Dried Blood Spot Biomarkers of Oxidative Stress and Inflammation Associated with Blood Pressure in Rural Senegalese Women with Incident Hypertension

Dried Blood Spots to Assess Cardiovascular-Kidney-Metabolic Health

Dried blood spot sampling offers a scalable strategy to close diagnostic gaps and improve global surveillance for cardiovascular-kidney-metabolic syndrome. However, assay performance and the extent of validity vary widely between biomarkers used in cardiovascular-kidney-metabolic health assessment under different settings and have not been well described. To fill this gap, we conducted a systematic search of the literature and a narrative synthesis through April 2024 and included reports with laboratory or field validation measuring biomarkers that can be used in cardiovascular-kidney-metabolic health assessment. We categorized assays into categories based on laboratory validation: excellent performance (r>0.95 with gold standard methods and coefficients of variation <5%), very good performance (r>0.90 and coefficients of variation <10%), reasonable performance (r>0.80 and coefficients of variation <15%), and poor performance (r<0.80 or coefficients of variation >15%). The extent of validation was determined by the total number of field validation studies with strong agreement. Hemoglobin A1c has strong laboratory and field validation and should be considered for expansion into clinical testing in low-resource settings. Traditional lipid biomarkers showed poor performance in field validation studies, but apoB (apolipoprotein B), creatinine, cystatin C, and NT-proBNP (N-terminal prohormone of brain natriuretic peptide) showed promising initial laboratory validation results and deserve greater attention in field validation studies. High-sensitivity C-reactive protein has strong laboratory and field validation but has limited clinical utility. Dried blood spot assays have been developed for biomarkers that offer mechanistic insights including inflammatory and vascular injury markers, fatty acids, malondialdehyde, asymmetric dimethylarginine, trimethylamine N-oxide, carnitines, and omics.

Trajectories of intimate partner violence and their relationship to stress among young women in South Africa: An HPTN 068 study

BACKGROUND

One in four South African women will experience intimate partner violence (IPV) in their lifetime, potentially increasing their biological stress. In South Africa, limited IPV and stress research has utilized multiple timepoints or examined modifying factors. Cash transfers (CTs) are associated with reduced IPV and stress and may be an intervention target.

AIMS

We used data-driven methods to identify longitudinal IPV trajectory groups among South African adolescent girls and young women (AGYW), estimate each group's association with stress, and assess modification by a CT.

METHODS

A total of 2,183 South African AGYW ages 13 to 24 years from the HIV Prevention Trials Network 068 study were randomized to a CT or control group. Physical IPV was measured five times (2011-2017), and stress was captured once (2018-2019). Stress measures included the Cohen Stress Scale and stress biomarkers (C-reactive protein (CRP), cytomegalovirus (CMV), herpes simplex virus type-1 (HSV-1)). Group-based trajectory modeling identified IPV trajectories; ordinal logistic regression estimated the association between trajectory group and stress.

RESULTS

A two-group quadratic trajectory model was identified (higher trajectory group = 26.7% of AGYW; lower trajectory group = 73.3%). In both groups, the probability of IPV increased from ages 13 to 17 years before declining in early adulthood. However, the higher group's probability peaked later and declined gradually. The higher trajectory group was associated with an increased odds of elevated CRP (OR: 1.41, 95% CI [1.11, 1.80]), but not with other stress measures. The CT modified the relationship with CMV: a positive association was observed among the usual care arm (OR: 1.59, 95% CI [1.11, 2.28]) but not the CT arm (OR: 0.85, 95% CI [0.61, 1.19]).

CONCLUSIONS

Sustained IPV risk during adolescence was associated with elevated CRP in young adulthood. The relationship between IPV and elevated CMV was attenuated among those receiving a CT, suggesting that CTs could possibly reduce biological stress due to IPV.

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.

Analysis of C-reactive protein from finger stick dried blood spot to predict high risk of cardiovascular disease

C-reactive protein (CRP) is an acute-phase protein involved in inflammation. Furthermore, CRP is an important biomarker used in diagnostics to predict risk of cardiovascular disease (CVD) in addition to monitoring bacterial and viral infections. To measure plasma CRP, venipuncture is still necessitated and has to be performed by trained phlebotomists. As a solution, dried blood spots (DBS) are used for minimally invasive at-home sampling of blood and can be send to diagnostic laboratories by regular mail. In this study, we included 53 patients that presented to the outpatient clinic of the University Medical Center Utrecht. Capillary finger stick was used to spot blood on a filter paper card and allowed to dry. After extraction of DBS, CRP was analyzed on an automated high-throughput chemistry analyzer. Additional validation steps regarding stability, effect of hematocrit, precision, and limits of blank and quantitation were conducted according to corresponding Clinical and Laboratory Standards Institute standards. An excellent regression analysis of R2 (95% confidence interval) = 0.986 (0.982-0.989) was found. This enabled correct classification for high CVD risk of all 25 cases with sensitivity (95% CI) of 1.00 (1.00-1.00) and specificity (95% CI) of 0.96 (0.89-1.03) and correct diagnosis of inflammation of 12/13 cases with sensitivity (95% CI) of 0.92 (0.77-1.07) and specificity (95% CI) of 1.00 (1.00-1.00). Furthermore, CRP was found to be stable for 31 days and observed hematocrit variation amongst patients was clinically acceptable. CRP from DBS can be accurately measured on an automated high-throughput chemistry analyzer and used to diagnose inflammation and classify high CVD risk. This method enables individuals to engage in at-home sampling of blood on DBS for (tele)diagnostics, screening programs, patient follow-up, and medication management.

Intimate partner violence is associated with cytomegalovirus among young women in rural South Africa: An HPTN 068 analysis

ABSTRACTStressful life circumstances (e.g. violence and poverty) have been associated with elevated biomarkers, including C-reactive protein (CRP), cytomegalovirus (CMV), and herpes simplex virus type-1 (HSV-1), among older adults in high-income settings. Yet, it remains unknown whether these relationships exist among younger populations in resource-limited settings. We therefore utilised a cohort of 1,279 adolescent girls and young women (AGYW) from the HIV Prevention Trials Network 068 study in rural South Africa to examine the associations between 6 hypothesized stressors (intimate partner violence (IPV), food insecurity, depression, socioeconomic status (SES), HIV, childhood violence) and 3 biomarkers that were measured using dried blood spots (CRP, CMV, and HSV-1). Ordinal logistic regression estimated the lagged and cross-sectional associations between each stressor and each biomarker. IPV was cross-sectionally associated with elevated CMV (OR = 2.45, 95% CI = 1.05,5.72), while low SES was cross-sectionally associated with reduced CMV (OR = 0.73, 95% CI = 0.58,0.93). AGYW with HIV had elevated biomarkers cross-sectionally (CRP: OR = 1.51, 95% CI = 1.08,2.09; CMV: OR = 1.86, 95% CI = 1.31,2.63; HSV-1: OR = 1.68, 95% CI = 1.17,2.41) and in a lagged analysis. The association between violence and CMV could help explain how violence results in stress and subsequently worse health among AGYW; however, additional research is needed to disentangle the longitudinal nature of IPV and stress.