Anthropometric predictors of incident type 2 diabetes mellitus in Iranian women

A 16-year prospective cohort study to evaluate effects of long-term fluctuations in obesity indices of prediabetics on the incidence of future diabetes

This study aimed to evaluate the patterns of changes in obesity indices over time in prediabetic subjects and to classify these subjects as either having a low, moderate, and high risk for developing diabetes in the future. This study was conducted among 1228 prediabetics. The patterns of changes in obesity indices based on three measurements including first, mean values during the follow-up period, and last visit from these indices were evaluated by using the latent Markov model (LMM). The mean (standard deviation) age of subjects was 44.0 (6.8) years and 73.6% of them were female. LMM identified three latent states of subjects in terms of change in all anthropometric indices: a low, moderate, and high tendency to progress diabetes with the state sizes (29%, 45%, and 26%), respectively. LMM showed that the probability of transitioning from a low to a moderate tendency to progress diabetes was higher than the other transition probabilities. Based on a long-term evaluation of patterns of changes in obesity indices, our results reemphasized the values of all five obesity indices in clinical settings for identifying high-risk prediabetic subjects for developing diabetes in future and the need for more effective obesity prevention strategies.

Effectiveness of Anthropometric Measurements for Identifying Diabetes and Prediabetes among Civil Servants in a Regional City of Northern Ethiopia: A Cross-Sectional Study

Methods

The study involved a cross-sectional survey carried out from October 2015 to February 2016 among 1504 subjects aged from 18 to 75 years of age. Receiver operating characteristic (ROC) was used to select the most effective anthropometric cut-off point among waist circumference, waist-to-hip ratio, waist-to-height ratio, and BMI for identifying prediabetic and diabetes. Statistical significance was declared at p value of ≤0.05.

Results

Waist circumference was found better for identifying diabetes (AUC = 0.69) and prediabetes (AUC = 0.63) in women, respectively. Waist-to-hip ratio was better identifying diabetes (AUC = 0.67) while waist circumference-to-height ratio was better identifying prediabetes (AUC = 0.63) in men compared to body mass index. The optimal cut-off point with maximum sensitivity and specificity of waist circumference for identifying diabetes and prediabetes was 83.5 cm and 82.9 cm in women, respectively. The optimal ut-off point with maximum sensitivity and specificity of waist-to-hip ratio for identifying diabetes and prediabetes was 0.97 and 0.82 in men, respectively.

Conclusion

Waist circumference and waist-to-hip ratio exhibited better discriminate performance than BMI for identifying prediabetes and diabetes in women and men, respectively.

A Novel Indicator of Children's Lipid Accumulation Product Associated with Impaired Fasting Glucose in Chinese Children and Adolescents

BACKGROUND

Diabetes is one of the most prevalent noncommunicable diseases worldwide. Children's lipid accumulation product (CLAP) is a novel indicator to show children's lipid accumulation and is effectively associated with metabolic syndrome among children and adolescents. The aim of the present study was to explore an association between CLAP and impaired fasting glucose (IFG) in Chinese children and adolescents.

METHODS

A total of 683 children and adolescents aged 8-15 years were recruited using the stratified cluster sampling method in this cross-sectional study and were measured for body height, weight, waist circumference (WC), abdominal skinfold thickness (AST), triglycerides (TG), fasting plasma glucose, dietary behaviors and physical activities. A logistic regression model and receiver operating characteristic (ROC) curve were used to compare the effects of CLAP for predicting IFG.

RESULTS

The prevalence of IFG in children and adolescents was 13.8%: 16.9% in boys and 10.1% in girls (P<0.05). The CLAP, height, weight, WC, AST, waist-to-height ratio (WHtR), and TG among boys with IFG were significantly higher than those among boys without IFG (P<0.05). The area under the ROC curve of CLAP for predicting IFG (0.637 (0.562-0.712)) was higher than those of WC, WHtR, AST, and TG. The cutoff point of P ₇₅ CLAP was the optimal value to predict IFG among boys, and the OR (95% CI) was 2.48 (1.40-4.42) and area under the ROC curve was 0.595 (0.513-0.676).

CONCLUSION

The CLAP was a novel indicator associated with IFG in Chinese boys, and it performed better than WC, WHtR, AST and TG.

Optimal cut-points of different anthropometric indices and their joint effect in prediction of type 2 diabetes: results of a cohort study

Background

To determine the anthropometric indices that would predict type 2 diabetes (T2D) and delineate their optimal cut-points.

Methods

In a cohort study, 7017 Iranian adults, aged 20–60 years, free of T2D at baseline were investigated. Using Cox proportional hazard models, hazard ratios (HRs) for incident T2D per 1 SD change in body mass index (BMI), waist circumference (WC), waist to height ratio (WHtR), waist to hip ratio (WHR), and hip circumference (HC) were calculated. The area under the receiver operating characteristics (ROC) curves (AUC) was calculated to compare the discriminative power of anthropometric variables for incident T2D. Cut-points of each index were estimated by the maximum value of Youden’s index and fixing the sensitivity at 75%. Using the derived cut-points, joint effects of BMI and other obesity indices on T2D hazard were assessed.

Results

During a median follow-up of 12 years, 354 men, and 490 women developed T2D. In both sexes, 1 SD increase in anthropometric variables showed significant association with incident T2D, except for HC in multivariate adjusted model in men. In both sexes, WHtR had the highest discriminatory power while HC had the lowest. The derived cut-points for BMI, WC, WHtR, WHR, and HC were 25.56 kg/m², 89 cm, 0.52, 0.91, and 96 cm in men and 27.12 kg/m², 87 cm, 0.56, 0.83, and 103 cm in women, respectively. Assessing joint effects of BMI and each of the obesity measures in the prediction of incident T2D showed that among both sexes, combined high values of obesity indices increase the specificity for the price of reduced sensitivity and positive predictive value.

Conclusions

Our derived cut-points differ between both sexes and are different from other ethnicities.

Electronic supplementary material

The online version of this article (10.1186/s12889-018-5611-6) contains supplementary material, which is available to authorized users.

Adiponectin gene variants and abdominal obesity in an Iranian population

INTRODUCTION

Waist-to-height ratio (WHtR) can be effective for the diagnosis of abdominal obesity and the risk of type 2 diabetes. The role of genetic factors in the development of obesity has been broadly recognized. Adiponectin's level is inversely correlated with body fat percentage and is reduced in obesity and type 2 diabetes. The aim of this study is to investigate the association between WHtR and adiponectin gene polymorphisms in Iranian population.

METHODS

This study was conducted on 610 subjects from two Iranian populations. Anthropometric characteristics were measured by routine methods. Blood samples were collected in tubes (3-5 mL) containing EDTA and were stored at 20 °C. After DNA extraction, genotyping was performed using PCR-RFLP technique.

RESULTS

There were statistically significant differences in genotype frequencies of -11391 G/A in centrally obese (WHtR >0.5) and noncentrally obese (WHtR ≤0.5) subjects (P value <0.044). In the former, the frequencies of GG and GA + AA genotypes were 89.4 and 10.6 %, respectively, while the frequencies of GG and GA + AA genotypes were 95.9 and 4.1 %, respectively, in noncentrally obese subjects.

CONCLUSIONS

The frequency of GG genotype was significantly increased in subjects with WHtR >0.5 compared to the other group. After adjustment for diabetes, abdominal obesity was significantly associated with the -11391 G/A polymorphism.

Is waist circumference a better predictor of diabetes than body mass index or waist-to-height ratio in Iranian adults?

Background:

Several measures of adiposity have been used for predicting diabetes. The results of studies regarding superiority of waist circumference (WC) to body mass index (BMI) are inconsistent. This study designed to compare the ability of different anthropometric measures in predicting diabetes and to determine their optimal cut-off values.

Methods:

A population-based cross-sectional study was conducted with 1,000 representative sample among adults aged 20–80 years in Babol, the Northern Iran. The demographic data were collected in a household survey, and the anthropometric measures of weight, height, waist, and hip circumference were measured with a standard method. Fasting blood sugar (FBS) ≥126 mg/dl was considered as diabetes. receiver operating characteristic analysis was used to estimate the predictive ability of different anthropometric indexes and their optimal cut-off values for high FBS.

Results:

The overall prevalence rate of diabetes was 14.0% (14.4% in men vs. 13.5% in women, P = 0.65). The prevalence rate was significantly higher in older age (>60 years), low educated and obese (P = 0.001). The mean of BMI, WC, waist-to-hip ratio (WHR), and waist-to-height ratio (WHtR) were significantly higher among diabetic in both sexes (P = 0.001). Among men, WC (area under the ROC curve [AUC] =0.64) and WHtR (AUC = 0.63) have slightly higher accuracy index compared with BMI (AUC = 0.62) or WHR (AUC = 0.60). In contrast, among women, WHtR (AUC = 0.69) and WC (AUC = 0.68) yielded slightly better predictive than BMI (AUC = 0.67). The optimal cut-off values obtained for BMI and WHtR were similar between two sexes (BMI = 24.95 kg/m² for men and BMI = 25.2 kg/m² for women, WHtR = 0.51 for both sexes) whereas the optimal cut-off value for WC was higher in men than women (98.5 cm men vs. 89.5 cm women).

Conclusions:

Overall WC and WHtR exhibited a slightly better discriminate performance than BMI for diabetes in both sexes, particularly in women.

Evidence Gap on the Prevalence of Non-conventional Risk Factors for Type 2 Diabetes in Iran

OBJECTIVES

Robust scientific evidence exists about the role of non-conventional risk factors in type 2 diabetes worldwide. The current epidemiological pattern of the disease in Iran suggests a precipitating role for these non-conventional risk factors. This review was performed to examine the research evidence suggesting a higher prevalence of non-conventional type 2 diabetes risk factors in Iran.

METHODS

MeSH keywords were applied to search several databases, including PUBMED, MEDLINE, AMED, EMBASE, Iran DOC, and the Scientific Information Database without a time limit from inception to September 2011. The quality of the non-interventional and population-based studies on Iranians included in these databases was assessed by the authors and any disagreement was resolved with consensus.

RESULTS

The literature search yielded 1847 publications, of which 62 were included in this study after eliminating non-relevant and overlapping papers. No study was found that verified a higher prevalence of the non-conventional type 2 diabetes risk factors in the Iranian population.

CONCLUSION

The identified evidence gap about the role of prominent non-conventional risk factors of type 2 diabetes in the Iranian population could be a major caveat in the application of an evidence-based approach to endorse or reject existing hypothesis about these risk factors. Studies on the prevalence of non-conventional biomarkers of type 2 diabetes among Iranians could be a promising area of research.

Prospective study of optimal obesity index cutoffs for predicting development of multiple metabolic risk factors: the Korean genome and epidemiology study

BACKGROUND

In this prospective cohort study, we estimated the risk of developing more than 1 metabolic risk factor, using different obesity indices. In addition, we investigated the relative usefulness of the obesity indices for predicting development of such risk factors and calculated optimal cutoffs for the obesity indices.

METHODS

The cohort comprised 10 038 representative residents of a small city and a rural county who were recruited in 2001-2002. Follow-up examinations were conducted every 2 years. Among the 3857 participants without metabolic syndrome at baseline, 1102 new cases occurred during the 6-year follow-up. Receiver operating characteristic (ROC) curves for the obesity indices were plotted to compare the usefulness of the obesity indices.

RESULTS

The numbers of new cases of multiple metabolic risk factors among people in the highest quintiles of body mass index (BMI), waist circumference (WC), waist-hip ratio (WHR), and waist-height ratio at the baseline examination were 2 to 3 times those in the lowest quintiles. The area under the ROC curve for WHR was significantly higher than that for BMI. The optimal BMI cutoff was 24 kg/m(2) in men and women, and the optimal WC cutoffs were 80 cm and 78 cm in men and women, respectively.

CONCLUSIONS

Both overall obesity and central obesity predicted risk of developing multiple metabolic risk factors, and WHR appeared to be a better discriminator than BMI. To prevent development of metabolic diseases among Koreans, it might be useful to lower the cutoff for abdominal obesity, as defined by WC.

Diabetes prediction, lipid accumulation product, and adiposity measures; 6-year follow-up: Tehran lipid and glucose study

Background

The body mass index (BMI) is the most commonly used marker for evaluating obesity related risks, however, central obesity measures have been proposed to be more informative. Lipid accumulation product (LAP) is an alternative continuous index of lipid accumulation, which is computed from waist circumference (WC, cm) and triglycerides (TGs, mmol/l): (WC-65) ×TG (men) and (WC-58) ×TG (women). We sought in this study to assess if LAP can outperform BMI, waist-to-height-ratio (WHtR), or waist-to-hip-ratio (WHpR) in identifying prevalent and predicting incident diabetes.

Results

The cross-sectional analyses were performed on a sample included 3,682 men and 4,989 women who were not pregnant, aged ≥ 20 years. According to the age (≥ 50 and <50 years) - and sex-specific analyses, odds ratios (ORs) of LAP for prevalent diabetes were higher than those of BMI, WHpR, or WHtR among women, after adjustment for mean arterial pressure and family history of diabetes. The OR of LAP in old men was lower than those of other adiposity measures; in young men, however, LAP was superior to BMI but identical to WHpR and WHtR in identifying prevalent diabetes. Except in young men, LAP showed highest area under the receiver operating characteristic curves (AROC) for prevalent diabetes (P for trend ≤ 0.005).

For longitudinal analyses, a total of 5,018 non-diabetic subjects were followed for ~6 years. The ORs of BMI, WHpR, and WHtR were the same as those of LAP in both sexes and across age groups; except in young men where LAP was superior to the BMI. AROCs of LAP were relatively the same as anthropometric adiposity measures.

Conclusions

LAP was a strong predictor of diabetes and in young individuals had better predictability than did BMI; it was, however, similar to WHpR and WHtR in prediction of incident diabetes.

San Antonio heart study diabetes prediction model applicable to a Middle Eastern population? Tehran glucose and lipid study

OBJECTIVES

To assess the validity of the San Antonio heart study (SAHS) diabetes prediction model in a large representative Iranian population.

METHODS

A risk function derived from data in the SAHS to predict the 7.5-year risk of diabetes, was tested for its ability to predict incident diabetes in 3,242 individuals aged >or=20 years. The performance or ability to accurately predict diabetes risk, of the SAHS function compared with the performance of risk functions developed specifically from the Tehran lipid and glucose study. Comparisons included goodness of fit, discrimination, and calibration.

RESULTS

The participants were followed for 6.3 years. The area under the receiver operating characteristic curve (AROC) for diabetes of SAHS model was 0.83 (95% CI 0.80-0.86). The model overestimated the risk of diabetes in TLGS population with the overall bias of 111%. After the recalibration, the model-predicted probability agreed well with the actual observed 6-year risk of diabetes.

DISCUSSION AND CONCLUSION

The American SAHS was a prediction model for diabetes with good discrimination in an Iranian target population after calibration.