Issues in Defining the Burden of Prediabetes Globally

Prediabetes in children and adolescents: An updated review

Prediabetes, the precursor of type 2 diabetes mellitus, is an intermediate stage between normal glucose homeostasis and overt diabetes. This asymptomatic metabolic state is increasingly prevalent in pediatric population and is very difficult to detect without appropriate screening. Studies have shown that a certain proportion of children with prediabetes will develop diabetes in a few years. Even more alarming is the evidence that youth-onset diabetes has a more aggressive clinical course with progressive beta-cell decline and accelerated end-organ damage. Despite its importance, several aspects involving prediabetes in childhood are disputed or unknown. This review presents the latest insights into this challenging entity and outlines a simplified screening approach to aid clinical practice. In summary, childhood prediabetes is an important clinical condition indicating the need for proper screening and timely intervention.

Data-driven subgroups of prediabetes and the associations with outcomes in Chinese adults

Prediabetes and its pathophysiology remain important issues. We aimed to examine the cluster characteristics of prediabetes and explore their associations with developing diabetes and its complications based on 12 variables representing body fat, glycemic measures, pancreatic β cell function, insulin resistance, blood lipids, and liver enzymes. A total of 55,777 individuals with prediabetes from the China Cardiometabolic Disease and Cancer Cohort (4C) were classified at baseline into six clusters. During a median of 3.1 years of follow-up, significant differences in the risks of diabetes and its complications between clusters were observed. The odds ratios of diabetes stepwisely increase from cluster 1 to cluster 6. Clusters 1, 4, and 6 have increased chronic kidney diseases risks, while the prediabetes in cluster 4, characterized by obesity and insulin resistance, confers higher risks of cardiovascular diseases compared with others. This subcategorization has potential value in developing more precise strategies for targeted prediabetes prevention and treatment.

Prevalence of prediabetes and association with cardiometabolic and renal factors. SIMETAP-PRED study

INTRODUCTION

Prediabetes is a major public health problem. The aims of the SIMETAP-PRED study were to determine the prevalence rates of prediabetes according to two diagnostic criteria, and to compare the association of cardiometabolic and renal risk factors between populations with and without prediabetes.

METHODS

Cross-sectional observational study conducted in Primary Care. Based random sample: 6,588 study subjects (response rate: 66%). Two diagnostic criteria for prediabetes were used: 1) prediabetes according to the Spanish Diabetes Society (PRED-SDS): Fasting plasma glucose (FPG) 110-125mg/dL or HbA1c 6.0% -6.4%; 2) prediabetes according to the American Diabetes Association (PRED-ADA): FPG 100-125mg/dL or HbA1c 5.7%-6.4%. The crude and sex- and age-adjusted prevalence rates, and cardiometabolic and renal variables associated with prediabetes were assessed.

RESULTS

The crude prevalence rates of PRED-SDS and PRED-ADA were 7.9% (95% CI 7.3-8.6%), and 22.0% (95% CI 21.0-23.0%) respectively, their age-adjusted prevalence rates were 6.6% and 19.1 respectively. The high or very high cardiovascular risk of the PRED-SDS or PRED-ADA populations were 68.6% (95%CI 64.5-72.6%) and 61.7% (95%CI 59.1-64.1%) respectively. Hypertension, hypertriglyceridemia, overweight, obesity, and increased waist-to-height ratio were independently associated with PRED-SDS. In addition to these factors, low glomerular filtration rate and hypercholesterolemia were also independently associated with PRED-ADA.

CONCLUSIONS

The prevalence of PRED-ADA triples that of PRED-SDS. Two thirds of the population with prediabetes had a high cardiovascular risk. Several cardiometabolic and renal risk factors were associated with prediabetes. Compared to the SDS criteria, the ADA criteria make the diagnosis of prediabetes easier.

Factors associated with progression of different prediabetic status to Diabetes: A Community-based cohort study

AIMS

To examine the predictive factors associated with the progression of different prediabetic status to diabetes.

METHODS

A two-year retrospective cohort study was conducted on 5741 participants aged 40 years or older. Finally, 1685 participants with prediabetes defined by IFG (impaired fasting glucose), IGT (impaired glucose tolerance) and CGI (combined IFG and IGT) were included. Logistic regression model was used to evaluate the risk of prediabetes progression to diabetes.

RESULTS

Of the 1685 subjects with prediabetes at baseline, 212 (12.6%) subjects progressed to diabetes and 1473 (87.4%) subjects did not. Logistic regression analysis demonstrated that people with CGI were associated with an increased risk of progressing to diabetes compared to those with IFG (OR, 95% CI: 3.127, 2.047-4.776). Moreover, males, obese people, people with increased BMI and WHR (Waist/ Hip ratio), and hypertension were positively associated with the progression to diabetes, while HOMA-β was negatively associated with the progression to diabetes.

CONCLUSIONS

Subjects with CGI are prone to progressed to diabetes compared to those with IFG or IGT in middle-aged and older person in China. More attention should be paid to male and obese prediabetic subjects, and measures should be taken to control the increase in their BMI and WHR.

Hemoglobin A1c in combination with fasting plasma glucose trumps fasting plasma glucose alone as predictive indicators for diabetes mellitus: an ambidirectional cohort study of Thai people with impaired fasting glucose

INTRODUCTION

This ambidirectional cohort study aimed to assess the performance of combining hemoglobin A1c (HbA1c) to fasting plasma glucose (FPG) for estimation of progression rate to diabetes mellitus (DM) and to explore the risk factors of DM in patients with impaired fasting glucose (IFG).

RESEARCH DESIGN AND METHODS

Patients with IFG were eligible for this study. IFG was defined as FPG of 100-125 mg/dL. Progression rates to DM were estimated using Kaplan-Meier analysis. Risk factors of DM were explored by Cox regression analysis.

RESULTS

3011 patients were enrolled with median follow-up time of 8 years (range: 6 months-29 years). Progression rates to DM in patients with FPG 100-109 mg/dL and 110-125 mg/dL were 2.64 and 4.79 per 100 person-years. After adjusting covariables, compared with patients with FPG 100-109 mg/dL plus normal HbA1c (<5.7%), hazard ratios (95% CI) of patients with FPG 110-125 plus normal HbA1c, FBG 100-109 plus abnormal HbA1c (5.7%-6.49%), and FPG 110-125 plus abnormal HbA1c were 5.89 (2.37 to 14.63), 16.30 (8.59 to 30.92), and 33.84 (16.41 to 69.78), respectively. Body mass index ≥27.5 kg/m², serum triglyceride level ≥150 mg/dL, family history of DM, and low level of high-density lipoprotein-cholesterol were independently associated with risk of DM in patients with IFG.

CONCLUSIONS

Patients with both IFG and abnormal HbA1c had higher risk of DM than patients with IFG alone. Therefore, performing HbA1c in combination with FPG helps to identify subgroups of people with IFG at highest risk of DM. These patients should have the highest priority in diabetes prevention programs, especially in countries with low and limited resources.

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.

Reversion from prediabetes to normoglycaemia after weight change in older persons: The KORA F4/FF4 study

BACKGROUND AND AIMS

In a non-interventional study of older persons, we assessed the impact of changes in BMI and waist circumference (WC) on reversion from glucose- and HbA1c-defined prediabetes to normoglycaemia (in short: reversion) and on persistence of normoglycaemia. Moreover, we studied whether reversion reduced cardiovascular risk.

METHODS AND RESULTS

From the population-based KORA S4/F4/FF4 cohort study conducted in Southern Germany, we utilized data from the second and third visit to the study center (median follow-up 6.5 years). We used two overlapping data sets, one with 563 persons with HbA1c<6.5% (mean age 69 years, 51.5% men), one with 510 persons with glucose-based prediabetes or normal glucose tolerance. We calculated proportions of reversion, and estimated adjusted relative risks for the association between initial BMI/WC and change of BMI/WC, respectively, and reversion (and persistence of normoglycaemia, respectively). We estimated 10-year cardiovascular risks using the Framingham 2008 score. Overall, 27.3% of persons with HbA1c-defined prediabetes and 9.2% of persons with glucose-based prediabetes returned to normoglycaemia during follow-up. Lower initial BMI/WC and reduction of BMI/WC were associated with larger probabilities of returning to normoglycaemia (e.g., for HbA1c 5.7-6.4%, RR = 1.24 (95% CI: 1.09-1.41) per 1 kg/m² decline of BMI). Moreover, reduction of BMI/WC increased probabilities of maintaining normoglycaemia (e.g., for glucose-based prediabetes, RR = 1.09 (1.02-1.16) per 1 kg/m² decline of BMI). 10-year cardiovascular risk was 5.6 (1.7-9.6) percentage points lower after reversion from glucose-based prediabetes to normoglycaemia.

CONCLUSION

In older adults, even moderate weight reduction contributes to reversion from prediabetes to normoglycaemia and to maintaining normoglycaemia.

Associations between haemoglobin A1c and mortality rate in the KORA S4 and the Heinz Nixdorf Recall population-based cohort studies

BACKGROUND

There is limited knowledge about mortality risk in persons with increased haemoglobin A_1c (HbA_1c ) levels below the diabetes threshold. Moreover, little is known about how associations between increased HbA_1c and mortality depend on the length of follow-up. Therefore, we studied associations between HbA_1c and mortality over long-term follow-up in persons with and without known diabetes.

METHODS

We used data from two German population-based cohort studies: KORA S4 Study (Southern Germany, n = 1458, baseline visits in 1999 to 2001, baseline age 55 to 74 years, mortality follow-up 16.8 years) and Heinz Nixdorf Recall (HNR) Study (Ruhr area, n = 4613, baseline visits in 2000 to 2003, baseline age 45 to 75 years, mortality follow-up 17.8 years). Adjusted log-linear models were fitted to estimate relative risks (RRs) with 95% confidence intervals (CI).

RESULTS

In both cohorts, participants with HbA_1c 39 to 41 mmol/mol (5.7%-5.9%) and HbA_1c 42 to 46 mmol/mol (6.0% to 6.4%) did not have a larger overall mortality risk than participants with HbA_1c  < 39 mmol/mol (5.7%): the corresponding adjusted RRs were 1.00 (95% CI: 0.83-1.21) and 1.01 (0.80-1.27) in KORA and 0.99 (0.82-1.21) and 0.83 (0.65-1.07) in the HNR Study. For the pooled cohorts, the RR for HbA_1c 39 to 46 mmol/mol (5.7%-6.4%) was 0.96 (0.85-1.07). Associations between newly detected diabetes (HbA_1c  ≥ 6.5%) and mortality were weak after 4 and 8 years of follow-up, but were stronger after 12 years of follow-up, whereas associations between previously known diabetes (baseline) and mortality decreased.

CONCLUSIONS

HbA_1c -defined pre-diabetes is not associated with overall mortality. For newly detected and previously known diabetes, mortality risks vary with length of follow-up.

The risk of hip fractures in individuals over 50 years old with prediabetes and type 2 diabetes - A longitudinal nationwide population-based study

BACKGROUND

The present study aimed to investigate the association between type 2 diabetes mellitus (T2DM) and hip fractures using a large-scale nationwide population-based cohort that is representative of the Republic of Korea. We determined the risks of hip fractures in individuals with prediabetes and T2DM with different diabetes durations, and compared them with the risks of hip fractures in individuals without T2DM.

METHODS

A total of 5,761,785 subjects over 50 years old who underwent the National Health Insurance Service medical checkup in 2009-2010 were included. Subjects were classified into 5 groups based on the diabetes status; Normal, Prediabetes, Newly-diagnosed T2DM, T2DM less than 5 years, and T2DM more than 5 years. They were followed from the date of the medical checkup to the end of 2016. The endpoint was a new development of hip fracture during follow-up. The hazard ratios (HRs) and 95% confidence intervals (CIs) of hip fractures for each group were analyzed using Cox proportional hazard regression models after adjusting for age, sex, smoking, alcohol drinking, regular exercise, body mass index, hypertension, dyslipidemia, and chronic kidney disease.

RESULTS

The HRs of hip fractures were 1 in the Normal group, 1.032 (95% CI: 1.009, 1.056) in the Prediabetes group, 1.168 (95% CI: 1.113, 1.225) in the Newly-diagnosed T2DM2, 1.543 (95% CI: 1.495, 1.592) in the T2DM less than 5 years and 2.105 (95% CI: 2.054, 2.157) in the T2DM more than 5 years. The secular trend of the HRs of hip fractures according to the duration of T2DM was statistically significant (P < .001). Subgroup analyses also showed the same increasing pattern of the HRs of hip fractures according to the duration of T2DM in both sexes and all age groups (50-64 years, 65-74 years, over 75 years).

CONCLUSIONS

In summary, this large-scale, retrospective, longitudinal, nationwide population-based cohort study of 5,761,785 subjects demonstrated that the risks of hip fractures started to increase in prediabetes and was associated linearly with the duration of T2DM. The secular trend of risks of hip fractures according to the duration of T2DM was consistent in both sexes and all age groups.

Intermediate hyperglycaemia to predict progression to type 2 diabetes (ELSA-Brasil): an occupational cohort study in Brazil

BACKGROUND

The burden of diabetes is increasing worldwide and diabetes can be prevented with intervention in people with impaired glucose tolerance (IGT). Intermediate hyperglycaemia defined without an oral glucose tolerance test as impaired fasting glucose (IFG) and high HbA_1c are also used to characterise risk. We aimed to assess the prognostic properties of five definitions of intermediate hyperglycaemia (also known as prediabetes) on the basis of their ability to predict who will progress to diabetes.

METHODS

The Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) is an occupational cohort study of active or retired civil servants, aged 35-74 years, recruited from public universities and research institutes in six state capital cities in Brazil. We excluded participants who provided insufficient information to ascertain diabetes status, those without information on relevant covariates, and those with diabetes. We classified type 2 diabetes on the basis of self-report, medication use, measures of fasting plasma glucose (FPG), 2 h plasma glucose, and HbA_1c. We used five laboratory definitions of intermediate hyperglycaemia: IGT (2 h plasma glucose ≥7·8 mmol/L [≥140 mg/dL]); IFG based on American Diabetes Association (ADA) criteria (FPG ≥5·5 mmol/L [≥100 mg/dL]); IFG based on WHO criteria (FPG ≥6·1 mmol/L [≥110 mg/dL]); HbA_1c based on ADA criteria (HbA_1c ≥39 mmol/mol [5·7%]); and HbA_1c based on International Expert Committee criteria, IEC-HbA_1c, (HbA_1c ≥42 mmol/mol [6·0%]). We estimated risk of each definition using Cox regression and overall predictability (area under the receiver operating characteristic curve [AUC]) using logistic regression.

FINDINGS

We recruited 15 105 participants from Aug 18, 2008, to Dec 20, 2010, and followed up for a mean of 3·7 (SD 0·63) years. Diabetes incidence rate was 2·0 per 100 person-years (95% CI 1·8-2·1). Among the 11 199 eligible participants, 6563 (59%) presented with some form of intermediate hyperglycaemia. ADA-IFG (4870/11 199 [43·5%), IEC-HbA_1c (1005 [9·0%]), and ADA-HbA_1c (2299 [20·5%]) poorly predicted diabetes (3·5-3·6 per 100 person-years). WHO-IFG (1140 [10·2%]) and IGT (2245 [20·0%]) predicted greater conversion (7·5 per 100 person-years and 5·8 per 100 person-years, respectively). All definitions presented either low sensitivity or specificity. Combinations of tests improved prognostic properties, with the combination of IGT or WHO-IFG showing the best, but still insufficient, predictability (sensitivity 67·7%, 95% CI 64·5-70·1; specificity 77·9%, 77·1-78·7). The AUC for the three underlying glycaemic tests was 65·0% (95% CI 63·0-66·9) for HbA_1c, 74·6% (72·7-76·4) for FPG, and 77·1% (75·4-78·8) for 2 h plasma glucose, whereas the AUC for a score composed of clinical information was 71·6% (69·8-73·3). When this score was combined with results of an oral glucose tolerance test, the AUC reached 82·4% (80·9-83·9).

INTERPRETATION

IFG based on WHO criteria and IGT predict diabetes progression better than do the other three definitions of intermediate hyperglycaemia, but their sensitivity is low. IFG based on ADA criteria has better sensitivity than the others, but classifies almost half of adults as having intermediate hyperglycaemia and poorly predicts diabetes. Combining glycaemic results with clinical information improves prognostic properties of those at risk.

FUNDING

The Brazilian Ministry of Health (Science and Technology Department), the Brazilian Ministry of Science, Technology and Innovation (Financiadora de Estudos e Projetos and Conselho Nacional de Desenvolvimento Científico e Tecnológico), and the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior-Brasil (CAPES).