Semaglutide Shifts Inflammation Blood Markers in Diabetes, With a Twist for Eye Disease

Semaglutide, the blockbuster glucagon-like peptide-1 receptor agonist better known by brand names such as Ozempic and Wegovy, has transformed the treatment of type 2 diabetes with its remarkable effects on blood sugar and body weight. But a new retrospective study from Saudi Arabia suggests the drug may also reshape the landscape of systemic inflammation in ways that differ depending on whether a patient has developed diabetic retinopathy, the sight-threatening complication that remains a leading cause of blindness in working-age adults. The findings, published in BMC Endocrine Disorders, offer an intriguing glimpse into how a single class of medication might leave distinct inflammatory fingerprints in different patient subgroups.

The research team, led by Amani Y. Alhalwani of King Saud bin Abdulaziz University for Health Sciences and the King Abdullah International Medical Research Center in Jeddah, set out to examine systemic inflammation index ratios among patients with type 2 diabetes who were receiving semaglutide. Rather than measuring inflammation with a single marker, the investigators relied on a family of derived ratios calculated from routine blood counts, including the neutrophil-to-lymphocyte ratio, the platelet-to-lymphocyte ratio, the monocyte-to-lymphocyte ratio, the monocyte-to-HDL cholesterol ratio, and a more unusual composite measure called the neutrophil-to-lymphocyte-to-platelet ratio, or NLPR. These indices have gained popularity in recent years because they are inexpensive, widely available, and increasingly recognized as sensitive barometers of the low-grade chronic inflammation that underlies many diabetic complications.

The study was conducted at the outpatient clinics of King Abdulaziz Medical City in Jeddah, drawing on the BestCare electronic medical records system to gather laboratory data at two time points: before patients started semaglutide and again after they had received at least 1 mg of the drug for three months. In total, 99 patients with type 2 diabetes were included in the analysis, 55 of them male and 44 female, with a mean age of 57.2 years and a standard deviation of 10.48 years. The researchers collected complete blood count parameters, including neutrophils, lymphocytes, platelets, and monocytes, along with lipid profile components such as total cholesterol, HDL cholesterol, LDL cholesterol, and triglycerides, and inflammatory markers including C-reactive protein and albumin. From these values they calculated the systemic inflammation index ratios that formed the core of their analysis.

Some of the results were exactly what one might expect from a drug in this class. Following semaglutide therapy, the patients showed statistically significant decreases in LDL cholesterol, total cholesterol, and triglycerides, reinforcing the well-documented lipid-lowering effects of GLP-1 receptor agonists. These metabolic improvements are a major reason the drugs have been embraced so widely, since dyslipidemia is a central driver of cardiovascular risk in type 2 diabetes. But the inflammatory picture proved far more surprising. Contrary to the expectation that dampening metabolic disease would also quiet systemic inflammation, the researchers observed statistically significant increases in several post-treatment inflammatory biomarkers, including albumin, the neutrophil-to-lymphocyte ratio, the platelet-to-lymphocyte ratio, and the NLPR.

The rise in these indices raises genuinely interesting questions about what semaglutide is doing beneath the surface. Albumin, often thought of simply as a protein that keeps fluid in the bloodstream, also behaves as a negative acute-phase reactant, and its increase after treatment could reflect changes in nutritional status, liver protein synthesis, or fluid balance as patients lose weight. Meanwhile, shifts in the relative proportions of neutrophils, lymphocytes, and platelets hint that the drug may be redistributing the immune cell landscape rather than simply suppressing it. The authors suggest that these changes point to a potential alteration in systemic inflammation following GLP-1 receptor agonist therapy, a finding that complicates the simple narrative of these medications as uniformly anti-inflammatory agents.

Perhaps the most striking aspect of the study emerged when the researchers stratified their correlation analysis by retinopathy status. In patients without diabetic retinopathy, the relationship between C-reactive protein and the neutrophil-to-lymphocyte-to-platelet ratio was negative after treatment. In patients with retinopathy, that same relationship flipped to positive. Neither pattern reached statistical significance, so the authors are careful not to overclaim, but the directional divergence between the two groups is the kind of signal that can seed future hypotheses. It suggests that the inflammatory milieu of a patient with established retinal microvascular disease responds differently to GLP-1 receptor agonist therapy than that of a patient whose retinae are still unaffected.

Diabetic retinopathy is fundamentally a disease of small blood vessels, driven by years of hyperglycemia, oxidative stress, and chronic inflammation that damage the delicate capillaries of the retina. Inflammatory indices such as the NLR and NLPR are thought to capture the balance between pro-inflammatory neutrophil activity and regulatory lymphocyte function, and elevated values have been associated with microvascular complications in several previous studies. If semaglutide differentially modulates these ratios depending on the presence or absence of retinopathy, it could mean that the drug interacts with distinct inflammatory pathways in patients who already have microvascular damage, or conversely that the early stages of retinal disease alter how the immune system responds to metabolic intervention.

The study has clear limitations that temper any rush to clinical application. As a retrospective cohort study based on chart reviews, it relied on existing medical records rather than prospective randomization, and it involved no direct contact with the subjects. The sample of 99 patients is modest, and the lack of statistically significant differences in the retinopathy-stratified correlations means the observed patterns should be treated as hypothesis-generating rather than conclusive. The authors themselves frame the increase in inflammatory biomarkers as suggesting a potential alteration in systemic inflammation and a potential predictor of retinopathy progression, language that appropriately signals uncertainty. Larger, longitudinal studies with formal retinal imaging outcomes would be needed to determine whether these index changes actually forecast worsening eye disease or merely reflect benign physiological adaptation.

Even so, the work lands at a moment of intense public fascination with GLP-1 receptor agonists, which are being studied for benefits far beyond diabetes, from cardiovascular protection to kidney disease and neurodegeneration. The idea that these drugs might leave measurable, subgroup-specific imprints on systemic inflammation adds a new dimension to that conversation. For clinicians, the message is one of cautious vigilance: routine inflammatory indices, already available in every complete blood count, could eventually help identify which patients with type 2 diabetes need closer retinal surveillance while on semaglutide. For researchers, the study provides a concrete starting point for dissecting how incretin-based therapies interact with the immune system in the context of microvascular disease. As semaglutide continues its march through medicine, studies like this one remind us that even the most celebrated drugs still hold surprises, and that the blood count sitting in a patient’s chart may contain clues to those surprises that are only now being read.

Subject of Research: Effects of the GLP-1 receptor agonist semaglutide on systemic inflammation index ratios in type 2 diabetes patients with and without retinopathy

Article Title: Investigation of GLP-1RA semaglutide and systemic inflammation index ratios in type 2 diabetes with and without retinopathy: a retrospective study

Article References: Alhalwani, A. Y., Hafez, S. Y., Alkhomri, Z., Bamusa, A., Alsubaie, N., Rayani, K., Alqanawi, Y., Hariri, S., Alsolami, B., Khan, M. A., & Alzahrani, A. (2026). Investigation of GLP-1RA semaglutide and systemic inflammation index ratios in type 2 diabetes with and without retinopathy: a retrospective study. BMC Endocrine Disorders. https://doi.org/10.1186/s12902-026-02558-7

Image Credits: AI Generated

DOI: 10.1186/s12902-026-02558-7

Keywords: semaglutide, GLP-1 receptor agonist, type 2 diabetes, diabetic retinopathy, systemic inflammation, neutrophil-to-lymphocyte ratio, C-reactive protein, inflammatory biomarkers, lipid profile, retrospective cohort study, microvascular complications, endocrinology