6527 Genetic variants may influence the glycemic response to sodium-glucose cotransporter-2 inhibitors in the Mass General Brigham Biobank
Authors: Li Josephine H , Barry Alexandra , Huerta-Chagoya Alicia , Szczerbinski Lukasz , Mercader Josep M , Florez Jose C , Leong Aaron 
Published: October 2024

Abstract
Disclosure: J.H. Li: None. A. Barry: None. A. Huerta-Chagoya: None. L. Szczerbinski: None. J.M. Mercader: None. J.C. Florez: Consulting Fee; Self; AstraZeneca. Grant Recipient; Self; Novo Nordisk. Speaker; Self; Novo Nordisk, Merck. A. Leong: None.
Background: Sodium-glucose cotransporter-2 inhibitors (SGLT2i) are increasingly prescribed for the treatment of type 2 diabetes, but there is interindividual variability in glycemic response. We investigated whether two genetic variants, rs33954001, a missense variant (p.His615Gln) in SLC5A1 encoding SGLT1, and rs8050500 near SLC5A2 encoding SGLT2, previously associated with glycemic traits in genome-wide association studies, had any influence on short-term glycated hemoglobin (HbA1c) lowering in patients on SGLT2i treatment. Methods: We identified 1,961 ancestrally diverse, genotyped individuals with documented exposure to a SGLT2i in the Mass General Brigham Biobank, a hospital-based biobank linked with patient medical records. Of these, 736 individuals had a baseline HbA1c ≥ 6% within 6 months of the index appearance of an SGLT2i and a follow-up HbA1c measured 6-12 months after. Genotyping was performed on the Illumina Multi-Ethnic Genotyping Array and the Illumina Global Screening Array. Variants were imputed with the TOPMed reference panel. Using linear regression models, we evaluated the additive effect of the genetic variants on HbA1c reduction, defined as baseline HbA1c minus follow-up HbA1c, adjusted for age, sex, 10 genetic ancestry principal components to account for population stratification, the number of concomitant glucose-lowering drug classes, and three covariates accounting for potential genotyping batch effects. To determine whether genetic effects varied by pretreatment glycemic control, we tested for a genotype × baseline HbA1c interaction and performed stratified analysis by baseline HbA1c (≥ 8% vs. &lt; 8%). Results: The mean age of participants was 63.7 years and 41% were female. The baseline HbA1c was 8.0 ± 1.9%. The mean HbA1c reduction was 0.6% over a mean follow-up time of 8.7 ± 1.6 months. None of the variants were associated with HbA1c reduction (p &gt; 0.05) in the whole dataset. However, in stratified analyses, among those with baseline HbA1c ≥ 8% (n = 382), we observed that carriers of the G allele at rs33954001 had a 0.5% greater HbA1c reduction (p = 0.048) compared to those with CC genotype. Further adjustment for baseline renal function did not modify results. In the Genotype-Tissue Expression (GTEx) portal, the G allele was associated with higher SLC5A1 expression in nerve (p = 1 × 10-8), esophageal mucosa (p = 4 × 10-5) and stomach (p = 9 × 10-5), but not kidney. In the Translational human pancreatic Islet Genotype tissue-Expression Resource (TIGER), the G allele was associated with SLC5A1 expression in pancreatic islets (p = 2 × 10-6). Conclusion: Genetic variation in SLC5A1 may partly explain heterogeneity in SGLT2i treatment effects among people with sub-optimally controlled diabetes, possibly due to differences in SLC5A1 tissue-specific expression. These findings require validation in large hospital-based biobanks or dedicated clinical trials.
Presentation: 6/2/2024