HbA1c for diagnosis of type 2 diabetes. Is there an optimal cut point to assess high risk of diabetes complications, and how well does the 6.5% cutoff perform?

Effects of Sitting and Supine Positions on Tongue Color as Measured by Tongue Image Analyzing System and Its Relation to Biometric Information

Tongue diagnosis is one of the important diagnostic methods in Kampo (traditional Japanese) medicine, in which the color and shape of the tongue are used to determine the patient's constitution and systemic symptoms. Tongue diagnosis is performed with the patient in the sitting or supine positions; however, the differences in tongue color in these two different positions have not been analyzed. We developed tongue image analyzing system (TIAS), which can quantify tongue color by capturing tongue images in the sitting and supine positions. We analyzed the effects on tongue color in two different body positions. Tongue color was quantified as L∗a∗b∗ from tongue images of 18 patients in two different body positions by taking images with TIAS. The CIEDE 2000 color difference equation (ΔE00) was used to assess the difference in tongue color in two different body positions. Correlations were also determined between ΔE00, physical characteristics, and laboratory test values. The mean and median ΔE00 for 18 patients were 2.85 and 2.34, respectively. Of these patients, 77.8% had a ΔE00 < 4.1. A weak positive correlation was obtained between ΔE00 and systolic blood pressure and fasting plasma glucose. Approximately 80% of patients' tongue color did not change between the sitting and supine positions. This indicates that the diagnostic results of tongue color are trustworthy even if medical professionals perform tongue diagnosis in two different body positions.

Impact of Anaemia on HbA1c Interpretation Among Normogylcaemic Individuals With Diabetes Mellitus: A Clinical Laboratory Observational Study

BACKGROUND AND AIM

Over the past decades, glycosylated haemoglobin (HbA1c) has been a gold standard for monitoring diabetes control over a long period, relative to blood glucose level (BGL) which measures short-term results. It is speculated that anaemia and factors that induce haemolysis may cause falsely elevated HbA1c leading to 'false positive' interpretations. This study aimed to investigate how anaemia impacts HbA1c.

METHODS

This was a pathology-based observational pilot study using archived data of diabetic subjects monitored with both BGL and HbA1c in regional New South Wales (NSW), Australia. A total of 28,487 cases of blood glucose results were pooled and those with HbA1c and anaemia results were evaluated for correlation with the BGL results. Data collection was limited to de-identified information from the laboratory information system, hence details on the ethnicity and medical history were unavailable. Descriptive frequencies and Pearson correlations were performed.

RESULTS

In the pooled data, 53.36% of individuals were females, and 50.54% had BGL ≥5.6 mmol/L. In the pilot dataset, the majority (64.86%) were males, 18.92% with BGL ≤5.6 mmol/L and 67.57% had HbA1c (≥6.5%). In the entire dataset, BGL was moderately and positively correlated with HbA1c (r = 0.6), whereas in the subset of individuals with normo-BGL and anaemia, the correlation was negative (r = -0.2).

DISCUSSION

This pilot investigation observed a pertinent issue, which is a negative correlation between glycaemia and HbA1c in patients with anaemia. HbA1c was falsely increased despite normal blood glucose levels in individuals with anaemia. This advances the speculation that anaemia falsely increases HbA1c. Therefore, caution is necessary while interpreting HbA1c results for patients with anaemia, and new methods for interpretation are required.

Patterns of diabetes testing for older adults without diabetes in Ontario's nursing homes: A population-based study

BACKGROUND

Asymptomatic diabetes testing may be of limited value for older nursing home residents, but most diabetes guidelines lack upper-age cutoffs for screening cessation. We evaluated patterns of glycated hemoglobin (HbA1c) and serum blood glucose (SBG) testing among older residents without diabetes in Ontario, Canada.

METHODS

This population-based retrospective cohort study used provincial health administrative data from ICES to identify older nursing home residents in Ontario without diabetes between January 1, 2015 and December 31, 2018. We examined HbA1c and glucose testing rates overall, by age, sex, and near end-of-life. The number of tests needed to identify one case of diabetes (using HbA1c thresholds of 6.5% and 8.0%) were also calculated.

RESULTS

Among 102,923 older nursing home residents (70.3% women; average age 85.6 ± SD 7.7 years), 46.1% of residents received ≥1 HbA1c test over an average follow-up period of 2.15 (± SD 1.49) years, and 18.2% of these tested residents received ≥4 HbA1c tests. The crude HbA1c testing rate was 52.6 tests/100 person-years (95% CI 52.3-52.9). Testing rates among residents aged ≥80 years was 50.7 HbA1c tests/100 person-years (95% CI 50.4-51.0), and 47.8 tests/100 person-years (95% CI 46.5-49.0) among residents near end-of-life. The number of tests to identify a case of diabetes (HbA1c ≥ 6.5%) was 44, while the number of tests to identify a case of actionable diabetes (HbA1c ≥ 8%) was 310. Less than 1% of residents with an HbA1c test met criteria for actionable diabetes.

CONCLUSIONS

Nursing home residents without diabetes receive frequent diabetes testing, with high testing rates even in residents over 80 years old and residents near end-of-life. The high number of tests needed to identify a case of actionable diabetes highlights the urgent need to re-evaluate diabetes testing practices in nursing homes.

[Diabetes mellitus: definition, classification, diagnosis, screening and prevention (Update 2023)]

Diabetes mellitus comprises of a group of heterogeneous disorders, which have an increase in blood glucose concentrations in common. The current classification for diabetes mellitus is presented and the main features of type 1 and type 2 diabetes are compared. Furthermore, the criteria for the correct biochemical diagnosis during fasting and oral glucose tolerance tests as well as the use of hemoglobin A1c (HbA1c) are summarized. The increasing prevalence of diabetes requires targeted screening for detecting diabetes and prediabetes in risk groups. This forms the basis for the early initiation of measures to prevent the onset of diabetes in these risk groups and to delay the progression of diabetes.

Effects of Resistant Starch Interventions on Metabolic Biomarkers in Pre-Diabetes and Diabetes Adults

Simple lifestyle changes can prevent or delay the onset of type 2 diabetes mellitus (T2DM). In addition to maintaining a physically active way of life, the diet has become one of the bases in managing TD2M. Due to many studies linking the ability of resistant starch (RS) to a substantial role in enhancing the nutritional quality of food and disease prevention, the challenge of incorporating RS into the diet and increasing its intake remains. Therefore, we conducted this review to assess the potential benefits of RS on metabolic biomarkers in pre-diabetes and diabetes adults based on available intervention studies over the last decade. Based on the conducted review, we observed that RS intake correlates directly to minimize possible effects through different mechanisms for better control of pre-diabetic and diabetic conditions. In most studies, significant changes were evident in the postprandial glucose and insulin incremental area under the curve (iAUC). Comparative evaluation of RS consumption and control groups also showed differences with inflammatory markers such as TNF-α, IL-1β, MCP-1, and E-selectin. Only RS2 and RS3 were extensively investigated and widely reported among the five reported RS types. However, a proper comparison and conclusion are deemed inappropriate considering the variations observed with the study duration, sample size, subjects and their metabolic conditions, intervention doses, and the intervention base products. In conclusion, this result provides interesting insights into the potential use of RS as part of a sustainable diet in diabetes management and should be further explored in terms of the mechanism involved.

Comparison of ETDRS 7-Field to 4-Widefield Digital Imaging in the Evaluation of Diabetic Retinopathy Severity

Purpose

To compare Early Treatment Diabetic Retinopathy Study (ETDRS) severity levels between two digital fundus imaging protocols for research studies of diabetic retinopathy: the gold standard 7-field (7F) imaging and the more recent 4-widefield (4W) imaging.

Methods

Two hundred twenty-two participants enrolled in the Diabetes Prevention Program Outcomes Study underwent concurrent 7F and 4W imaging. The ETDRS levels from 220 paired gradable images were determined by masked graders. Each image was graded by two independent graders with adjudication by a senior grader, if necessary. Percent agreement between graders and between imaging protocols was evaluated with kappa statistics and weighted kappa statistics.

Results

Of 220 gradable eyes, diabetic retinopathy was seen in 11.8%; this was mild in 10.4% and more than mild in 1.4% using 7F imaging. The ETDRS levels showed exact agreement of 95% between 7F and 4W imaging (weighted kappa 0.86). Intergrader agreement for each modality had exact agreement of 89% (weighted kappa of 0.73) for 7F and 91% (weighted kappa 0.77) for 4W.

Conclusions

There is substantial agreement in the ETDRS severity level between the 7F and 4W digital imaging protocols, demonstrating that the two imaging protocols are interchangeable. Both 4W and 7F digital imaging protocols can be used for assessing ETDRS levels, even in populations with minimal diabetic retinopathy.

Translational Relevance

The 4W protocol requires fewer images than the 7F, is more comfortable for the patients, is easier for photographic capture, and provides diabetic retinopathy data that is equivalent to the 7F imaging protocol.

Global coagulation assays in patients with diabetes mellitus

BACKGROUND

There is significant heterogeneity in the incidence and severity of diabetes-associated vascular complications and there is no routine biomarker that accurately predicts these outcomes. This pilot study investigates the role of global coagulation assays in patients with diabetes mellitus.

METHODS

In this cross-sectional study, patients with diabetes not on anticoagulation or dialysis and without active malignancy were recruited from endocrinology clinics. Blood samples were collected for global coagulation assays including thromboelastography (TEG), thrombin generation using calibrated automated thrombogram (CAT), and fibrin generation and fibrinolysis using the overall hemostatic potential (OHP) assay. The results were compared with healthy controls.

RESULTS

A total of 147 adult patients including 19 with type 1 diabetes (T1DM), 120 with type 2 diabetes (T2DM), and eight with latent autoimmune diabetes were recruited. Compared with 153 healthy controls, patients with diabetes demonstrated higher maximum amplitude (68.6 vs 60.2 mm, p < 0.001) on TEG, and higher OHP (9.3 vs 6.4, p < 0.001) with comparable CAT parameters. Patients with T2DM were more hypercoagulable than those with T1DM on most biomarkers. Higher maximum amplitude, velocity index, and OHP were associated with increased risk of complications (C-stat 0.82). Patients with history of microvascular complications appear to have more hypercoagulable thrombin and fibrin generation than those without.

CONCLUSION

Patients with diabetes have more hypercoagulable profiles on global coagulation assays, particularly patients with T2DM and those with microvascular complications. Further studies with longitudinal follow-up are ongoing to evaluate the utility of global coagulation assays in predicting long-term patient outcomes.

The retinopathy-derived HbA1c threshold of 6.5% for type 2 diabetes also captures the risk of diabetic nephropathy in NHANES

AIM

To determine if an HbA1c diagnostic threshold of less than 6.5% (<48 mmol/mol) could be identified based on a urinary albumin-creatinine ratio (UACR) of 30 mg/g or higher in subjects not known to have diabetes.

METHODS

A UACR was measured for 20 158 participants in the 2011-2018 nationally representative cross-sectional National Health and Nutrition Examination Surveys (NHANES; cycles 7-10 inclusive).

RESULTS

There was a significant trend for an increasing risk with a UACR of 30 mg/g or higher across increasing HbA1c categories (P < .0001). This trend was mainly attributable to the high prevalence of raised UACR in the 7.0% or higher HbA1c subgroup of subjects not previously diagnosed with diabetes. None of the odds ratios in the lower HbA1c subgroups versus the HbA1c subgroup of less than 5.0% reached significance. There were racial/ethnic differences in UACR risk (P < .0001), with White and Black subjects exhibiting little increased risk (vs. HbA1c <5.0%) until they reached an HbA1c of 7.0%, while Asian and Hispanic subjects showed some increased, but non-significant, risks at lower HbA1c levels. Maximizing the area under receiver operating characteristic curves from logistic regressions predicted an ideal HbA1c threshold of 5.8%, but there was little variation in area from 5.5% to 7.0%.

CONCLUSION

A clinically useful diagnostic threshold below 6.5% for HbA1c for elevated UACR risk was not identified, with an increased risk only obvious at an HbA1c of 7.0% or higher. Thus, the retinopathy-derived HbA1c threshold of 6.5% also captures the risk of diabetic nephropathy in NHANES.

Influence of Serum Albumin on HbA1c and HbA1c-Defined Glycemic Status: A Retrospective Study

Background: Glycated hemoglobin (HbA1c) is commonly used in the diagnosis and evaluation of glycemic control in diabetes, and it may be influenced by several non-glycemic and glycemic factors, including albumin. This retrospective study investigated the influence of albumin on HbA1c and HbA1c-defined glycemic status. Methods: The demographic, hematological, and biochemical data were collected for 11,922 patients undergoing routine physical examination. Univariate and multivariate linear regression analyses, stratified analyses and interaction analyses, and multiple logistic regression were conducted to identify the association between albumin and HbA1c in people with different glycemic status. Results: HbA1c levels were inversely associated with serum albumin level (P < 0.0001) in all participants. Risk factors leading to the association included age > 45 years, high fasting plasma glucose (≥7.0 mmol/L), and anemia. The negative association between HbA1c and albumin was curved (P < 0.0001) and had a threshold effect in the HbA1c-defined diabetic population; the association was significantly stronger when the albumin level fell below 41.4 g/L (β: -0.31, 95% CI: -0.45 to -0.17, P < 0.0001). A 2 g/L increase in albumin reduced the odds of HbA1c-defined dysglycemia, diabetes, and poor glycemia control by 12% to 36%, after adjustment for all possible confounders. Conclusions: HbA1c was inversely associated with albumin level in all participants, and the association was significantly stronger in people with diabetes (defined by HbA1c criteria). For diabetic patients with lower albumin level, there was an increased risk of an erroneous HbA1c-based identification and management of glycemic status.

Association of glycosylated haemoglobin HbA1c levels with outcome in patients with COVID-19: A Retrospective Study

Patients with hyperglycemia tend to be susceptible to Coronavirus disease 2019 (COVID‐19). However, the association of HbA1c level with outcome of COVID‐19 patients was unclear. We performed a retrospective study of 2880 cases of COVID‐19 admitted in Tongji Hospital, Wuhan, China, among which 922 had detected the HbA1c levels. We found that COVID‐19 patients with either lower levels of HbAlc (3%‐4.9%) or higher levels of HbAlc (≥6%) were associated with elevated all‐cause mortality. Meanwhile, we observed that HbAlc levels were highly correlated with haemoglobin (Hb) and total cholesterol (TC) (P < .0001), moderately correlated with albumin (ALB) and high‐sensitive C reaction protein (hs‐CRP) (0.0001 < P<.001), and relatively low correlated with low‐density lipoprotein cholesterol (LDL‐C) (.001 < P<.01). These associated cofactors might together contribute to the clinical outcome of COVID‐19 patients. Furthermore, the mortality was higher in COVID‐19 patients with newly diagnosed diabetes mellitus (DM) compared with COVID‐19 patients with history of DM. Moreover, in patients with history of DM, the mortality was decreased in patients treated with anti‐hyperglycaemic drugs. In summary, our data showed that the in‐hospital mortality was increased in COVID‐19 patients with lower or higher levels of HbAlc. Meanwhile, initiation of appropriate anti‐hyperglycaemic treatment might improve the clinical outcome in COVID‐19 patients.

Diagnosing type 2 diabetes using Hemoglobin A1c: a systematic review and meta-analysis of the diagnostic cutpoint based on microvascular complications

AIMS

Diabetic microvascular complications of retinopathy, nephropathy and neuropathy may occur at hemoglobin A1c levels (HbA1c) below the 6.5% (48 mmol/mol) diagnostic threshold. Our objective was to assess the validity of the HbA1c diagnostic cutpoint of 6.5% based upon published evidence of the prevalence of retinopathy, nephropathy and neuropathy as markers of diabetes.

METHODS

Data Sources PubMed, Embase, Cochrane, Scopus and CINAHL from 1990-March 2019, grey literature sources. Study Selection All studies reported after 1990 (to ensure standardized HbA1c values) where HbA1c levels were presented in relation to prevalence of retinopathy, nephropathy or neuropathy in subjects not known to have diabetes. Data Extraction Studies were screened independently, data abstracted, and risk of bias appraised. Data Synthesis Data were synthesized using HbA1c categories of < 6.0% (< 42 mmol/mol), 6.0-6.4% (42-47 mmol/mol) and ≥ 6.5% (≥ 48 mmol/mol). Random-effects meta-analyses were conducted for retinopathy, nephropathy and neuropathy prevalence stratified by HbA1c categories. Random-effects multivariable meta-regression was conducted to identify predictors of retinopathy prevalence and sources of between-study heterogeneity.

RESULTS

Pooled mean prevalence was: 4.0%(95% CI: 3.2-5.0%) for retinopathy, 10.5% (95% CI: 4.0-19.5%) for nephropathy, 2.5% (95% CI: 1.1-4.3%) for neuropathy. Mean prevalence when stratified for HbA1c < 6.0%, 6.0-6.4% and ≥ 6.5% was: retinopathy: 3.4% (95% CI: 1.8-5.4%), 2.3% (95% CI: 1.6-3.2%) and 7.8%(95% CI: 5.7-10.3%); nephropathy: 7.1% (95% CI: 1.7-15.9%), 9.6% (95% CI: 0.8-26.4%) and 17.1% (95% CI: 1.0-46.9%); neuropathy: 2.1% (95% CI: 0.0-6.8%), 3.4% (95% CI: 0.0-11.6%) and 2.8% (95% CI: 0.0-12.8%). Multivariable meta-regression showed HbA1c ≥ 6.5% (OR: 4.05; 95% CI: 1.92-8.57%), age > 55 (OR: 3.23; 95% CI 1.81-5.77), and African-American race (OR: 10.73; 95% CI: 4.34-26.55), to be associated with higher retinopathy prevalence. Marked heterogeneity in prevalence estimates was found across all meta-analyses (Cochran's Q-statistic p < 0.0001).

CONCLUSIONS

The prevalence of nephropathy and moderate retinopathy was increased in subjects with HbA1c values ≥ 6.5% confirming the high specificity of this value for diagnosing T2DM; however, at HbA1c < 6.5% retinopathy increased at age > 55 years and, most strikingly, in African-Americans, suggesting there may be excess microvascular complication prevalence (particularly nephropathy) in individuals below the diabetes diagnostic threshold.

Does Perioperative Hemoglobin A1c Level Affect the Incidence, Pattern and Mortality of Lower Extremity Amputation?

BACKGROUND

We hypothesized that perioperative HbA1c influenced the pattern and outcomes of Lower Extremity Amputation (LEA).

METHODS

A retrospective analysis was conducted for all patients who underwent LEA between 2000 and 2013. Patients were categorized into 5 groups according to their perioperative HbA1c values [Group 1 (<6.5%), Group 2 (6.5-7.4%), Group 3 (7.5-8.4%), Group 4 (8.5-9.4%) and Group 5 (≥9.5%)]. We identified 848 patients with LEA; perioperative HbA1c levels were available in 547 cases (Group 1: 18.8%, Group 2: 17.7%, Group 3: 15.0%, Group 4: 13.5% and Group 5: 34.9%). Major amputation was performed in 35%, 32%, 22%, 10.8% and 13.6%, respectively.

RESULTS

The overall mortality was 36.5%; of that one quarter occurred during the index hospitalization. Mortality was higher in Group 1 (57.4%) compared with Groups 2-5 (46.9%, 38.3%, 36.1% and 31.2%, respectively, p=0.001). Cox regression analysis showed that poor glycemic control (Group 4 and 5) had lower risk of mortality post-LEA [hazard ratio 0.57 (95% CI 0.35-0.93) and hazard ratio 0.46 (95% CI 0.31-0.69)]; this mortality risk persisted even after adjustment for age and sex but was statistically insignificant. The rate of LEA was greater among poor glycemic control patients; however, the mortality was higher among patients with tight control.

CONCLUSION

The effects of HbA1c on the immediate and long-term LEA outcomes and its therapeutic implications need further investigation.

[Diabetes mellitus-Definition, classification, diagnosis, screening and prevention (Update 2019)]

Diabetes mellitus comprises a group of heterogeneous disorders, which have an increase in blood glucose concentrations in common. The current classification for diabetes mellitus is presented and the main features of type 1 and type 2 diabetes are compared. Furthermore, the criteria for the correct biochemical diagnosis during fasting and oral glucose tolerance tests as well as the use of hemoglobin A1c (HbA1c) are summarized. The increasing prevalence of diabetes requires targeted screening for detecting diabetes and prediabetes in risk groups. This forms the basis for the early initiation of measures to prevent the onset of diabetes in these risk groups and to delay the progression of diabetes.

Regression From Prediabetes to Normal Glucose Regulation and Prevalence of Microvascular Disease in the Diabetes Prevention Program Outcomes Study (DPPOS)

OBJECTIVE

Regression from prediabetes to normal glucose regulation (NGR) was associated with reduced incidence of diabetes by 56% over 10 years in participants in the Diabetes Prevention Program Outcomes Study (DPPOS). In an observational analysis, we examined whether regression to NGR also reduced risk for microvascular disease (MVD).

RESEARCH DESIGN AND METHODS

Generalized estimating equations were used to examine the prevalence of aggregate MVD at DPPOS year 11 in people who regressed to NGR at least once (vs. never) during the Diabetes Prevention Program (DPP). Logistic regression assessed the relationship of NGR with retinopathy, nephropathy, and neuropathy, individually. Generalized additive models fit smoothing splines to describe the relationship between average A1C during follow-up and MVD (and its subtypes) at the end of follow-up.

RESULTS

Regression to NGR was associated with lower prevalence of aggregate MVD in models adjusted for age, sex, race/ethnicity, baseline A1C, and treatment arm (odds ratio [OR] 0.78, 95% CI 0.65-0.78, P = 0.011). However, this association was lost in models that included average A1C during follow-up (OR 0.95, 95% CI 0.78-1.16, P = 0.63) or diabetes status at the end of follow-up (OR 0.92, 95% CI 0.75-1.12, P = 0.40). Similar results were observed in examination of the association between regression to NGR and prevalence of nephropathy and retinopathy, individually. Risk for aggregate MVD, nephropathy, and retinopathy increased across the A1C range.

CONCLUSIONS

Regression to NGR is associated with a lower prevalence of aggregate MVD, nephropathy, and retinopathy, primarily due to lower glycemic exposure over time. Differential risk for the MVD subtypes begins in the prediabetes A1C range.

Decline in ankle-brachial index is stronger in poorly than in well controlled diabetes: Results from the Heinz Nixdorf Recall cohort study

BACKGROUND AND AIMS

The ankle-brachial index (ABI) is a marker of atherosclerosis and a diagnostic criterion for peripheral arterial disease (PAD). We studied the association between HbA1c and ABI in subjects with and without diabetes.

METHODS

In the Heinz Nixdorf Recall Study, a population-based cohort study in Germany (N = 4,814, age 45-75 years), ABI was measured at baseline, at 5- and 10-year follow-up. Subjects with ABI <0.9, ABI >1.4 or self-reported PAD at baseline were excluded from analyses. In 3199 participants, we assessed associations between HbA1c and incident PAD (ABI < 0.9) and change in ABI, respectively, using logistic and linear regression models. Subjects without diabetes, with HbA1c < 5.7% were used as reference group.

RESULTS

Compared to the reference group, 10-year decline in ABI was -0.066 (95% confidence interval: -0.117; -0.016) and -0.021 (-0.063; 0.021) in subjects with poorly (≥7.0% HbA1c) and well (<7.0% HbA1c) controlled previously known diabetes; -0.010 (-0.054; 0.034) in those with newly detected diabetes diagnosed by HbA1c ≥ 6.5%, and -0.005 (-0.023; 0.013) in those without diabetes, with HbA1c 5.7-6.4%. For poorly controlled diabetes, odds ratios for low ABI (<0.9) were 3.5 (1.6-7.9), and 3.1 (1.3-7.0) after 5- and 10-year follow-up, respectively. The incidence of Mönckeberg disease (ABI > 1.4) was low (6/288 (2.4%) over 5 years).

CONCLUSIONS

Decline in ABI was stronger in poorly than well-controlled diabetes. Subjects with newly detected diabetes diagnosed by the new HbA1c criterion (≥6.5%) did not show an increased decline in ABI over 10 years.

Association of characteristics of people with type 2 diabetes mellitus with discordant values of fasting glucose and HbA1c

BACKGROUND

Primary care physicians frequently encounter people with type 2 diabetes mellitus (T2DM) with discordant values for fasting glucose and HbA1c. The aim of this study was to identify the prevalence and characteristics of people in whom blood glucose and HbA1c did not match.

METHODS

Overall, 64 553 people with T2DM from 939 general or internal medicine practices (Disease Analyzer database, Germany; January 2013-December 2015) were analyzed. Multivariable logistic regression models were used to identify associations between baseline clinical characteristics, comorbidity, and glucose-lowering treatment and discordance of fasting glucose and HbA1c values measured at the same visit.

RESULTS

Overall, 8582 (13%) patients had fasting glucose ≥140 mg/dL and HbA1c <7% (<53 mmol/mol), and 6508 (10%) had HbA1c ≥7% (≥53 mmol/mol) and fasting glucose <140 mg/dL. Using patients with both fasting glucose <140 mg/dL and HbA1c <7% as the reference (n = 31 834; 49%), solitary high fasting glucose values (and HbA1c <7%) were positively associated with higher age, male sex, longer diabetes duration, obesity, liver disease, low estimated glomerular filtration rate (eGFR), and glucose-lowering treatment. High HbA1c (and fasting glucose <140 mg/dL) was positively related to longer diabetes duration, obesity, neuropathy, retinopathy, low eGFR, and insulin treatment. There were lower odds of having solitary increased HbA1c ≥7% (fasting glucose <140 mg/dL) with higher age, hypertension, depression, and the number of diabetes patients (>200) per practice.

CONCLUSIONS

A considerable number of people with T2DM in primary care practices have discordant fasting blood glucose and HbA1c values. People who have discordant glycemic values have different characteristics.

Predicting diabetic retinopathy and identifying interpretable biomedical features using machine learning algorithms

BACKGROUND

The risk factors of diabetic retinopathy (DR) were investigated extensively in the past studies, but it remains unknown which risk factors were more associated with the DR than others. If we can detect the DR related risk factors more accurately, we can then exercise early prevention strategies for diabetic retinopathy in the most high-risk population. The purpose of this study is to build a prediction model for the DR in type 2 diabetes mellitus using data mining techniques including the support vector machines, decision trees, artificial neural networks, and logistic regressions.

RESULTS

Experimental results demonstrated that prediction performance by support vector machines performed better than the other machine learning algorithms and achieved 79.5% and 0.839 in accuracy and area under the receiver operating characteristic curve using percentage split (i.e., data set divided into 80% as trainning and 20% as test), respectively. Evaluated by three-way data split scheme (i.e., data set divided into 60% as training, 20% as validation, and 20% as independent test), our method obtained slightly lower performance compared to percentage split, which suggested that three-way data split is a better way to evaluate the real performance and prevent overestimation. Moreover, we incorporated approaches proposed in previous studies to evaluate our data set and our prediction performance outperformed the other previous studies in most evaluation measures. This lends support to our assumption that appropriate machine learning algorithms combined with discriminative clinical features can effectively detect diabetic retinopathy.

CONCLUSIONS

Our method identifies use of insulin and duration of diabetes as novel interpretable features to assist with clinical decisions in identifying the high-risk populations for diabetic retinopathy. If duration of DM increases by 1 year, the odds ratio to have DMR is increased by 9.3%. The odds ratio to have DR is increased by 3.561 times for patients who use insulin compared to patients who do not use insulin. Our results can be used to facilitate development of clinical decision support systems for clinical practice in the future.

Can Cardiovascular Epidemiology and Clinical Trials Close the Risk Management Gap Between Diabetes and Prediabetes?

PURPOSE OF REVIEW

We reviewed published literature to determine the relationship between A1c and cardiovascular disease (CVD) and summarize the need and implications for CVD risk reduction with interventions, focusing in the prediabetic A1c range (<6.5%).

RECENT FINDINGS

Strong evidence supports a continuous relationship between A1c and CVD-even below the current levels of A1c-defined prediabetes and after adjustment for known risk factors for CVD. Clinical trials have demonstrated a reduction in CV morbidity and/or mortality when interventions are invoked in the prediabetic A1c range. Guidelines advocating CV risk factor management in prediabetes have not been widely adopted, subsequently leading to comparable coronary heart disease risk between people with prediabetes (HR = 1.9, 95% CI 1.7-2.1 vs normoglycemia) and diabetes itself (HR=2.0, 95% CI 1.8-2.2 vs no diabetes). This review highlights the missed opportunity to utilize multiple risk factor interventions to reduce CVD in high-risk people with prediabetes.

[Diabetes mellitus: definition, classification and diagnosis]

Diabetes mellitus comprises of a group of heterogeneous disorders, which have an increase in blood glucose concentrations in common. The current classifications for diabetes mellitus type 1-4 are described and the main features of type 1 and type 2 diabetes are compared to allow for better discrimination between these diabetes types. Furthermore, the criteria for the correct biochemical diagnosis during fasting and oral glucose tolerance tests as well as the use of hemoglobin A1c (HbA1c) are summarized. These data form the basis of the recommendations of the Austrian Diabetes Association for the clinical praxis of diabetes treatment.

Tumor Necrosis Factor/Sphingosine-1-Phosphate Signaling Augments Resistance Artery Myogenic Tone in Diabetes

Diabetes strongly associates with microvascular complications that ultimately promote multiorgan failure. Altered myogenic responsiveness compromises tissue perfusion, aggravates hypertension, and sets the stage for later permanent structural changes to the microcirculation. We demonstrate that skeletal muscle resistance arteries isolated from patients with diabetes have augmented myogenic tone, despite reasonable blood glucose control. To understand the mechanisms, we titrated a standard diabetes mouse model (high-fat diet plus streptozotocin [HFD/STZ]) to induce a mild increase in blood glucose levels. HFD/STZ treatment induced a progressive myogenic tone augmentation in mesenteric and olfactory cerebral arteries; neither HFD nor STZ alone had an effect on blood glucose or resistance artery myogenic tone. Using gene deletion models that eliminate tumor necrosis factor (TNF) or sphingosine kinase 1, we demonstrate that vascular smooth muscle cell TNF drives the elevation of myogenic tone via enhanced sphingosine-1-phosphate (S1P) signaling. Therapeutically antagonizing TNF (etanercept) or S1P (JTE013) signaling corrects this defect. Our investigation concludes that vascular smooth muscle cell TNF augments resistance artery myogenic vasoconstriction in a diabetes model that induces a small elevation of blood glucose. Our data demonstrate that microvascular reactivity is an early disease marker and advocate establishing therapies that strategically target the microcirculation.

Can HbA1c replace OGTT for the diagnosis of diabetes mellitus among Chinese patients with impaired fasting glucose?

BACKGROUND

HbA1c ≥ 6.5% has been recommended as a diagnostic criterion for the detection of diabetes mellitus (DM) since 2010 because of its convenience, stability and significant correlation with diabetic complications. Nevertheless, the accuracy of HbA1c compared to glucose-based diagnostic criteria varies among subjects of different ethnicity and risk profile.

OBJECTIVES

This study aimed to evaluate the accuracy of HbA1c for diagnosing DM compared to the diagnosis by oral glucose tolerance test (OGTT) and the optimal HbA1c level to diagnose DM in primary care Chinese patients with impaired fasting glucose (IFG).

METHODS

A cross-sectional study was carried out in three public primary care clinics in Hong Kong. About 1128 Chinese adults with IFG (i.e. FG level between 5.6 and 6.9 mmol/l in the past 18 months) were recruited to receive paired OGTT and HbA1c tests. Sensitivities and specificities of HbA1c at different threshold levels for predicting DM compared to the diagnosis by OGTT were evaluated. A receiver operating characteristic (ROC) curve was used to determine the optimal cut-off level.

RESULTS

Among the 1128 subjects (mean age 64.2±8.9 year, 48.8% male), 229 (20.3%) were diagnosed to have DM by OGTT. The sensitivity and specificity of HbA1c ≥6.5% were 33.2% and 93.5%, respectively, for predicting DM diagnosed by OGTT. The area under the ROC curve was 0.770, indicating HbA1c had fair discriminatory power. The optimal cut-off threshold of HbA1c was 6.3% for discriminating DM from non-DM, with sensitivity and specificity of 56.3% and 85.5%, respectively. HbA1c ≥ 5.6% has the highest sensitivity and negative predictive value of 96.1% and 94.5%, respectively.

CONCLUSIONS

HbA1c ≥ 6.5% is highly specific in identifying people with DM, but it may miss the majority (66.8%) of the DM cases. An HbA1c threshold of <5.6% is more appropriate to be used for the exclusion of DM. OGTT should be performed for the confirmation of DM among Chinese patients with IFG who have an HbA1c between 5.6% and 6.4%.

Consumption of Polyphenol-Rich Zingiber Zerumbet Rhizome Extracts Protects against the Breakdown of the Blood-Retinal Barrier and Retinal Inflammation Induced by Diabetes

The present study investigates the amelioration of diabetic retinopathy (DR) by Zingiber zerumbet rhizome ethanol extracts (ZZRext) in streptozotocin-induced diabetic rats (STZ-diabetic rats). ZZRext contains high phenolic and flavonoid contents. STZ-diabetic rats were treated orally with ZZRext (200, 300 mg/kg per day) for three months. Blood-retinal barrier (BRB) breakdown and increased vascular permeability were found in diabetic rats, with downregulation of occludin, and claudin-5. ZZRext treatment effectively preserved the expression of occludin, and claudin-5, leading to less BRB breakdown and less vascular permeability. Retinal histopathological observation showed that the disarrangement and reduction in thickness of retinal layers were reversed in ZZRext-treated diabetic rats. Retinal gene expression of tumor necrosis factor-α, interleukin (IL)-1β, IL-6, vascular endothelial growth factor, intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 were all decreased in ZZRext-treated diabetic rats. Moreover, ZZRext treatment not only inhibited the nuclear factor κB (NF-κB) activation, but also downregulated the protein expression of p38 mitogen-activated protein kinase (MAPK) in diabetic retina. In conclusion, the results suggest that the retinal protective effects of ZZRext occur through improved retinal structural change and inhibiting retinal inflammation. The antiretinopathy property of ZZRext might be related to the downregulation of p38 MAPK and NF-κB signal transduction induced by diabetes.

HbA1c and Lower Extremity Amputation Risk in Patients With Diabetes

In this meta-analysis, we aimed to assess glycosylated hemoglobin (HbA1c) level and lower extremity amputation (LEA) risk in patients with diabetes. Systematic computerized searches of the PubMed and Web of Knowledge were performed. We compared HbA1c level between groups with LEA and without LEA by meta-analysis; we also examined the dose–response relationship between HbA1c level and LEA risk. Sixteen studies were included in the meta-analysis. Eleven studies with 43 566 patients compared HbA1c between groups with and without LEA. The mean HbA1c (%) ranged from 8.3 to 12.5 in the group with LEA and from 7.4 to 11.3 in the group without LEA. The pooled weighted mean difference was 1.110 (95% confidence interval = 0.510-1.709; Z = 3.63, P = .008). The funnel plot was symmetrical, and Begg’s test ( z = 0.00, P = 1.000) and Egger’s test ( t = −0.02, P = .984) suggested no significant publication bias. Six studies with 109 933 patients included in the dose–response meta-analysis. The LEA incidence ranged from 0.3% to 14.6% between different HbA1c levels. Dose–response meta-analysis showed statistically significant association between HbA1c and LEA risk (χ2 = 65.51, P = .000). In linear model, the odds ratio for LEA incidence was 1.229 (95% confidence interval = 1.169-1.292) for every 1% HbA1c increase. In the spline model, the odds ratio of LEA risk increased with HbA1c levels, especially when HbA1c ranged from 5% to 9%. Our meta-analysis indicates that high level of HbA1c is an important risk factor for LEA in patients with diabetes. This evidence supports the strategy for lowering glucose levels to reduce amputation in patients with diabetes.

Treatment-dependent and treatment-independent risk factors associated with the risk of diabetes-related events: a retrospective analysis based on 229,042 patients with type 2 diabetes mellitus

BACKGROUND

The aim of this study was to analyse which factors predict the real-world macro-/microvascular event, hospitalisation and death risk in patients with type 2 diabetes mellitus. Furthermore, we aimed to investigate whether there exists both an under- and over-treatment risk of these patients.

METHODS

We used a German claims/clinical data set covering the years 2010-12. Diabetes-related events were defined as (1) macro-, (2) microvascular events leading to inpatient hospitalisation, (3) other hospitalisations with type 2 diabetes mellitus as main diagnosis, (4) all-cause death and (5) a composite outcome including all event categories 1-4. Factors associated with event risk were analysed by a Kaplan-Meier curve analysis and by multivariable Cox regression models.

RESULTS

229,042 patients with type 2 diabetes mellitus (mean age 70.2 years; mean CCI 6.03) were included. Among factors that increased the event risk were patients' age, male gender, the adapted Charlson Comorbidity Index, the adapted Diabetes Complication Severity Index, previous events, and number of prescribed chronic medications. For systolic blood pressure/HbA1C, a double-J/U-curve pattern was detected: HbA1C of 6-6.5% (42-48 mmol/mol) and systolic blood pressure of 130-140 mmHg (17.3-18.7kPa) were associated with the lowest event risk, values below/above that range were associated with higher risk. However, this pattern was mainly driven by the death risk and was much less clearly observed for the macrovascular/microvascular/hospitalization risk and for young/less comorbid patients.

CONCLUSIONS

Both blood pressure and HbA1C seem to be very important treatment targets, especially in comorbid old patients. It is of particular clinical importance that both over- and under-treatment pose a threat to patients with type 2 diabetes mellitus.

Diabetes is associated with persistent pain after hip and knee replacement

BACKGROUND AND PURPOSE

In some patients, for unknown reasons pain persists after joint replacement, especially in the knee. We determined the prevalence of persistent pain following primary hip or knee replacement and its association with disorders of glucose metabolism, metabolic syndrome (MetS), and obesity.

PATIENTS AND METHODS

The incidence of pain in the operated joint was surveyed 1-2 years after primary hip replacement (74 patients (4 bilateral)) or primary knee replacement (119 patients (19 bilateral)) in 193 osteoarthritis patients who had participated in a prospective study on perioperative hyperglycemia. Of the 155 patients who completed the survey, 21 had undergone further joint replacement surgery during the follow-up and were excluded, leaving 134 patients for analysis. Persistent pain was defined as daily pain in the operated joint that had lasted over 3 months. Factors associated with persistent pain were evaluated using binary logistic regression with adjustment for age, sex, and operated joint.

RESULTS

49 of the 134 patients (37%) had a painful joint and 18 of them (14%) had persistent pain. A greater proportion of knee patients than hip patients had a painful joint (46% vs. 24%; p = 0.01) and persistent pain (20% vs. 4%; p = 0.007). Previously diagnosed diabetes was strongly associated with persistent pain (5/19 vs. 13/115 in those without; adjusted OR = 8, 95% CI: 2-38) whereas MetS and obesity were not. However, severely obese patients (BMI ≥ 35) had a painful joint (but not persistent pain) more often than patients with BMI < 30 (14/21 vs. 18/71; adjusted OR = 5, 95% CI: 2-15).

INTERPRETATION

Previously diagnosed diabetes is a risk factor for persistent pain in the operated joint 1-2 years after primary hip or knee replacement.

Risk of diabetes among patients receiving primary androgen deprivation therapy for clinically localized prostate cancer

PURPOSE

Androgen deprivation therapy may increase diabetes risk. As the benefits of primary androgen deprivation therapy for localized prostate cancer are controversial, and most prostate cancer survivors are of advanced age with comorbidities, it is important to determine if primary androgen deprivation therapy increases the risk of diabetes and to determine the susceptibility factors.

MATERIALS AND METHODS

We conducted a retrospective cohort study of 12,191 men diagnosed with incident localized prostate cancer during 1995 to 2008, age 35 to 100 years, and without diabetes or receipt of prostatectomy or radiation 1 year after diagnosis. Patients were enrolled in 1 of 3 managed health plans and followed through 2010. Primary androgen deprivation therapy was defined as androgen deprivation therapy within 1 year after diagnosis. Incident diabetes was ascertained using inpatient and outpatient diagnosis codes, diabetes medications and hemoglobin A1c values. We estimated primary androgen deprivation therapy associated diabetes risk using Cox proportional hazard models in conventional and propensity score analyses.

RESULTS

Diabetes developed in 1,203 (9.9%) patients during followup (median 4.8 years) with incidence rates of 2.5 and 1.6 events per 100 person-years in the primary androgen deprivation therapy and nonprimary androgen deprivation therapy groups, respectively. Primary androgen deprivation therapy was associated with a 1.61-fold increased diabetes risk (95% CI 1.38-1.88). The number needed to harm was 29. The association was stronger in men age 70 or younger than in older men (HR 2.25 vs 1.40, p value for interaction=0.008).

CONCLUSIONS

Primary androgen deprivation therapy may increase diabetes risk by 60% and should be used with caution when managing localized prostate cancer. Because of the consistent association between androgen deprivation therapy and greater diabetes risk across disease states, we recommend routine screening and lifestyle interventions to reduce the risk of diabetes in men receiving androgen deprivation therapy.