Cut-off values of fasting and post-load plasma glucose and HbA1c for predicting Type 2 diabetes in community-dwelling Japanese subjects: the Hisayama Study

The Risk Factors for Development of Type 2 Diabetes: Panasonic Cohort Study 4

(1) Background: As no study has evaluated the risk factors contributing to the development of type 2 diabetes according to body weight mass (BMI) categories in a large cohort and over a long period in a Japanese population, we aimed to assess them in 46,001 Japanese individuals; (2) Methods: This long-term retrospective cohort study included individuals who participated in a medical health checkup program at Panasonic Corporation from 2008 to 2018. In total, 3,208 participants developed type 2 diabetes. The BMI at 2008 were divided into 3 groups: BMI < 22 kg/m², 22 ≤ BMI < 25 kg/m², and BMI ≥ 25 kg/m² to evaluate the risk factors for type 2 diabetes; (3) Results: Cox regression analyses revealed that the significant risk factors were age, BMI, systolic blood pressure, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides, fasting plasma glucose, current smoking status, and alcohol consumption in populations with BMI ≥ 25.0 kg/m². The risk factors in the population with 22 ≤ BMI < 25 kg/m² were identical to that of BMI ≥ 25.0 kg/m² excluding systolic blood pressure, low-density lipoprotein cholesterol, and skipping breakfast. However, in the population with BMI < 22.0 kg/m², no association was found as to BMI, SBP, LDL cholesterol level, and triglycerides; (4) Conclusions: The risk factors for developing diabetes were quite different between the population with BMI < 22 kg/m² and the population with 22 ≤ BMI < 25 kg/m² or BMI ≥ 25 kg/m² in a Japanese population.

Awareness of diabetic retinopathy among diabetes mellitus patients visiting a hospital of North India

Context:

Diabetic retinopathy (DR) is a major cause of visual disability leading to irreversible blindness. Awareness of diabetes and its ocular co-morbidities may help in preventing vision loss.

Aim:

To assess the awareness of diabetic retinopathy among diabetic mellitus patients visiting a hospital in North India.

Setting and Design:

Cross-sectional study conducted at an outpatient clinic of ophthalmology department of a hospital.

Materials and Methods:

An interviewer-administered, pre-tested, semi-structured questionnaire was used to evaluate the awareness of DR for the period from July 2020 to January 2021.

Results:

A total of 272 patients with diabetes mellitus (44.4% females and 55.5% males) were included in the study. The mean age of the study population was 53.4 ± 10 years. Of the 272 patients, 79% were aware that diabetes can affect the eyes, and 69.5% knew that DR can lead to blindness. Regarding prevention and treatment of DR, 58.1% of patients were aware that good glycemic control prevents DR and 52.6% knew that DR can be treated. Physicians were the main source of information in 47.4% of patients. The participants were not compliant with a routine retinal assessment with only 26.5% of them having previous fundus examination for DR screening.

Conclusion:

Most of the participants were aware of DR but there existed major deficits in the knowledge and behavior of diabetic patients toward management of DR. There is a need to create awareness about DR and emphasize the importance of retinal screening to reduce visual disability caused by diabetes.

The association between the reduction of body weight and new-onset type 2 diabetes remission in middle-aged Japanese men: Population-based Panasonic cohort study 8

AIM

This study aimed to investigate the association between change in body weight (BW) and type 2 diabetes remission in Japanese men with new-onset type 2 diabetes.

METHODS

This study enrolled 1,903 patients with new-onset type 2 diabetes between 2008 and 2013 from a medical health checkup program conducted by the Panasonic Corporation, Osaka, Japan. The baseline was defined as the year of new-onset diabetes. We assessed the type 2 diabetes remission five years after baseline and the association between the change in BW and type 2 diabetes remission using logistic regression analyses. To evaluate the predictive performance of the change in BW, we employed the receiver operating characteristic curves and the area under the receiver operating characteristic (ROC) curve (AUC).

RESULTS

The BW loss was associated with type 2 diabetes remission in the participants with a BMI ≥25 kg/m² but not in the participants with a BMI <25 kg/m². The odds ratios were 1.96 (95% CI: 1.19-3.29) and 3.72 (95% CI: 2.14-6.59) in the participants with a loss of 5-9.9% and loss of ≥10% for five years, respectively, in the participants with a BMI ≥25 kg/m² (reference; stable group [0.9% gain to 0.9% loss]). The AUC and cut-off values for the rate of change in BW for type 2 diabetes remission were 0.59 and 5.0%.

DISCUSSION

Body weight loss of ≥5% effectively achieved diabetes remission in Japanese men with a BMI ≥25 kg/m² and new-onset type 2 diabetes.

Fasting plasma glucose level in the range of 90-99 mg/dL and the risk of the onset of type 2 diabetes: Population-based Panasonic cohort study 2

Aim/Introduction

As the association between a fasting glucose concentration of 90–99 mg/dL and the onset of type 2 diabetes is still controversial, we aimed to assess it in 37,148 Japanese individuals with a normal plasma glucose concentration.

Materials and Methods

This long‐term retrospective cohort study included individuals having a medical checkup at Panasonic Corporation from 2008 to 2018. In total, 1,028 participants developed type 2 diabetes.

Results

Cox regression analyses revealed that the risk for the onset of diabetes increased by 9.0% per 1 mg/dL increase in fasting plasma glucose concentration in subjects with the concentration ranging from 90 to 99 mg/dL. Compared with individuals with a fasting glucose concentration of ≤89 mg/dL, the adjusted hazard ratios for developing diabetes were 1.53 (95% CI; 1.22–1.91), 1.76 (95% CI; 1.41–2.18), 1.89 (95% CI; 1.52–2.35), 3.17 (95% CI; 2.61–3.84), and 3.41 (95% CI; 2.79–4.15) at fasting plasma glucose concentrations of 90–91, 92–93, 94–95, 96–97, and 98–99 mg/dL, respectively. In populations with obesity, the adjusted hazards ratios for developing diabetes were 1.56 (95% CI; 1.15–2.09), 1.82 (95% CI; 1.37–2.40), 2.05 (95% CI; 1.55–2.69), 3.53 (95% CI; 2.79–4.46), and 3.28 (95% CI; 2.53–4.22) at fasting plasma glucose concentrations of 90–91, 92–93, 94–95, 96–97, and 98–99 mg/dL, respectively.

Conclusions

This study demonstrates that the risk of type 2 diabetes among subjects having a fasting plasma glucose concentration of 90–99 mg/dL, is progressively higher with an increasing level of fasting plasma glucose concentration in a Japanese people.

Identifying Africans with undiagnosed diabetes: Fasting plasma glucose is similar to the hemoglobin A1C updated Atherosclerosis Risk in Communities diabetes prediction equation

AIMS

Seventy percent of Africans living with diabetes are undiagnosed. Identifying who should be referred for testing is critical. Therefore we evaluated the ability of the Atherosclerosis Risk in Communities (ARIC) diabetes prediction equation with A1C added (ARIC + A1C) to identify diabetes in 451 African-born blacks living in America (66% male; age 38 ± 10y (mean ± SD); BMI 27.5 ± 4.4 kg/m²).

METHODS

All participants denied a history of diabetes. OGTTs were performed. Diabetes diagnosis required 2-h glucose ≥200 mg/dL. The five non-invasive (Age, parent history of diabetes, waist circumference, height, systolic blood pressure) and four invasive variables (Fasting glucose (FPG), A1C, triglycerides (TG), HDL) were obtained. Four models were tested: Model-1: Full ARIC + A1C equation; Model-2: All five non-invasive variables with one invasive variable excluded at a time; Model-3: All five non-invasive variables with one invasive variable included at a time; Model-4: Each invasive variable singly. Area under the receiver operator characteristic curve (AROC) predicted diabetes. Youden Index identified optimal cut-points.

RESULTS

Diabetes occurred in 7% (30/451). Model-1, the full ARIC + A1C equation, AROC = 0.83. Model-2: With FPG excluded, AROC = 0.77 (P = 0.038), but when A1C, HDL or TG were excluded AROC remained unchanged. Model-3 with all non-invasive variables and FPG alone, AROC=0.87; but with A1C, TG or HDL included AROC declined to ≤0.76. Model-4: FPG as a single predictor, AROC = 0.87. A1C, TG, or HDL as single predictors all had AROC ≤ 0.74. Optimal cut-point for FPG was 100 mg/dL.

CONCLUSIONS

To detect diabetes, FPG performed as well as the nine-variable updated ARIC + A1C equation.

Comparing different definitions of prediabetes with subsequent risk of diabetes: an individual participant data meta-analysis involving 76 513 individuals and 8208 cases of incident diabetes

Objective

There are currently five widely used definition of prediabetes. We compared the ability of these to predict 5-year conversion to diabetes and investigated whether there were other cut-points identifying risk of progression to diabetes that may be more useful.

Research design and methods

We conducted an individual participant meta-analysis using longitudinal data included in the Obesity, Diabetes and Cardiovascular Disease Collaboration. Cox regression models were used to obtain study-specific HRs for incident diabetes associated with each prediabetes definition. Harrell's C-statistics were used to estimate how well each prediabetes definition discriminated 5-year risk of diabetes. Spline and receiver operating characteristic curve (ROC) analyses were used to identify alternative cut-points.

Results

Sixteen studies, with 76 513 participants and 8208 incident diabetes cases, were available. Compared with normoglycemia, current prediabetes definitions were associated with four to eight times higher diabetes risk (HRs (95% CIs): 3.78 (3.11 to 4.60) to 8.36 (4.88 to 14.33)) and all definitions discriminated 5-year diabetes risk with good accuracy (C-statistics 0.79-0.81). Cut-points identified through spline analysis were fasting plasma glucose (FPG) 5.1 mmol/L and glycated hemoglobin (HbA1c) 5.0% (31 mmol/mol) and cut-points identified through ROC analysis were FPG 5.6 mmol/L, 2-hour postload glucose 7.0 mmol/L and HbA1c 5.6% (38 mmol/mol).

Conclusions

In terms of identifying individuals at greatest risk of developing diabetes within 5 years, using prediabetes definitions that have lower values produced non-significant gain. Therefore, deciding which definition to use will ultimately depend on the goal for identifying individuals at risk of diabetes.

Association between locomotive syndrome and blood parameters in Japanese middle-aged and elderly individuals: a cross-sectional study

Background

Locomotive syndrome (LS) is associated with weakness and loss of function in the musculoskeletal organs. We aimed to determine the association between LS components and blood parameters in middle-aged and elderly individuals.

Methods

We included 223 middle-aged and elderly individuals in this study (104 men and 119 women; age: 40–85 years). All participants were asked to fast for at least 3 h before the venous blood samples were obtained and the hemoglobin, total protein, glycated hemoglobin (HbA1c), growth hormone, albumin and lipid profile were measured. Three functional tests, the stand-up test, the two-step test, and the 25-question geriatric locomotive function scale (GLFS) were used to assess the risk of LS. Walking speed was assessed by the 10-m walking test. Maximal isometric muscle strengths of the knee extensors were examined, and the weight bearing index (knee extension strength/body weight) was calculated. To assess an independent association between blood parameters and LS, the area under the receiver operating characteristic curve analysis (area under the curve, sensitivity, and specificity) and a binary logistic regression analysis were performed with adjustment for age.

Results

Of the 223 subjects, 119 (53.3%) fulfilled the diagnostic criteria for LS (including a two-step test score < 1.3, difficulty with one-leg standing from 40 cm in the stand-up test, and a 25-question GLFS score ≥ 7). Increased levels of HbA1c were significant risk factors for LS with an OR of 2.62 (OR_95%CI = 1.43–4.80), as determined by a logistic regression analysis. Additionally, dehydroepiandrosterone-sulfate (DHEA-S) levels were significant only in the male subjects (OR = 0.992 [OR_95%CI = 0.986–0.998]), at a threshold of 88 (AUC; 0.70, sensitivity; 79.6%, specificity; 49.1%). Moreover, 101 of 223 participants (41 men, 60 women) were analyzed for serum albumin levels, with a prevalence of LS at 55.4%, indicating that low levels of albumin were significant risk factors for LS (OR = 0.148 [OR_95%CI = 0.023–0.954], p = 0.0445).

Conclusions

These results suggest that higher HbA1c and lower albumin are associated with the prevalence of LS in Japanese middle-aged and elderly individuals. Furthermore, low DHEA-S levels may be useful screening tools for LS in men.

Plasma glucose in screening for diabetes and pre-diabetes: how much is too much? Analysis of fasting plasma glucose and oral glucose tolerance test in Sri Lankans

BACKGROUND

Fasting plasma glucose (FPG) is the most commonly used screening tool for diabetes in Sri Lanka. Cut-off values from American Diabetes Association recommendations are adopted in the absence of local data. We aimed to establish FPG cut offs for Sri Lankans to screen for diabetes and pre-diabetes.

METHODS

Data on FPG and diabetes/pre-diabetes status were obtained from Sri Lanka Diabetes and Cardiovascular Study (SLDCS), a community based island wide observational study conducted in 2005-6. Sensitivity specificity and area under the ROC curve were calculated for different FPG values.

RESULTS

Study included 4014 community dwelling people after excluding people already on treatment for diabetes or pre-diabetes. Mean age was 45.3 (± 15) years and 60.4% were females. FPG cut off of 5.3 mmol/L showed better sensitivity and specificity than 5.6 mmol/L in detecting diabetes (87.8% and 84.4% Vs 80.8% and 92.1%) and pre-diabetes (54.7% and 87.0% Vs 43.8% and 94.2%).

CONCLUSIONS

A lower FPG cut off of 5.3 mmol/L has a better sensitivity and acceptable specificity in screening for diabetes and pre-diabetes in Sri Lankan adults.

The risk of type 2 diabetes mellitus according to 2-h plasma glucose level: The Korean Genome and Epidemiology Study (KoGES)

BACKGROUND

Although impaired glucose tolerance (IGT) is a definite risk factor for type 2 diabetes mellitus (T2DM), there is limited information about the risk stratification for incident T2DM within IGT group. Thus, we aimed to evaluate the incidental risk for T2DM according to 2-h plasma glucose (2-h PG) level of oral glucose tolerance test (OGTT) and phenotype of IGT.

METHODS

7654 Korean participated in the Korean Genome and Epidemiology Study (KoGES) were stratified by 2-h PG levels of OGTT, and followed up for 63,665 person-years. Cox proportional hazards model was used to calculate the hazard ratios (HRs) and 95% confidential interval (CI) for T2DM according to 2-h PG levels of OGTT with adjustment for multiple covariates. Subgroup analysis was performed by gender and the presence of impaired fasting glucose (IFG) or not.

RESULTS

Within IGT, the adjusted HRs for T2DM significantly increased proportionally to 2-h PG level [<140mg/dL: reference, 140-159mg/dL: 3.07 (2.67-3.54), 160-179mg/dL: 5.44 (CI 4.66-6.34), 180-199mg/dL: 7.91 (CI 6.53-9.59)]. IGT combined with IFG had the profoundly increased HRs than isolated IFG. Even within normal glucose tolerance (NGT), 2-h PG level≥120mg/dL had the higher risk for T2DM than other NGT groups. These associations were more dominant in male than female.

CONCLUSION

The highest level of 2h-PG (180-199mg/dL) in IGT and IGT with IFG were strong predictor for T2DM. 2-h PG of 120-139mg/dL was more significantly associated with T2DM within NGT, and male was more susceptible for T2DM than female.

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 IFG_5.6 (FPG mmol/L 5.6 to 6.9 mmol/L or 100 mg/dL to 125 mg/dL), IFG_6.1 (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 (HbA1c_5.7: HbA1c 5.7% to 6.4% or 39 mmol/mol to 46 mmol/mol; HbA1c_6.0: 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 IFG_5.6, IFG_6.1, IGT and the combination of IFG/IGT increased with length of follow-up. Cumulative incidence was highest with IFG/IGT, followed by IGT, IFG_6.1 and IFG_5.6. Limited data showed a higher T2DM incidence associated with HbA1c_6.0 compared to HbA1c_5.7. 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: IFG_5.6: HR 4.32 (95% CI 2.61 to 7.12), 8 studies, 9017 participants; IFG_6.1: 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; HbA1c_5.7: HR 5.55 (95% CI 2.77 to 11.12), 4 studies, 5223 participants; HbA1c_6.0: 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.

Long-Term Risk of Hypertension in Normoglycemia and Prediabetes, and Their Relation to the Change of Glycemic State

BACKGROUND

Although increasing evidence has suggested the significant association between dysglycemia and hypertension, this association is less well described in prediabetes. Additionally, it is unclear how risk of hypertension varies according to the change of glycemic state.

METHODS

Five thousand four hundred thirteen nondiabetic Koreans were dichotomized into normoglycemia (NG) and prediabetes group and followed-up for 10 years. Cox proportional hazard model was used to evaluate hazard ratios (HRs) with 95% confidence interval (CI) [adjusted HRs (95% CI)] for the development of hypertension. Subgroup analysis was conducted in subdivided glycated hemoglobin (HbA1c) with <5.7%, 5.7-5.9%, and 6.0-6.4% and 2 hour post-load glucose (2 hr-PG) with <140, 140-169, and 170-199 mg/dl. The glycemic states are NG, prediabetes, and diabetes mellitus (DM), which are used in evaluating the change of glycemic state during follow-up in baseline NG (NG → NG, NG → prediabetes, and NG → DM) and baseline prediabetes (prediabetes → prediabetes and prediabetes → DM).

RESULTS

Compared with NG, prediabetes was not significantly associated with the risk of hypertension [1.11 (0.997-1.23)]. HbA1c ≥5.7% [1.13 (1.02-1.26)] and 2 hr-PG ≥140 mg/dl [1.15 (1.004-1.31)] were marginally associated with the risk of hypertension. In subgroup analysis, only 2 hr-PG of 170-199 mg/dl showed the significantly increased risk of hypertension [1.37 (1.09-1.73)]. Compared with the maintaining glycemic state, the progression of glycemic state had the significantly increased risk of hypertension [NG → prediabetes; 1.41 (1.19-1.67), NG→DM; 1.77 (1.36-2.30), and prediabetes → DM; 1.32 (1.13-1.55)].

CONCLUSION

The progression of glycemic state was a strong determinant on the development of hypertension.

Longitudinal follow up of dysglycemia in overweight and obese pediatric patients

OBJECTIVE

To examine factors related to progression of dysglycemia in overweight and obese youth in a large primary care setting.

RESEARCH DESIGN AND METHODS

10- to 18-year-old youth with body mass index (BMI) > 85 percentile and first-time A1c 5.7%-7.9% (39-63 mmol/mol) were identified retrospectively through electronic medical records (EMR). Levels of dysglycemia were defined as low-range prediabetes (LRPD; A1c 5.7%-5.9% [39-41 mmol/mol]), high-range prediabetes (HRPD; A1c 6.0%-6.4% [42-46 mmol/mol]), or diabetes-range (A1c 6.5%-7.9% [48 mmol/mol]). Follow-up A1c and BMI were extracted from the EMR. Follow up was truncated at the time of initiation of diabetes medication.

RESULTS

Of 11 000 youth, 547 were identified with baseline dysglycemia (mean age 14.5 ± 2.2 years, 70% Hispanic, 23% non-Hispanic Black, 7% other). Of these, 206 had LRPD, 282 HRPD, and 59 diabetes. Follow-up A1c was available in 420 (77%), with median follow up of 12-22 months depending on A1c category. At follow-up testing, the percent with diabetes-range A1c was 4% in youth with baseline LRPD, 8% in youth with baseline HRPD, and 33% in youth with baseline diabetes-range A1c. There was a linear association between BMI increase and worsening A1c for LRPD (P < .001) and HRPD (P = .003).

CONCLUSIONS

Most adolescents with an initial prediabetes or diabetes-range A1c did not have a diabetes-range A1c on follow up. Moreover, prediabetes-range A1c values do not all convey equal risk for the development of diabetes, with lower rates of progression for youth with initial A1c <6%. In youth with prediabetes-range A1c, BMI stabilization was associated with improvement of glycemia.

Associations of HbA1c and fasting plasma glucose with incident diabetes: Implications for pre-diabetes thresholds in a Japanese population

AIMS

This study assessed pre-diabetes (pre-DM) cutoffs for HbA1c and fasting plasma glucose (FPG) that were associated with an increased risk of incident DM.

METHODS

We evaluated 2267 non-diabetic Japanese health-check examinees (HbA1c: <6.5% [<48mmol/mol] and FPG: <7.0mmol/L) who were 30-79 years old and were followed-up for 5 years. Incident DM was defined as HbA1c of ≥6.5% (≥48mmol/mol), FPG of ≥7.0mmol/L, or physician-diagnosed DM.

RESULTS

During 11047 person-years, we identified 99 incident DM cases (4.3%). The incidence of DM increased with increasing baseline HbA1c or FPG levels, and the change points (95% confidence intervals) were 5.7% (5.6-5.7%; 39mmol/mol [38-39mmol/mol]) for HbA1c and 5.5mmol/L (5.5-5.6mmol/L) for FPG. The adjusted hazard ratios (HRs) for incident DM per one standard deviation-increase in HbA1c and FPG were 5.5 (4.4-6.8) and 4.0 (3.2-4.8), respectively. The adjusted HRs for incident DM were significantly higher at HbA1c of 5.7-6.4% (39-46mmol/mol) or FPG of 5.5-6.9mmol/L, compared to HbA1c of <5.7% (<39mmol/mol) or FPG of <5.5mmol/L.

CONCLUSION

The lower cut-offs for pre-DM may be 5.7% (39mmol/mol) for HbA1c and 5.5mmol/L for FPG in this Japanese population.

Cut-off points of homeostasis model assessment of insulin resistance, beta-cell function, and fasting serum insulin to identify future type 2 diabetes: Tehran Lipid and Glucose Study

AIMS

To determine cut-off points of homeostasis model assessment of insulin resistance (HOMA-IR), β-cell function (HOMA-B), insulin sensitivity (HOMA-S), and fasting insulin for identifying the subjects with type 2 diabetes mellitus (T2DM) in Iranian adults using data from a prospective population-based study.

METHODS

From participants of Tehran Lipid and Glucose Study, 4942 Iranian subjects, aged 20-86 years, were followed for incident T2DM. Fasting serum insulin was determined by the electrochemiluminescence immunoasaay. The associations between HOMA-IR, HOMA-B, HOMA-S, and fasting insulin and incident T2DM were evaluated using Cox proportional hazards models. The receiver operator characteristic curve analysis was used to determine the cut-off points of HOMA-IR, HOMA-B, HOMA-S, and fasting insulin.

RESULTS

After 9.2 year follow-up, 346 (7.0 %) incident cases of T2DM were identified; the risk-factor-adjusted hazard ratios for HOMA1-IR, HOMA2-IR, HOMA1-B, HOMA2-B, HOMA1-S, HOMA2-S, and insulin were 1.15, 1.70, 0.732, 0.997, 0.974, 0.986, and 1.01 in women and 1.37, 1.67, 0.588, 0.993, 0.986, 0.991, and 1.06 in men, respectively (all p < 0.05 except for HOMA2-B in women). Optimal cut-off points for HOMA1-IR, HOMA2-IR, HOMA1-B, HOMA2-B, HOMA1-S, HOMA2-S, and insulin were 1.85, 1.41, 86.2, 72.5, 54.1, 63.7, and 11.13 µU/ml in women and 2.17, 1.18, 67.1, 74.6, 46.1, 74.1, and 9.16 µU/ml in men, respectively.

CONCLUSIONS

HOMA-IR, HOMA-B (except for HOMA2-B in women), HOMA-S, and fasting insulin were independent predictors of T2DM. Optimal cut-off points of HOMA-IR, HOMA-B, HOMA-S, and fasting serum insulin were determined from a population-based study for identifying incident T2DM.

Diabetes mellitus: The epidemic of the century

The epidemic nature of diabetes mellitus in different regions is reviewed. The Middle East and North Africa region has the highest prevalence of diabetes in adults (10.9%) whereas, the Western Pacific region has the highest number of adults diagnosed with diabetes and has countries with the highest prevalence of diabetes (37.5%). Different classes of diabetes mellitus, type 1, type 2, gestational diabetes and other types of diabetes mellitus are compared in terms of diagnostic criteria, etiology and genetics. The molecular genetics of diabetes received extensive attention in recent years by many prominent investigators and research groups in the biomedical field. A large array of mutations and single nucleotide polymorphisms in genes that play a role in the various steps and pathways involved in glucose metabolism and the development, control and function of pancreatic cells at various levels are reviewed. The major advances in the molecular understanding of diabetes in relation to the different types of diabetes in comparison to the previous understanding in this field are briefly reviewed here. Despite the accumulation of extensive data at the molecular and cellular levels, the mechanism of diabetes development and complications are still not fully understood. Definitely, more extensive research is needed in this field that will eventually reflect on the ultimate objective to improve diagnoses, therapy and minimize the chance of chronic complications development.

Evaluation of glycated hemoglobin (HbA1c) for diagnosing type 2 diabetes and prediabetes among Palestinian Arab population

The purpose of the study is to compare the potential of HbA1c to diagnose diabetes among Palestinian Arabs compared to fasting plasma glucose (FPG). A cross-sectional sample of 1370 Palestinian men (468) and women (902) without known diabetes and above the age of 30 years were recruited. Whole blood was used to estimate HbA_1c and plasma for FPG and total lipid profile. Fasting plasma glucose was used as a reference to diagnose diabetes (≥ 126 mg/dL) and prediabetes (100–125 mg/dL). The area under the receiver operating characteristic curve (AUC) for HbA_1c was 81.9% to diagnose diabetes and 63.9% for prediabetes. The agreement between HbA_1c and diabetes as diagnosed by FPG was moderate (ĸ  =  0.498) and low with prediabetes (ĸ = 0.142). The optimal cut-off value for HbA1c to diagnose diabetes was ≥ 6.3% (45 mmol/mol). The sensitivity, specificity and the discriminant ability were 65.6% (53.1–76.3%), 94.5% (93.1–95.6%), 80.0% (72.8–87.3%), respectively. However, using cut-off value of ≥ 6.5% (48 mmol/mol) improved specificity. At this cut-off value, the sensitivity, specificity and the discriminant ability were 57.4% (44.9–69.0%), 97.1% (96.0–97.9%) and 77.3% (71.0–83.5%). For diagnosing prediabetes with HbA1c between 5.7–6.4% (39–46 mmol/mol), the sensitivity, specificity and the discriminant ability were 62.7% (57.1–67.9%), 56.3% (53.1–59.4%) and 59.5% (56.3–62.5%), respectively. HbA_1c at cut-off value of ≥ 6.5% (48 mmol/mol) by itself diagnosed 5.3% and 48.3% as having diabetes and prediabetes compared to 4.5% and 24.2% using FPG, respectively. Mean HbA_1c and FPG increase significantly with increasing body mass index. In conclusion, the ROC curves showed HbA1c could be used for diagnosing diabetes when compared to FPG but not for prediabetes in Palestinians Arabs even though only about 50% of the diabetic subjects were identified by the both HbA1c and FPG.

Use of high-normal levels of haemoglobin A(1C) and fasting plasma glucose for diabetes screening and for prediction: a meta-analysis

BACKGROUND

Using high-normal levels of haemoglobin A1C (Abnormal-A1C ) or fasting plasma glucose (FPG) (Abnormal-FPG) for diabetes screening are expected to improve the ability to detect persons with or at high risk of diabetes. We assessed the diagnostic and predictive capacity for diabetes of Abnormal-A1C and Abnormal-FPG. We compared these to the combined use of the two measures to the single use of either measurement.

METHODS

We analysed 31 eligible cross-sectional or cohort studies that assessed diagnostic or predictive ability, respectively, by using lower A1C and FPG cutoff values than recommended by current diabetes criteria. Positive and negative likelihood ratios (LR+ and LR-) were calculated to assess the ability to confirm or exclude diabetes, respectively, on the basis of a bivariate random-effects model.

RESULTS

With both Abnormal-A1C and Abnormal-FPG, the pooled LR+ was above 4 for diagnosing diabetes and above 3 for predicting diabetes. However, the pooled LR- for predicting diabetes was higher with Abnormal-A1C (0.48) and Abnormal-FPG (0.49) in comparison with that for diagnosing diabetes (0.27, Abnormal-A1C ; 0.28, Abnormal-FPG). In eight studies that assessed the predictive ability of the combination of A1C and FPG, using either Abnormal-A1C or Abnormal-FPG could lower LR- to 0.17 from 0.43 for only Abnormal-A1C and from 0.38 for only Abnormal-FPG. Accordingly, LR+ was also lowered to 2.37 from 3.36 for only Abnormal-A1C and from 3.84 for only-Abnormal-FPG.

CONCLUSION

The use of the two blood glucose tests had insufficient capacity to identify subjects at high risk for diabetes but had considerable capacity to identify undiagnosed diabetes.