Incidence of type 2 diabetes by HbA1c and OGTT: the Isfahan Diabetes Prevention Study

Novel anthropometric indices for predicting type 2 diabetes mellitus

BACKGROUND

This study aimed to compare anthropometric indices to predict type 2 diabetes mellitus (T2DM) among first-degree relatives of diabetic patients in the Iranian community.

METHODS

In this study, information on 3483 first-degree relatives (FDRs) of diabetic patients was extracted from the database of the Endocrinology and Metabolism Research Center of Isfahan University of Medical Sciences. Overall, 2082 FDRs were included in the analyses. A logistic regression model was used to evaluate the association between anthropometric indices and the odds of having diabetes. Furthermore, a receiver operating characteristic (ROC) curve was applied to estimate the optimal cutoff point based on the sensitivity and specificity of each index. In addition, the indices were compared based on the area under the curve (AUC).

RESULTS

The overall prevalence of diabetes was 15.3%. The optimal cutoff points for anthropometric measures among men were 25.09 for body mass index (BMI) (AUC = 0.573), 0.52 for waist-to-height ratio (WHtR) (AUC = 0.648), 0.91 for waist-to-hip ratio (WHR) (AUC = 0.654), 0.08 for a body shape index (ABSI) (AUC = 0.599), 3.92 for body roundness index (BRI) (AUC = 0.648), 27.27 for body adiposity index (BAI) (AUC = 0.590), and 8 for visceral adiposity index (VAI) (AUC = 0.596). The optimal cutoff points for anthropometric indices were 28.75 for BMI (AUC = 0.610), 0.55 for the WHtR (AUC = 0.685), 0.80 for the WHR (AUC = 0.687), 0.07 for the ABSI (AUC = 0.669), 4.34 for the BRI (AUC = 0.685), 39.95 for the BAI (AUC = 0.583), and 6.15 for the VAI (AUC = 0.658). The WHR, WHTR, and BRI were revealed to have fair AUC values and were relatively greater than the other indices for both men and women. Furthermore, in women, the ABSI and VAI also had fair AUCs. However, BMI and the BAI had the lowest AUC values among the indices in both sexes.

CONCLUSION

The WHtR, BRI, VAI, and WHR outperformed other anthropometric indices in predicting T2DM in first-degree relatives (FDRs) of diabetic patients. However, further investigations in different populations may need to be implemented to justify their widespread adoption in clinical practice.

A Prediction Model Based on Noninvasive Indicators to Predict the 8-Year Incidence of Type 2 Diabetes in Patients with Nonalcoholic Fatty Liver Disease: A Population-Based Retrospective Cohort Study

Background

The prevention of type 2 diabetes (T2D) and its associated complications has become a major priority of global public health. In addition, there is growing evidence that nonalcoholic fatty liver disease (NAFLD) is associated with an increased risk of diabetes. Therefore, the purpose of this study was to develop and validate a nomogram based on independent predictors to better assess the 8-year risk of T2D in Japanese patients with NAFLD.

Methods

This is a historical cohort study from a collection of databases that included 2741 Japanese participants with NAFLD without T2D at baseline. All participants were randomized to a training cohort (n = 2058) and a validation cohort (n = 683). The data of the training cohort were analyzed using the least absolute shrinkage and selection operator method to screen the suitable and effective risk factors for Japanese patients with NAFLD. A cox regression analysis was applied to build a nomogram incorporating the selected features. The C-index, receiver operating characteristic curve (ROC), calibration plot, decision curve analysis, and Kaplan-Meier analysis were used to validate the discrimination, calibration, and clinical usefulness of the model. The results were reevaluated by internal validation in the validation cohort.

Results

We developed a simple nomogram that predicts the risk of T2D for Japanese patients with NAFLD by using the parameters of smoking status, waist circumference, hemoglobin A1c, and fasting blood glucose. For the prediction model, the C-index of training cohort and validation cohort was 0.839 (95% confidence interval (CI), 0.804-0.874) and 0.822 (95% CI, 0.777-0.868), respectively. The pooled area under the ROC of 8-year T2D risk in the training cohort and validation cohort was 0.811 and 0.805, respectively. The calibration curve indicated a good agreement between the probability predicted by the nomogram and the actual probability. The decision curve analysis demonstrated that the nomogram was clinically useful.

Conclusions

We developed and validated a nomogram for the 8-year risk of incident T2D among Japanese patients with NAFLD. Our nomogram can effectively predict the 8-year incidence of T2D in Japanese patients with NAFLD and helps to identify people at high risk of T2D early, thus contributing to effective prevention programs for T2D.

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.

Association of Lipid Profile with Type 2 Diabetes in First-Degree Relatives: A 14-Year Follow-Up Study in Iran

PURPOSE

Dyslipidemia is claimed to be associated with an increased risk of type 2 diabetes mellitus (T2DM). However, first-degree relatives (FDRs) of patients with T2DM are reported to be at higher risk. The aim of this study was to evaluate the association between serum lipid profile and T2DM incidence in FDRs.

PATIENTS AND METHODS

Information on 1222 T2DM FDRs during 14 years of follow-up was retrieved. All individuals were examined for diabetes status and dyslipidemia once a year. We used a Bayesian joint longitudinal-survival model to assess the association.

RESULTS

Our data showed that a 10 mg/dL increase in triglycerides (TG), very-low-density lipoprotein (VLDL), and non-high-density lipoprotein (non-HDL) cholesterol levels during the follow-up period was associated with an increased risk of diabetes by 5%, 29%, and 6.6%, respectively. Moreover, for every one-unit increase in the TG to HDL ratio, the T2DM incidence increased by 35%. Subgroup analysis also showed that the increased risk of diabetes was significant only in female FDRs, so that a 10 mg/dL increase in TG and VLDL cholesterol level and a one-unit increase in TG to HDL ratio in female FDRs resulted in an increased risk of diabetes by 7.8%, 46%, and 64%, respectively. However, analysis of HDL, low-density lipoprotein (LDL), total cholesterol (TC), TC to HDL, and LDL to HDL cholesterol levels/ratios did not find any statistically significant associations.

CONCLUSION

Increases in TG, VLDL, non-HDL cholesterol level, and TG to HDL ratio are associated with an increased risk of T2DM in FDRs, especially in female FDRs.

Diabetes Care in Iran: Where We Stand and Where We Are Headed

BACKGROUND

The prevalence of diabetes has steadily increased in Iran from the time of the first published nationally representative survey in 1999 and despite efforts and strategies to reduce disease burden.

OBJECTIVES

The aim of the present review was to describe the current status of diabetes care in Iran.

METHODS

A selective review of the relevant literature, focusing on properly conducted studies, describing past and present diabetes care strategies, policies, and outcomes in Iran was performed.

FINDINGS

The quality of diabetes care has gradually improved as suggested by a reduction in the proportion of undiagnosed patients and an increase in affordability of diabetes medications. The National Program for Prevention and Control of Diabetes has proven successful at identifying high-risk individuals, particularly in rural and remote-access areas. Unfortunately, the rising tide of diabetes is outpacing these efforts by a considerable margin.

CONCLUSIONS

Substantial opportunities and challenges in the areas of prevention, diagnosis, and management of diabetes exist in Iran that need to be addressed to further improve the quality of care and clinical outcomes.

Low Levels of High-Density Lipoprotein Cholesterol Do Not Predict the Incidence of Type 2 Diabetes in an Iranian High-Risk Population: The Isfahan Diabetes Prevention Study

OBJECTIVES

To evaluate the ability of low-level fasting high-density lipoprotein cholesterol (HDLC) to predict the incidence of type 2 diabetes (T2D) in an Iranian high-risk population.

METHODS

Seven-year follow-up data (n = 1,775) in non-diabetic first-degree relatives (FDR) of consecutive patients with T2D aged 30-70 years were analyzed. The primary outcome was the diagnosis of T2D based on repeated oral glucose tolerance test (OGTT). We used Cox proportional hazard models to estimate the hazard ratio (HR) for the incidence of T2D across quartiles of HDLC, and plotted a receiver operating characteristic (ROC) curve to assess discrimination.

RESULTS

The highest quartile compared with the lowest quartile of HDLC was associated with T2D in age- and gender-adjusted models (HR: 0.83, 95% CI: 0.73-0.95). Further adjustment for fasting plasma glucose and cholesterol attenuated the association for T2D incidence (HR: 0.93, 95% CI: 0.80-1.08). The area under the ROC curve for HDLC was 54.1% (95% CI: 50.2-58.0).

CONCLUSIONS

HDLC level was a weak predictor of T2D in an Iranian high-risk population, independent of age and gender.

Utility of serum lipid ratios for predicting incident type 2 diabetes: the Isfahan Diabetes Prevention Study

BACKGROUND

In this study, we evaluate the association between triglyceride to high-density lipoprotein cholesterol (TG/HDL) ratio and total cholesterol (TC) to HDL (TC/HDL) ratio and the risks of type 2 diabetes (T2D) in an Iranian high-risk population.

METHODS

We analysed 7-year follow-up data (n = 1771) in non-diabetic first-degree relatives of consecutive patients with T2D 30-70 years old. The primary outcome was the diagnosis of T2D based on repeated oral glucose tolerance tests. We used Cox proportional hazard models to estimate hazard ratio for incident T2D across tertiles of TG/HDL and TC/HDL ratios and plotted a receiver operating characteristic (ROC) curve to assess discrimination.

RESULTS

The highest tertile of TG/HDL and TC/HDL ratios compared with the lowest tertile was not associated with T2D in age- and gender-adjusted models (HR 0.99, 95% CI: 0.88, 1.11 for TG/HDL ratio and 1.10, 95% CI: 0.97, 1.23 for TC/HDL ratio). Further adjustment for waist circumference or body mass index, fasting plasma glucose, and low-density lipoprotein cholesterol did not appreciably alter the hazard ratio compared with the age- and gender-adjusted model. The area under the ROC curve for TG/HDL ratio was 57.7% (95% CI: 54.0, 61.5) and for TC/HDL ratio was 55.1% (95% CI: 51.2, 59.0).

CONCLUSIONS

TG/HDL and TC/HDL ratios were not robust predictors of T2D in high-risk individuals in Iran. Copyright © 2015 John Wiley & Sons, Ltd.

The Visceral Adiposity Index in Comparison with Easily Measurable Anthropometric Markers Did Not Improve Prediction of Diabetes

OBJECTIVES

We evaluated the ability of the visceral adiposity index (VAI) compared to hypertriglyceridemic-waist (HTGW) phenotype, body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR) and waist-to-hip ratio (WHR) as a possible predictor of diabetes in a nondiabetic high-risk population.

METHODS

We analyzed 7-year follow-up data in nondiabetic first-degree relatives of consecutive patients 30 to 70 years of age with type 2 diabetes and with at least 1 follow-up examination (N=1720). The primary outcome was the diagnosis of type 2 diabetes based on repeated oral glucose tolerance tests. We examined the incidence of type 2 diabetes across quintiles of the VAI and plotted a receiver operating characteristic (ROC) curve to compare the abilities of predicting type 2 diabetes of the VAI, BMI, WC, WHR and WHtR.

RESULTS

The highest quintile of VAI compared with the lowest quintile was associated with type 2 diabetes in age- and gender-adjusted models (OR 2.45; 95% CI 1.56, 3.86). Those with the HTGW phenotype were 2.36 times (OR 2.36; 95% CI: 161, 3.44) more likely to develop type 2 diabetes than those with normal WCs and normal triglyceride levels. On ROC curve analysis, almost similar areas under the ROC were found for BMIs (60.9%; 95% CI: 57.1, 64.6); WC (61.0%, 95% CI 57.4, 64.5); WHtR (62.6%; 95% CI: 59.1, 66.2); WHR (55.7%; 95% CI 52.2, 59.3) and VAI (58.3%; 95% CI: 54.5, 62.1).

CONCLUSIONS

These data provide further evidence that VAI and HTGW are robust predictors of type 2 diabetes, but the predictive power was similar to that of BMI, WC, WHtR and WHR in our study population.

Utility of hypertriglyceridemic waist phenotype for predicting incident type 2 diabetes: The Isfahan Diabetes Prevention Study

Aim/Introduction

We evaluated the association between hypertriglyceridemic waist (HTW) phenotype and the risks of type 2 diabetes in an Iranian high‐risk population.

Materials and Methods

We analyzed 7‐year follow‐up data (n = 1,865) in non‐diabetic first‐degree relatives of consecutive patients with type 2 diabetes aged 30–70 years. The primary outcome was the diagnosis of type 2 diabetes based on repeated oral glucose tolerance tests. We used multiple logistic regressions to estimate the odds ratio (OR) for incident type 2 diabetes across four groups according to baseline fasting serum triglycerides (TG) level and waist circumference (WC): normal WC and normal TG, normal WC and high TG, enlarged WC and normal TG, and HTW (enlarged WC high TG).

Results

The HTW phenotype at baseline was associated with the incidence of type 2 diabetes. Those with HTW were 2.4‐fold (OR 2.36, 95% confidence interval 1.61–3.44), those with normal WC high TG were 1.9‐fold (OR 1.87, 95% confidence interval 1.29–2.70) and those with enlarged WC but normal TG were 2.8‐fold (OR 2.84, 95% confidence interval 1.96–4.13) more likely to develop type 2 diabetes than those with normal WC and normal TG.

Conclusions

These data provide further evidence that the HTW phenotype is a robust predictor of type 2 diabetes in high‐risk individuals in Iran, and the predictive power is not higher than that of simple enlarged WC and normal TG, emphasizing the importance of enlarged WC to the development of type 2 diabetes.

The product of triglycerides and glucose in comparison with fasting plasma glucose did not improve diabetes prediction

AIMS

Previous study has reported that triglycerides-glucose (TyG) index, a product of triglycerides and fasting plasma glucose (FPG), might be useful in the prediction of incident type 2 diabetes (T2D). We evaluated the ability of the TyG index compared to FPG and OGTT as possible diabetes predictor in nondiabetic first-degree relatives (FDRs) of patients with T2D.

METHODS

A total of 1,488 FDRs without diabetes of consecutive patients with T2D 30-70 years old (361 men and 1,127 women) were examined and followed for a mean (SD) of 6.9 (1.7) years for diabetes incidence. We examined the incidence of diabetes across quartiles of the TyG index and plotted a receiver operating characteristic (ROC) curve to assess discrimination. At baseline and through follow-up, participants underwent a standard 75-g two-hour oral glucose tolerance test.

RESULTS

During 10,124 person-years of follow-up, 41 men and 154 women developed T2D. Those in the top quartile of TyG index were 3.4 times more likely to develop T2D than those in the bottom quartile (odds ratio 3.36; 95 % CI 1.83, 6.19). On ROC curve analysis, a higher area under the ROC was found for FPG (76.2; 95 % CI 71.9, 80.6), 1-hPG (81.0, 95 % CI 77.2, 84.9) and 2-hPG (76.5; 95 % CI 72.3, 80.8) than for TyG index (65.1; 95 % CI 60.5, 69.7).

CONCLUSIONS

TyG index is predicted T2D in high-risk individuals in Iran but FPG, 1-hPG and 2-hPG appeared to be more robust predictor of T2D in our study population.

Associations of hip circumference and height with incidence of type 2 diabetes: the Isfahan diabetes prevention study

The aim of this study was to determine the effects of hip circumference (HC) and height on diabetes incidence in non-diabetic first-degree relatives (FDRs) of patients with type 2 diabetes. A total of 1,092 (254 men and 838 women) non-diabetics FDRs ≥ 30 years old in 2003-2005 were followed through 2010 for the occurrence of type 2 diabetes. At baseline and through follow-ups, participants were underwent a standard 75 g 2-h oral glucose tolerance test. The incidence of type 2 diabetes was 17.0 (95% CI: 13.7, 20.2) (13.0 men and 18.1 women) per 1,000 person-year based on 6,015 person-years of follow-up. Height was inversely associated with diabetes incidence. The age-, gender-, and waist-adjusted relative risk (95% CI) of diabetes was 0.54 (0.31, 0.93) for highest quartile of height and 0.59 (0.25, 1.37) for highest quartile of HC compared with lowest quartile. These data indicate that height was inversely associated with diabetes incidence, independently of gender among FDRs of patients with type 2 diabetes.

1-Hour plasma glucose in obese youth

Adults with normal glucose tolerance (NGT) but exaggerated plasma glucose excursion at 1 h (1HPG) following the oral glucose tolerance test (OGTT) have significantly higher risk of developing impaired glucose tolerance (IGT) or diabetes. Aim of the study will be to characterize the metabolic phenotype of NGT obese youth according to values of 1HPG. To accomplish this aim, obese patients (N = 1,454; 761 men; 79 IGT; BMI z-score 2.56 ± 0.16 SDS; age 11 ± 0.7 years) from two data sets were analyzed. In all patients, empirical parameters of insulin metabolism were calculated in fasting condition and following an OGTT (1.75 mg of glucose per kilogram/body weight). Receiver-operating characteristic (ROC) analysis was performed in the first group (training set, N = 920) to establish the cutoff value of 1HPG best identifying IGT. The second set (validation set, N = 534) served to verify the goodness of the model and the identified cutoff values. 1HPG ≥ 132.5 mg/dl identified IGT with 80.8% sensitivity and 74.3% specificity in the training set (AUC 0.855, 95% CI 0.808-0.902, p < 0.0001), and 70.3% sensitivity and 80% specificity in the validation set (AUC 0.81, 95% CI 0.713-0.907, p < 0.0001), respectively. NGT patients with 1HPG ≥ 132.5 mg/dl had a metabolic phenotype (triglycerides, insulin action, and secretion) that was in between those of NGT patients with 1HPG below the threshold and IGT patients (p < 0.0001 for all the comparisons). 1HPG ≥ 132.5 mg/dl seems to be associated with increased metabolic risk in obese youth, identifying patients with lower insulin sensitivity, early secretion, and higher total insulin secretion than in obese mates with lower 1HPG.