Glycated Hemoglobin Measurement: Comparison of Three Methods Versus High Performance Liquid Chromatography

Prevalence and associated factors of chronic kidney disease among Truká Indigenous adults in Cabrobó, Brazil: a population-based study

Background

The prevalence of chronic kidney disease (CKD) is increasing worldwide, especially in developing countries, due to factors such as lifestyle changes and the rise of non-communicable diseases. Populations living in socioeconomically disadvantaged areas are subject to a higher burden of CKD. However, the burden of CKD on Brazilian Indigenous people, especially those undergoing an advanced urbanisation process, has not yet been described.

Methods

This cross-sectional study included 1715 Truká Indigenous adults from Cabrobó, Brazil. CKD was defined according to the Kidney Disease Improving Global Outcomes guidelines classification as a urinary albumin/creatinine ratio ≥30 mg/g and/or an estimated glomerular filtration rate <60 mL/min/1.73 m2. Univariate and multiple logistic regression models were used to evaluate factors associated with CKD. Odds ratio (OR) with a 95% confidence interval (CI) was used to measure association.

Findings

Out of the 1654 participants analysed (61 excluded due to missing data), the prevalence of CKD was 10% (95% CI, 8.6%-11.5%), with a higher prevalence in women compared to men (12.4% versus 6.9%, p < 0.001). The mean age was 40.5 years, with 55.6% being women. In univariate analysis, female sex (OR, 1.9; 95% CI, 1.3-2.7), age ≥60 years (OR, 4.6; 95% CI, 3.2-6.6), cardiovascular disease (OR, 2.1; 95% CI, 1.1-4.1), and dyslipidemia (OR, 1.6; 95% CI, 1.1-2.4) were identified as associated factors with CKD. Multiple logistic regression analysis identified age ≥60 years, female sex, and dyslipidemia as independently associated factors with CKD.

Interpretation

The prevalence of CKD among Truká Indigenous adults analysed is high and affects a higher proportion of women. Our study found no association between hypertension, diabetes, obesity, and CKD risk, despite their high prevalence. These findings assist in developing early CKD detection strategies in Brazilian Indigenous communities, supporting disease treatment and prevention.

Funding

National Council for Scientific and Technological Development (CNPq)-Ministry of Science, Technology, and Innovation of Brazil, and the Maria Emília Foundation.

Advances in electrochemical biosensors employing carbon-based electrodes for detection of biomarkers in diabetes mellitus

Background and purpose

The increase in diabetes cases has become a major concern in the healthcare sector, necessitating the development of efficient and minimal diagnostic methods. This study aims to provide a comprehensive examination of electrochemical biosensors for detecting diabetes mellitus biomarkers, with a special focus on the utilization of carbon-based electrodes.

Review approach

A detailed analysis of electrochemical biosensors incorporating various carbon electrodes, including screen-printed carbon electrodes, glassy carbon electrodes, and carbon paste electrodes, is presented. The advantages of carbon-based electrodes in biosensor design are highlighted. The review covers the detection of several key diabetes biomarkers, such as glucose, glycated hemoglobin (HbA1c), glycated human serum albumin (GHSA), insulin, and novel biomarkers.

Key results

Recent developments in electrochemical biosensor technology over the last decade are summarized, emphasizing their potential in clinical applications, particularly in point-of-care settings. The utilization of carbon-based electrodes in biosensors is shown to offer significant advantages, including enhanced sensitivity, selectivity, and cost-effectiveness.

Conclusion

This review underscores the importance of carbon-based electrodes in the design of electrochemical biosensors and raises awareness for the detection of novel biomarkers for more specific and personalized diabetes mellitus cases. The advancements in this field highlight the potential of these biosensors in future clinical applications, especially in point-of-care diagnostics.

Quantification of Glycated Hemoglobin in Total Hemoglobin by a Simultaneous Dual-Signal Acquisition Approach

The glycated hemoglobin (HbA1c) level, which is defined as the ratio of HbA1c to total hemoglobin (tHb, including glycated and unglycated hemoglobin), is considered one of the preferred indicators for diabetes monitoring. Generally, assessment of the HbA1c level requires separate determination of tHb and HbA1c concentrations after a complex separation step. This undoubtedly increases the cost of the assay, and the loss or degradation of HbA1c during the separation process results in a decrease in the accuracy of the assay. Therefore, this study explored a dual-signal acquisition method for the one-step simultaneous evaluation of tHb and HbA1c. Quantification of tHb: graphene adsorbed carbon quantum dots and methylene blue were utilized as the substrate material and linked to the antibody. tHb was captured on the substrate by the antibody. The unique heme group on tHb catalyzed the production of •OH from H2O2 to degrade methylene blue on the substrate, and a quantitative relationship between the tHb concentration and the methylene blue oxidation current signal was constructed. Quantification of HbA1c: complex labels with HbA1c recognition were made of ZIF-8-ferrocene-gold nanoparticles-mercaptophenylboronic acid. The specific recognition of the boronic acid bond with the unique cis-diol structure of HbA1c establishes a quantitative relationship between the oxidation current of the label-loaded ferrocene and the concentration of HbA1c. Thus, the HbA1c level can be assessed with only one signal readout. The sensor exhibited extensive detection ranges (0.200-600 ng/mL for tHb and 0.100-300 ng/mL for HbA1c) and low detection limits (4.00 × 10-3 ng/mL for tHb and 1.03 × 10-2 ng/mL for HbA1c).

A Non-Invasive Hemoglobin Detection Device Based on Multispectral Photoplethysmography

The measurement of hemoglobin is a vital index for diagnosing and monitoring diseases in clinical practice. At present, solutions need to be found for the soreness, high risk of infection, and inconvenient operation associated with invasive detection methods. This paper proposes a method for non-invasively detecting hemoglobin levels based on multi-wavelength photoplethysmography (PPG) signals. AFE4490 and TMUX1109 were used to implement the low-cost collection of an eight-LED transmissive PPG signal. We used seven regular LEDs and one broadband LED (Osram SFH4737) as light sources. Additionally, a finger clip integrating multiple sensors was designed and manufactured via 3D printing to simultaneously monitor the LED-sensor distance and the pressure from the tester's finger during PPG signal acquisition. We used a method to extract features from PPG signals using a sliding-window's variance and an evaluation metric for PPG signals based on the AdaCost classification. Data were gathered from 56 participants from the Nephrology department, including 16 anemic patients. Pearson correlation analysis was conducted on the collected data to remove any data with a weak correlation. The advantage of using a broadband LED as a light source was also demonstrated. Several non-invasive hemoglobin regression models were created by applying AdaBoost, BPNN, and Random Forest models. The study's results indicate that the AdaBoost model produced the best performance, with a mean absolute error (MAE) of 2.67 g/L and a correlation coefficient (R2) of 0.91 The study results show that the device we designed and manufactured can achieve effective non-invasive hemoglobin detection and represents a new methodological approach to obtaining measurements that can be applied in a clinical setting.

Epidemiology of chronic kidney disease in older indigenous peoples of Brazil: findings from a cross-sectional survey

BACKGROUND

Chronic kidney disease (CKD) is a prevalent disease worldwide, with increasing incidence particularly in low- and middle-income countries. Indigenous communities have poorer CKD outcomes due to limited access to healthcare. They are also experiencing a shift toward a sedentary lifestyle and urbanization-related dietary changes, increasing the risk of CKD-related risk factors.

AIM

To determine the prevalence of CKD in older Brazilian indigenous and identify the main associated risk factors.

METHODS

This cross-sectional study analyzed demographic and clinical data of 229 older indigenous individuals aged 60 years and above in 2022-2023. CKD was defined as an estimated glomerular filtration rate < 60 mL/min/1.73 m2 or a urinary albumin-creatinine ratio > 30 mg/g. Data were presented categorically and analyzed using the Chi-square test or Fisher's exact test.

RESULTS

The prevalence of CKD in the population was 26.6%, with higher prevalence in women and increasing with age. The prevalence of hypertension and diabetes was 67.7% and 24.0%, respectively, and these comorbidities were associated with CKD: hypertension (OR = 5.12; 95% CI 2.2-11.9) and diabetes (OR = 5.5; 95% CI 3.7-8.2). No association was found between the prevalence of CKD and obesity, dyslipidemia, cardiovascular disease, or smoking.

DISCUSSION

The study found a higher prevalence of CKD among older indigenous populations in Brazil compared to non-indigenous populations, which is exacerbated by risk factors, such as aging, hypertension, diabetes, and lifestyle changes, emphasizing the importance of early detection and intervention in these communities.

CONCLUSION

Older persons' indigenous individuals have a high prevalence of CKD, which is correlated with factors, such as sex, age, diabetes mellitus, and hypertension.

Urbanization and kidney dysfunction in Brazilian indigenous people: a burden for the youth

OBJECTIVE

The aim of this study was to investigate whether the degree of urbanization influences the prevalence of chronic kidney disease in Brazilian indigenous people.

METHODS

This is a cross-sectional study conducted between 2016 and 2017 in northeastern Brazil and includes individuals aged between 30 and 70 years from two specific indigenous groups who volunteered to participate in the study: the Fulni-ô people (lowest degree of urbanization) and the Truká group (greater degree of urbanization). Cultural and geographical parameters were used to characterize and measure the magnitude of urbanization. We excluded individuals with known cardiovascular disease or renal failure who required hemodialysis. Chronic kidney disease was defined as a single measurement of an estimated glomerular filtration rate <60 mL/min/1.73 m2 using the Chronic Kidney Disease Epidemiology Collaboration creatinine equation.

RESULTS

A total of 184 indigenous people from the Fulni-ô group and 96 from the Truká group with a median age of 46 years (interquartile range: 15.2) were included. We found a chronic kidney disease rate of 4.3% in the total indigenous population, generally affecting an older population: 41.7% over 60 years old (p<0.001). The Truká people had a chronic kidney disease prevalence of 6.2%, with no differences in kidney dysfunction across age groups. The Fulni-ô participants had a chronic kidney disease prevalence of 3.3%, with a higher proportion of kidney dysfunction in older participants (of the six Fulni-ô indigenous people with chronic kidney disease, five were older).

CONCLUSION

Our results suggest that a higher degree of urbanization seems to negatively influence the prevalence of chronic kidney disease in Brazilian indigenous people.