> ## Content Index > Fetch the complete content index at: https://nephspace.com/llms.txt > Use this file to discover other available public pages before exploring further. # SGLT2 inhibitors raise hemoglobin by about 0.6 g/dL. Bonus, or something to watch? - URL: https://nephspace.com/sglt2-inhibitors-hemoglobin-meta-analysis/ - Published: 2026-11-02T11:55:00.000Z - Updated: 2026-11-02T11:54:59.000Z - Description: Across 85 randomized, double-blind trials and about 70,000 participants, hemoglobin rose about 0.6 g/dL more on SGLT2 inhibitors than on control. The authors call the effect small and its clinical significance unclear; the editorial leans toward benefit, with a caution about erythrocytosis. - Author: Dr Wael Hussein - Tags: CKD and cardiometabolic, #story, #has-audio, #research, #full-story, Stories **🎧 Listen:** [Weekly · Nov 2](https://nephspace.com/weekly-nov-2/), from 01:28. ### The question SGLT2 inhibitors are guideline therapy for most of our patients with CKD, and hemoglobin has been known to creep up on them since the earliest trials. The first explanation was hemoconcentration from the drugs' diuretic effect. How big is the rise, what drives it, and does it matter? ### What the review did A systematic review and random-effects meta-analysis of 85 randomized, double-blind trials (PubMed, Web of Science and CENTRAL to July 22, 2026; registered in PROSPERO), in adults with cardiovascular disease, type 2 diabetes, heart failure, CKD or type 1 diabetes. Open-label trials and conference abstracts were excluded. In all, 70,543 participants, mean age 62, 36% women, median trial duration 24 weeks; 78 trials were placebo-controlled and 7 used an active comparator. Agents included empagliflozin, dapagliflozin, canagliflozin, ertugliflozin, ipragliflozin, luseogliflozin, sotagliflozin and bexagliflozin. Hemoglobin was reported in 46 trials (about 34,000 participants) and hematocrit in 74\. Certainty of evidence was moderate for hemoglobin and hematocrit. ### What they found - **Hemoglobin** rose 0.55 g/dL on SGLT2 inhibitors and fell 0.08 g/dL on control, a difference of 0.60 g/dL (95% CI, 0.55 to 0.66). - **Hematocrit** rose 2.17 percentage points vs −0.13, a difference of 2.36 points (2.19 to 2.52). For scale, the authors note that erythropoiesis-stimulating agents raise the hematocrit by roughly 5 to 11 points. - The average effect was similar across disease groups (0.53 to 0.66 g/dL), although heterogeneity between individual trials was high (I² 82% for hemoglobin). - Longer treatment and higher doses gave larger differences: about 0.71 g/dL at 48 weeks. - **Mechanism:** erythropoietin rose 2.11 mIU/mL (8 trials), red-cell concentration rose, and ferritin and transferrin saturation fell with serum iron unchanged, a pattern the authors read as stored iron being drawn into new red cells. The hematocrit-to-hemoglobin ratio (3.73) exceeded the roughly 3.0 expected from red-cell expansion alone, which suggests some contribution from plasma-volume contraction. ### Why it matters The authors call the increases small and of uncertain clinical significance, and note they may help explain the quality-of-life gains reported with these drugs. In the accompanying editorial, Drs. Kai-Uwe Eckardt and Mark Koury argue the rise is likely to contribute to anemia management in CKD, pointing out that mediation analyses have identified it as a strong mediator of the drugs' cardiovascular and kidney benefits, and that its size is similar to or slightly below that of intravenous iron. They add a caution: SGLT2 inhibitors can also cause erythrocytosis, and when that happens the benefits of continuing should be weighed against the risk of thromboembolic complications. Because the effect is dose-dependent, dose reduction, or stopping and restarting at a lower dose, is an option. ### Read alongside: the altitude study A small retrospective study published in Kidney360 in August (SGaLTItude) followed 206 patients with CKD on SGLT2 inhibitors at sea level in France, in the French Alps and in Mexico City. Hemoglobin rose by about 1 g/dL or more at every altitude over 12 months (1.4 at sea level, 1.4 in the Alps, 1.0 in Mexico City), with no significant overall interaction between time and altitude, although altitude itself was associated with hemoglobin and time-by-altitude interactions did appear among women and among patients at CKD stages 4 to 5\. By 12 months, erythrocytosis had developed in 19.5% of men and 3.8% of women. Eight thrombotic events occurred in seven patients, six of them ischemic strokes and all arterial; every one occurred above 2,000 m. In the six with stroke, hemoglobin had risen far more than in everyone else (about 3.1 g/dL at 6 months and 4.6 at 12, against 0.7 and 1.0), and only one met the formal definition of erythrocytosis. The authors suggest the magnitude of the rise may matter more than the absolute level, echoing the overshoot concerns from the ESA trials. Our take: with seven affected patients, all at one site whose cohort also had more heart disease, this is a signal to watch rather than evidence of cause. ### Caveats The meta-analysis reports laboratory markers, not clinical outcomes, and the authors say so explicitly. It pools trial-level results, not individual patient data, so it cannot say what proportion of patients had a large rise or how quickly any individual's hemoglobin climbed. Red-cell mass was never directly measured. Heterogeneity between trials was substantial, only 7.3% of participants had iron biomarker data, and women made up 36% of participants. Our take for practice: a gentle rise is probably a quiet bonus. A large rise, particularly in a man or at altitude, is worth a second look, and the editorial's advice on erythrocytosis is the practical place to start. --- **The source:** Yang Y, Yang C, Wang Y, et al. Sodium-Glucose Cotransporter 2 Inhibitor Use and Levels of Hemoglobin, Markers of Iron Metabolism, and Erythropoiesis: A Systematic Review and Meta-Analysis of Randomized Clinical Trials. JAMA. Published online October 24, 2026\. doi:10.1001/jama.2026.19921 [Read the original](https://doi.org/10.1001/jama.2026.19921?ref=nephspace.com) **Also discussed:** - Eckardt KU, Koury MJ. Increased Hemoglobin With Sodium-Glucose Transporter 2 Inhibitors — A Consistent Extra Benefit? JAMA. Published online October 24, 2026\. doi:10.1001/jama.2026.22329 [Link](https://doi.org/10.1001/jama.2026.22329?ref=nephspace.com) - Aoun M, Madero M, Fernández Yepez AK, et al. Impact of Altitude on Hemoglobin Response to Sodium-Glucose Cotransporter 2 Inhibitors in CKD: The SGaLTItude Study. Kidney360\. Published online August 4, 2026\. doi:10.34067/KID.0000001305 [Link](https://doi.org/10.34067/KID.0000001305?ref=nephspace.com) **🎧 Listen:** [Weekly · Nov 2](https://nephspace.com/weekly-nov-2/), from 01:28. *Physician-led, AI-assisted. Dr. Wael Hussein chooses every item NephSpace covers and reviews and edits every story before it is published. The first draft was written in our own words with AI (Claude, by Anthropic) from the full text of the paper, its editorial and the Kidney360 altitude study and checked against our reading notes; Dr. Hussein then reviewed and edited it. For education and information only, not medical advice. Please talk to your own physician or care team about your health. Clinicians: read the original before changing practice. See our* [*disclaimer*](https://nephspace.com/disclaimer/) *and* [*disclosures*](https://nephspace.com/disclosures/)*. Spotted an error?* [*Tell us*](mailto:hello@nephspace.com?subject=Correction)*.*