Polygenic Risk Score for Liver Fat Predicts Earlier Onset of Type 2 Diabetes in an East Asian Population

Liver, pancreas fat deposition and volume have been associated with type 2 diabetes (T2D) risk by Mendelian randomization study. However, it is unknown whether genetic variation in these traits impact on T2D onset, insulin resistance and drug use. We hypothesized that (1) genetic predisposition to smaller pancreas would be associated with earlier onset of T2D and earlier need for insulin; (2) genetic predisposition to higher pancreas and liver fat would be associated with greater insulin resistance, earlier onset of T2D and earlier need for insulin. This study utilized three Chinese cohorts of genotyped T2D patients in Hong Kong: Hong Kong Diabetes Register (HKDR, n=6011), Hong Kong Diabetes Biobank Phase 1 (HKDB-P1, n=6662) and Hong Kong Diabetes Biobank Phase 2 (HKDB-P2, n= 5899). We used lead SNPs (single nucleotide polymorphisms) associated with pancreas volume (13 SNPs), fat (7 SNPs) and liver fat (8 SNPs) from UK Biobank (n>32,000) to construct PRS (Polygenic risk score) in these cohorts. Linear regression models were employed to examine the associations between PRS and age of T2D onset and insulin resistance. Multivariable cox regression models were employed to examine association with time to insulin use. All models included age (except for age of T2D onset), sex and top 4 genetic principal components as covariates. To assess the confounding effects of BMI, we also performed BMI subgroup analysis by stratifying individuals into underweight, normal and overweight groups. Our analyses found that higher PRS for liver fat, but not pancreatic size or fat predicts earlier onset of T2D in HKDB-P1 (p<0.001, t=−3.43). The direction of association in HKDB-P2 was consistent though not significant. When stratified by BMI, higher PRS for liver fat predicts earlier onset of T2D in HKDB-P1 (p= 0.002, t=−3.14) and HKDB-P2 (p=0.029, t=−2.19) among the overweight group. Our results highlighted a PRS of liver fat as a potential biomarker for age of T2D onset, which needs further validation. Disclosure G.Yu: None. C.Huang: None. A.Luk: Research Support; Novo Nordisk, Boehringer-Ingelheim, Bayer Inc., Speaker's Bureau; Eli Lilly and Company. E.S.H.Lau: None. Hong kong diabetes biobank study group: n/a. R.C.Ma: Advisory Panel; AstraZeneca, Merck & Co., Inc., Other Relationship; Bayer Inc., Boehringer-Ingelheim, Research Support; Tricida, Inc., Roche Diagnostics, Novo Nordisk. C.H.Tam: None. M.Shi: None. B.Fan: None. C.K.Lim: Stock/Shareholder; GemVCare Ltd. J.C.Chan: Board Member; Asia Diabetes Foundation, Consultant; Bayer Inc., Celltrion, Boehringer Ingelheim and Eli Lilly Alliance, Sanofi, Research Support; AstraZeneca, Servier Laboratories, Viatris Inc., Hua Medicine, Merck KGaA, Applied Therapeutics Inc., Lee Powder, Pfizer Inc., Speaker's Bureau; Novartis, Stock/Shareholder; GemVCare Ltd. M.N.Weedon: None. R.A.Oram: Consultant; Janssen Research & Development, LLC, Research Support; Randox R & D. Funding Research Grants Council of the Hong Kong Special Administrative Region (CU-R4012-18); Croucher Foundation