A simple blood measurement already familiar to cardiologists may be quietly signaling how badly diabetes is damaging the kidneys, according to new research from Vietnam. In a cross-sectional study of 201 outpatients with type 2 diabetes treated at University Medical Center Ho Chi Minh City, scientists found that serum homocysteine, an amino acid intermediate produced during methionine metabolism, rose steadily as kidney function declined and discriminated surprisingly well between patients with and without chronic kidney disease. With diabetes rates climbing across much of Asia and diabetic kidney disease now accounting for up to half of all end-stage kidney disease cases, the findings point to a potentially valuable adjunct to the two conventional markers—albuminuria and estimated glomerular filtration rate—that clinicians currently rely on, both of which carry well-recognized limitations at the bedside.
The research team, publishing in Health Science Reports, recruited adults with type 2 diabetes from the outpatient department between December 2023 and December 2025, excluding anyone with acute kidney injury, acute infection, active liver disease, malignancy, or use of medications known to distort homocysteine levels, such as methotrexate or antiepileptic drugs. Each participant provided a fasting venous blood sample after eight to twelve hours without food, along with an early-morning urine specimen. Serum homocysteine was quantified by chemiluminescent immunoassay, creatinine by an enzymatic method, and cystatin C by immunoturbidimetry, while kidney function was estimated using the modern 2021 CKD-EPI equation that combines creatinine and cystatin C. Chronic kidney disease was operationally defined as an estimated glomerular filtration rate below 60 mL/min/1.73 m² and/or a urinary albumin-to-creatinine ratio above 30 mg/g.
The cohort was strikingly skewed toward renal disease: 164 of the 201 participants, or 81.6 percent, met the study definition of chronic kidney disease, while only 37 did not. Patients with kidney disease were significantly older, averaging nearly 66 years compared with just over 60 years in the spared group, but sex, body mass index, blood pressure, and HbA1c were statistically indistinguishable between the two groups. What separated them most clearly was biochemistry. Homocysteine averaged 15.93 μmol/L in the kidney disease group versus 10.68 μmol/L among those without, and the diseased group also carried markedly higher creatinine, cystatin C, and albuminuria alongside drastically lower filtration rates.
Perhaps the most visually compelling result was the stepwise climb of homocysteine across the full spectrum of renal impairment. Stratified by filtration rate, mean homocysteine rose from 10.3 μmol/L in patients with preserved function to 15.5 μmol/L at moderate impairment and 20.5 μmol/L in the most advanced stages, a gradient that held with high statistical significance. The same monotonic pattern appeared across albuminuria categories, from 13.4 μmol/L in patients with normal urinary albumin to 16.9 μmol/L in those with heavy protein loss. The authors note that the scatter of values widened considerably at advanced disease, hinting at growing heterogeneity in homocysteine metabolism and clearance as the kidneys fail.
Correlation analysis reinforced the picture. Homocysteine correlated strongly and positively with both creatinine and cystatin C, with coefficients of 0.67 for each, and inversely with estimated glomerular filtration rate at −0.59, while showing only weak associations with age and albuminuria and none at all with blood pressure or glycemic control. That asymmetry is mechanistically telling: it suggests that in this cohort, circulating homocysteine tracks impaired glomerular filtration far more closely than it tracks direct glomerular injury, implying the molecule may largely accumulate because the failing kidney cannot clear it, rather than serving as an independent report of inflammatory damage within the kidney tissue itself.
The predictive mathematics was equally striking. In univariable logistic regression, every 1 μmol/L rise in homocysteine increased the odds of chronic kidney disease by 28 percent. Receiver operating characteristic analysis yielded an area under the curve of 0.79, and a Youden-derived threshold of 11.35 μmol/L delivered balanced performance, with 76 percent sensitivity and 78 percent specificity. Notably, adding age and HbA1c to a multivariable model nudged the area under the curve only to 0.812, and a formal DeLong comparison found that this increment was not statistically significant, meaning homocysteine alone carried nearly all of the discriminative information the combined model offered. Higher homocysteine also remained associated with kidney disease after adjustment for age and glycemic control.
Why would homocysteine and kidney damage be entwined? Experimental work has implicated several converging pathways. Elevated homocysteine promotes the generation of reactive oxygen species, fueling oxidative stress and NF-κB–mediated inflammation that can injure the delicate endothelial cells of the renal microvasculature. It also interferes with DNA methylation, potentially inducing epigenetic changes in gene regulation that reshape renal structure under chronic hyperglycemia, and it has been tied experimentally to glomerulosclerosis, TGF-β1–driven fibrosis, and podocyte apoptosis that increases the leakiness of the glomerular filter. Yet the authors are careful to stress that a cross-sectional design cannot untangle cause from consequence: homocysteine may help drive renal injury, or it may simply accumulate as an innocent bystander of failing clearance.
The team therefore ran a sensitivity analysis using albuminuria alone, independent of the filtration criterion, as the outcome. Homocysteine remained associated with albuminuria, with an odds ratio of 1.08, but its discriminatory power dropped sharply to an area under the curve of 0.628, reinforcing the conclusion that the biomarker’s strongest signal lies in reflecting reduced filtration rather than pinpointing glomerular barrier injury. The authors also caution that the 11.35 μmol/L cutoff was derived and evaluated in the same cohort and, given the marked imbalance between disease groups and the convenience sampling design, should be regarded as exploratory rather than a validated screening threshold pending external confirmation in larger, more representative diabetic populations.
Limitations temper the enthusiasm appropriately. The single-center design, the absence of data on folate and vitamin B12 status, metformin exposure, smoking, alcohol, and dietary protein all leave room for residual confounding, and no longitudinal follow-up was available to test whether rising homocysteine actually precedes declining kidney function. Still, the large sample relative to prior Vietnamese studies and the use of the contemporary creatinine–cystatin C filtration equation lend the findings credibility. The research team proposes clear next steps: prospective cohort studies to establish temporality, interventional trials of homocysteine-lowering strategies such as folate and B-vitamin supplementation, and integrated prognostic models combining homocysteine with emerging biomarkers like NGAL and KIM-1, alongside population-specific thresholds adjusted for age, sex, nutrition, and ethnicity.
If those studies succeed, the implications for a country like Vietnam—and for the many nations riding the same wave of metabolic disease—could be substantial. A homocysteine assay is inexpensive, widely available on automated platforms, and already ordered in cardiovascular workups, meaning the infrastructure to deploy it as an adjunctive kidney risk marker largely exists. For the roughly one in five adults with diabetes who will progress toward kidney failure, an early, easily repeated warning signal that outperforms conventional markers in simplicity and matches them in this cohort’s discrimination would represent a genuinely meaningful advance. For now, the message is one of cautious promise: homocysteine is not yet ready for the clinic as a standalone kidney test, but the evidence that it mirrors diabetic renal decline, stage by stage, has grown decidedly harder to ignore.
Subject of Research: The association between serum homocysteine levels and chronic kidney disease severity in Vietnamese outpatients with type 2 diabetes.
Article Title: Association Between Serum Homocysteine and Chronic Kidney Disease Severity in Vietnamese Outpatients With Type 2 Diabetes: A Cross‐Sectional Study
Article References: Ho, L. N., Van Tran, T., Tran, T. T. T., Le, N. T., Quach, L. H., Thanh, K. M., Tran, H. N., Hoang, H. K., Tran, H. H., & Le, T. Q. (2026). Association Between Serum Homocysteine and Chronic Kidney Disease Severity in Vietnamese Outpatients With Type 2 Diabetes: A Cross‐Sectional Study. Endocrinology, Diabetes & Metabolism, 9(5), Article e70339. https://doi.org/10.1002/edm2.70339
Image Credits: AI Generated
DOI: 10.1002/edm2.70339
Keywords: homocysteine, chronic kidney disease, type 2 diabetes, estimated glomerular filtration rate, albuminuria, biomarker, Vietnam, diabetic kidney disease, cystatin C, ROC analysis, cross-sectional study, renal function
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Jerry Hayes. (September 23, 2026). Homocysteine Blood Test Shows Strong Link to Kidney Disease Severity in Diabetic Patients. Scienmag. https://scienmag.com/homocysteine-blood-test-shows-strong-link-to-kidney-disease-severity-in-diabetic-patients/
Jerry Hayes. “Homocysteine Blood Test Shows Strong Link to Kidney Disease Severity in Diabetic Patients.” Scienmag, 23 September 2026, https://scienmag.com/homocysteine-blood-test-shows-strong-link-to-kidney-disease-severity-in-diabetic-patients/. Accessed 23 September 2026.
Jerry Hayes. “Homocysteine Blood Test Shows Strong Link to Kidney Disease Severity in Diabetic Patients.” Scienmag. September 23, 2026. https://scienmag.com/homocysteine-blood-test-shows-strong-link-to-kidney-disease-severity-in-diabetic-patients/
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Tags: adjunct diagnostic tools for kidney function assessmentalbuminuriaamino acid metabolism in kidney diseaseassessment of chronic kidney disease in diabetesbiomarkerChronic kidney diseasecross-sectional studycross-sectional study on homocysteine and kidney healthcystatin Cdiabetes-related end-stage kidney diseasediabetic kidney diseasediabetic kidney disease biomarkersemerging blood markers for kidney damageestimated glomerular filtration ratehomocysteineHomocysteine blood testkidney disease severity in diabeticslimitations of albuminuria and GFR markersrenal functionROC analysisserum homocysteine and renal functionType 2 diabetesVietnamVietnam-based research on diabetic nephropathy
