Elaine Holmes

Background
Evidence increasingly suggests a connection between cardiovascular disease and brain health in later life; however, the mechanistic pathways from human studies remain unclear. This study aimed to investigate whether urinary metabolites account for part of the association between cognition and cardiometabolic risk.

Methods
Data from 606 participants (aged 48–60; 55% female; 45.5% Black/African American) in the Year 30 follow-up of the Coronary Artery Risk Development in Young Adults Study were analyzed. Urinary metabolites were profiled using nuclear magnetic resonance spectroscopy and liquid chromatography-mass spectrometry; brain magnetic resonance imaging data were available for 281 participants. Structural equation models were used to assess pathways linking cardiometabolic factors to cognitive outcome, with urinary metabolites and brain MRI-derived parameters as mediators.

Results
Fasting glucose showed a negative association with cognition. Valine, isoleucine, leucine, and phenylalanine were positively associated with fasting glucose. Valine and aminoadipic acid also showed positive associations between fasting glucose and cognition, while tryptophan was correlated with both fasting glucose and cognition. Indole-3-acetic acid showed negative associations with systolic blood pressure and fasting glucose. Brain MRI-derived parameters in memory-related medial temporal areas were associated with waist circumference.

Conclusions
Urinary metabolites and brain imaging markers were linked with hyperglycemia, obesity, and cognitive performance, highlighting multimodal biomarkers relevant to global cognitive function in individuals with cardiometabolic risk.

Broad-spectrum viral biomarkers offer a promising approach to distinguishing viral from bacterial infections, thereby reducing inappropriate antibiotic use and improving diagnostic response during emerging infectious disease outbreaks. Among these, the deoxydidehydronucleoside (ddhN) class of nucleoside derivatives has emerged as a potential tool for early detection of viral infections in settings where pathogen-specific diagnostics are unavailable. To assess the clinical utility of these compounds, we investigated the metabolism and excretion rates of four principal ddhN metabolites, 3'-deoxy-3',4'-didehydrocytidine (ddhC), 3'-deoxy-3',4'-didehydrocytidine-5'-carboxylate (ddhC-5'CA), 3'-deoxy-3',4'-didehydrouridine (ddhU), and 3'-deoxy-3',4'-didehydrocytidine-5'-homocysteine (ddhC-5'Hcy), in the Sprague-Dawley rat model following a single intravenous dose. Time-resolved biological sampling was used to characterize urinary excretion and downstream biotransformation. All four metabolites exhibited rapid urinary clearance, ranging from approximately 3 to 8 h, consistent with a transient acute-phase profile. Notably, ddhC-5'Hcy underwent extensive biotransformation, with key metabolites produced via functionalization and conjugation identified following integration of nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS) analyses. No adverse clinical signs were observed in any treatment group at any time point. These findings support further research into the ddhN series as markers of active viral infection for clinical application, particularly in critical care environments, where timely differentiation of infectious etiology is essential.

Paediatric burn injuries are a global health concern with long-term health consequences, such as psychological, immune, and cardiovascular complications, that can persist even after non-severe injuries. Emerging evidence suggests that biological sex may influence post-burn outcomes in children, as female burn survivors have been shown to experience higher mortality, scarring, anxiety, depression, and poorer quality of life compared to males. This study addresses a critical research gap by examining sex-specific lipidomic and inflammatory responses following paediatric non-severe burn injury. Children under five years were recruited as a part of the Childhood Burn Injury Biobank at hospital admission, with longitudinal follow-ups, and non-burn controls aged 1 and 3 were collected from the ORIGINS cohort. Plasma lipid profiling and acute-phase glycoprotein systemic inflammatory markers (GlycA and GlycB) were quantified using metabolic phenotyping with hair cortisol provided as a longitudinal measure of stress. Lipidomic analysis revealed acute-phase disruptions in fatty acids and lysophospholipids in both sexes but only females demonstrated a persistent increase of arachidonic acid (FA 20:4) and depletion of monoacylglycerols more than a year post-injury. Females also had significantly higher acute-phase GlycA/GlycB levels around the time of injury and exhibited increasing variability in hair cortisol over time, while male burn survivors did not. These findings highlight a sex-specific response between lipid metabolism, systemic inflammation and stress in paediatric recovery from non-severe burns. Understanding these differences may guide the development of targeted psychological and physiological strategies to improve long-term outcomes for young burn survivors.

Background: Epidemiological evidence shows that fruit and vegetable (FV) intake reduces cardiovascular risk. Comparative effects of diets with different FV types on cardiometabolic disease risk markers remain unclear.

Objectives: This study aimed to compare the effects of standardised diets differing in FV types on vascular function, other cardiometabolic disease risk markers, urinary and plasma biomarkers in free-living adults with untreated prehypertension.

Methods: In a 9-wk randomised, controlled, crossover trial at 2 centres, 39 adults consumed standardised, provided diets with either 8 daily portions of common FV (apple, banana, pear, bell pepper, carrot, tomato), 8 daily portions of citrus and cruciferous FV, or 2 daily portions (low FV diet, control) for 2 wk per arm, with a 1-wk washout. Adherence was assessed using 24-h urinary potassium, sodium, and targeted plasma carotenoids and metabolites. The primary outcome was office blood pressure; secondary outcomes included pulse wave velocity (pwv), augmentation index standardised at 75 beats per minute (AIX75), lipids, and C-reactive protein (CRP). Between-group differences were assessed using linear mixed models with diet and period as fixed effects, and participant as random effect.

Results: Thirty-six participants completed the study (67% male, mean age 54±6 y; systolic BP 131.7±9.0 mmHg, total cholesterol: 5.4±1.1 mmol/L). No between-group differences were observed in office BP, PWV, AIX75, or CRP. Both common and citrus fruits and cruciferous FV diets tended to increase 24-h urinary potassium (by 6.94 mmol/24-h, P≤0.1; 8.0 mmol/24-h, P≤0.06, respectively), while 24-h urinary sodium remained comparable across diets (P≥0.87). Common FV diet significantly increased α- and β-carotene, and lycopene (P≤6.3x10-4), whereas citrus fruits and cruciferous FV increased lutein/zeaxanthin, β-cryptoxanthin, proline betaine, N-methylproline, and S-methyl-L-cysteine sulfoxide (P≤6.9x10-8). Common FV diet reduced total (-0.19 mmol/L, 95% confidence interval (CI): -0.32,-0.05), LDL (-0.15 mmol/L, 95% CI: -0.26,-0.03), and HDL (-0.05 mmol/L, 95% CI: -0.09,-0.00) cholesterol, whereas citrus and cruciferous FV reduced urinary creatinine (-1.19 mmol/24-h, 95% CI: -2.27,-0.11). No effects were observed on weight and physical activity.

Conclusions: Objective biomarkers confirmed FV adherence and suggest that FV types differentially modulate lipid and metabolic responses within 2 wk, without measurable vascular effects.

Introduction
The biomarkers and the mechanisms underlying the cognitive decline in ageing are not fully clarified although they might be effective for dementia prevention. We comprehensively explore metabolites associated with cognitive function by conducting metabolomics analysis in a cohort study of general Japanese men.

Methods
The study population was 672 Japanese men aged 46-83 years without stroke, who were randomly selected for the SESSA study from Kusatsu City, Japan. Metabolomics using liquid chromatography mass spectrometry (LC-MS) was conducted on plasma samples, focusing on lipid metabolism. The 442 metabolites were identified. The cognitive function was assessed by Cognitive Abilities Screening Instrument (CASI), and CASI score less than 82 was defined as having mild cognitive impairment (MCI). We examined the metabolites among groups with and without MCI using principal component analysis and partial least squares regression (PLS) or PLS rank order of groups. Multivariable adjusted logistic regression estimated the odds ratios (ORs) and 95%CI of MCI for the extracted metabolites per standard deviation. The 9 domain specific MCI using median value of each domain specific CASI score as cutoff points were also examined. KEGG pathway analysis was done to clarify the linked pathway for the extracted metabolites.

Results
The prevalence of MCI was 5.5%. The 22 metabolites were statistically significantly associated with CASI score (q <0.05 in PLS, 21 metabolites in the positive direction and 1 metabolite in the negative direction). Phosphatidylcholines (PC) and Lysophosphatidylcholines (LPC) were associated with low risk of MCI (OR(95%CI): PC16:0/20:3; 0.51(0.32-0.51), LPC18:2/0.0; 0.59 (0.36-0.96), LPC20:3/0.0; 0.48(0.28-0.82)), phenacetylcarnitine was associated with the high risk of MCI (OR (95%CI); 1.33 (1.01-1.75)) (q <0.05). The analysis for domain specific MCI extracted the metabolites for short term memory, language abilities and category fluency. The Linoleic acid metabolism pathway was statistically significantly associated with CASI score.

Conclusion
Glycerophosphocolines such as PC16:0/20:3, LPC18:2/0.0 and LPC20:3/0.0 were reduced in participants with MCI, and those metabolites associated with low risk of MCI. Linoleic acid metabolism might be important for prevention of dementia among Japanese.

Methoxyacetic acid (MAA) is a testicular toxin that targets spermatocytes and round spermatids by disrupting mitochondrial function, leading to cellular energy depletion. Male Sprague-Dawley rats were given single oral doses of MAA (150 or 650 mg/kg), resulting in no mortality but transient toxicity signs and modest body weight effects, especially at the higher dose. Histopathology revealed dose- and time-dependent testicular damage, with selective germ cell necrosis by 48 h and extensive germ cell loss, spermatic giant cells, and epididymal inflammation observed in high-dose animals by 168 h. Metabolic analysis using high resolution 1H NMR spectroscopy and OPLS-DA identified elevated urinary excretion of N-butyryl glycine, a marker of mitochondrial dysfunction and impaired β-oxidation. The persistence of N-butyryl glycine and altered energy metabolites up to 168 h indicates sustained mitochondrial stress and disruption of ATP-dependent processes essential for spermatogenesis. Moreover, the close structural similarity between MAA and butyrate raises the possibility that MAA interacts directly with enzymes involved in butyryl-CoA turnover during the terminal steps of β-oxidation in rodents.

Background and aims: Diabetic retinopathy (DR) is a major complication of diabetes mellitus and a leading cause of blindness globally. Early detection and intervention underpin optimal DR management and remain challenging. The underlying biological mechanisms are also poorly understood. This study examined comprehensive plasma lipid profiles using a targeted approach to detect potential DR biomarkers.

Materials and methods: We utilised data and samples from 762 adult participants with type 2 diabetes (mean age 64.5 years, 54.3% males, median diabetes duration 7.0 years) from the community-based longitudinal Fremantle Diabetes Study Phase II. All had DR status (none, mild non-proliferative diabetic retinopathy (NPDR), moderate NPDR, or severe NPDR or worse) assessed by colour fundus photography at baseline and at the Year 4 or 6 review. Ultra-performance liquid chromatography-tandem mass spectrometry was used for plasma lipid profiling using baseline samples. Multiple logistic regression was used to identify baseline associates of i) any new or worsening DR and ii) any incident DR. The likelihood ratio test (LRT) was used to evaluate the incremental contribution of potential new lipid biomarkers. The net reclassification improvement (NRI) was also calculated.

Results: Any new/worsening DR was observed in 121 participants (16%) and 35 of 495 without DR at baseline (7.0%) developed DR during follow-up. We detected five lipids independently associated with one or both DR outcomes, specifically cholesterol ester (20:4), fatty acid (20:3), lysophosphatidylglycerol (18:0), lysophosphatidylglycerol (18:1) and phosphatidylcholine (18:0_20:3). For any new/worsening DR, the inclusion of lipid parameters (cholesterol ester (20:4), fatty acid (20:3) and lysophosphatidylglycerol (18:1)) in addition to conventional risk factors (systolic hypertension, HbA1c, blood glucose-lowering treatment intensity and urinary albumin:creatinine) added significantly to the conventional model (LRT, P=0.00002). The NRI gain for at a moderate cut-off of 10% was 5.7% (SE 2.8%; P=0.043). For incident DR, inclusion of lipid parameters (fatty acid (20:3), lysophosphatidylglycerol (18:0) and phosphatidylcholine (18:0_20:3)) with HbA1c as the only conventional risk factor improved model performance (LRT, P=0.00001). The NRI gain at a moderate cut-off of 5% risk of incident DR was 28.3% (P=0.002).

Conclusion: These data demonstrate that disturbances in lipid metabolism are associated with DR progression in type 2 diabetes. The present five lipid biomarkers have not been identified as determinants of incident DR in limited previous longitudinal studies but have the potential to improve DR risk prediction and provide novel insights into the mechanistic pathways underlying the development and progression of DR.