Contributions of A1c, fasting plasma glucose, and 2-hour plasma glucose to prediabetes prevalence: NHANES 2011-2014

Prevalence, Trends, and Subsequent Outcomes of Prediabetes in the United States, 1999-2018

OBJECTIVE

To determine prevalence, trends, and subsequent outcomes of prediabetes defined by American Diabetes Association (ADA), World Health Organization (WHO), and International Expert Committee (IEC) criteria in the US between 1999 and 2018.

METHODS

Ten cycles of cross-sectional National Health and Nutrition Examination Survey data were included. Prediabetes was defined by ADA, WHO, and IEC criteria. Unadjusted or covariate adjusted prevalence and trends of prediabetes were estimated. Cox proportional regression model was performed to evaluate the association between prediabetes and all-cause, cardiovascular, or diabetes-related mortality.

RESULTS

Among the 59369 participants included (weighted mean age, 41.1 years; 48.7% male), the prevalence of prediabetes was 29.4% in ADA criteria, 16.3% in WHO criteria, and 5.0% in IEC criteria. The covariate adjusted prevalence of prediabetes defined by ADA criteria increased significantly in at least two folds from 15.6% in 1999-2002 to 37.3% in 2015-2018 (p < 0.001). Similar significant increased trends were observed in WHO and IEC criteria (p < 0.001). Compared with normal glycemia, prediabetes participants had higher adjusted risk of diabetes-related mortality irrespective of the criteria used (ADA: hazard ratio [HR] 9.11 [95% CI, 5.83-14.22]; WHO: HR 5.35 [95% CI, 3.01-9.51]; IEC: HR 9.64 [95% CI, 5.92-15.71]). No significant associations between prediabetes and all-cause or cardiovascular mortality were observed in the adjusted models.

CONCLUSIONS

In the US, approximately 1 in 3 individuals have prediabetes according to ADA criteria. The prevalence of prediabetes has shown a significant and more than twofold increase over the past two decades, posing an elevated risk of diabetes-related mortality, regardless of the criteria applied.

Reframing prediabetes: A call for better risk stratification and intervention

Prediabetes is an intermediate state of glucose homeostasis whereby plasma glucose concentrations are above normal but below the threshold of diagnosis for diabetes. Over the last several decades, criteria for prediabetes have changed as the cut points for normal glucose concentration and diagnosis of diabetes have shifted. Global consensus does not exist for prediabetes criteria; as a result, the clinical course and risk for type 2 diabetes vary. At present, we can identify individuals with prediabetes based on three glycemic tests (hemoglobin A1c, fasting plasma glucose, and 2-h plasma glucose during an oral glucose tolerance test). The majority of individuals diagnosed with prediabetes meet only one of these criteria. Meeting one, two, or all glycemic criteria changes risk for type 2 diabetes, but this information is not widely known and does not currently guide intervention strategies for individuals with prediabetes. This review summarizes current epidemiology, prognosis, and intervention strategies for individuals diagnosed with prediabetes and suggests a call for more precise risk stratification of individuals with prediabetes as elevated (one prediabetes criterion), high risk (two prediabetes criteria), and very high risk (three prediabetes criteria). In addition, the roles of oral glucose tolerance testing and continuous glucose monitoring in the diagnostic criteria for prediabetes need reassessment. Finally, we must reframe our goals for prediabetes and prioritize intensive interventions for those at high and very high risk for type 2 diabetes.

Total added sugar consumption is not significantly associated with risk for prediabetes among U.S. adults: National Health and Nutrition Examination Survey, 2013-2018

Prediabetes affects 38% of U.S. adults and is primarily linked to added sugars consumed from sugar-sweetened beverages. It is unclear if total dietary intake of added sugar also increases the risk for prediabetes. This study examined if total (g/day) and percent intakes of <10%, 10-15%, or >15% added sugar increase the odds for prediabetes in U.S. adults. A cross-sectional, secondary analysis using 2013-2018 NHANES data was conducted. This study included data from U.S. adults ≥ 20 years with normoglycemia (N = 2,154) and prediabetes (N = 3,152) with 1-2 days of dietary recall information. Prediabetes was defined as a hemoglobin A1c of 5.7%-6.4% or a fasting plasma glucose of 100-125 mg/dL. Survey-weighted logistic regression was used to estimate odds ratios of prediabetes based on usual intakes of added sugar (total and percent intakes) using the National Cancer Institute Method. Differences in prediabetes risk and total and percent intakes of added sugar were compared by race/ethnicity. The sample's total energy intake from added sugar was 13.9%. Total (unadjusted: OR: 1.01, 95% CI: .99-1.00, p = .26; adjusted: OR: 1.00, 95% CI: .99-1.00, p = .91) and percent intakes of added sugar (unadjusted [<10%: (ref); 10-15%: OR: .93, 95% CI: .77-1.12, p = .44; >15%: OR: 1.03, 95% CI: .82-1.28, p = .82] and adjusted [<10%: (ref); 10-15%: OR: .82, 95% CI: .65-1.04, p = .09; >15%: OR: .96, 95% CI: .74-1.24, p = .73]) were not significantly associated with an increased odds of prediabetes. Prediabetes risk did not differ by race/ethnicity for total (unadjusted model [p = .65]; adjusted model [p = .51]) or percent (unadjusted model [p = .21]; adjusted model [p = .11]) added sugar intakes. In adults ≥20 years with normoglycemia and prediabetes, total added sugar consumption did not significantly increase one's risk for prediabetes and risk estimates did not differ by race/ethnicity. Experimental studies should expand upon this work to confirm these findings.

Diagnosis and Management of Prediabetes: A Review

Importance

Prediabetes, an intermediate stage between normal glucose regulation and diabetes, affects 1 in 3 adults in the US and approximately 720 million individuals worldwide.

Observations

Prediabetes is defined by a fasting glucose level of 100 to 125 mg/dL, a glucose level of 140 to 199 mg/dL measured 2 hours after a 75-g oral glucose load, or glycated hemoglobin level (HbA1C) of 5.7% to 6.4% or 6.0% to 6.4%. In the US, approximately 10% of people with prediabetes progress to having diabetes each year. A meta-analysis found that prediabetes at baseline was associated with increased mortality and increased cardiovascular event rates (excess absolute risk, 7.36 per 10 000 person-years for mortality and 8.75 per 10 000 person-years for cardiovascular disease during 6.6 years). Intensive lifestyle modification, consisting of calorie restriction, increased physical activity (≥150 min/wk), self-monitoring, and motivational support, decreased the incidence of diabetes by 6.2 cases per 100 person-years during a 3-year period. Metformin decreased the risk of diabetes among individuals with prediabetes by 3.2 cases per 100 person-years during 3 years. Metformin is most effective for women with prior gestational diabetes and for individuals younger than 60 years with body mass index of 35 or greater, fasting plasma glucose level of 110 mg/dL or higher, or HbA1c level of 6.0% or higher.

Conclusions and Relevance

Prediabetes is associated with increased risk of diabetes, cardiovascular events, and mortality. First-line therapy for prediabetes is lifestyle modification that includes weight loss and exercise or metformin. Lifestyle modification is associated with a larger benefit than metformin.

Effect of maternal pregestational diabetes mellitus on congenital heart diseases

BACKGROUND

The increasing population of diabetes mellitus in adolescent girls and women of childbearing age contributes to a large number of pregnancies with maternal pregestational diabetes mellitus. Congenital heart diseases are a common adverse outcome in mothers with pregestational diabetes mellitus. However, there is little systematic information between maternal pregestational diabetes mellitus and congenital heart diseases in the offspring.

DATA SOURCES

Literature selection was performed in PubMed. One hundred and seven papers were cited in our review, including 36 clinical studies, 26 experimental studies, 31 reviews, eight meta-analysis articles, and six of other types.

RESULTS

Maternal pregestational diabetes mellitus poses a high risk of congenital heart diseases in the offspring and causes variety of phenotypes of congenital heart diseases. Factors such as persistent maternal hyperglycemia, oxidative stress, polymorphism of uncoupling protein 2, polymorphism of adiponectin gene, Notch 1 pathway, Nkx2.5 disorders, dysregulation of the hypoxia-inducible factor 1, and viral etiologies are associated with the occurrence of congenital heart diseases in the offspring of mothers with pregestational diabetes mellitus. Treatment options including blood sugar-reducing, anti-oxidative stress drug supplements and exercise can help to prevent maternal pregestational diabetes mellitus from inducing congenital heart diseases.

CONCLUSIONS

Our review contributes to a better understanding of the association between maternal pregestational diabetes mellitus and congenital heart diseases in the offspring and to a profound thought of the mechanism, preventive and therapeutic measurements of congenital heart diseases caused by maternal pregestational diabetes mellitus.

Serum glycolipids mediate the relationship of urinary bisphenols with NAFLD: analysis of a population-based, cross-sectional study

BACKGROUND

Bisphenol A (BPA) and its substitutes bisphenol S (BPS) and bisphenol F (BPF) are endocrine-disrupting chemicals widely used in consumer products, which have been proposed to induce various human diseases. In western countries, one of the most common liver diseases is non-alcoholic fatty liver disease (NAFLD). However, studies on the associations of the three bisphenols with NAFLD in human beings are scarce.

METHODS

We included 960 participants aged ≥ 20 years from the NHANES 2013-16 who had available data on levels of urinary BPA, BPS and BPF. The hepatic steatosis index (HSI) > 36 was used to predict NAFLD. Logistic regression analysis and mediation effect analysis were used to evaluate the associations among bisphenols, glycolipid-related markers and NAFLD.

RESULTS

A total of 540 individuals (56.3%) were diagnosed with NAFLD, who had higher concentrations of BPA and BPS but not BPF than those without NAFLD. An increasing trend in NAFLD risks and HSI levels was observed among BPA and BPS tertiles (p for trend < 0.05). After adjustment for confounders, elevated levels of BPA or BPS but not BPF were significantly associated with NAFLD. The odds ratio for NAFLD was 1.581 (95% confidence intervals [CI]: 1.1-2.274, p = 0.013) comparing the highest with the lowest tertile of BPA and 1.799 (95%CI: 1.2462.597, p = 0.002) for BPS. Mediation effect analysis indicated that serum high-density lipoprotein cholesterol and glucose had a mediating effect on the relationships between bisphenols and NAFLD.

CONCLUSIONS

The present study showed that high exposure levels of BPA and BPS increased NAFLD incidence, which might be mediated through regulating glycolipids metabolism. Further studies on the role of bisphenols in NAFLD are warranted.

Hyperglycemia in Pregnancy and Women's Health in the 21st Century

Hyperglycemia is the commonest medical condition affecting pregnancy and its incidence is increasing globally in parallel with the twin epidemics of diabetes and obesity. Both pre-pregnancy diabetes and gestational diabetes are associated with short term pregnancy complications, with the risk of immediate complications generally broadly rising with more severe hyperglycemia. In this article we firstly consider these risks and their optimal management during pregnancy and then broaden our scope to consider the long-term implications of hyperglycemia in pregnancy as it relates to overall maternal and offspring health in a life course perspective.

Statin therapy is not warranted for a person with high LDL-cholesterol on a low-carbohydrate diet

PURPOSE OF REVIEW

Although there is an extensive literature on the efficacy of the low carbohydrate diet (LCD) for weight loss and in the management of type 2 diabetes, concerns have been raised that the LCD may increase cardiovascular disease (CVD) risk by increasing the level of low-density lipoprotein cholesterol (LDL-C). We have assessed the value of LDL-C as a CVD risk factor, as well as effects of the LCD on other CVD risk factors. We have also reviewed findings that provide guidance as to whether statin therapy would be beneficial for individuals with high LDL-C on an LCD.

RECENT FINDINGS

Multiple longitudinal trials have demonstrated the safety and effectiveness of the LCD, while also providing evidence of improvements in the most reliable CVD risk factors. Recent findings have also confirmed how ineffective LDL-C is in predicting CVD risk.

SUMMARY

Extensive research has demonstrated the efficacy of the LCD to improve the most robust CVD risk factors, such as hyperglycemia, hypertension, and atherogenic dyslipidemia. Our review of the literature indicates that statin therapy for both primary and secondary prevention of CVD is not warranted for individuals on an LCD with elevated LDL-C who have achieved a low triglyceride/HDL ratio.

Cost-effectiveness analysis of using oral magnesium supplementation in the treatment of prediabetes

INTRODUCTION

Evidence from clinical trials supports the efficacy of oral magnesium supplementation in the treatment of glucose-related disorders. Thus, we evaluate the cost-effectiveness of using oral magnesium chloride (MgCl₂) in prediabetes treatment.

METHODS

A cost-effectiveness analysis was performed. For such purpose, we used original information from a randomized controlled clinical trial. Analysis was carried out based on a health services provider perspective, a 10-year time horizon, and 3% discount rate for costs and effectiveness. Taking into account risk factor profiles, a Markov micro-simulation model was used, and a probabilistic sensibility analysis was performed.

RESULTS

The oral MgCl₂ was dominant with lower cost and greater effectiveness as compared with placebo. As compared with placebo, 22.3% and 22.0% of men using MgCl₂ did not develop diabetes or cardiovascular disease. The cost per person of using MgCl₂ as compared with placebo, in the individuals without complications, was $2206 versus $4048 USD for men, and $1984 versus $3272 USD for women. The sensitivity analysis confirmed the robustness of the base case.

CONCLUSIONS

Our results suggest that using oral MgCl₂ for at least 4 months, in adults with prediabetes and hypomagnesemia, is a cost-effective option for reducing complications and direct medical costs.

The performance of glycated albumin as a biomarker of hyperglycemia and cardiometabolic risk in children and adolescents in the United States

OBJECTIVE

Diabetes and prediabetes are growing concerns among US youth. Fasting glucose (FG) and HbA1c are standard diabetes screening tests, but HbA1c may be unreliable in some settings and fasting is burdensome in children. Glycated albumin (GA) is a non-fasting test that was recently cleared for clinical use in the United States, but studies in youth without diabetes are limited.

RESEARCH DESIGN AND METHODS

We conducted a cross-sectional analysis in 6826 youth without diabetes aged 8-19 years in the 1999-2004 National Health and Nutrition Examination Survey. We evaluated the associations of GA with HbA1c, FG, and cardiometabolic risk factors.

RESULTS

GA was poorly correlated with HbA1c (ρ = 0.074) and FG (ρ = -0.047) and was negatively associated with body mass index (BMI) and cardiometabolic risk factors. Compared to youth in the highest tertile of GA (≥13.5%), those in the lowest GA tertile (<12.4%) had a higher prevalence of obesity (29.9% vs. 7.6%), low high-density lipoprotein cholesterol (29.7% vs. 16.5%), and hypertensive blood pressure (4.0% vs. 2.7%). These inverse associations persisted after adjustment for age, sex, race/ethnicity, serum albumin, and C-reactive protein.

CONCLUSIONS

GA was poorly correlated with traditional markers of hyperglycemia in youth without diabetes. Counterintuitively, there was a negative association between GA and BMI. Among youth without diabetes, GA does not identify youth at high cardiometabolic risk, and it does not appear to be an appropriate biomarker for screening of hyperglycemia.

Prevalence of dysglycemia and associated risk factors in patients with pancreatic benign and low-grade malignant tumors before pancreatic surgery: A prospective observational study

BACKGROUND

Pancreatic benign and low-grade malignant tumors (PBLMT) have experienced a rapid increase in incidence rates worldwide. Few studies have focused on the glucose metabolism status of patients with PBLMT before pancreatic surgery.

METHODS

From August 2017 to June 2018, 70 patients with PBLMT were prospectively screened for abnormalities in glucose metabolism by an oral glucose tolerance test (OGTT) before pancreatic surgery. Patients were classified as having normal glucose tolerance (NGT), prediabetes mellitus (pre-DM), or new-onset DM (NOD) according to the American Diabetes Association (ADA) criteria. Glucose metabolism indices were calculated based on the OGTT parameters. Tumor volume and remnant pancreatic volume (RPV) were measured by computed tomography.

RESULTS

Forty-nine of 70 patients with PBLMT developed dysglycemia (pre-DM and NOD). RPV was smaller in the pre-DM (57.44 ± 18.20 cm³ vs. 70.48 ± 14.08 cm³, P = 0.001) and NOD groups (37.38 ± 20.40 cm³ vs. 70.48 ± 14.08 cm³, P < 0.001) than in the NGT group. The homeostasis model assessment of β-cell function (HOMA2-β), insulinogenic index (IGI), and insulin secretion/insulin resistance index (ISSI-2) were worse in the pre-DM and NOD groups compared with NGT group (all P < 0.05). After univariate and multivariate analyses, age over 60 years (P = 0.049, OR = 5.76, 95% CI: 1.01-32.92) and RPV less than 49.36 cm³ (P = 0.024, OR = 8.59, 95% CI: 1.34-55.22) were recognized as independent risk factors for dysglycemia. The analysis of all patients revealed inverse correlations between RPV and both in age (r = -0.28, P = 0.019) and tumor volume (r = -0.28, P = 0.032). Positive correlations were found between RPV and both IGI (r = 0.29, P = 0.019) and ISSI-2 (r = 0.39, P = 0.0011).

CONCLUSION

In patients with PBLMT, 70% had dysglycemia before surgery. Old age and a reduction in RPV were independent risk factors for developing dysglycemia before pancreatic surgery. The decisions to treat PBLMT with resection should hinge more on the risk of dysglycemia as well as potential malignancy.

Racial differences in prediabetes prevalence by test type for the US pediatric and adult population: NHANES 1999-2016

BACKGROUND

Previous studies have shown that US estimates of prediabetes or diabetes differ depending on test type, fasting plasma glucose (FPG) vs hemoglobin A1c (HbA1c). Given age, race, and test differences reported in the literature, we sought to further examine these differences in prediabetes detection using a nationally representative sample.

METHODS

Using the National Health and Nutrition Examination Survey (NHANES) 1999-2016, individuals were identified as having prediabetes with an HbA1c of 5.7% to 6.4% or a FPG of 100 to 125 mg/dL. We excluded individuals with measurements in the diabetic range. We ran generalized estimating equation logistic regressions to examine the relationship between age, race, and test type with interactions, controlling for sex and body mass index. We compared the difference in predicted prediabetes prevalence detected by impaired fasting glycemia (IFG) vs HbA1c by race/ethnicity among children and adults separately using adjusted Wald tests.

RESULTS

The absolute difference in predicted prediabetes detected by IFG vs HbA1c was 19.9% for white adolescents, 0% for black adolescents, and 20.1% for Hispanic adolescents; 21.4% for white adults, -1.2% for black adults, and 19.2% for Hispanic adults. Using adjusted Wald tests, we found the absolute differences between black vs white and black vs Hispanic individuals to be significant, but, not between Hispanic and white individuals among children and adults separately.

CONCLUSIONS

These observations highlight differences in test performance among racial/ethnic groups. Our findings corroborate the need for further studies to determine appropriate HbA1c cutoff levels for diagnosis of prediabetes by age group and race.

Diabetes in ageing: pathways for developing the evidence base for clinical guidance

Older adults with diabetes are heterogeneous in their medical, functional, and cognitive status, and require careful individualisation of their treatment regimens. However, in the absence of detailed information from clinical trials involving older people with varying characteristics, there is little evidence-based guidance, which is a notable limitation of current approaches to care. It is important to recognise that older people with diabetes might vary in their profiles according to age category, functional health, presence of frailty, and comorbidity profiles. In addition, all older adults with diabetes require an individualised approach to care, ranging from robust individuals to those residing in care homes with a short life expectancy, those requiring palliative care, or those requiring end-of-life management. In this Review, our multidisciplinary team of experts describes the current evidence in several important areas in geriatric diabetes, and outlines key research gaps and research questions in each of these areas with the aim to develop evidence-based recommendations to improve the outcomes of interest in older adults.

Low carbohydrate diet: are concerns with saturated fat, lipids, and cardiovascular disease risk justified?

PURPOSE OF REVIEW

There is an extensive literature on the efficacy of the low carbohydrate diet (LCD) for weight loss, and in the improvement of markers of the insulin-resistant phenotype, including a reduction in inflammation, atherogenic dyslipidemia, hypertension, and hyperglycemia. However, critics have expressed concerns that the LCD promotes unrestricted consumption of saturated fat, which may increase low-density lipoprotein (LDL-C) levels. In theory, the diet-induced increase in LDL-C increases the risk of cardiovascular disease (CVD). The present review provides an assessment of concerns with the LCD, which have focused almost entirely on LDL-C, a poor marker of CVD risk. We discuss how critics of the LCD have ignored the literature demonstrating that the LCD improves the most reliable CVD risk factors.

RECENT FINDINGS

Multiple longitudinal clinical trials in recent years have extended the duration of observations on the safety and effectiveness of the LCD to 2-3 years, and in one study on epileptics, for 10 years.

SUMMARY

The present review integrates a historical perspective on the LCD with a critical assessment of the persistent concerns that consumption of saturated fat, in the context of an LCD, will increase risk for CVD.

Pitfalls of HbA1c in the Diagnosis of Diabetes

Many health care providers screen high-risk individuals exclusively with an HbA1c despite its insensitivity for detecting dysglycemia. The 2 cases presented describe the inherent caveats of interpreting HbA1c without performing an oral glucose tolerance test (OGTT). The first case reflects the risk of overdiagnosing type 2 diabetes (T2D) in an older African American male in whom HbA1c levels, although variable, were primarily in the mid-prediabetes range (5.7-6.4% [39-46 mmol/mol]) for many years although the initial OGTT demonstrated borderline impaired fasting glucose with a fasting plasma glucose of 102 mg/dL [5.7 mmol/L]) without evidence for impaired glucose tolerance (2-hour glucose ≥140-199 mg/dl ([7.8-11.1 mmol/L]). Because subsequent HbA1c levels were diagnostic of T2D (6.5%-6.6% [48-49 mmol/mol]), a second OGTT performed was normal. The second case illustrates the risk of underdiagnosing T2D in a male with HIV having normal HbA1c levels over many years who underwent an OGTT when mild prediabetes (HbA1c = 5.7% [39 mmol/mol]) developed that was diagnostic of T2D. To avoid inadvertent mistreatment, it is therefore essential to perform an OGTT, despite its limitations, in high-risk individuals, particularly when glucose or fructosamine and HbA1c values are discordant. Innate differences in the relationship between fructosamine or fasting glucose to HbA1c are demonstrated by the glycation gap or hemoglobin glycation index.

Exploring the role of goal setting in weight loss for adults recently diagnosed with pre-diabetes

Background

The management of prediabetes in the community setting is a global priority. We evaluated the feasibility of a 6-month multilevel practice nurse-led prediabetes dietary intervention which involved goal setting. The aim of this paper is to explore the weight loss goals and strategies reported by participants to achieve their weight loss goals as recorded by practice nurses, and report on factors that influenced dietary behaviours.

Methods

This study used a convergent mixed-methods design. A six-month pragmatic non-randomised pilot study with a qualitative process evaluation was conducted in two neighbouring provincial cities in New Zealand. A structured dietary intervention delivered by practice nurses was implemented in four practices in 2014–2016. Content analysis of the text and descriptive statistics were used to analyse the data.

Results

One hundred and fifty seven people with prediabetes were enrolled (85 intervention, 72 control). The intervention group lost a mean 1.3 kg more than the control group (p < .0.001). The majority of the intervention group indicated either a high level of readiness (n = 42, 53%) or some readiness (n = 31, 39%) to make food changes. The majority of weight loss goals aligned with clinical guidelines (between 5 and 10% of body weight). While just over half (n = 47, 55%) demonstrated weight loss at the end of the six month period, the majority of participants did not achieve their predetermined weight loss goal (n = 78, 83%). Gender, ethnicity and budget were not related to weight loss at six months. Readiness to change and reported challenges to making dietary changes were related to weight loss at six months. Negative factors or set-backs included sporadic adherence to diet due to other health problems, change in context or environment and coping with ill health, most notably stress and low mood.

Conclusions

The data relating to weight loss and dietary goals provided insight into the challenges that people faced in making dietary changes for weight loss across a six month period. Simplifying goal setting to those goals with the greatest potential clinical impact or the greatest significance to the person, in a socially supportive environment, may increase the success of goal achievement.

Trial registration

ANZCTR ACTRN1261500080656. Registered 3 August 2015 (Retrospectively registered). https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=366560&isReview=true

Review of methods for detecting glycemic disorders

Prediabetes (intermediate hyperglycemia) consists of two abnormalities, impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) detected by a standardized 75-gram oral glucose tolerance test (OGTT). Individuals with isolated IGT or combined IFG and IGT have increased risk for developing type 2 diabetes (T2D) and cardiovascular disease (CVD). Diagnosing prediabetes early and accurately is critical in order to refer high-risk individuals for intensive lifestyle modification. However, there is currently no international consensus for diagnosing prediabetes with HbA1c or glucose measurements based upon American Diabetes Association (ADA) and the World Health Organization (WHO) criteria that identify different populations at risk for progressing to diabetes. Various caveats affecting the accuracy of interpreting the HbA1c including genetics complicate this further. This review describes established methods for detecting glucose disorders based upon glucose and HbA1c parameters as well as novel approaches including the 1-hour plasma glucose (1-h PG), glucose challenge test (GCT), shape of the glucose curve, genetics, continuous glucose monitoring (CGM), measures of insulin secretion and sensitivity, metabolomics, and ancillary tools such as fructosamine, glycated albumin (GA), 1,5- anhydroglucitol (1,5-AG). Of the approaches considered, the 1-h PG has considerable potential as a biomarker for detecting glucose disorders if confirmed by additional data including health economic analysis. Whether the 1-h OGTT is superior to genetics and omics in providing greater precision for individualized treatment requires further investigation. These methods will need to demonstrate substantially superiority to simpler tools for detecting glucose disorders to justify their cost and complexity.

Prevalence of pre-diabetes and undiagnosed diabetes in the Mollerussa prospective observational cohort study in a semi-rural area of Catalonia

OBJECTIVES

To assess the prevalence of undiagnosed diabetes and pre-diabetes in the healthy population in the Mollerussa cohort. As a secondary objective, to identify the variables associated with these conditions and to describe the changes in glycaemic status after 1 year of follow-up in subjects with pre-diabetes.

DESIGN

Prospective observational cohort study.

SETTING

General population from a semi-rural area.

PARTICIPANTS

The study included 583 participants without a diagnosis of diabetes recruited between March 2011 and July 2014.

RESULTS

The prevalence of undiagnosed diabetes was 20, 3.4% (95% CI 2.6 to 4.2) and that of pre-diabetes was 229, 39.3% (37.3 to 41.3). Among those with pre-diabetes, 18.3% had isolated impaired fasting plasma glucose (FPG) (FPG: 100 to <126 mg/dL), 58.1% had isolated impaired glycated haemoglobin (HbA1c) (HbA1c 5.7 to <6.5) and 23.6% fulfilled both criteria. Follow-up data were available for 166 subjects; 41.6%(37.8 to 45.4) returned to normoglycaemia, 57.6% (57.8 to 61.4) persisted in pre-diabetes and 0.6% (0 to 1.2) progressed to diabetes. Individuals with pre-diabetes had worse cardiometabolic risk profiles and sociodemographic features than normoglycaemic subjects. In the logistic regression model, variables significantly associated with pre-diabetes were older age (OR; 95% CI) (1.033; 1.011 to 1.056), higher physical activity (0.546; 0.360 to 0.827), body mass index (1.121; 1.029 to 1.222) and a family history of diabetes (1.543; 1.025 to 2.323). The variables significantly associated with glycaemic normalisation were older age (0.948; 0.916 to 0.982) and body mass index (0.779; 0.651 to 0.931).

CONCLUSIONS

Among adults in our region, the estimated prevalence of undiagnosed diabetes was 3.4% and that of pre-diabetes was 39.3%. After a 1-year follow-up, a small proportion of subjects (0.6%) with pre-diabetes progressed to diabetes, while a high proportion (41.6%) returned to normoglycaemia. Individuals with pre-diabetes who returned to normoglycaemia were younger and had a lower body mass index.

The Natural Course of Impaired Fasting Glucose

Impaired glucose regulation, including diabetes and prediabetes, poses a huge global problem not only in health but also in the epidemiological and economic areas. These disorders are often detected too late or remain unrecognized. The article aims to provide a review of the prevalence, etiology, and natural history of impaired fasting glucose (IFG). We focus on the progression of isolated IFG to full-fledged type 2 diabetes and the factors conducive to the development of diabetes. The knowledge about it could help design an optimal management program for the prevention of diabetes in patients with IFG; a program that would be patient-tailored and based on the underlying pathophysiology.

Body surface area and glucose tolerance - The smaller the person, the greater the 2-hour plasma glucose

BACKGROUND

The oral glucose tolerance test (OGTT) is standardized globally with a uniform glucose load of 75 g to all adults irrespective of body size. An inverse association between body height and 2-hour postload plasma glucose (2hPG) has been demonstrated. Our aim was to evaluate the relationship between body surface area (BSA) and plasma glucose values during an OGTT.

METHODS

An OGTT was performed on 2659 individuals at increased cardiovascular risk aged between 45 and 70 years of age, who had not previously been diagnosed with diabetes or cardiovascular disease. Their BSA was calculated according to the Mosteller formula. Study subjects were divided into five BSA levels corresponding to 12.5, 25, 25, 25, and 12.5% of the total distribution.

FINDINGS

When adjusted for age, sex, waist circumference, alcohol intake, current smoking, and leisure-time physical activity, BSA level showed an inverse linear relationship with the 2hPG in all categories of glucose tolerance (p for linearity < 0.001). Moreover, the smaller the adjusted BSA of the study person, the higher the proportion of newly diagnosed type 2 diabetes based on 2hPG in the OGTT.

INTERPRETATION

Body size has a considerable impact on the findings from a standardized OGTT. Smaller persons are more likely to be diagnosed as glucose intolerant than relatively larger sized individuals.

FUNDING

This work was supported by the State Provincial Office of Western Finland, the Central Satakunta Health Federation of Municipalities, Satakunta Hospital District, and the Hospital District of Southwest Finland.

RESEARCH IN CONTEXT

Evidence before this study. We searched PubMed using the MeSH terms "glucose tolerance test", "body surface area", "body height", "body size", "glucose tolerance", "insulin resistance", "blood glucose" and "diabetes mellitus" on March 10, 2019 without language restrictions. We also used Cited Reference Search in Web of Science for relevant articles. The oral glucose tolerance test (OGTT) is standardized globally with a uniform glucose load of 75 g to all adults irrespective of body size. An inverse association between body height and 2-hour postload plasma glucose (2hPG) has been demonstrated. Several studies have shown that 2hPG predicts all-cause mortality better than elevated fasting glucose. However, body height or body surface area are not usually adjusted in epidemiological studies. It is well known that short adult stature is a risk factor for cardiovascular and all-cause mortality. Added value of this study. This is the first study to assess the relationship of body surface area and 2hPG in a typical primary care population at increased cardiovascular risk. Body surface area has a considerable impact on the result of a standardized OGTT. Smaller individuals are more likely to be diagnosed as glucose intolerant than relatively larger sized individuals. Implications of all the available evidence. There is a possibility that the diagnosis of type 2 diabetes made by an OGTT is a false positive result in a relatively small individual, and a false negative result in a relatively larger individual. Association of 2hPG concentrations and mortality may be influenced by body size as confounding factor. Given that the OGTT is a time and effort consuming test both for patients and laboratory personnel, validity of the OGTT for different body sizes should be reconsidered.

Evidence in support of the International Association of Diabetes in Pregnancy study groups' criteria for diagnosing gestational diabetes mellitus worldwide in 2019

Gestational diabetes mellitus, the most frequent medical complication of pregnancy, affects 5-6% of women in the United States with the use of the currently predominant Carpenter-Coustan criteria, which still represent the preferred approach of the American College of Obstetricians and Gynecologists. Alternative criteria proposed by the International Association of Diabetes in Pregnancy Study Groups would likely increase gestational diabetes mellitus prevalence to 15-20%, because of both a 1-step testing policy and the requirement for only 1 elevated glucose value for diagnosis. Increasing gestational diabetes mellitus prevalence relates to older maternal age and the increasing prevalence of overweight and obesity. This increased gestational diabetes mellitus prevalence is consistent with 29.3% prevalence of prediabetes and 4.5% prevalence of known diabetes outside pregnancy in US adults from 20-44 years of age. Gestational diabetes mellitus according to the International Association of Diabetes in Pregnancy Study Groups criteria is associated with almost twice the risk of large-for-gestational-age babies, increased fetal adiposity, neonatal hyperinsulinemia and preeclampsia, and a 50% higher risk of preterm delivery and shoulder dystocia. The recent publication of the Hyperglycemia and Adverse Pregnancy Outcome Follow Up Study provides further evidence regarding the influence of gestational diabetes mellitus on long-term maternal and infant health. This study clearly demonstrates that hyperglycemia in pregnancy, untreated and identified post hoc by the International Association of Diabetes in Pregnancy Study Groups criteria, carries a 41.5% risk of maternal prediabetes (odds ratio, 3.72; 95% confidence interval, 3.09-4.47) and 10.7% risk of type 2 diabetes (odds ratio, 7.63; 95% confidence interval, 5.33-10.95) after 11.4 years of follow up. Gestational diabetes mellitus was also associated with higher rates of childhood overweight and obesity (prevalence 39.3% with maternal gestational diabetes mellitus; odds ratio, 1.5; 95% confidence interval, 1.56-2.44). This article places these findings in the context of other recent studies that have demonstrated that interventions that include lifestyle measures and/or metformin offer a >50% reduction in the risk of women with gestational diabetes mellitus experiencing the development of overt diabetes mellitus after their index gestational diabetes mellitus pregnancy. Although prevention of obesity and prediabetes in offspring by pregnancy treatment of gestational diabetes mellitus has not been demonstrated to date, we argue that the immediate pregnancy benefits and opportunities for long-term improvements in maternal health justify a reevaluation of the current ambivalent approach taken by the American College of Obstetricians and Gynecologists to gestational diabetes mellitus diagnosis, which currently allow for a choice of alternative criteria. The Carpenter-Coustan or National Diabetes Data Group criteria, listed as preferred criteria by American College of Obstetricians and Gynecologists, markedly limit the frequency of gestational diabetes mellitus in comparison with the International Association of Diabetes in Pregnancy Study Groups criteria and limit the opportunity for immediate and long-term follow up and treatment. We consider that new information from the Hyperglycemia and Pregnancy Outcome Follow Up Study and other recent publications on long-term maternal and offspring risk provides compelling arguments for a more comprehensive approach to the promotion of maternal and infant health through all the life cycle.

Gestational diabetes mellitus

Hyperglycaemia that develops during pregnancy and resolves after birth has been recognized for over 50 years, but uniform worldwide consensus is lacking about threshold hyperglycaemic levels that merit a diagnosis of 'gestational diabetes mellitus' (GDM) and thus treatment during pregnancy. GDM is currently the most common medical complication of pregnancy, and prevalence of undiagnosed hyperglycaemia and even overt diabetes in young women is increasing. Maternal overweight and obesity, later age at childbearing, previous history of GDM, family history of type 2 diabetes mellitus and ethnicity are major GDM risk factors. Diagnosis is usually performed using an oral glucose tolerance test (OGTT), although a non-fasting, glucose challenge test (GCT) is used in some parts of the world to screen women for those requiring a full OGTT. Dietary modification and increased physical activity are the primary treatments for GDM, but pharmacotherapy, usually insulin, is used when normoglycaemia is not achieved. Oral hypoglycaemic agents, principally metformin and glibenclamide (glyburide), are also used in some countries. Treatment improves immediate pregnancy outcomes, reducing excess fetal growth and adiposity and pregnancy-related hypertensive disorders. GDM increases the risk of long-term complications, including obesity, impaired glucose metabolism and cardiovascular disease, in both the mother and infant. Optimal management of mother and infant during long-term follow-up remains challenging, with very limited implementation of preventive strategies in most parts of the world.

Development of Diabetes after Pancreaticoduodenectomy: Results of a 10-Year Series Using Prospective Endocrine Evaluation

BACKGROUND

Limited literature is available on the development of impaired glucose tolerance and diabetes mellitus after pancreaticoduodenectomy. The primary aim was to define the diabetic phenotype and correlate preoperative glycemic laboratory results to new-onset diabetes after pancreaticoduodenectomy.

STUDY DESIGN

In this prospective study, perioperative fasting and postprandial (oral glucose tolerance test) plasma glucose, glycated hemoglobin, insulin, and c-peptide were measured in consecutive patients undergoing pancreaticoduodenectomy by the senior author from 2006 to 2017. American Diabetes Association definitions were used for glycemic classifications. Multivariate risk factor analysis was performed.

RESULTS

Of 774 identified patients, 371 diabetics were excluded and 403 patients were included: 167 and 236 were preoperatively classified as nondiabetic and prediabetic, respectively. The incidence rates of diabetes at 120 months post pancreaticoduodenectomy were 9.0% (nondiabetics), 22.0% (prediabetics), and 16.6% (overall). Patients in whom diabetes developed demonstrated a 3-fold larger difference between oral glucose tolerance test and fasting glucose (Δ), and 2-fold larger Δinsulin and Δc-peptide values. Tiered multivariate analysis identified glycated hemoglobin >5.4% with a relative risk (RR) of 2.944 (p = 0.047) as an independent predictor of impaired glucose tolerance and diabetes mellitus. Analysis of patients stratified by preoperative classification identified fasting glucose >95 mg/dL (nondiabetics, RR 1.925; p = 0.002), and glycated hemoglobin ≥5.4% (prediabetics, RR 3.125; p = 0.040) as independent risk factors for diabetes. Compared with nondiabetics, prediabetics classified by any laboratory results demonstrated an RR of 2.471 (p = 0.001) for diabetes developing postoperatively. There was no association between primary pathology, advancing age, or BMI and increased risk of diabetes development.

CONCLUSIONS

Diabetes will develop after pancreaticoduodenectomy in approximately 16.6% of patients. A preoperative glycated hemoglobin >5.4% independently predicts new-onset diabetes. Pre- and postoperative endocrine analysis remains paramount for proper patient risk stratification.