consumed a HFD, the type of dietary fat differentially affected the abundance of endoplasmic reticulum resident protein 44 kDa (ERp44), sirtuin 1 (SIRT1) and peroxisome proliferator-activated receptor-γ (PPARγ) mRNAs, all of which are involved in the post-translational processing of adiponectin required for its secretion.

Leptin, RBP-4, resistin and visfatin serum concentrations did not change during fasting, whereas modest alterations were observed after refeeding.

Conclusions:

The short-term consumption of a HFD affected adiponectin localization in adipose tissue, thereby decreasing its secretion to a different magnitude depending on the dietary fat source. Evaluating the fasting serum concentration of adipokines was not sufficient to identify alterations in their secretion, whereas postprandial values provided additional information as dynamic indicators.