Higher Lactate Linked to Worse Kidney-Function Measures
Lactate may reflect concurrent metabolic or circulation-related stress accompanying kidney dysfunction, but this study does not establish a disease-specific biomarker, causal mechanism or clinically useful protein marker.
Evidence
Higher blood lactate, a substance produced during metabolism, was associated with less favorable kidney-function measures in one exploratory study of diabetic kidney disease. Published September 15, 2026, the study combined clinical cohorts, rat experiments and computational analysis, as detailed in the lactate and diabetic kidney disease briefing.
The main intensive-care cohort, drawn from the MIMIC-IV database, included 593 patients classified as having diabetic kidney disease. Elevated lactate was associated with higher serum creatinine, a blood marker used to assess kidney function, after statistical adjustment. The regression coefficient—a measure of association within the model—was 0.13, with a 95% confidence interval of 0.004–0.256. This uncertainty range only narrowly excludes zero, the value indicating no modeled association. The reported P value was 0.044; P values assess compatibility with a no-association model, not clinical importance. An external eICU cohort supported the association using the same lactate and creatinine measures and regression approach.
In rats, researchers removed the right kidney and induced diabetes with streptozotocin, creating a diabetic-kidney-disease-like injury model. Blood measurements and tissue staining assessed kidney injury. Lactate correlated positively with cystatin C, another blood marker of kidney function. The reported partial rank correlation—an adjusted measure of how two measurements move together—was 0.748, with a P value of 0.0081.
Computational network analysis identified 43 overlapping molecular targets connecting lactate and diabetic kidney disease. The associated pathways mainly involved inflammation, fibrosis—tissue scarring—and metabolism.
Analysis
Interpretation: The clinical and rat findings point in the same direction, but they involve different kidney markers and different settings. These are complementary components of one study, not independent confirmation.
The authors interpret lactate as potentially reflecting metabolic or blood-flow-related stress occurring alongside kidney dysfunction, rather than a disease-specific marker or cause. The molecular network suggests relationships worth testing; it does not validate a protein biomarker or establish clinical usefulness.
Limitations
The observational clinical associations do not establish causation or show that lactate predicts future kidney decline. Disease identification relied on diagnostic codes, allowing possible misclassification. Consistent confirmation using urine albumin measurements or kidney-filtration estimates over time was not feasible for every admission. The intensive-care setting also limits conclusions about other patient groups.
The rat model cannot separate the effects of kidney removal from those of high blood sugar. Its small sample and possible separation between experimental groups warrant caution when interpreting the correlation.
The briefing does not specify the exact rat or external-cohort sample sizes, an external-cohort effect estimate, or the scaling needed to translate the clinical coefficient into practical units. The computational targets require experimental validation.
What to watch
A prospective study measuring lactate before subsequent kidney-function changes, with consistent disease confirmation and adjustment for acute illness and circulation-related stress, would address important gaps in the clinical evidence. Confidence in predictive usefulness would increase if lactate improved prediction of later kidney-filtration decline beyond existing kidney markers, with a clearly scaled effect estimate and uncertainty interval.