Summary
A medRxiv preprint meta-analysis of 11 studies found that higher continuous glucose monitoring time in range was associated with lower odds of diabetic kidney disease. Most included studies were cross-sectional, so the findings do not establish cause and effect.
A systematic review and meta-analysis posted as a medRxiv preprint on September 23, 2026, found that higher continuous glucose monitoring (CGM) time in range was associated with lower odds of diabetic kidney disease (DKD) in adults with type 1 or type 2 diabetes. Across 11 studies, each 10-percentage-point increase in time in range corresponded to lower odds, but the evidence was largely cross-sectional and cannot show that increasing time in range prevents kidney disease.
The review defined time in range (TIR) as the proportion of time glucose was between 70 and 180 mg/dL. The authors searched PubMed, Embase, Cochrane CENTRAL and Scopus through March 2026. They pooled study estimates using a random-effects model. The preprint reports that the review followed PRISMA guidelines and was registered with PROSPERO as CRD420261377763.
What the review found
The 11 included studies covered 7,182 adults: seven studies involved people with type 2 diabetes and four involved people with type 1 diabetes. Ten studies were cross-sectional and one was a retrospective cohort. Reported kidney outcomes included albuminuria, estimated glomerular filtration rate decline, or composite measures of nephropathy.
The pooled odds ratio was 0.89 per 10-percentage-point higher TIR (95% confidence interval 0.84–0.95; P = 0.002). In other words, higher TIR was associated with about 11% lower odds of DKD for each 10-point increment. This is a relative change in odds, not an 11-percentage-point reduction in a person’s absolute chance of kidney disease. Results remained statistically significant when the authors repeated the analysis while leaving out one study at a time. The overall analysis showed substantial between-study heterogeneity (I² = 69.6%), meaning study estimates varied more than would be expected from sampling differences alone.
In the four studies that adjusted for HbA1c, the pooled odds ratio was 0.91 per 10-point TIR increment (95% CI 0.86–0.97; P = 0.015). The authors reported no detectable heterogeneity in this subgroup (I² = 0%). This finding suggests the association was not fully accounted for by average glycemia in those studies, though the subgroup was small.
How to interpret the association
TIR complements measures such as HbA1c by describing how much time glucose readings fall within a specified range. The review’s results point to a possible relationship between this measure and kidney outcomes, but most of the underlying evidence measured TIR and DKD at a single point in time. Those studies cannot establish which came first or whether improving TIR would lower DKD risk.
The authors identify prospective studies using standardized CGM protocols and pre-specified kidney endpoints as a next step. The report is a preprint and has not yet undergone peer review, so its findings should be read as preliminary evidence rather than a clinical recommendation.