Combining HbA1c and glycated albumin improves detection of dysglycaemia in mixed-ancestry South Africans

Second-order scattering sensor based on the Zn0.97La0.03O compound for selective and stable detection of glycated albumin

Here, we presented a second-order scattering sensor based on the Zn0.97La0.03O compound (LaZnO) for selective and stable detection of glycated albumin (GA, glycemic long-term biomarker). The LaZnO sample was obtained through the co-precipitation method and then characterized using microscopic and spectroscopic techniques. Furthermore, the selectivity, molecular interference, temporal stability, and pH effects of the LaZnO SOS signal in the absence and presence of GA were investigated. The results indicate the stability of the SOS signal over more than 60 days. Assays conducted within the pH range of 5 to 8 indicate that the detection of GA remains unaffected under the given conditions. Selectivity studies show that the SOS signal of LaZnO is reduced only upon contact with GA, while interference studies show that detection is not affected by other chemical species. Additionally, the calibration curve test showed high sensitivity of the material, with a detection limit of 0.55 µg/ml. All the results suggest that LaZnO can deliver efficiency, selectivity, accuracy, and fast response as a GA biosensor, emphasizing LaZnO's usefulness in detecting protein biomarkers.

Fructosamine is Not a Reliable Test for the Detection of Hyperglycemia: Insight from the Africans in America Study

Objective

To improve detection of abnormal glucose tolerance (Abnl-GT), attention has moved beyond the oral glucose tolerance test (OGTT), to non-fasting markers of glycemia, specifically, HbA1c, fructosamine (FA) and glycated albumin (GA). Emerging data suggest that in African descent populations, the combination of HbA1c and GA is superior to the combination of HbA1c and FA. However, the diagnosis of Abnl-GT is usually based on tests which are performed only once. As reproducibility of Abnl-GT diagnosis by HbA1c, fructosamine (FA) and glycated albumin (GA) is unknown, reproducibility of Abnl-GT diagnosis by HbA1c, FA and GA were assessed in 209 African-born Blacks living in America.

Methods

At Visits 1 and 2 (9 ± 4 days apart), samples were obtained for HbA1c, FA and GA levels. Glucose tolerance status was determined at Visit 1 by OGTT. Reproducibility was based on the К-statistic and paired t-tests. Thresholds for the diagnosis of Abnl-GT by FA and GA which corresponded to an HbA1c of 5.7% were 235umol/L and 14.6%, respectively.

Results

Abnl-GT occurred in 38% (80/209). Diagnostic reproducibility was excellent for HbA1c (К≥0.86) and GA (К≥0.89), but only moderate for FA (К=0.59). Neither HbA1c nor GA levels varied between visits (both P≥0.3). In contrast, FA was significantly lower at Visit 2 than Visit 1(P<0.01).

Conclusion

As HbA1c and GA provided similar diagnostic results on different days and FA did not, HbA1C and GA are superior to FA in both clinical care settings and epidemiologic studies.

Strikes and Gutters: Biomarkers and anthropometric measures for predicting diagnosed diabetes mellitus in adults in low- and middle-income countries

The management of diabetes necessitates the requirement of reliable health indices, specifically biomarkers and anthropometric measures, to detect the presence or absence of the disease. Nevertheless, limited robust empirical evidence exists regarding the optimal metrics for predicting diabetes in adults, particularly within low- and middle-income countries. This study investigates objective and subjective indices for screening diabetes in these countries.

METHODS

Data for this study was sourced from surveys conducted among adults (aged 18 years and above) in seventeen (17) countries. Self-reported diabetes status, fifty-four biomarkers, and twenty-six core and twenty-eight estimated anthropometric indices, including weight, waist circumference, body mass index, glycaemic triglycerides, and fasting blood glucose, were utilised to construct lasso regression models.

RESULTS

The study revealed variances in diabetes prediction outcomes across different countries. Central adiposity measures, fasting plasma glucose and glycaemic triglycerides demonstrated superior predictive capabilities for diabetes when compared to body mass index. Furthermore, fasting plasma or blood glucose, serving as a biomarker, emerged as the most accurate predictor of diabetes.

CONCLUSIONS

These findings offer critical insights into both general and context-specific tools for diabetes screening. The study proposes that fasting plasma glucose and central adiposity indices should be considered as routine screening tools for diabetes, both in policy interventions and clinical practice. By identifying adults with or at higher risk of developing diabetes and implementing appropriate interventions, these screening tools possess the potential to mitigate diabetes-related complications in low- and middle-income countries.

Diagnostic accuracy of two confirmatory tests for diabetes mellitus in adult Ugandans with recently diagnosed tuberculosis

Objective

The optimal confirmatory tests for diabetes mellitus (DM) in patients with tuberculosis (TB) vary across populations. This study aimed to evaluate the performance of two confirmatory tests for DM against the oral glucose tolerance test (OGTT) as the reference test in adult Ugandans with recently diagnosed TB.

Methods

A total of 232 adult participants receiving TB treatment underwent initial screening for DM with random blood glucose (RBG) measurement. Participants with a RBG level ⩾6.1 mmol/l received additional screening with fasting blood glucose (FBG), laboratory-measured glycated haemoglobin (HbA1c) and an OGTT. Using the latter as the gold standard and reference test, we evaluated the diagnostic accuracy of laboratory-measured HbA1c and FBG.

Results

Of the 232 participants initially screened for DM using RBG measurement, 117 participants (50.4%) had RBG level ⩾6.1 mmol/l and were scheduled to return for additional blood glucose testing. Of these, 75 (64.1%) participants returned for FBG and HbA1c measurements. A diagnosis of DM was made in 32 participants, corresponding to a prevalence of 13.8% [95% CI 9.9-18.9].The areas under the curve (AUC) for FBG and laboratory-measured HbA1c were 0.69 [95% CI 0.47-0.90] and 0.65 [95% CI 0.43-0.87], respectively. The sensitivity and specificity of a FBG level of ⩾7 mmol/l were 57.1% [95% CI 18.4-90.1] and 74.6% [95% CI 62.5-84.5], respectively, whereas the sensitivity and specificity for laboratory-measured HbA1c of ⩾6.5 mmol/l (48 mmol/mol) were 14.3% [95% CI 0.40-57.9] and 95.3% (86.9-99.0%), respectively.

Conclusion

FBG may be better than laboratory-measured HbA1c in confirming DM in adult Ugandans with recently diagnosed TB. However, because of the small study sample size, larger studies evaluating the diagnostic utility of these diabetes screening tests in adult Ugandans with TB are needed to confirm these findings.