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.

Prevalência de atipias de significado indeterminado e sua relação com o papilomavírus em uma população de Caxias do Sul / Prevalence of atypias of indetermined meaning and its relationship with papilomavirus in a population of Caxias do Sul

Objetivo: Analisar a prevalência dos resultados positivos para ASC em uma população da rede privada em Caxias do Sul e sua associação com o HPV. Métodos: Foram analisados resultados de exames citopatológicos do colo uterino no período de 2015 a 2017. Para presença de HPV foram avaliados os resultados histopatológicos da biópsia e de biologia molecular por reação em cadeia polimerase (PCR). Resultados: A prevalência de ASC foi de 2,48%, sendo que 58% das pacientes realizaram seguimento. A histopatologia mostrou prevalência de HPV, associado às lesões cervicais em 46,4% e 59,4% para ASC-US e ASC-H respectivamente. A prevalência de HPV no teste de PCR foi de 30,4%, sendo os subtipos mais prevalentes o HPV16 e 18. Conclusão: O percentual de exames de ASC em uma população de Caxias do Sul mostrou-se dentro dos valores adequados. Na histopatologia houve uma maior associação de ASC-H com lesões de alto grau e presença de HPV. Isso mostra a necessidade e a importância do seguimento das pacientes com resultados de ASC, principalmente para ASC-H.

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.

HbA1c Test as a Tool in the Diagnosis of Gestational Diabetes Mellitus.

AIMS: Gestational diabetes mellitus (GDM) is a prevalent and potentially serious condition which may put both mothers and neonates at risk. The current recommendation for diagnosis is the oral glucose tolerance test (OGTT). This study aimed to determine the usefulness of HbA1c test as a diagnostic tool for GDM as compared to the traditional criteria based on the OGTT. METHODS: This was a diagnostic test accuracy study. We performed OGTT and HbA1c test in women attending prenatal visits at a tertiary hospital. GDM was defined according to WHO1999 or ADA/WHO 2013 criteria. ROC curve was used to evaluate the diagnostic performance of HbA1c. Sensitivity, specificity and likelihood ratios for different HbA1c cut-off points were calculated. RESULTS: Of the 262 women in the third trimester of gestation enrolled in the study, 86 (33%) were diagnosed with GDM. Only five of these women presented HbA1c ≥48 mmol/mol (6.5%). This cut-off point presented 100% specificity but very low sensitivity (7%). Based on ROC curve, and considering OGTT as the reference criterion, HbA1c ≥40 mmol/mol (5.8%) showed adequate specificity in diagnosing GDM (94.9%) but low sensitivity (26.4%). Unlike, HbA1c values of 31 mmol/mol (5.0%) presented adequate sensitivity (89.7%) but low specificity (32.6%) to detect GDM. For women with HbA1c ≥40 mmol/mol (5.8%), the positive and negative likelihood ratios were 5.14 (95%CI 2.49-10.63) and 0.78 (0.68-0.88), respectively. The post-test probability of GDM was about 40%, representing a 4.0-fold increase in the mean pre-test probability. This cut-off point could eliminate the need for the unpleasant and laborious OGTT tests in almost one third of cases, as 38% of patients with GDM may be diagnosable by HbA1c test alone. CONCLUSIONS: Our results show that combined HbA1c and OGTT measurements may be useful in diagnosing GDM.

Factors affecting A1C in non-diabetic individuals: Review and meta-analysis.

We carried out a systematic review and meta-analyses of studies that evaluated the possible effects of anemia, variant hemoglobin, and uremia on A1C levels in individuals without diabetes (DM). Medline and Embase were searched for studies that measured A1C values in groups with and without iron deficiency anemia (IDA) and/or iron deficiency (ID), variant hemoglobin and/or uremia by standardized methods. The difference between A1C levels in the groups with and without interferences was obtained by using random-effects meta-analysis and the effect size was presented as absolute difference of means (95% CI). Ten studies fulfilled the inclusion criteria, providing data from 11,176 participants without DM. There were no statistically significant differences in A1C in the presence of IDA/ID, HbS, and uremia by HPLC and uremia by immunoassay [0.79% (95% IC -0.39; 1.97), -0.13% (95% IC -0.51; 0.26), 0.15% (95% CI -0.58; 0.88) and -0.19% (95% CI -0.78; 0.40), respectively]. The effects of HbAS and uremia on A1C levels are within the expected individual variation and should not affect A1C results to diagnose DM. However, the effects of IDA/ID remain inconclusive and further studies are needed to clarify the glycation mechanisms in individuals with IDA/ID without diabetes.

HbA1C, glicemia de jejum e teste oral de tolerância à glicose no diagnóstico de diabetes: que teste usar? / HbA1C, fasting glycemia and oral glucose tolerance test in the diagnosis of diabetes: which test?

Introdução: Tradicionalmente, a glicemia de jejum (GJ) e o teste oral de tolerância à glicose (TOTG), têm sido recomendados para o diagnóstico do diabetes melito (DM). Recentemente, a hemoglobina glicada/HbA1c (A1C) foi recomendada como nova ferramenta diagnóstica e seu uso isolado está sendo preconizado. Objetivo: Analisar a concordância diagnóstica entre GJ, TOTG e A1C no diagnóstico de DM. Métodos: Indivíduos atendidos no Hospital de Clínicas de Porto Alegre para a realização de TOTG foram incluídos no estudo. A1C, GJ, glicemia 2h após a ingestão de 75 g de glicose, perfil lipídico e história clínica foram analisados. Testes T-Student, qui-quadrado, Mann-Whitney U e coeficiente kappa foram utilizados conforme o caso. Resultados: No total, 498 indivíduos participaram do estudo. Pelos critérios baseados na glicemia, 115 indivíduos foram diagnosticados com DM (26 pela GJ, 53 pelo TOTG e 36 por ambos os testes). Pelos valores de A1C, apenas 56 indivíduos apresentaram valor de A1C _6,5% e foram diagnosticados com DM (27 pela A1C isolada e 29 pela A1C e também pela GJ e/ou TOTG). A concordância diagnóstica entre os critérios baseados na glicemia e A1C é fraca (kappa = 0,217; P<0,001). Pacientes diagnosticados pelo critério A1C _6,5% isolado possuem perfil cardiovascular desfavorável quando comparados com os indíviduos que são classificados pelos critérios baseados na glicemia. Conclusão: Os diferentes testes diagnósticos identificam diferentes indivíduos com risco de diabetes. A utilização de algoritmos empregando os testes GJ, TOTG e/ou A1C parece ser mais adequada para garantir a correta classificação dos indivíduos com DM.

Background: Traditionally, fasting glycemia (FG) and oral glucose tolerance test (OGTT) were recommended for diabetes (DM) diagnosis. Recently, glycated hemoglobin/HbA1c (A1C) was recommended as a new diagnostic tool ant its isolated use is preferred. Aim: To analyze the agreement between GJ, TOTG and A1C in diagnosing DM. Methods: Individuals referred to Hospital de Clínicas de Porto Alegre for OGTT were included in this study. A1C, FG, OGTT, lipid profile and clinical history were analyzed. T-Student, Qui-square, Mann-Whitney U tests and kappa coefficient were used accordingly. Results: A total of 498 individuals participated in the study. By glycemia-based criteria, 115 individuals were classified with DM (26 by GJ, 53 by TOTG and 36 by both tests). By A1C criterion, only 56 individuals had A1C _6.5% and were classified with DM (27 by A1C only and 29 by A1C and FG and/or OGTT). The diagnostic agreement between glycemia-based criteria and A1C is poor (kappa = 0,217; P<0,001). Patients classified as diabetic only by A1C test had a cardiovascular unfavorable profile compared to patients classified by glycemia-based criteria. Conclusion: Different diagnostic tests identified different individuals at risk of DM. The use of algorithms with FG, OGTT and/or A1C tests seems to be more adequate to assure the correct classification of diabetic individuals.