Intra-individual variation of glucose, specific insulin and proinsulin concentrations measured by two oral glucose tolerance tests in a general Caucasian population: the Hoorn Study

The Effect of the Oral Contraceptive Pill on Acute Glycaemic Response to an Oral Glucose Bolus in Healthy Young Women: A Randomised Crossover Study

Background/Objective: The oral contraceptive pill (OCP) is widely used by women worldwide, yet the influence of the OCP on carbohydrate metabolism remains under-investigated, with existing studies being few and largely cross-sectional. The study objective was to assess, for the first time, the effect of the combined OCP on postprandial glycaemic response to an oral glucose bolus, using a randomised crossover design. Methods: The effect of a combined monophasic OCP phase on glucose homeostasis and metabolic profile was investigated in 21 healthy young women, who were regular users of either androgenic or anti-androgenic OCP formulations. Plasma glycaemic markers (glucose, insulin and C-peptide) were assessed prior to a 60 g glucose drink (fasting) and for a further 4 h postprandially; once during the "active" (hormone-containing) pill phase and once during the "inactive" (hormone-free) pill phase of the OCP usage cycle. Results: Despite no change in fasting values, in androgenic pill users, postprandial glucose and insulin responses to an oral glucose bolus were ~100% and ~50% greater, respectively, during the active versus inactive phase. In contrast, in anti-androgenic pill users there was no significant change in response between the two OCP usage cycle phases. Conclusions: These findings highlight an acute, but potentially detrimental, influence of the combined OCP on glucose homeostasis, particularly in users of formulations containing androgenic progestogens. Given the high global prevalence of OCP use and increasingly common prolonged active pill regimens, which may continue for months, years or even decades, potential cumulative effects of such changes on metabolic risk demand further investigation.

Different Measures of Hyperglycemia Are Negatively Associated With Skin Microvascular Flowmotion: The Maastricht Study

OBJECTIVE

Diabetes can lead to microvascular complications such as diabetic neuropathy, nephropathy, and retinopathy. Hyperglycemia may initiate microvascular function impairment early in the course of diabetes, even prior to its clinical establishment during the pre-diabetes stage. Microvascular vasomotion, that is, the rhythmic arteriolar constriction and dilation, is an important function that regulates oxygen and nutrient delivery within the tissue and regulates peripheral resistance. Using laser Doppler flowmetry (LDF), vasomotion in skin microcirculation can be measured as flowmotion. Changes in flowmotion have been shown in individuals with obesity, and type 1 or type 2 diabetes mellitus. However, no data are available on associations between hyperglycemia and flowmotion in the general population. Our aim was to study whether measures of hyperglycemia were associated with different components of skin microvascular flowmotion (SMF) in a population-based cohort (The Maastricht Study).

METHODS

Data from 7293 participants of The Maastricht Study were used. SMF was measured using LDF. Endothelial, neurogenic and myogenic component SMF power were used as dependent variables. We investigated the associations of glucose metabolism status (normal glucose metabolism, prediabetes, and type 2 diabetes mellitus), measures of hyperglycemia (fasting plasma glucose [FPG], 2-h post-load glucose [2 h-PG], HbA1c, advanced glycation end-products [AGEs] assessed as skin autofluorescence [SAF]), and indices of glucose variability (incremental glucose peak [IGP] and continuous glucose monitoring [CGM] -assessed as standard deviation [SD]) with each component of SMF power. We used linear regression analyses with adjustments for confounders, and trend analyses.

RESULTS

We observed consistent negative associations between HbA1c levels and all three (endothelial, neurogenic, and myogenic) skin microvascular flowmotion (SMF) powers in the additionally adjusted model. Similarly, in the conservative model, we found that multiple hyperglycemia metrics such as GMS trend, PreD, T2DM, FPG, 2 h-PG, and HbA1c were consistently negatively associated with all three SMF powers.

CONCLUSIONS

We showed that skin microvascular flowmotion is reduced in individuals with (pre)diabetes. In addition, different measures of hyperglycemia are negatively associated with skin microvascular flowmotion.

Higher adiposity predicts greater intra-individual inconsistencies in postprandial glycemic measurements-an analysis of three randomized controlled trials in Asian populations

BACKGROUND/OBJECTIVES

Acute glycemic responses offer important insights into glucose homeostasis although the repeatability of these measurements particularly in Asian populations remains unclear. This research aimed to critically investigate the inconsistencies of the postprandial glycemic profile within individuals, and identify potential variables predicting greater inconsistencies.

SUBJECTS/METHODS

This was a secondary analysis of three randomized controlled trials which fed subjects with glucose (and other carbohydrate-rich foods), and measured postprandial blood glucose at regular intervals. Intra-individual rank-order consistency in the glycemic profile between acute glucose treatments was evaluated and compared against demographic, anthropometric and cardio-metabolic health related indicators to delineate potential confounding variables. Correlations between the incremental area under curve at 120 min (iAUC120 min) for glucose and the carbohydrate-rich foods were further explored.

RESULTS

Rank-order consistency was identified to be moderate, with intra-individual inconsistencies marginally lower than inter-individual inconsistencies. Notably, greater inconsistencies within individuals were directly correlated with BMI and fat-mass index (P < 0.01) albeit non-significant for age, ethnicity, and other cardio-metabolic health-related risk indicators. Across the trials, there were positive monotonic correlations between the iAUC120 min for glucose and simple sugars (sucrose, isomaltulose), as well as different varieties of rice (jasmine white, Bapatla brown, Bapatla white; p < 0.05). However, there were a lack of associations between iAUC120 min for glucose with pastas (semolina and wholegrain penne, spaghetti) and mee pok noodles.

CONCLUSION

There are inherent inconsistencies in postprandial glycemic measurements within individuals, particularly among those with higher adiposity. These confounders need to be kept in mind for appropriate and meaningful interpretations of glycemia.

Global, regional and national burdens of nutritional deficiencies, from 1990 to 2019

The epidemiological and burden characteristics of nutritional deficiencies (ND) have been evolving, and it is crucial to identify geographical disparities and emerging trends. This study aimed to analyse the global, regional and national trends in the burden of ND over the past 30 years. Data were obtained from the Global Burden of Disease (GBD) 2019 database for the period 1990-2019. The study examined the incidence rates and disability-adjusted life years (DALY) of ND at various levels. Globally, the incidence rate of ND decreased from 2226·2 per 100 000 in 2019 to 2096·3 per 100 000 in the same year, indicating a decline of 5·8 %. The average annual percentage change (AAPC) was -0·21 (-0·31, -0·11). Similarly, DALY, prevalence and mortality rates of ND exhibited significant declines (AAPC = -3·21 (-3·45, -2·96), AAPC = -0·53 (-0·55, -0·51) and AAPC = -4·97 (-5·75, -4·19), respectively). The incidence rate of ND varied based on age group, sex, cause and geographical area. Moreover, a negative association was observed between incidence and the sociodemographic index. At the regional level, the South Asia and sub-Saharan Africa regions had the highest incidence rates of ND. In conclusion, the global incidence rate of ND showed a mixed pattern, while the DALY rate consistently declined. Additionally, prevalence and mortality rates of ND decreased between 1990 and 2019.

Continuous glucose monitoring and intrapersonal variability in fasting glucose

Plasma fasting glucose (FG) levels play a pivotal role in the diagnosis of prediabetes and diabetes worldwide. Here we investigated FG values using continuous glucose monitoring (CGM) devices in nondiabetic adults aged 40-70 years. FG was measured during 59,565 morning windows of 8,315 individuals (7.16 ± 3.17 days per participant). Mean FG was 96.2 ± 12.87 mg dl-1, rising by 0.234 mg dl-1 per year with age. Intraperson, day-to-day variability expressed as FG standard deviation was 7.52 ± 4.31 mg dl-1. As there are currently no CGM-based criteria for diabetes diagnosis, we analyzed the potential implications of this variability on the classification of glycemic status based on current plasma FG-based diagnostic guidelines. Among 5,328 individuals who would have been considered to have normal FG based on the first FG measurement, 40% and 3% would have been reclassified as having glucose in the prediabetes and diabetes ranges, respectively, based on sequential measurements throughout the study. Finally, we revealed associations between mean FG and various clinical measures. Our findings suggest that careful consideration is necessary when interpreting FG as substantial intraperson variability exists and highlight the potential impact of using CGM data to refine glycemic status assessment.

Associations of normal fasting glucose levels and of insulin resistance with degenerative rotator cuff tear : Normoglycemia and rotator cuff tear

BACKGROUND

The upper normoglycemic range has been proposed as a risk factor for degenerative rotator cuff tendon tear (RCT), and insulin resistance has been suggested as a risk factor for tendinopathy. However, no research has established their association with degenerative RCT in the general population. This study aimed to determine whether fasting glucose levels and insulin resistance are risk factors for degenerative RCT in the normoglycemic population and identify the risk range for fasting glucose.

METHODS

This study included 418 normoglycemic participants from a rural cohort. Participants completed questionnaires, physical exams, blood tests, and MRI evaluations of both shoulders. Insulin resistance was assessed using a triglyceride/high-density-lipoprotein (TG/HDL) ≥ 3.5. Logistic regression analysis was used to determine the association between fasting glucose level, TG/HDL ≥ 3.5, and other factors and degenerative RCT. The study calculated the areas under the receiver operating characteristic curve (AUC) to determine the more appropriate predicting value between the scale and categorical values of fasting glucose levels, and compared the AUCs using the DeLong method.

RESULTS

In the multivariable analyses, both scale and categorical values of fasting glucose levels, and TG/HDL ≥ 3.5 were significantly associated with degenerative RCT. Fasting glucose levels ≥ 90.5 mg/dL (OR: 3.87, 95% CI: 2.10-7.06) in scale value and 90-99 mg/dL (OR: 4.13, 95% CI: 2.87-8.12) in categorical value were significantly associated with degenerative RCT (P < .001). The AUC of the scale value of fasting glucose levels ≥ 90.5 mg/dL was 0.68. The AUC of the categorical value of fasting glucose levels of 90-99 mg/dL was 0.70. Because of the significantly larger AUC of the categorical value of fasting glucose levels of 90-99 mg/dL, those fasting glucose levels were determined to be independently associated with degenerative RCT (P < .001).

CONCLUSIONS

High fasting glucose levels within the normal range may link to increase insulin resistance and risk of degenerative RCT. Normoglycemic levels of 90-99 mg/dL and insulin resistance may be risk factors for degenerative RCT.

LEVEL OF EVIDENCE

Level III, prognostic study.

Should Prediabetes be Treated Pharmacologically?

OBJECTIVE

In this commentary I will evaluate whether prediabetes should be treated pharmacologically. To consider this question, certain information concerning prediabetes is relevant.

BACKGROUND INFORMATION

(1) Prediabetes is not independently associated with cardiovascular disease; the other factors in the metabolic syndrome increase that risk; (2) various tests and criteria for diagnosing prediabetes are recommended, yielding prevalences varying from 6% to 38% depending on which are used; (3) one-third of patients with prediabetes revert to normal over time; (4) up to two-thirds of patients with prediabetes do not develop diabetes; (5) people with prediabetes have insulin resistance and impaired insulin secretion; (6) although pharmacological treatment of the dysglycemia temporarily lowers it, when the drugs are discontinued, incident diabetes develops similarly as that in those who received placebos; (7) when the drugs are discontinued, there are no changes in insulin resistance or impaired insulin secretion; (8) incident diabetes was similar at 10 years in people remaining on metformin in the Diabetes Prevention Program Outcome Study compared with those who did not receive the drug; (9) no current drugs will directly increase insulin secretion (except sulfonylureas and glinides which have not been used to treat prediabetes because of hypoglycemia concerns); (10) sufficient weight loss to lower insulin resistance by nutritional means is challenging and especially difficult to maintain.

CONCLUSIONS

Pharmacological treatment of the dysglycemia of prediabetes is not warranted. On the other hand, the ability of high doses of glucagon-like peptide (GLP)-1 receptor agonists and the combination of a GLP-1 receptor agonist and the glucose-dependent insulinotropic polypeptide (GIP) to lower weight by 15% and 20%, respectively, deserves consideration for the treatment of prediabetes. This amount of weight loss should decrease insulin resistance, allowing endogenous insulin secretion to be more effective and lower the risk for developing diabetes.

Guidelines and Recommendations for Laboratory Analysis in the Diagnosis and Management of Diabetes Mellitus

BACKGROUND

Numerous laboratory tests are used in the diagnosis and management of diabetes mellitus. The quality of the scientific evidence supporting the use of these assays varies substantially.

APPROACH

An expert committee compiled evidence-based recommendations for laboratory analysis in screening, diagnosis, or monitoring of diabetes. The overall quality of the evidence and the strength of the recommendations were evaluated. The draft consensus recommendations were evaluated by invited reviewers and presented for public comment. Suggestions were incorporated as deemed appropriate by the authors (see Acknowledgments). The guidelines were reviewed by the Evidence Based Laboratory Medicine Committee and the Board of Directors of the American Association for Clinical Chemistry and by the Professional Practice Committee of the American Diabetes Association.

CONTENT

Diabetes can be diagnosed by demonstrating increased concentrations of glucose in venous plasma or increased hemoglobin A1c (HbA1c) in the blood. Glycemic control is monitored by the people with diabetes measuring their own blood glucose with meters and/or with continuous interstitial glucose monitoring (CGM) devices and also by laboratory analysis of HbA1c. The potential roles of noninvasive glucose monitoring, genetic testing, and measurement of ketones, autoantibodies, urine albumin, insulin, proinsulin, and C-peptide are addressed.

SUMMARY

The guidelines provide specific recommendations based on published data or derived from expert consensus. Several analytes are found to have minimal clinical value at the present time, and measurement of them is not recommended.

Reproducibility of Glycemic Measures Among Dysglycemic Youth and Adults in the RISE Study

AIMS

Previous work found poor reproducibility for measures of glycemia in individuals at risk for dysglycemia. Differences between youth and adults have not been assessed. Using youth and adults in the Restoring Insulin Secretion Study, we tested variability and classification concordance for hemoglobin A1C (HbA1c), fasting and 2-hour glucose from oral glucose tolerance tests (OGTTs).

METHODS

HbA1c and glucose on repeated samples obtained ∼6 weeks apart were compared in 66 youth (mean age 14.2 years) and 354 adults (52.7 years). Changes, coefficient of variation (CV), and concordance of diagnostic categories between the 2 visits were compared.

RESULTS

Mean difference between the 2 visits in HbA1c was higher in youth than adults (P < .001), while fasting glucose was similar and 2-hour glucose was lower in youth (P = .051). CV was smallest for HbA1c compared to fasting and 2-hour glucose. For HbA1c, youth had higher CV (P < .001); whereas CV for 2-hour glucose was lower for youth (P = .041). Classification concordance by HbA1c was lower in youth (P = .004). Using OGTT or HbA1c for classification, intervisit variability produced discordant classification in 20% of youth and 28% of adults. Using both fasting glucose and HbA1c, intervisit variability reduced discordant classification to 16% of adults while not improving classification in youth.

CONCLUSIONS

Poor reproducibility and lack of classification concordance highlight the limitations of one-time testing, with important implications for assessing eligibility in clinical trials. Consideration should be given to using more than a single parameter for screening and diagnosis, especially when classification category is important.

Guidelines and Recommendations for Laboratory Analysis in the Diagnosis and Management of Diabetes Mellitus

BACKGROUND

Numerous laboratory tests are used in the diagnosis and management of diabetes mellitus. The quality of the scientific evidence supporting the use of these assays varies substantially.

APPROACH

An expert committee compiled evidence-based recommendations for laboratory analysis in screening, diagnosis, or monitoring of diabetes. The overall quality of the evidence and the strength of the recommendations were evaluated. The draft consensus recommendations were evaluated by invited reviewers and presented for public comment. Suggestions were incorporated as deemed appropriate by the authors (see Acknowledgments). The guidelines were reviewed by the Evidence Based Laboratory Medicine Committee and the Board of Directors of the American Association of Clinical Chemistry and by the Professional Practice Committee of the American Diabetes Association.

CONTENT

Diabetes can be diagnosed by demonstrating increased concentrations of glucose in venous plasma or increased hemoglobin A1c (Hb A1c) in the blood. Glycemic control is monitored by the people with diabetes measuring their own blood glucose with meters and/or with continuous interstitial glucose monitoring (CGM) devices and also by laboratory analysis of Hb A1c. The potential roles of noninvasive glucose monitoring, genetic testing, and measurement of ketones, autoantibodies, urine albumin, insulin, proinsulin, and C-peptide are addressed.

SUMMARY

The guidelines provide specific recommendations based on published data or derived from expert consensus. Several analytes are found to have minimal clinical value at the present time, and measurement of them is not recommended.

Skeptical Look at the Clinical Implication of Metabolic Syndrome in Childhood Obesity

Metabolic syndrome (MetS) is defined by a cluster of several cardio-metabolic risk factors, specifically visceral obesity, hypertension, dyslipidemia, and impaired glucose metabolism, which together increase risks of developing future cardiovascular disease (CVD) and type 2 diabetes mellitus (T2D). This article is a narrative review of the literature and a summary of the main observations, conclusions, and perspectives raised in the literature and the study projects of the Working Group of Childhood Obesity (WGChO) of the Italian Society of Paediatric Endocrinology and Diabetology (ISPED) on MetS in childhood obesity. Although there is an agreement on the distinctive features of MetS, no international diagnostic criteria in a pediatric population exist. Moreover, to date, the prevalence of MetS in childhood is not certain and thus the true value of diagnosis of MetS in youth as well as its clinical implications, is unclear. The aim of this narrative review is to summarize the pathogenesis and current role of MetS in children and adolescents with particular reference to applicability in clinical practice in childhood obesity.

Consumption of sweetened beverages is associated with the incidence of type 2 diabetes in Brazilian adults (CUME project)

BACKGROUND AND AIM

To evaluate the association between the energy consumption of sweetened beverages (SBs) adjusted for daily energy intake and the incidence of type 2 diabetes.

METHODS AND RESULTS

This was a prospective study with 2480 type 2 diabetes mellitus (T2DM)-free Cohort of Universities of Minas Gerais (CUME) participants at baseline and 2-4 years of follow-up. A longitudinal analysis was performed with generalized equation estimation to verify the effect of SB consumption, adjusted for sociodemographic and lifestyle variables, on the incidence of T2DM. The incidence of T2DM was 2.78%. The median calorie intake of daily SB consumption adjusted for energy was 47.7 kcal/day. Participants with the highest consumption of SBs (≥47.7 kcal/day) were 63% (odds ratio [OR] = 1.63; p value-0.049) more likely to acquire T2DM over time compared to the lowest consumption (<47.7 kcal/day).

CONCLUSIONS

Higher energy consumption from SBs favored a higher incidence of T2DM among CUME participants. The results reinforce the need for marketing restrictions on these foods and taxation to reduce the consumption of these beverages to prevent T2DM and other chronic noncommunicable diseases.

No Indices of Increased Type 2 Diabetes Risk in Individuals with Reactive Postprandial Hypoglycemia

Reactive postprandial hypoglycemia (RPH) is an understudied condition that lacks clinical definition, knowledge of future health implications, and an understanding of precise underlying mechanisms. Therefore, our study aimed to assess the glycemic response after glucose ingestion in individuals several years after the initial evaluation of RPH and to compare glucose regulation in individuals with RPH vs. healthy volunteers. We assessed the inter- and intra-individual differences in glucose, insulin, and C-peptide concentrations during 5-h oral glucose tolerance tests (OGTTs); the surrogate markers of insulin resistance (HOMA-IR and Matsuda index); and beta-cell function (distribution index and insulinogenic index). The study included 29 subjects with RPH (all females, aged 39 (28, 46) years) and 11 sex-, age-, and body mass index (BMI)-matched controls. No biochemical deterioration of beta-cell secretory capacity and no progression to dysglycemia after 6.4 ± 4.2 years of follow-up were detected. RPH subjects were not insulin resistant, and their insulin sensitivity did not deteriorate. RPH subjects exhibited no differences in concentrations or in the shape of the glucose-insulin curves during the 5-h OGTTs compared to age- and BMI-matched controls. No increased incident type 2 diabetes risk indices were evident in individuals with RPH. This dictates the need for further research to investigate the magnitude of future diabetes risk in individuals experiencing RPH.

(Pre)diabetes, glycemia, and daily glucose variability are associated with retinal nerve fiber layer thickness in The Maastricht Study

Retinopathy and neuropathy in type 2 diabetes are preceded by retinal nerve fibre layer (RNFL) thinning, an index of neurodegeneration. We investigated whether glucose metabolism status (GMS), measures of glycaemia, and daily glucose variability (GV) are associated with RNFL thickness over the entire range of glucose tolerance. We used cross-sectional data from The Maastricht Study (up to 5455 participants, 48.9% men, mean age 59.5 years and 22.7% with type 2 diabetes) to investigate the associations of GMS, measures of glycaemia (fasting plasma glucose [FPG], 2-h post-load glucose [2-h PG], HbA1c, advanced glycation endproducts [AGEs] assessed as skin autofluorescence [SAF]) and indices of daily GV (incremental glucose peak [IGP] and continuous glucose monitoring [CGM]-assessed standard deviation [SD]) with mean RNFL thickness. We used linear regression analyses and, for GMS, P for trend analyses. We adjusted associations for demographic, cardiovascular risk and lifestyle factors, and, only for measures of GV, for indices of mean glycaemia. After full adjustment, type 2 diabetes and prediabetes (versus normal glucose metabolism) were associated with lower RNFL thickness (standardized beta [95% CI], respectively - 0.16 [- 0.25; - 0.08]; - 0.05 [- 0.13;  0.03]; P_trend = 0.001). Greater FPG, 2-h PG, HbA1c, SAF, IGP, but not CGM-assessed SD, were also associated with lower RNFL thickness (per SD, respectively - 0.05 [- 0.08; - 0.01]; - 0.06 [- 0.09; - 0.02]; - 0.05 [- 0.08; - 0.02]; - 0.04 [- 0.07; - 0.01]; - 0.06 [- 0.12; - 0.01]; and - 0.07 [- 0.21; 0.07]). In this population-based study, a more adverse GMS and, over the entire range of glucose tolerance, greater glycaemia and daily GV were associated with lower RNFL thickness. Hence, early identification of individuals with hyperglycaemia, early glucose-lowering treatment, and early monitoring of daily GV may contribute to the prevention of RNFL thinning, an index of neurodegeneration and precursor of retinopathy and neuropathy.

Health-related quality of life for normal glycaemia, prediabetes and type 2 diabetes mellitus: Cross-sectional analysis of the ADDITION-PRO study

AIMS

We estimated and compared health-related quality of life for individuals with normal glucose tolerance, prediabetes and diabetes.

METHODS

Participants in the ADDITION-PRO study, Denmark, who attended a health assessment between 2009 and 2011, and who completed the 3-level EuroQoL 5-dimensions (EQ-5D-3L) questionnaire were included. For the present study, they were classified as normal glucose tolerance, prediabetes and diabetes (screen-detected and known) using the 2019 American Diabetes Association criteria. Prediabetes was defined as impaired fasting glucose, impaired glucose tolerance or HbA1c between 5.7-6.4% (39-47 mmol/mol). EQ-5D-3L data were converted into utility scores using Danish and UK values, where '1' equals full health and '0' equals death. Regression models estimated the association between utility and the different glucose health states.

RESULTS

The mean EQ-5D-3L score in the sample population was 0.86 ± 0.17 (median 0.85, interquartile range 0.76 to 1) using UK values. Almost half of the sample (48%) reported full health with an EQ-5D score of '1'. Individuals with known diabetes reported the lowest EQ-5D-3L utility scores (0.81 ± 0.20), followed by individuals with screen-detected diabetes (0.85 ± 0.19), prediabetes (0.86 ± 0.17) and normal glucose tolerance (0.90 ± 0.15). The differences were statistically significant for normal glucose and known diabetes relative to prediabetes, after adjusting for sex, age, smoking, BMI and physical activity. These findings also held using Danish values albeit the differences were of smaller magnitude.

CONCLUSIONS

Having prediabetes and diabetes was significantly associated with lower health-related quality of life relative to normal glucose tolerance. Our estimates will be useful to inform the value of interventions to prevent diabetes or prediabetes.

Historical review of the diagnosis of prediabetes/intermediate hyperglycemia: Case for the international criteria

In 1997, the ADA recommended an IFG criterion for diagnosing prediabetes/intermediate hyperglycemia of FPG concentrations of 6.1-6.9 mmol/L (110-125 mg/dL). In 2003, they lowered it to 5.6-6.9 mmol/L (100-125 mg/dL) to equalize developing diabetes between IGT and IFG. International organizations accepted the first IFG criterion but not the second. The ADA subsequently recommended HbA1c levels for diagnosing prediabetes/intermediate hyperglycemia of 39-47 mmol/mol (5.7-6.4%) based on a model that utilized the composite risk of developing diabetes and CVD. However, the evidence that the intermediate hyperglycemia that defines prediabetes is independently associated with CVD is weak. Rather, the other risk factors for CVD in the metabolic syndrome are responsible. The WHO opined that prediabetes/intermediate hyperglycemia could not be diagnosed by HbA1c levels but the Canadians and Europeans recommended its diagnosis by values of 42-47 mmol/mol (6.0-6.4%). With the ADA criteria, approximately one-half of people are normal on re-testing, one-third spontaneously revert to normal over time and two-thirds never develop diabetes in their lifetimes. The international criteria for prediabetes/intermediate hyperglycemia increase the risk of developing diabetes and might motivate these individuals to more seriously undertake lifestyle interventions as a preventive measure.

Discordance Between Glucose Levels Measured in Interstitial Fluid vs in Venous Plasma After Oral Glucose Administration: A Post-Hoc Analysis From the Randomised Controlled PRE-D Trial

Aims

The oral glucose tolerance test (OGTT) is together with haemoglobin A1c (HbA1c) gold standard for diagnosing prediabetes and diabetes. The objective of this study was to assess the concordance between glucose values obtained from venous plasma versus interstitial fluid after oral glucose administration in 120 individuals with prediabetes and overweight/obesity.

Methods

120 adults with prediabetes defined by HbA1c 39-47 mmol/mol and overweight or obesity who participated in the randomised controlled PRE-D trial were included in the study. Venous plasma glucose concentrations were measured at 0, 30, 60 and 120 minutes during a 75 g oral glucose tolerance test (OGTT) performed on three different occasions within a 26 weeks period. During the OGTT, the participants wore a CGM device (IPro2, Medtronic), which assessed glucose concentrations every five minutes.

Results

A total of 306 OGTTs with simultaneous CGM measurements were obtained. Except in fasting, the CGM glucose values were below the OGTT values throughout the OGTT period with mean (SD) differences of 0.2 (0.7) mmol/L at time 0 min, -1.1 (1.3) at 30 min, -1.4 (1.8) at 60 min, and -0.5 (1.1) at 120 min). For measurements at 0 and 120 min, there was a proportional bias with an increasing mean difference between CGM and OGTT values with increasing mean of the two measurements.

Conclusions

Due to poor agreement between the OGTT and CGM with wide 95% limits of agreement and proportional bias at 0 and 120 min, the potential for assessing glucose tolerance in prediabetes using CGM is questionable.

Definition and Classification of Diabetes and Prediabetes and Emerging Data on Phenotypes

Diabetes diagnosis has important implications for individuals. Diagnostic criteria for fasting and 2-hour plasma glucose and HbA1c are universally agreed. Intermediate hyperglycemia/prediabetes is a risk factor for diabetes and cardiovascular disease. Because risk is a continuum, determining cut-point is problematic and reflected in significant differences in recommended fasting glucose and HbA1c criteria. Many types of diabetes are recognized. Diabetes classification systems are limited by a lack of understanding of etiopathogenetic pathways leading to diminished β-cell function. The World Health Organization classification system is designed to assist clinical care decisions. Newly recognized phenotypic clusters of diabetes might inform future classification systems.

Association between dietary patterns and prediabetes, undetected diabetes or clinically diagnosed diabetes: results from the KORA FF4 study

PURPOSE

Diet is one of the most important modifiable risk factors for the development of type 2 diabetes. Here, we aim to identify dietary patterns and to investigate their association with prediabetes, undetected diabetes and prevalent diabetes.

METHODS

The present study included 1305 participants of the cross-sectional population-based KORA FF4 study. Oral glucose tolerance test (OGTT) measurements together with a physician-confirmed diagnosis allowed for an accurate categorization of the participants according to their glucose tolerance status into normal glucose tolerance (n = 698), prediabetes (n = 459), undetected diabetes (n = 49), and prevalent diabetes (n = 99). Dietary patterns were identified through principal component analysis followed by hierarchical clustering. The association between dietary patterns and glucose tolerance status was investigated using multinomial logistic regression models.

RESULTS

A Prudent pattern, characterized by high consumption of vegetables, fruits, wholegrains and dairy products, and a Western pattern, characterized by high consumption of red and processed meat, alcoholic beverages, refined grains and sugar-sweetened beverages, were identified. Participants following the Western pattern had significantly higher chances of having prediabetes (odds ratio [OR] 1.92; 95% confidence interval [CI] 1.35, 2.73), undetected diabetes (OR 10.12; 95% CI 4.19, 24.43) or prevalent diabetes (OR 3.51; 95% CI 1.85, 6.67), compared to participants following the Prudent pattern.

CONCLUSION

To our knowledge, the present study is one of the few investigating the association between dietary patterns and prediabetes or undetected diabetes. The use of a reference group exclusively including participants with normal glucose tolerance might explain the strong associations observed in our study. These results suggest a very important role of dietary habits in the prevention of prediabetes and type 2 diabetes.

The heterogeneity of reversion to normoglycemia according to prediabetes type is not explained by lifestyle factors

Healthy lifestyle interventions and drug therapies are proven to have a positive preventative influence on normal glucose regulation in prediabetes. However, little is known on the specific role that these factors play on reversion to normal glycemia according to type of prediabetes. We used data from the Observational prospective cohort study, The Cohort study in Primary Health Care on the Evolution of Patients with Prediabetes from 2012 to 2015. A total of 1184 individuals aged 30-74 years old were included and classified based on the ADA in three mutually exclusive groups using either fasting plasma glucose (FPG) levels (from 100 to 125 mg/dl, FPG group), HbA_1c (5.7-6.4%, HbA1c group) or both impaired parameters. Information on lifestyle factors and biochemical parameters were collected at baseline. Reversion to normal glucose regulation was calculated at third year of follow-up. Relationship of lifestyle factor and type of prediabetes with reversion were estimated using odds ratios (ORs) with 95% confidence intervals (95% CIs) adjusting by different groups of confounders. Proportion of reversion rates were 31% for FPG group, 31% for HbA1c group and 7.9% for both altered parameters group, respectively. Optimal life style factors such as BMI < 25 kg/m²[OR (95% CI): 1.90 (1.20-3.01)], high adherence to Mediterranean diet 1.78 (1.21-2.63) and absence of abdominal obesity 1.70 (1.19-2.43) were the strongest predictors for reversion to normal glucose. However, those did not modify the ORs of reversion to normal glucose. Taking as reference those with both impaired parameters, subjects with FPG impairment (FPG group) had an OR of 4.87 (3.10-7.65) and 3.72 (2.39-5.78) for HbA1c group. These estimates remained almost the same after further adjustment for biochemical parameters and lifestyle factors (4.55(2.84-7.28) and 3.09 (1.92-4.97), respectively). Optimal lifestyle factors showed to be a positive predictor for reversion to normal glucose regulation however, the differences of reversion risk according type of prediabetes are not explained by lifestyle factors.

Lipoprotein Insulin Resistance Index Reflects Liver Fat Content in Patients With Nonalcoholic Fatty Liver Disease

The recently developed lipoprotein insulin resistance index (LP-IR) incorporates lipoprotein particle numbers and sizes and is considered to reflect both hepatic and peripheral IR. As tissue IR is a strong component of nonalcoholic fatty liver disease (NAFLD) pathogenesis, we aimed to assess the degree by which LP-IR associates with hepatic fat content. This was a single-center retrospective analysis of patients with NAFLD. LP-IR, the homeostasis model assessment of insulin resistance (HOMA-IR), and adipose tissue IR (Adipo-IR) were measured simultaneously. Liver fat content was estimated by FibroScan controlled attenuated parameter. Associations were assessed using Spearman's correlation and multivariate linear regression. The study included 61 patients. LP-IR was correlated with HOMA-IR (ρ = 0.30; P = 0.02), typically thought to reflect hepatic IR, but not with Adipo-IR (ρ = 0.15; P = 0.25). Liver fat content was significantly associated with Adipo-IR (ρ = 0.48; P < 0.001), LP-IR (ρ = 0.35; P = 0.005), and to a lesser degree with HOMA-IR (ρ = 0.25; P = 0.051). The association of liver fat with LP-IR was limited to patients without diabetes (ρ = 0.60; P < 0.0001), whereas no association was seen in those with diabetes. In a multivariate model, Adipo-IR, LP-IR, and diabetes were independently associated with liver fat and together explained 35% of the variability in liver fat. Conclusion: LP-IR is a reasonable measure of IR in non-diabetic patients with NAFLD and is associated with hepatic fat content. Although adipose tissue is the major contributor to liver fat, the additional contribution of nonadipose tissues can be easily estimated using LP-IR.

Impact of disease activity on impaired glucose metabolism in patients with rheumatoid arthritis

Objective

To explore glucose metabolism in rheumatoid arthritis (RA) and its association with insulin resistance (IR) risk factors and disease activity indicators, including matrix metalloproteinase-3 (MMP3).

Methods

This single-center study included 127 non-diabetic subjects: 90 RA patients and 37 matched controls. IR-related risk factors, disease activity (DAS28-ESR/CRP), concentrations of inflammation markers, MMP3, glucose, specific insulin, and C-peptide (a marker of β-cell secretion) were determined. Homeostasis Model Assessment was used to establish insulin resistance (HOMA2-IR) and sensitivity (HOMA2-%S). Associations of HOMA2 indices with IR-related risk factors, inflammation markers, and RA activity were tested using multiple regression analyses.

Results

RA patients had significantly increased HOMA2-IR index than controls. In the RA group, multivariate analysis revealed DAS28-ESR, DAS28-CRP, tender joint counts, patient’s global assessment, and MMP3 level as significant positive predictors for HOMA2-IR (β = 0.206, P = 0.014; β = 0.192, P = 0.009; β = 0.121, P = 0.005; β = 0.148, P = 0.007; β = 0.075, P = 0.025, respectively), and reciprocal negative for HOMA2-%S index. According to the value of the coefficient of determination (R²), DAS28-ESR ≥ 5.1 has the largest proportion of variation in both HOMA2-IR indices. DAS28-ESR ≥ 5.1 and ESR were independent predictors for increased C-peptide concentration (β = 0.090, P = 0.022; β = 0.133, P = 0.022). Despite comparability regarding all IR-related risk factors, patients with DAS28-ESR ≥ 5.1 had higher HOMA2-IR than controls [1.7 (1.2–2.5) vs. 1.2 (0.8–1.4), P = 0.000]. There was no difference between patients with DAS28-ESR < 5.1 and controls [1.3 (0.9–1.9) vs. 1.2 (0.8–1.4), P = 0.375].

Conclusions

RA activity is an independent risk factor for impaired glucose metabolism. DAS28-ESR ≥ 5.1 was the main contributor to this metabolic disturbance, followed by MMP3 concentration, outweighing the impact of classic IR-related risk factors.

A systems biology approach to understand gut microbiota and host metabolism in morbid obesity: design of the BARIA Longitudinal Cohort Study

INTRODUCTION

Prevalence of obesity and associated diseases, including type 2 diabetes mellitus, dyslipidaemia and non-alcoholic fatty liver disease (NAFLD), are increasing. Underlying mechanisms, especially in humans, are unclear. Bariatric surgery provides the unique opportunity to obtain biopsies and portal vein blood-samples.

METHODS

The BARIA Study aims to assess how microbiota and their metabolites affect transcription in key tissues and clinical outcome in obese subjects and how baseline anthropometric and metabolic characteristics determine weight loss and glucose homeostasis after bariatric surgery. We phenotype patients undergoing bariatric surgery (predominantly laparoscopic Roux-en-Y gastric bypass), before weight loss, with biometrics, dietary and psychological questionnaires, mixed meal test (MMT) and collect fecal-samples and intra-operative biopsies from liver, adipose tissues and jejunum. We aim to include 1500 patients. A subset (approximately 25%) will undergo intra-operative portal vein blood-sampling. Fecal-samples are analyzed with shotgun metagenomics and targeted metabolomics, fasted and postprandial plasma-samples are subjected to metabolomics, and RNA is extracted from the tissues for RNAseq-analyses. Data will be integrated using state-of-the-art neuronal networks and metabolic modeling. Patient follow-up will be ten years.

RESULTS

Preoperative MMT of 170 patients were analysed and clear differences were observed in glucose homeostasis between individuals. Repeated MMT in 10 patients showed satisfactory intra-individual reproducibility, with differences in plasma glucose, insulin and triglycerides within 20% of the mean difference.

CONCLUSION

The BARIA study can add more understanding in how gut-microbiota affect metabolism, especially with regard to obesity, glucose metabolism and NAFLD. Identification of key factors may provide diagnostic and therapeutic leads to control the obesity-associated disease epidemic.

Approaches to screening for hyperglycaemia in pregnant women during and after the COVID-19 pandemic

AIM

To evaluate the diagnostic and prognostic performance of alternative diagnostic strategies to oral glucose tolerance tests, including random plasma glucose, fasting plasma glucose and HbA_1c , during the COVID-19 pandemic.

METHODS

Retrospective service data (Cambridge, UK; 17 736 consecutive singleton pregnancies, 2004-2008; 826 consecutive gestational diabetes pregnancies, 2014-2019) and 361 women with ≥1 gestational diabetes risk factor (OPHELIA prospective observational study, UK) were included. Pregnancy outcomes included gestational diabetes (National Institute of Health and Clinical Excellence or International Association of Diabetes and Pregnancy Study Groups criteria), diabetes in pregnancy (WHO criteria), Caesarean section, large-for-gestational age infant, neonatal hypoglycaemia and neonatal intensive care unit admission. Receiver-operating characteristic curves and unadjusted logistic regression were used to compare random plasma glucose, fasting plasma glucose and HbA_1c performance.

RESULTS

Gestational diabetes diagnosis was significantly associated with random plasma glucose at 12 weeks [area under the receiver-operating characteristic curve for both criteria 0.81 (95% CI 0.79-0.83)], fasting plasma glucose [National Institute of Health and Clinical Excellence: area under the receiver-operating characteristic curve 0.75 (95% CI 0.65-0.85); International Association of Diabetes and Pregnancy Study Groups: area under the receiver-operating characteristic curve 0.92 (95% CI 0.85-0.98)] and HbA_1c at 28 weeks' gestation [National Institute of Health and Clinical Excellence: 0.83 (95% CI 0.75-0.90); International Association of Diabetes and Pregnancy Study Groups: 0.84 (95% CI 0.77-0.91)]. Each measure predicts some, but not all, pregnancy outcomes studied. At 12 weeks, ~5% of women would be identified using random plasma glucose ≥8.5 mmol/l (sensitivity 42%; specificity 96%) and at 28 weeks using HbA_1c ≥39 mmol/mol (sensitivity 26%; specificity 96%) or fasting plasma glucose ≥5.2-5.4 mmol/l (sensitivity 18-41%; specificity 97-98%).

CONCLUSIONS

Random plasma glucose at 12 weeks, and fasting plasma glucose or HbA_1c at 28 weeks identify women with hyperglycaemia at risk of suboptimal pregnancy outcomes. These opportunistic laboratory tests perform adequately for risk stratification when oral glucose tolerance testing is not available.

Causal Evaluation of Laboratory Markers in Type 2 Diabetes on Cancer and Vascular Diseases Using Various Mendelian Randomization Tools

Multiple studies have demonstrated the effects of type 2 diabetes (T2D) on various human diseases; however, most of these were observational epidemiological studies that suffered from many potential biases including reported confounding and reverse causations. In this article, we investigated whether cancer and vascular disease can be affected by T2D-related traits, including fasting plasma glucose (FPG), 2-h postprandial glucose (2h-PG), and glycated hemoglobin A1c (HbA1c) levels, by using Mendelian randomization (MR). The summary statistics for FPG, 2h-PG, and HbA1c level were obtained through meta-analyses of large-scale genome-wide association studies that included data from 133,010 nondiabetic individuals from collaborating Meta-analysis of Glucose and Insulin Related Traits Consortium studies. Thereafter, based on the statistical assumptions for MR analyses, the most reliable approaches including inverse-variance-weighted (IVW), MR-Egger, MR-Egger with a simulation extrapolation (SIMEX), weighted median, and MR-pleiotropy residual sum and outlier (MR-PRESSO) methods were applied to identify traits affected by FPG, 2h-PG, and HbAlc. We found that coronary artery disease is affected by FPG, as per the IVW [log odds ratio (logOR): 0.21; P = 0.012], MR-Egger (SIMEX) (logOR: 0.22; P = 0.014), MR-PRESSO (logOR: 0.18; P = 0.045), and weighted median (logOR: 0.29; P < 0.001) methods but not as per the MR-Egger (logOR: 0.13; P = 0.426) approach. Furthermore, low-density lipoprotein cholesterol levels are affected by HbA1c, as per the IVW [beta (B): 0.23; P = 0.015), MR-Egger (B: 0.45; P = 0.046), MR-Egger (SIMEX) (B: 0.27; P = 0.007), MR-PRESSO (B; 0.14; P = 0.010), and the weighted median (B: 0.15; P = 0.012] methods. Further studies of the associated biological mechanisms are required to validate and understand the disease-specific differences identified in the TD2-related causal effects of each trait.

Are normoglycaemic individuals at risk of depression? The depression-dysglycaemic phenotype from a European population-based cross-sectional study

BACKGROUND

Depression is a chronic non communicable disease. It is a growing public health concern with established links with a number of co-morbidities, including diabetes mellitus. The study aimed to estimate the prevalence of depression at a population level, establish the depression sub-population phenotypic characteristics while exploring for links between depression and a spectrum of glycemic abnormalities.

METHODS

A nationally representative cross-sectional study was conducted in Malta between 2014 and 2016. Participants were categorized into different sub-populations according to their glycaemic status. Depression prevalence rates and phenotypic characteristics for each sub-population were established. Multiple regression analysis was performed to identify links with depression.

RESULTS

Depression was prevalent in 17.15% (CI 95%: 16.01-18.36) with a female predominance. Those with known (as opposed to newly diagnosed) diabetes had the highest depression prevalence when compared to other glycemic sub-groups. These also exhibited a significant link with self-reported depression. However, at a population level, depression was mostly prevalent within the normoglycaemic sub-population.

CONCLUSIONS

The study confirms the strong link between diabetes and depression, especially, in a high risk dysglycaemic population. Of public health concern is the high depression occurrence within the normoglycaemic sub-population, which attributed for the majority of the Maltese population. In order to reduce the impact of mental health on the population, physicians may consider implementing depression screening clinical tools as part of their routine health check-ups at primary care level, irrespective of the glycaemic status of their patients.

Association between fasting glucose levels and adhesive capsulitis in a normoglycemic population: a case-control study

BACKGROUND

Hyperglycemia is the most commonly cited risk factor for adhesive capsulitis. However, no study has established whether fasting glucose levels within the normoglycemic range are associated with idiopathic adhesive capsulitis (IAC). This study hypothesized that increments of fasting glucose levels within the normoglycemic range would be linked to IAC. This study investigated any association between normoglycemic fasting glucose levels and IAC.

METHODS

This case-control study comprised a group of 151 patients with IAC without intrinsic shoulder lesions, extrinsic causes, or known metabolic risk factors such as diabetes, dyslipidemia, and thyroid dysfunction. The control group comprised 453 age- and sex-matched persons seeking general check-ups at the authors' health promotion center during the same period as the case group. Control subjects had normal shoulder function, no previous diagnosis of adhesive capsulitis or of metabolic disease, and no history of trauma or of shoulder surgery. The studied variables were body mass index, serum lipid profiles, thyroid hormone levels, fasting glucose levels, glycosylated hemoglobin A1c, and high-sensitivity C-reactive protein. Fasting glucose levels were studied as scale data and categorical data (<85, 85-89, 90-94, and 95-99 mg/dL). Multivariable conditional logistic regression analysis evaluated the matched sets of subjects. Odds ratios and 95% confidence intervals were determined for various potentially associated factors.

RESULTS

Fasting glucose level, hypercholesterolemia, and high-sensitivity C-reactive protein were significantly associated with IAC (P ≤ .030). Fasting glucose levels in the <85 mg/dL quartile were significantly negatively associated with IAC (P ≤ .001). In contrast, fasting glucose levels in the 90-94 mg/dL quartile or higher were significantly positively associated with IAC (P ≤ .034).

CONCLUSION

IAC is positively associated with fasting glucose levels of 90-99 mg/dL, which are currently considered normoglycemic.

Testing for gestational diabetes during the COVID-19 pandemic. An evaluation of proposed protocols for the United Kingdom, Canada and Australia

AIMS

We assessed how altered diagnostic processes and criteria for gestational diabetes mellitus (GDM) recommended by the United Kingdom (UK), Canada and Australia for use during the COVID-19 pandemic would affect both GDM frequency and related adverse outcomes.

METHODS

Secondary analysis of 5974 HAPO study women with singleton pregnancies who underwent 75 g OGTTs and HbA1c assays between 24 and 32 weeks' gestation and who received no treatment for GDM.

RESULTS

All post COVID-19 modified pathways reduced GDM frequency - UK (81%), Canada (82%) and Australia (25%). Canadian women whose GDM would remain undetected post COVID-19 (missed GDMs) displayed similar rates of pregnancy complications to those with post COVID-19 GDM. Using UK modifications, the missed GDM group were at slightly lower risk whilst the women missed using the Australian modifications were at substantially lower risk.

CONCLUSIONS

The modifications in GDM diagnosis proposed for the UK, Canada and Australia result in differing reductions of GDM frequency. Each has both potential benefits in terms of reduction in potential exposure to COVID-19 and costs in terms of missed opportunities to influence pregnancy and postpartum outcomes. These factors should be considered when deciding which protocol is most appropriate for a particular context.

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.

Glycemic index of pulses and pulse-based products: a review

Pulses are a major source for plant-based proteins, with over 173 countries producing and exporting over 50 million tons annually. Pulses provide many of the essential nutrients and vitamins for a balanced and healthy diet, hence are health beneficial. Pulses have been known to lower glycemic index (GI), as they elicit lower post prandial glycemic responses, and can prevent insulin resistance, Type 2 diabetes and associated complications. This study reviews the GI values (determined by in vivo methodology) reported in 48 articles during the year 1992-2018 for various pulse type preparations consumed by humans. The GI ranges (glucose and bread as a reference respectively) for each pulse type were: broad bean (40 ± 5 to 94 ± 4, 75 to 93), chickpea (5 ± 1 to 45 ± 1, 14 ± 3 to 96 ± 21), common bean (9 ± 1 to 75 ± 8, 18 ± 2 to 99 ± 11), cowpea (6 ± 1 to 56 ± 0.2, 38 ± 19 to 66 ± 7), lentil (10 ± 3 to 66 ± 6, 37 to 87 ± 6), mung bean (11 ± 2 to 90 ± 9, 28 ± 1 to 44 ± 6), peas (9 ± 2 to 57 ± 2, 45 ± 8 to 93 ± 9), pigeon peas (7 ± 1 to 54 ± 1, 31 ± 4), and mixed pulses (35 ± 5 to 66 ± 23, 69 ± 42 to 98 ± 29). It was found that the method of preparation, processing and heat applications tended to affect the GI of pulses. In addition, removal of the hull, blending, grinding, milling and pureeing, reduced particle size, contributed to an increased surface area and exposure of starch granules to the amylolytic enzymes. This was subsequently associated with rapid digestion and absorption of pulse carbohydrates, resulting in a higher GI. High or increased heat applications to pulses were associated with extensive starch gelatinization, also leading to a higher GI. The type of reference food used (glucose or white bread) and the other nutrients present in the meal also affected the GI.

Physiological factors contributing to HbA1c in the normal and pre-diabetic range: a cross-sectional analysis

PURPOSE

Little is known about the underlying physiology that contributes to Haemoglobin A1c (HbA_1c) in the normal and pre-diabetic range. We determined the contribution of fasting plasma glucose (FPG), 2-h plasma glucose (2hPG), insulin secretion, insulin sensitivity and endogenous glucose production to HbA_1c levels in the normal and pre-diabetic range.

METHODS

A total of 62 Danish men and women with normal or impaired glucose regulation were studied. HbA_1c levels were measured and participants underwent an oral glucose tolerance test with measurements of FPG and 2hPG, an intravenous glucose tolerance test for determination of first-phase insulin release, and a hyperinsulinaemic euglycaemic clamp for estimation of peripheral and hepatic insulin sensitivity. Associations of HbA_1c with the different measures of glucose metabolism were analysed by linear regression analysis.

RESULTS

HbA_1c levels ranged from 28 to 45 mmol/mol (4.7-6.3%) in the study population. 1 SD higher (log) FPG concentration (~1 mmol/L) was associated with 2 mmol/mol higher HbA_1c concentration (P < 0.001). In comparison, 1 SD higher levels of (log) first-phase insulin secretion or (log) disposition index were associated with 1.5 mmol/mol lower HbA_1c levels (P < 0.05). HbA_1c was not associated with peripheral or hepatic insulin sensitivity, endogenous glucose production or 2hPG levels.

CONCLUSION

HbA_1c levels within the normal and pre-diabetic range seem to reflect decreased insulin secretion to a higher extent than insulin resistance. Therefore, early prevention strategies for high-risk individuals identified by HbA_1c are not straightforward. More research on how to improve the health of beta cells either directly or indirectly in high-risk individuals is needed.

White Matter Connectivity Abnormalities in Prediabetes and Type 2 Diabetes: The Maastricht Study

OBJECTIVE

Prediabetes and type 2 diabetes are associated with structural brain abnormalities, often observed in cognitive disorders. Besides visible lesions, (pre)diabetes might also be associated with alterations of the intrinsic organization of the white matter. In this population-based cohort study, the association of prediabetes and type 2 diabetes with white matter network organization was assessed.

RESEARCH DESIGN AND METHODS

In the Maastricht Study, a type 2 diabetes-enriched population-based cohort study (1,361 subjects with normal glucose metabolism, 348 with prediabetes, and 510 with type 2 diabetes assessed by oral glucose tolerance test; 52% men; aged 59 ± 8 years), 3 Tesla structural and diffusion MRI was performed. Whole-brain white matter tractography was used to assess the number of connections (node degree) between 94 brain regions and the topology (graph measures). Multivariable linear regression analyses were used to investigate the associations of glucose metabolism status with network measures. Associations were adjusted for age, sex, education, and cardiovascular risk factors.

RESULTS

Prediabetes and type 2 diabetes were associated with lower node degree after full adjustment (standardized [st]β_Prediabetes = -0.055 [95% CI -0.172, 0.062], stβ_{Type2diabetes} = -0.256 [-0.379, -0.133], P _trend < 0.001). Prediabetes was associated with lower local efficiency (stβ = -0.084 [95% CI -0.159, -0.008], P = 0.033) and lower clustering coefficient (stβ = -0.097 [95% CI -0.189, -0.005], P = 0.049), whereas type 2 diabetes was not. Type 2 diabetes was associated with higher communicability (stβ = 0.148 [95% CI 0.042, 0.253], P = 0.008).

CONCLUSIONS

These findings indicate that prediabetes and type 2 diabetes are associated with fewer white matter connections and weaker organization of white matter networks. Type 2 diabetes was associated with higher communicability, which was not yet observed in prediabetes and may reflect the use of alternative white matter connections.

Size and Shape of Associations of OGTT as Well as Mediating Effects on Adverse Pregnancy Outcomes Among Women With Gestational Diabetes Mellitus: Population-Based Study From Southern Han Chinese

Objective: To explore the size and shape association of OGTT values with adverse pregnancy complications among women with gestational diabetes mellitus (GDM) in Southern Han Chinese population and further analyze their mediating effects with maternal age in outcomes. Methods: 6,861 women with GDM were included in the study. Logistic regression was used to identify the correlations between OGTT values and adverse pregnancy outcomes of GDM. Restricted cubic spline nested logistic regression was conducted to investigate potential non-linear and linear associations. Mediating effect among maternal age, OGTT and adverse outcomes were explored. Results: Women with GDM had a mean age of 31.83, and 24.49% had advanced maternal age (≥35 years). In logistic regression with adjustment, compared with lower OGTT0 (<5.1 mmol/L), GDM patients with higher OGTT0 (≥5.1 mmol/L) exhibited 1.891 (95% CI: 1.441-2.298, P < 0.001), 1.284 (1.078-1.529, P = 0.005), 1.285 (1.065-1.550, P = 0.009), and 1.302 (1.067-1.590, P = 0.010) times increased risk of hypertensive disorders of pregnancy (HDP), preterm, neonatal hyperbilirubinemia, and macrosomia, respectively. GDM patients with higher OGTT1 (≥10 mmol/L) had only found to exhibited 1.473-fold (1.162-1.867, P = 0.001) increasing risk of HDP than those with lower OGTT1 (<10 mmol/L). No adverse outcome was identified to associate with higher OGTT2 (≥8.5 mmol/L). Linear relationships (non-linear P > 0.05) were observed between OGTT0 and HDP, preterm, neonatal hyperbilirubinemia, and macrosomia in both maternal age groups (<35 and ≥35 years). Non-linear associations of OGTT1 with incidence of HDP, preterm, and neonatal hyperbilirubinemia were detected in GDM patients younger than 35 years (non-linear P = 0.037, P = 0.049, P = 0.039, respectively), rising more steeply at higher values. Similar non-linearity was noted for OGTT2 with HDP in older patients. All OGTT values had significant mediating effects on some special complications caused by higher age. Conclusion: Higher fasting plasma glucose was more strongly linked to adverse pregnancy outcomes among GDM patients. Both linearity and Non-linearity of associations between glucose and complications should be taken into account. A careful reconsideration of GDM with hierarchical and individualized management according to OGTT is needed.

The oral glucose tolerance test-derived incremental glucose peak is associated with greater arterial stiffness and maladaptive arterial remodeling: The Maastricht Study

Background

Daily glucose variability may contribute to vascular complication development irrespective of mean glucose values. The incremental glucose peak (IGP) during an oral glucose tolerance test (OGTT) can be used as a proxy of glucose variability. We investigated the association of IGP with arterial stiffness, arterial remodeling, and microvascular function, independent of HbA_1c and other confounders.

Methods

IGP was calculated as the peak minus baseline plasma glucose value during a seven-point OGTT in 2758 participants (age: 60 ± 8 years; 48% women) of The Maastricht Study, an observational population-based cohort. We assessed the cross-sectional associations between IGP and arterial stiffness (carotid-femoral pulse wave velocity [cf-PWV], carotid distensibility coefficient [carDC]), arterial remodeling (carotid intima-media thickness [cIMT]; mean [CWS_mean] and pulsatile [CWS_puls] circumferential wall stress), and microvascular function (retinal arteriolar average dilatation; heat-induced skin hyperemia) via multiple linear regression with adjustment for age, sex, HbA_1c, cardiovascular risk factors, lifestyle factors, and medication use.

Results

Higher IGP was independently associated with higher cf-PWV (regression coefficient [B]: 0.054 m/s [0.020; 0.089]) and with higher CWS_mean (B: 0.227 kPa [0.008; 0.446]). IGP was not independently associated with carDC (B: − 0.026 10⁻³/kPa [− 0.112; 0.060]), cIMT (B: − 2.745 µm [− 5.736; 0.245]), CWS_puls (B: 0.108 kPa [− 0.054; 0.270]), retinal arteriolar average dilatation (B: − 0.022% [− 0.087; 0.043]), or heat-induced skin hyperemia (B: − 1.380% [− 22.273; 19.513]).

Conclusions

IGP was independently associated with aortic stiffness and maladaptive carotid remodeling, but not with carotid stiffness, cIMT, and microvascular function measures. Future studies should investigate whether glucose variability is associated with cardiovascular disease.

A Critical Evaluation of Wet Biomarkers for Huntington's Disease: Current Status and Ways Forward

There is an unmet clinical need for objective biomarkers to monitor disease progression and treatment response in Huntington's disease (HD). The aim of this review is, therefore, to provide practical advice for biomarker discovery and to summarise studies on biofluid markers for HD. A PubMed search was performed to review literature with regard to candidate saliva, urine, blood and cerebrospinal fluid biomarkers for HD. Information has been organised into tables to allow a pragmatic approach to the discussion of the evidence and generation of practical recommendations for future studies. Many of the markers published converge on metabolic and inflammatory pathways, although changes in other analytes representing antioxidant and growth factor pathways have also been found. The most promising markers reflect neuronal and glial degeneration, particularly neurofilament light chain. International collaboration to standardise assays and study protocols, as well as to recruit sufficiently large cohorts, will facilitate future biomarker discovery and development.

Accuracy of the 13C-glucose breath test to identify insulin resistance in non-diabetic adults

AIMS

To assess the validity of the ¹³C-glucose breath test (¹³C-GBT) to identify insulin resistance (IR) in non-diabetic individuals, using hyperinsulinemic-euglycemic clamps as gold standard. This validity was compared with that of other IR surrogates.

METHODOLOGY

Non-diabetic adults were studied in a cross-sectional design. In a first appointment, oral glucose tolerance tests were conducted simultaneously with ¹³C-GBTs. Oral 75 g glucose dissolved in 150 ml water, followed by 1.5 mg/Kg body weight U-¹³C-glucose dissolved in 50 ml water, was administered. Breath and blood samples were collected at baseline and at 30-min intervals. The percentages of glucose-oxidized dose at given periods were calculated. Clamps were conducted a week later. A clamp-derived M value ≤ 6.0 mg/kg*min was used as cut-off. ROC curves were constructed for ¹³C-GBT, fasting insulin, HOMA, and ISI-composite.

RESULTS

Thirty-eight subjects completed the study protocol. The correlation coefficient between the ¹³C-GBT derived glucose-oxidized dose at 180 min and M values was 0.524 (p = 0.001). The optimal value to identify IR with the ¹³C-GBT was 4.23% (AUC 0.81; ₉₅CI 0.66, 0.96; accuracy 0.82, ₉₅CI 0.66, 0.92). The ¹³C-GBT sensitivity (0.88) was higher than HOMA and fasting insulin sensitivities (0.83 and 0.75 respectively), while their specificities were comparable (0.71, 0.71, and 0.79, respectively). The sensitivity of ISI-C was higher (0.92) than that of the ¹³C-GBT, but its specificity was poor (0.36). The accuracy of the ¹³C-GBT was superior to that of the other studied surrogates.

CONCLUSIONS

The ¹³C-GBT is a valid and accurate method to detect IR in non-diabetic adults. Therefore, it is potentially useful in clinical and community settings.

Catheter-Based Measurements of Absolute Coronary Blood Flow and Microvascular Resistance: Feasibility, Safety, and Reproducibility in Humans

BACKGROUND

The principle of continuous thermodilution can be used to calculate absolute coronary blood flow and microvascular resistance (R). The aim of the study is to explore the safety, feasibility, and reproducibility of coronary blood flow and R measurements as measured by continuous thermodilution in humans.

METHODS AND RESULTS

Absolute coronary flow and R can be calculated by thermodilution by infusing saline at room temperature through a dedicated monorail catheter. The temperature of saline as it enters the vessel, the temperature of blood and saline mixed in the distal part of the vessel, and the distal coronary pressure were measured by a pressure/temperature sensor-tipped guidewire. The feasibility and safety of the method were tested in 135 patients who were referred for coronary angiography. No significant adverse events were observed; in 11 (8.1%) patients, bradycardia and concomitant atrioventricular block appeared transiently and were reversed immediately on interruption of the infusion. The reproducibility of measurements was tested in a subgroup of 80 patients (129 arteries). Duplicate measurements had a strong correlation both for coronary blood flow (ρ=0.841, P<0.001; intraclass correlation coefficient=0.89, P<0.001) and R (ρ=0.780, P<0.001; intraclass correlation coefficient=0.89, P<0.001). In Bland-Altman plots, there was no significant bias or asymmetry.

CONCLUSIONS

Absolute coronary blood flow (in L/min) and R (in mm Hg/L/min or Wood units) can be safely and reproducibly measured with continuous thermodilution. This approach constitutes a new opportunity for the study of the coronary microcirculation.

Placental exosomes viewed from an 'omics' perspective: implications for gestational diabetes biomarkers identification

Exosomes are defined as extracellular vesicles that are released from cells upon fusion of an intermediate endocytic compartment - the multivesicular body - with the plasma membrane. Recently, placenta-derived exosomes have gained special attention, since they play a crucial role in the communication between the mother and fetus. It is known that the concentration of placenta-derived exosomes in the maternal bloodstream is higher in patients with preeclampsia or gestational diabetes mellitus. However, their composition in terms of the content of proteins, nucleic acids or lipids is uncertain. In this work, we reviewed the recent advances in placental exosomes characterization through omics-based methods, and their potential to predict gestational diabetes mellitus.

Intestinal Glucose Absorption Is a Key Determinant of 1-Hour Postload Plasma Glucose Levels in Nondiabetic Subjects

CONTEXT

One-hour postload hyperglycemia, defined as 1-hour plasma glucose (1hPG) ≥ 155 mg/dL during an oral glucose tolerance test (OGTT), has been proposed as an independent predictor of type 2 diabetes. Recent evidence suggests that 1-hour hyperglycemia can be explained by enhanced duodenal glucose absorption, which in turn may increase the rate of appearance of oral glucose in the systemic circulation (RaO). However, the impact of RaO on 1hPG and 1-hour glucose excursions (incremental area under the curve calculated through the first hour after glucose ingestion; glucose iAUC1h) is still unknown.

OBJECTIVE

We quantified the relative contribution of postload RaO to 1hPG and glucose iAUC1h with respect to other major glucose homeostatic mechanisms in nondiabetic participants.

PARTICIPANTS AND METHODS

Model-derived β-cell function, insulin clearance, glucose metabolic fluxes, and peripheral and hepatic insulin sensitivity were measured during a 75-g OGTT by a double tracer method in 23 nondiabetic volunteers.

RESULTS

Early insulin secretion, whole-body insulin sensitivity, and plasma glucose disposal were significantly impaired in participants with 1hPG ≥ 155 mg/dL (n = 11), who also showed nominally greater RaO (19%; P = 0.10). In multivariable models, postload RaO showed an independent effect on both 1hPG and glucose iAUC1h (partial r2 = 0.26 and 0.48, respectively; P < 0.003). The relative contribution of RaO to 1hPG (23%) and glucose iAUC1h (30%) was similar to that of early insulin secretion and peripheral insulin sensitivity and greater than that of hepatic insulin sensitivity.

CONCLUSIONS

Our data highlight the primary role of RaO as a major determinant of 1-hour postprandial glucose excursions in nondiabetic participants.

Is fasting plasma glucose in early pregnancy a better predictor of adverse obstetric outcomes than glycated haemoglobin?

OBJECTIVES

To determine, in a multi-ethnic cohort, the suitability of first-trimester fasting plasma glucose and HbA1c levels in non-diabetic range to identify women without diabetes at increased pregnancy risk.

STUDY DESIGN

A retrospective analysis of a prospective cohort between April 2013 and September 2015. Universal testing for fasting plasma glucose and HbA1c levels at the first antenatal blood sampling was performed and women were screened for gestational diabetes mellitus at 24-28 weeks' gestation. Primary outcomes were macrosomia and pre-eclampsia, and secondary outcomes preterm delivery, Caesarean section and large-for-gestational age. Different fasting plasma glucose and HbA1c cut-off levels were assessed for associations with outcomes.

RESULTS

1,228 pregnancies were included for outcome analysis. After adjustment for potential confounders, no association was found between fasting plasma glucose levels and pregnancy outcomes. Women with an HbA1c ≥5.8% (39.9 mmol/mol) showed an increased risk of macrosomia (OR 2.69, 95% CI 1.16-6.24); an HbA1c ≥5.9% (41 mmol/mol) threshold was independently associated with a three-fold risk of pre-eclampsia (95% CI 1.03-9.9) and an HbA1c ≥6.0% (42.1 mmol/mol) with a four-fold risk of large-for-gestational age (95% CI 1.49-11.07).

CONCLUSIONS

In a multi-ethnic population, first-trimester fasting plasma glucose levels were not a better predictor of pregnancy complications than HbA1c. Further, an early HbA1c ≥5.8% (39.9 mmol/mol) threshold is already associated with an increased risk of macrosomia.

Glucose metabolism in patients with psoriasis

BACKGROUND

Epidemiological studies strongly suggest that psoriasis predisposes to type 2 diabetes. Several theories have been proposed to explain how these disease entities might be pathophysiologically connected.

OBJECTIVES

Our primary objective was to elucidate whether clinical data support the notion of common pathophysiological denominators in patients with psoriasis and type 2 diabetes, and thus to delineate the association between the two conditions that has arisen on the basis of epidemiological studies.

METHODS

We reviewed clinical studies investigating parameters of glucose metabolism in patients with psoriasis. The PubMed and Embase databases were searched for studies investigating glucose metabolism in adult patients with psoriasis as a primary or secondary end point. Studies had to include a relevant control group.

RESULTS

Twenty-six clinical studies reporting on insulin resistance, glucose tolerance or insulin secretion were eligible for review. The results were widely conflicting, with less than half of the studies showing results suggestive of defective glucose metabolism in patients with psoriasis. In general, the studies suffered from a lack of information regarding possible confounders and patient characteristics. Furthermore, the research methods varied, and in all but one study they might not have been appropriate to detect early and subtle defects in glucose metabolism.

CONCLUSIONS

The available literature does not unequivocally support common pathophysiological denominators in psoriasis and type 2 diabetes. Well-designed clinical studies are needed to expose potential diabetogenic defects in the glucose metabolism in patients with psoriasis.

Factors associated with undiagnosed diabetes among adults with diabetes: Results from the Hispanic Community Health Study/Study of Latinos (HCHS/SOL)

AIMS

To investigate sociodemographic and health factors associated with undiagnosed diabetes among adults with diabetes in the Hispanic Community Health Study/Study of Latinos (HCHS/SOL).

METHODS

Among 3384 adults with self-reported diabetes or undiagnosed diabetes in the baseline HCHS/SOL, we estimated odds ratios (OR) of being undiagnosed for demographic, cultural, access to care, and health factors.

RESULTS

Among individuals with diabetes, 37.0% were undiagnosed. After adjustment and compared to people of Mexican heritage, people of Cuban and South American heritage had 60% (OR = 1.60, 95% CI = 1.02-2.50) and 91% (OR = 1.91, 1.16-3.14) higher odds of being undiagnosed, respectively. Individuals with a higher odds of being undiagnosed were women (OR = 1.64, 1.26-2.13), those with no health insurance (OR = 1.31, 1.00-1.71), individuals who received no healthcare in the past year (OR = 3.59, 2.49-5.16), those who were overweight (vs. normal weight) (OR = 1.60, 1.02-2.50), and those with dyslipidemia (OR = 1.38, 1.10-1.74). Individuals with lower odds of being undiagnosed were those with a family history of diabetes (OR = 0.54, 0.43-0.68), and those with hypertension (OR = 0.46, 0.36-0.58).

CONCLUSIONS

Variation by Hispanic heritage group, sex, and access to medical care highlight where concentrated efforts are need to improve diabetes awareness. Our findings will inform clinical and public health practices to improve diabetes awareness among vulnerable populations.

The Impact of the Affordable Care Act (ACA) Medicaid Expansion on Visit Rates for Diabetes in Safety Net Health Centers

OBJECTIVE

To (1) compare clinic-level uninsured, Medicaid-insured, and privately insured visit rates within and between expansion and nonexpansion states before and after the Affordable Care Act (ACA) Medicaid expansion among the 3 cohorts of patient populations; and (2) assess whether there was a change in clinic-level overall, primary care visits, preventive care visits, and diabetes screening rates in expansion versus nonexpansion states from pre-ACA to post-ACA Medicaid expansion.

METHODS

Electronic health record data on nonpregnant patients aged 19 to 64 years, with ≥1 ambulatory visit between 01/01/2012 and 12/31/2015 (n = 483,912 in expansion states; n = 388,466 in nonexpansion states) from 198 primary care community health centers were analyzed. Using a difference-in-difference methodology, we assessed changes in visit rates pre-ACA versus post-ACA among a cohort of patients with diabetes, prediabetes, and no diabetes.

RESULTS

Rates of uninsured visits decreased for all cohorts in expansion and nonexpansion states. For all cohorts, Medicaid-insured visit rates increased significantly more in expansion compared with nonexpansion states, especially among prediabetic patients (+71%). In nonexpansion states, privately insured visit rates more than tripled for the prediabetes cohort and doubled for the diabetes and no diabetes cohorts. Rates for glycosylated hemoglobin screenings increased in all groups, with the largest changes among no diabetes (rate ratio, 2.26; 95% CI, 1.97-2.56) and prediabetes cohorts (rate ratio, 2.00; 95% CI, 1.80-2.19) in expansion states.

CONCLUSION

The ACA reduced uninsurance and increased access to preventive care for vulnerable patients, especially those with prediabetes. These findings are important to consider when making decisions regarding altering the ACA.

Predictive Accuracy of Surrogate Indices for Hepatic and Skeletal Muscle Insulin Sensitivity

Context

Surrogate indices of muscle and hepatic insulin sensitivity derived from an oral glucose tolerance test (OGTT) are frequently used in clinical studies. However, the predictive accuracy of these indices has not been validated.

Design

In this cross-sectional study, hyperinsulinemic-euglycemic glucose clamp with tritiated glucose infusion and a 75-g OGTT were performed in individuals (n = 659, aged 18 to 49 years, body mass index of 16 to 64 kg/m²) with varying degrees of glucose tolerance. A calibration model was used to assess the ability of OGTT-derived, tissue-specific surrogate indices [hepatic insulin resistance index (HIRI) and muscle insulin sensitivity index (MISI)] to predict insulin sensitivity/resistance indices derived from the reference glucose clamp [Hepatic-IR_basal, a product of fasting plasma insulin and hepatic glucose production (HGP), Hepatic-IR_clamp, reciprocal of the percent suppression of HGP during the insulin clamp corrected for plasma insulin concentration, and Muscle-IS_clamp, a measure of peripheral glucose disposal]. Predictive accuracy was assessed by root mean squared error of prediction and leave-one-out, cross-validation-type square root of the mean squared error of prediction.

Results

HIRI and MISI were correlated with their respective clamp-derived indices. HIRI was negatively related to Muscle-IS_clamp (r = -0.62, P < 0.0001) and MISI correlated with Hepatic-IR derived from the clamp (Hepatic-IR_basal: r = -0.48, P < 0.0001 and Hepatic-IR_clamp: r = -0.41, P < 0.0001). However, the accuracy of HIRI and MISI to predict Hepatic-IR (basal or during clamp) was not significantly different. Likewise, the ability of HIRI and MISI to predict Muscle-IS_clamp was also similar.

Conclusion

Our findings indicate that the surrogate indices derived from an OGTT are accurate in predicting insulin sensitivity but are not tissue specific.

MicroRNA, Proteins, and Metabolites as Novel Biomarkers for Prediabetes, Diabetes, and Related Complications

Type 2 diabetes mellitus (T2DM) is no more a lifestyle disease of developed countries. It has emerged as a major health problem worldwide including developing countries. However, how diabetes could be detected at an early stage (prediabetes) to prevent the progression of disease is still unclear. Currently used biomarkers like glycated hemoglobin and assessment of blood glucose level have their own limitations. These classical markers can be detected when the disease is already established. Prognosis of disease at early stages and prediction of population at a higher risk require identification of specific markers that are sensitive enough to be detected at early stages of disease. Biomarkers which could predict the risk of disease in people will be useful for developing preventive/proactive therapies to those individuals who are at a higher risk of developing the disease. Recent studies suggested that the expression of biomolecules including microRNAs, proteins, and metabolites specifically change during the progression of T2DM and related complications, suggestive of disease pathology. Owing to their omnipresence in body fluids and their association with onset, progression, and pathogenesis of T2DM, these biomolecules can be potential biomarker for prognosis, diagnosis, and management of disease. In this article, we summarize biomolecules that could be potential biomarkers and their signature changes associated with T2DM and related complications during disease pathogenesis.

Prevalence and predictive factors of early postpartum diabetes among women with gestational diabetes in a single-center cohort

OBJECTIVE

To determine the prevalence of diabetes at 6-12 weeks postpartum among women with gestational diabetes mellitus (GDM), and to identify prenatal postpartum diabetes predictors.

METHODS

In the present prospective cohort study, glucose statuses of consecutive women newly diagnosed with hyperglycemia during pregnancy were evaluated at 6-12 weeks postpartum between November 1, 2015, and November 1, 2016, at Tygerberg Hospital, Cape Town, South Africa. Women with known diabetes were excluded.

RESULTS

There were 78 patients included; 36 (46%) patients had abnormal postpartum glucose values (21 [27%] diabetes; 15 [19%] pre-diabetes) and 29 (37%) had overt diabetes in pregnancy. In univariate analyses, GDM diagnosis before 24 weeks of pregnancy (P<0.001), degree of hyperglycemia at diagnosis (P=0.001), need for insulin (P=0.001), glycosylated hemoglobin (HbA1c) in the month preceding delivery (P=0.006), older than 36 years (P=0.039), family history of diabetes (P=0.048), and preterm labor (P=0.039) were risk factors for postpartum diabetes. Multivariate analyses confirmed family history of diabetes (OR 7.45, 95% CI 1.05-52.76; P=0.044), HbA1c at diagnosis (OR 5.33, 95% CI 2.25-12.60; P<0.001), and age (OR 8.8, 95% CI 1.35-58.45; P=0.023), as robust predictors of diabetes after GDM.

CONCLUSION

The high prevalence of diabetes supports early postpartum oral glucose tolerance testing. Several women had undiagnosed diabetes. The risk factors identified could be useful for prenatal risk stratification.

A long-term mechanistic computational model of physiological factors driving the onset of type 2 diabetes in an individual

A computational model of the physiological mechanisms driving an individual's health towards onset of type 2 diabetes (T2D) is described, calibrated and validated using data from the Diabetes Prevention Program (DPP). The objective of this model is to quantify the factors that can be used for prevention of T2D. The model is energy and mass balanced and continuously simulates trajectories of variables including body weight components, fasting plasma glucose, insulin, and glycosylated hemoglobin among others on the time-scale of years. Modeled mechanisms include dynamic representations of intracellular insulin resistance, pancreatic beta-cell insulin production, oxidation of macronutrients, ketogenesis, effects of inflammation and reactive oxygen species, and conversion between stored and activated metabolic species, with body-weight connected to mass and energy balance. The model was calibrated to 331 placebo and 315 lifestyle-intervention DPP subjects, and one year forecasts of all individuals were generated. Predicted population mean errors were less than or of the same magnitude as clinical measurement error; mean forecast errors for weight and HbA1c were ~5%, supporting predictive capabilities of the model. Validation of lifestyle-intervention prediction is demonstrated by synthetically imposing diet and physical activity changes on DPP placebo subjects. Using subject level parameters, comparisons were made between exogenous and endogenous characteristics of subjects who progressed toward T2D (HbA1c > 6.5) over the course of the DPP study to those who did not. The comparison revealed significant differences in diets and pancreatic sensitivity to hyperglycemia but not in propensity to develop insulin resistance. A computational experiment was performed to explore relative contributions of exogenous versus endogenous factors between these groups. Translational uses to applications in public health and personalized healthcare are discussed.