The effect of Dipeptidyl peptidase 4 (DPP-4) inhibitors on hemoglobin level in diabetic kidney disease: A retrospective cohort study.

Anemia typically develops early in the course of diabetic kidney disease (DKD). There are data to show that dipeptidyl-peptidase-4 (DPP-4) inhibitors affect hematopoietic growth factor activity and hemoglobin level. We retrospectively reviewed 443 DKD patients who were started on DDP-4 inhibitor therapy in 2019. Their hemoglobin level at baseline (6-12 months before treatment), pretreatment (0-6 months before treatment), and post-treatment periods (within 6 months after DPP-4 inhibitor), concomitant estimated glomerular filtration rate (eGFR), HbA1c, peripheral blood white cell and platelet counts were reviewed. The severity of kidney failure was classified according to the Kidney Disease: Improving Global Outcomes stages. The hemoglobin level had a small but significant decline from 11.98 ± 2.07 to 11.87 ± 2.12 g/dL from pretreatment to post-treatment period (paired Student t test, P < .0001). From the pre- to post-treatment period, the decline of hemoglobin level was 0.10 ± 0.89 g/dL, which was significantly less than that from baseline to pretreatment period (0.24 ± 0.90 g/dL, P = .0008). The change in hemoglobin level had a positive correlation with the change in HbA1c level (R = 0.218, P < .0001), but did not correlate with the type of DPP-4 inhibitor or pretreatment eGFR. There was no significant change in peripheral blood white cell or platelet count during the same period. DPP-4 inhibitor ameliorates hemoglobin decline in DKD. The effect of DPP-4 inhibitor on hemoglobin is statistically significant but clinically modest, and did not correlate with the concomitant change in kidney function.