Glycated albumin in the detection of diabetes during COVID-19 hospitalization.

BACKGROUND: Diabetes has emerged as an important risk factor for COVID-19 adverse outcomes during hospitalization. We investigated whether the measurement of glycated albumin (GA) may be useful in detecting newly diagnosed diabetes during COVID-19 hospitalization. METHODS: In this cross-sectional test accuracy study we evaluated HCPA Biobank data and samples from consecutive in-patients, from 30 March 2020 to 20 December 2020. ROC curves were used to analyse the performance of GA to detect newly diagnosed diabetes (patients without a previous diagnosis of diabetes and admission HbA1c ≥6.5%). RESULTS: A total of 184 adults (age 58.6 ± 16.6years) were enrolled, including 31 with newly diagnosed diabetes. GA presented AUCs of 0.739 (95% CI 0.642-0.948) to detect newly diagnosed diabetes. The GA cut-offs of 19.0% was adequate to identify newly diagnosed diabetes with high specificity (85.0%) but low sensitivity (48.4%). CONCLUSIONS: GA showed good performance to identify newly diagnosed diabetes and may be useful for identifying adults with the condition in COVID-19-related hospitalization.

Diabetes associates with mortality in critically ill patients with SARS-CoV-2 pneumonia: No diabetes paradox in COVID-19.

Background: Diabetes mellitus (DM) is not associated with increased mortality in critically ill patients, a phenomenon known as the "diabetes paradox". However, DM is a risk factor for increased mortality in patients with COVID-19. This study aims to investigate the association of DM and stress-induced hyperglycemia at intensive care unit (ICU) with mortality in this population. Methods: This is a retrospective study. Electronic medical records from patients admitted from March 2020 to September 2020 were reviewed. Primary outcome was mortality. Secondary outcomes were ICU and hospital mortality and stay, and need for mechanical ventilation and renal replacement therapy. Results: 187 patients were included. Overall mortality was 43.2%, higher in patients with DM (55.7% vs. 34%; p = 0.007), even after adjustment for age, hypertension, and disease severity. When patients were separated into groups, named normoglycemia (without DM and glycemia ≤140 mg/dL), stress-induced hyperglycemia (without DM and glycemia >140 mg/dL), and DM (previous diagnosis or HbA1c ≥ 6.5%), the mortality rate was 25.8%, 37.3%, and 55.7%, respectively (p = 0.021). Mortality was higher in patients with higher glycemic variability. No statistical difference related to secondary outcomes was observed. Conclusions: DM, hyperglycemia, and glycemic variability associated with increased mortality in critically ill patients with severe COVID-19, but did not increase the rates of other clinical outcomes. More than stress-induced hyperglycemia, DM was associated with mortality.

Glycated albumin in diabetes mellitus: a meta-analysis of diagnostic test accuracy.

OBJECTIVES: Guidelines recommend the diagnosis of diabetes should be based on either plasma glucose or glycated hemoglobin (HbA1C) findings. However, lately studies have advocated glycated albumin (GA) as a useful alternative to HbA1c. We conducted a systematic review and meta-analysis to determine the overall diagnostic accuracy of GA for the diagnosis of diabetes. CONTENT: We searched for articles of GA diabetes diagnostic accuracy that were published up to August 2021. Studies were selected if reported an oral glucose tolerance test as a reference test, measured GA levels by enzymatic methods, and had data necessary for 2 × 2 contingency tables. A bivariate model was used to calculate the pooled estimates. SUMMARY: This meta-analysis included nine studies, totaling 10,007 individuals. Of those, 3,106 had diabetes. The studies showed substantial heterogeneity caused by a non-threshold effect and reported different GA optimal cut-offs for diagnosing diabetes. The pooled diagnostic odds ratio (DOR) was 15.93 and the area under the curve (AUC) was 0.844, indicating a good level of overall accuracy for the diagnosis of diabetes. The effect of the GA threshold on diagnostic accuracy was reported at 15.0% and 17.1%. The optimal cut-off for diagnosing diabetes with GA was estimated as 17.1% with a pooled sensitivity of 55.1% (95% CI 36.7%-72.2%) and specificity of 94.4% (95% CI 85.3%-97.9%). OUTLOOK: GA has good diabetes diagnostic accuracy. A GA threshold of 17.1% may be considered optimal for diagnosing diabetes in previously undiagnosed individuals.

Polymorphisms in ACE1, TMPRSS2, IFIH1, IFNAR2, and TYK2 Genes Are Associated with Worse Clinical Outcomes in COVID-19.

Although advanced age, male sex, and some comorbidities impact the clinical course of COVID-19, these factors only partially explain the inter-individual variability in disease severity. Some studies have shown that genetic polymorphisms contribute to COVID-19 severity; however, the results are inconclusive. Thus, we investigated the association between polymorphisms in ACE1, ACE2, DPP9, IFIH1, IFNAR2, IFNL4, TLR3, TMPRSS2, and TYK2 and the clinical course of COVID-19. A total of 694 patients with COVID-19 were categorized as: (1) ward inpatients (moderate symptoms) or patients admitted at the intensive care unit (ICU; severe symptoms); and (2) survivors or non-survivors. In females, the rs1990760/IFIH1 T/T genotype was associated with risk of ICU admission and death. Moreover, the rs1799752/ACE1 Ins and rs12329760/TMPRSS2 T alleles were associated with risk of ICU admission. In non-white patients, the rs2236757/IFNAR2 A/A genotype was associated with risk of ICU admission, while the rs1799752/ACE1 Ins/Ins genotype, rs2236757/IFNAR2 A/A genotype, and rs12329760/TMPRSS2 T allele were associated with risk of death. Moreover, some of the analyzed polymorphisms interact in the risk of worse COVID-19 outcomes. In conclusion, this study shows an association of rs1799752/ACE1, rs1990760/IFIH1, rs2236757/IFNAR2, rs12329760/TMPRSS2, and rs2304256/TYK2 polymorphisms with worse COVID-19 outcomes, especially among female and non-white patients.

SARS-CoV-2 nucleic acid shedding is variable for every person.

INTRODUCTION: Considering the persistent positivity on RT-qPCR tests, the results of SARS-CoV-2 were monitored to evaluate the viral RNA shedding period. METHODS: Between March and June 2020, the sequential results of 29 healthcare workers' were monitored using RT-qPCR. RESULTS: More than 50% of the individuals remained RT-qPCR positive after 14 days. Furthermore, this is the first study to describe positive RT-qPCR for SARS-CoV-2 in a healthcare worker with mild symptoms 95 days after the first positive test. CONCLUSIONS: Sequential RT-qPCR results were heterogeneous, and the viral RNA shedding period is unique for each person.

Factors associated with glycated albumin in adults without diabetes.

BACKGROUND AND AIMS: Glycated albumin is a glycemic marker useful in short-term monitoring and in situations when a glycated hemoglobin test is not reliable. This study aims to evaluate glycated albumin levels and its associated factors in normoglycemic adults from Southern Brazil. METHOD: 136 individuals, without diabetes or pre-diabetes, were included in this cross-sectional study. Levels of glycated albumin, glycated hemoglobin, and other biochemical markers were measured. RESULTS: Glycated albumin levels ranged from 11.1% to 17.5% (2.5th and 97.5th percentiles). Glycated albumin/glycated hemoglobin ratio was 2.8±0.2. Glycated albumin did not differ according to gender and age groups. However, in overweight individuals, levels of glycated albumin and glycated albumin/glycated hemoglobin ratio were lower and weakly and negatively correlated with body mass index. CONCLUSIONS: Glycated albumin levels in Brazilians were similar to those previously described in other populations. Glycated albumin seems to be irrespective of gender or age, but weakly correlated with weight. These aspects should be taken into account in the interpretation of glycated albumin results.

Is there a role for glycated albumin in the diagnosis of gestational diabetes mellitus?

BACKGROUND: Studies in the general population have advocated glycated albumin (GA) as a useful alternative to glycated haemoglobin (HbA1c) under conditions wherein the latter does not reflect glycaemic status accurately. There are few studies in other populations, especially in pregnant women. Therefore, the aim of this study was to assess the clinical utility of GA in the diagnosis of gestational diabetes mellitus (GDM). MATERIALS AND METHODS: This diagnostic test accuracy study was performed in 149 Brazilian women at 24-28 weeks of gestation referred for an oral glucose tolerance test (OGTT) in a tertiary university hospital. Receiver Operating Characteristic (ROC) curves were used to access the performance of GA and HbA1c in the diagnosis of GDM by the reference OGTT. RESULTS: GDM by OGTT (IADPSG criteria) was detected in 18.8% of participants. According to ROC analysis, the area under the curve (AUC) for GA was 0.531 (95% CI: 0.405-0.658, p = 0.065) lower than that for HbA1c [0.743 (95% CI: 0.636-0.849; p ≤ 0.001] for the detection of GDM (p = 0.004). The equilibrium cut-off value for GA was 12.6%; sensitivity and specificity in this cut-off point were 53.6% and 54.2%, respectively. CONCLUSIONS: GA at 24-28 weeks of gestation does not have ability to correctly discriminate those with and without GDM. In summary, the lack of sensitivity found in our results do not support the solely use of GA in the diagnosis of GDM.

The usefulness of glycated albumin for post-transplantation diabetes mellitus after kidney transplantation: A diagnostic accuracy study.

BACKGROUND: There is no study evaluating the use of glycated albumin (GA) for the detection of post-transplantation diabetes mellitus (PTDM) in kidney transplant recipients. We evaluated the overall accuracy of GA at four months after kidney transplantation. METHODS: Diagnostic test accuracy study including 134 kidney transplant recipients without pre-existing diabetes. Receiver operator characteristic (ROC) curve was used to estimate sensitivity, specificity, likelihood ratios and area under the curve (AUC) for GA, considering oral glucose tolerance test (OGTT) and/or glycated hemoglobin (HbA1c) as reference criteria. RESULTS: Thirty-three patients were diagnosed with PTDM by OGTT and/or HbA1c ≥ 6.5%. GA showed moderate accuracy to detect PTDM [AUC 0.673 (95% CI 0.557-0.789, p < 0.01)]. The use of OGTT and/or HbA1c ≥ 6.2% increased the number of PTDM cases from 33 to 38, and AUC was 0.713 (95% CI 0.608-0.819, p < 0.01). GA ≥ 17% showed specificity close to 90% when OGTT and/or HbA1c ≥ 6.5% were used as reference tests. CONCLUSIONS: GA showed low diagnostic accuracy for the detection of PTDM at the fourth month after transplantation. The use of a single GA point is not enough for the screening and diagnosis of PTDM; however, GA ≥ 17% presented high specificity to rule in the disease after kidney transplantation.

Urinary peptidomics and bioinformatics for the detection of diabetic kidney disease.

The aim of this study was to establish a peptidomic profile based on LC-MS/MS and random forest (RF) algorithm to distinguish the urinary peptidomic scenario of type 2 diabetes mellitus (T2DM) patients with different stages of diabetic kidney disease (DKD). Urine from 60 T2DM patients was collected: 22 normal (stage A1), 18 moderately increased (stage A2) and 20 severely increased (stage A3) albuminuria. A total of 1080 naturally occurring peptides were detected, which resulted in the identification of a total of 100 proteins, irrespective of the patients' renal status. The classification accuracy showed that the most severe DKD (A3) presented a distinct urinary peptidomic pattern. Estimates for peptide importance assessed during RF model training included multiple fragments of collagen and alpha-1 antitrypsin, previously associated to DKD. Proteasix tool predicted 48 proteases potentially involved in the generation of the 60 most important peptides identified in the urine of DM patients, including metallopeptidases, cathepsins, and calpains. Collectively, our study lightened some biomarkers possibly involved in the pathogenic mechanisms of DKD, suggesting that peptidomics is a valuable tool for identifying the molecular mechanisms underpinning the disease and thus novel therapeutic targets.

Glycated albumin as a diagnostic tool in diabetes: An alternative or an additional test?

INTRODUCTION: Studies have revealed that glycated albumin (GA) is a useful alternative to HbA1c under conditions wherein the latter does not reflect glycaemic status accurately. Until now, there are few studies with non-Asians subjects that report on the validity of GA test in diagnosis of type 2 diabetes mellitus (DM). Thus, the aim of this study was to assess the clinical utility of GA in diagnosis of DM. MATERIALS AND METHODS: This diagnostic test accuracy study was performed in 242 Brazilian individuals referred for OGTT in a tertiary university hospital. ROC curves were used to access the performance of GA and HbA1c in the diagnosis of DM by oral glucose tolerance test (OGTT). RESULTS: OGTT, HbA1c and GA were performed in all 242 participants (40.5% male, age 54.4 ± 13.0 years [mean ± SD], body mass index 28.9 ± 6.3 kg/m2). DM by OGTT was detected in 31.8% of individuals. The equilibrium threshold value of GA ≥14.8% showed sensitivity of 64.9% and specificity of 65.5% for the diagnosis of DM. The AUC for GA [0.703 (95% CI 0.631-0.775)] was lower than for HbA1c [0.802 (95% CI 0.740-0.864)], p = 0.028. A GA value of 16.8% had similar accuracy for detecting DM as defined by HbA1c ≥6.5% (48 mmol/mol) with sensitivity of 31.2% and specificity of 93.3% for both tests. However, GA detects different subjects from those detected by HbA1c and OGTT. CONCLUSIONS: GA detected different individuals with DM from those detected by HbA1c, though it showed overall diagnostic accuracy similar to HbA1c in the diagnosis of DM. Therefore, GA should be used as an additional test rather than an alternative to HbA1c or OGTT and its use as the sole DM diagnostic test should be interpreted with caution.

Combined creatinine-cystatin C CKD-EPI equation significantly underestimates measured glomerular filtration rate in people with type 2 diabetes mellitus.

AIM: To evaluate the accuracy of creatinine and cystatin C (cysC) equations to estimate glomerular filtration rate (GFR) in type 2 diabetes mellitus (DM) patients and healthy adults. METHODS: Case-control study including 84 patients with type 2 DM and 100 healthy adults with measured GFR (mGFR)≥60mL/min/1.73m2. GFR was measured by 51Cr-EDTA and estimated (eGFR) by the following equations using creatinine, cysC or both markers: Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI), Caucasian Asian Pediatrics and Adults (CAPA), CKD-EPI creatinine-cystatin C (CKDEPI-CC), and CKD-EPI cystatin C (CKDEPIcysC). Agreement was evaluated by Bland & Altman analysis. RESULTS: Healthy individuals were 66% females, aged 38±14years; they presented mGFR 112±19mL/min/1.73m2 and eGFR by CKD-EPI, CKDEPI-CC, CKDEPIcysC and CAPA equations, respectively, 108±17, 102±15, 97±16 and 93±16mL/min/1.73m2. DM group were 50% females, aged 59±19years and presented mGFR 104±27 and eGFR 87±19, 80±18, 74±20 and 73±18mL/min/1.73m2, respectively. All equations significantly underestimated mGFR, excepting creatinine-based CKD-EPI in the healthy group. The performance was considerably worse for GFRs above 120mL/min/1.73m2. CONCLUSION: In both healthy and type 2 DM patients, cystatin C-based equations, including the combined CKD-EPI creatinine-cystatin equation, failed to improve the accuracy of GFR estimation, especially for normal and high normal GFR values.

Effect of iron supplementation on HbA1c levels in pregnant women with and without anaemia.

BACKGROUND: Iron deficiency anaemia has been associated with higher HbA1c levels. However, during and after iron supplementation there is a decrease in HbA1c results, causing a misinterpretation. Our aim was to analyse the effect of iron supplementation on HbA1c levels in nondiabetic pregnant women with and without anaemia. METHODS: Pregnant women in prenatal care, without gestational diabetes (GDM) or previous diabetes mellitus (DM) that performed an oral glucose tolerance test (OGTT) in the third trimester of pregnancy were invited to participate. Clinical and laboratorial analyses were performed, including standardized questionnaire, OGTT, full blood count and HbA1c. RESULTS: A total of 231 pregnant women without DM or GDM were included in the study. According to anaemia and/or iron supplementation, we divided women in: no iron and no anaemia - Group 1 (N=86); no iron and with anaemia - Group 2 (N=29); iron and no anaemia - Group 3 (N=87); iron and anaemia - Group 4 (N=29). There was statistically a significant, although no clinically relevant, difference between HbA1c values in pregnant women in Groups 1 and 4 [5.1±0.4% (32±4.4mmol/mol) and 4.8±0.3% (29±3.3mmol/mol), P<0.01; respectively]. HbA1c values in pregnant women in Groups 1, 2 and 3 were similar, independently of anaemia [5.1±0.4% (32±4.4mmol/mol); 5.0±0.4% (31±4.4mmol/mol) and 5.0±0.4% (31±4.4mmol/mol); p>0.05; respectively]. CONCLUSIONS: Iron supplementation during pregnancy does not affect HbA1c levels and has no clinical impact in the final interpretation of results in the absence of anaemia or presence of mild anaemia. Interpreting HbA1c results in pregnant women during iron therapy and with moderate or severe anaemia still requires caution.

Variability of glycated hemoglobin levels in the first year post renal transplantation in patients without diabetes.

BACKGROUND: Glycated hemoglobin (HbA1c) is an alternative test used for the diagnosis and monitoring of diabetes in kidney transplant recipients. Immunosuppressive drugs are the most important risk factors related with changes in the glucose metabolism after transplant. It is still unknown if they impact on the variability of HbA1c. We assessed the variability of HbA1c levels in a group of renal transplant recipients without diabetes during the first year after transplant. METHODS: We estimated the variability of HbA1c in a group of 95 Brazilian kidney transplant recipients. Three EDTA whole blood samples were collected from each patient, one every four months for twelve months, totalizing 285 blood specimens. HbA1c values were measured by HPLC (Bio-Rad Variant™ II Turbo analyzer). Estimations were calculated according to Fraser and Harris method. RESULTS: There was no difference in HbA1c mean levels between men and women. Within-subject and between-subject biological variations were 4.42% and 7.05%, respectively. The reference change value calculated for HbA1c was 16.15% and the index of individuality was 0.63. CONCLUSIONS: Kidney transplant patients without diabetes presented higher HbA1c within-subject variation than individuals without diabetes from the general population. This should be considered when interpreting HbA1c results in the diagnosis and management of diabetes after kidney transplantation.

Glycated albumin: a potential biomarker in diabetes.

Diabetes mellitus (DM) is a chronic and metabolic disease that presents a high global incidence. Glycated hemoglobin (A1C) is the reference test for long-term glucose monitoring, and it exhibits an association with diabetic chronic complications. However, A1C is not recommended in clinical situations which may interfere with the metabolism of hemoglobin, such as in hemolytic, secondary or iron deficiency anemia, hemoglobinopathies, pregnancy, and uremia. The glycated albumin (GA) is a test that reflects short-term glycemia and is not influenced by situations that falsely alter A1C levels. GA is the higher glycated portion of fructosamine. It is measured by a standardized enzymatic methodology, easy and fast to perform. These laboratory characteristics have ensured the highlight of GA in studies from the last decade, as a marker of monitoring and screening for DM, as well as a predictor of long-term outcomes of the disease. The aim of this review was to discuss the physiological and biochemistry characteristics of the GA, as well as its clinical utility in DM.

Oxidized LDL but not total LDL is associated with HbA1c in individuals without diabetes.

OBJECTIVE: This study investigates the association between HbA1c, LDL and oxi-LDL in individuals without diabetes (DM). METHODS: One hundred and ninety-six individuals, without DM, were enrolled and divided into three groups according to HbA1c and fasting plasma glucose values. HbA1c, oxi-LDL, LDL, and other biochemical measurements of lipid profile were also carried out. RESULTS: oxi-LDL levels showed significant differences among all groups and group 3 presented higher values [34U/L (27-46); 44U/L (37-70); and 86U/L (49-136); p<0.001; for groups 1, 2 and 3, respectively]. There was also a significant difference in oxi-LDL/HDL and oxi-LDL/LDL ratios among all groups (p<0.001). There was no significant difference in total cholesterol (TC), triglycerides and LDL values among groups. HbA1c showed moderate positive associations with oxi-LDL (r=0.431; p<0.001), oxi-LDL/HDL ratio (r=0.423, p<0.001), and oxi-LDL/LDL ratio (r=0.359, p<0.001). There were lower associations between HbA1c and TC (r=0.142; p=0.048), triglycerides (r=0.155; p=0.030), LDL (r=0.148; p=0.039), non-HDL (r=0.192; p=0.007) and Apo B (r=0.171, p<0.001). The positive associations between HbA1c and oxi-LDL, oxi-LDL/HDL and oxi-LDL/LDL ratios remained significant even after adjustment by multiple linear regression analysis for the variables alcohol consumption, use of medicine, BMI, and age. CONCLUSIONS: oxi-LDL levels are significantly associated with HbA1c in non-diabetic individuals. However, the levels of traditional atherogenic lipids only showed a weak association with HbA1c levels. Those at high risk of developing DM or cardiovascular disease have higher levels of oxi-LDL. These data favor to the use of HbA1c as a biomarker to identify individuals at risk of developing complications even in non-diabetic glycemic levels.

Influence of age, gender and body mass index on late-night salivary cortisol in healthy adults.

BACKGROUND: Late-night salivary cortisol (LNSC) is one of the most reliable tests to screen for endogenous Cushing syndrome. This test is simple, inexpensive and noninvasive and has high sensitivity and specificity. The aim of our study was to analyze the putative influence of age, gender and body mass index (BMI) on LNSC levels in a healthy population. METHODS: Cross-sectional study conducted in healthy adults. Midnight saliva samples were collected at home. Participants refrained from teeth brushing, eating or drinking for 2 h prior to collection. Salivary cortisol measured by electrochemiluminescence immunoassay (ECLIA). The study was approved by the Ethics Committee of the hospital (number 140073). RESULTS: We evaluated 122 nonsmoking healthy volunteers. Mean age was 35±14 years (range, 18-74 years); 63% were women. Mean BMI was 24±3 kg/m2, blood pressure 115/74 mmHg and fasting plasma glucose 4.8±0.5 mmol/L. LNSC presented a non-Gaussian distribution; the median was 3.58 (range, 0.55-8.55) nmol/L (0.13 [range, 0.02-0.31] µg/dL), and the 97.5th percentile (P97.5) was 8.3 nmol/L (0.3 µg/dL). Multiple linear regression disclosed a significant positive association between salivary cortisol levels and age (r2=0.21, p<0.001), but no association with gender (p=0.105) or BMI (p=0.119). Accordingly, participants aged >50 years had significantly higher salivary cortisol as compared to those aged <50 years (5.24 nmol/L [0.19 µg/dL] vs. 3.31 nmol/L [0.12 µg/dL], respectively, p<0.001). CONCLUSIONS: The maximum reference value (P97.5) of LNSC was set at 8.3 nmol/L (0.3 µg/dL) using ECLIA. Advanced age was associated with higher LNSC levels, with no evident influence of gender or BMI.

Glycated albumin: a potential biomarker in diabetes

ABSTRACT Diabetes mellitus (DM) is a chronic and metabolic disease that presents a high global incidence. Glycated hemoglobin (A1C) is the reference test for long-term glucose monitoring, and it exhibits an association with diabetic chronic complications. However, A1C is not recommended in clinical situations which may interfere with the metabolism of hemoglobin, such as in hemolytic, secondary or iron deficiency anemia, hemoglobinopathies, pregnancy, and uremia. The glycated albumin (GA) is a test that reflects short-term glycemia and is not influenced by situations that falsely alter A1C levels. GA is the higher glycated portion of fructosamine. It is measured by a standardized enzymatic methodology, easy and fast to perform. These laboratory characteristics have ensured the highlight of GA in studies from the last decade, as a marker of monitoring and screening for DM, as well as a predictor of long-term outcomes of the disease. The aim of this review was to discuss the physiological and biochemistry characteristics of the GA, as well as its clinical utility in DM.

Effect of ethnicity on HbA1c levels in individuals without diabetes: Systematic review and meta-analysis.

AIMS/HYPOTHESIS: Disparities in HbA1c levels have been observed among ethnic groups. Most studies were performed in patients with diabetes mellitus (DM), which may interfere with results due to the high variability of glucose levels. We conducted a systematic review and meta-analysis to investigate the effect of ethnicity on HbA1c levels in individuals without DM. METHODS: This is a systematic review with meta-analysis. We searched MEDLINE and EMBASE up to September 2016. Studies published after 1996, performed in adults without DM, reporting HbA1c results measured by certified/standardized methods were included. A random effects model was used and the effect size was presented as weighted HbA1c mean difference (95% CI) between different ethnicities as compared to White ethnicity. RESULTS: Twelve studies met the inclusion criteria, totalling data from 49,238 individuals. There were significant differences between HbA1c levels in Blacks [0.26% (2.8 mmol/mol); 95% CI 0.18 to 0.33 (2.0 to 3.6), p <0.001; I2 = 90%, p <0.001], Asians [0.24% (2.6 mmol/mol); 95% CI 0.16 to 0.33 (1.7 to 3.6), p <0.001; I2 = 80%, p = 0.0006] and Latinos [0.08% (0.9 mmol/mol); IC 95% 0.06 to 0.10 (0.7 to 1.1); p <0.001; I2 = 0%; p = 0.72] when compared to Whites. CONCLUSIONS/INTERPRETATION: This meta-analysis shows that, in individuals without DM, HbA1c values are higher in Blacks, Asians, and Latinos when compared to White persons. Although small, these differences might have impact on the use of a sole HbA1c point to diagnose DM in all ethnic populations.

Diagnostic accuracy of glycated hemoglobin for post-transplantation diabetes mellitus after kidney transplantation: systematic review and meta-analysis.

Background: Early detection of post-transplantation diabetes mellitus (PTDM) allows prompt clinical and pharmacological interventions, reducing the chance of adverse outcomes. We conducted a systematic review and meta-analysis to determine the overall diagnostic accuracy of glycated hemoglobin (HbA1c) for the diagnosis of renal PTDM. Methods: We searched MEDLINE, Embase and SCOPUS up to June 2016. Studies that included adults without previous diabetes were selected if they reported an oral glucose tolerance test as a reference test, HbA1c levels measured by standardized methods and data necessary for drawing 2 × 2 tables. A bivariate model was used to calculate the pooled estimates. Results: Based on 2057 kidney recipients from six studies, an HbA1c cut-off point of 6.5% in early months after transplant resulted in sensitivity of 0.48 [95% confidence interval (95% CI) 0.31-0.65], specificity of 0.96 (95% CI 0.95-0.97), positive likelihood ratio (PLR) of 12.0 (95% CI 7.4-19.5) and negative likelihood ratio (NLR) of 0.54 (95% CI 0.38-0.77). Based on 1888 kidney recipients from four studies, an HbA1c cut-off point of 6.2% early after transplant resulted in sensitivity of 0.76 (95% CI 0.49-0.91), specificity of 0.89 (95% CI 0.86-0.92), PLR of 7.18 (95% CI 5.29-9.75) and NLR of 0.27 (95% CI 0.11-0.65). Conclusion: HbA1c cut-off points of 6.5% and 6.2% presented high specificity but low/moderate sensitivity to diagnose PTDM.