SAT032 Circulating Neprilysin Activity Is Increased In Type 2 Diabetes And Fatty Liver Disease, And Reduces Following Bariatric Surgery And Liraglutide Therapy
Authors: Sampson Kjeldsen Sasha Alexandra , Lotte Gluud Lise , Werge Mikkel , Steen Pedersen Julie , Bendtsen Flemming , Alexiadou Kleopatra , Tan Tricia , Torekov Signe S , Iepsen Eva W , Jensen Nicole J , Richter Michael , Hartmann Bolette , Holst Jens J , Holst Birgitte , Holt Joachim , Madsbad Sten , Svane Maria S , Bojsen-Møller Kirstine N , Wewer Albrechtsen Nicolai J 
Published: October 2023

Abstract
Disclosure: S.A. Kjeldsen: None. L. Gluud: None. M. Werge: None. J. Pedersen: None. F. Bendtsen: None. K. Alexiadou: None. T. Tan: None. S.S. Torekov: None. E.W. Iepsen: None. N.J. Jensen: None. M. Richter: None. B. Hartmann: None. J.J. Holst: None. B. Holst: None. J. Holt: None. S. Madsbad: None. M.S. Svane: None. K.N. Bojsen-Møller: None. N.J. Wewer Albrechtsen: None.
The neutral endopeptidase neprilysin (NEP) cleaves peptides important for metabolism, including GLP-1. Plasma levels of GLP-1 are reduced in patients with T2D, but the reason is unknown. Long-term treatment with the NEP inhibitor sacubitril (in combination with valsartan) improves glycemic control in individuals with T2D and heart failure. Here, we investigate plasma activity and protein levels of NEP in patients with obesity, T2D, and/or NAFLD diagnosed using biopsy or ultrasound, following bariatric surgery (RYGB and sleeve gastrectomy), and after treatment with GLP-1. We hypothesized that NEP activity (NEPa) is increased in patients with T2D, and that GLP-1 agonism reduces NEPa in a weight loss-independent manner. Here we show that plasma levels of NEPa are increased by 51% in patients with T2D (n=33) compared to individuals with normal glucose tolerance (NGT, n=160) (mean ± SD; 2734 ± 3646 vs. 1809 ± 2039 pmol/ml/min, P=0.02). Plasma NEPa was not increased in obesity (n=188) compared to lean controls (n=15) (1944 ± 2392 vs. 1373 ± 1918, P=0.4), but was increased by 76% in NAFLD (n=51) compared to non-NAFLD controls (n=43) (2629 ± 3219 vs. 1497 ± 1404, P=0.02). There were no differences in plasma NEP protein between any of the comparator groups, suggesting that changes in NEPa in metabolic disease are post-translational modifications of the enzyme or other mechanisms influencing NEPa. Bariatric surgery (RYGB, n=66 and SG, n=20) reduced plasma NEPa by 60% (P&lt;0.001), while plasma NEP protein levels were unaltered or increased in individuals with and without preoperative T2D. Six weeks GLP-1 (liraglutide) treatment (3 mg/day) in individuals with overweight and obesity (n=14) reduced NEPa by 28% (P=0.04; apparent after 4 weeks), and at follow-up (3 weeks after discontinuation) NEPa levels returned to baseline, whereas NEP protein levels were unchanged throughout the study. In a study of individuals with obesity randomized to complete a 52-week weight maintenance intervention by diet or liraglutide (1.2 mg/day) following an 8-week diet-induced weight loss period, plasma NEPa was not affected by the initial 12% weight loss (n=48, P=0.3). However, plasma NEPa reduced in response to 52-week liraglutide therapy (n=15, P=0.05). A 90-minute low dose infusion of native GLP-1 (7-36 amide,1 pmol/kg/min) in individuals with overweight and obesity (n=19) did not alter plasma NEPa, which suggests that the attenuating effects on NEPa with GLP-1R agonism is not acute. In conclusion, our data support that plasma NEPa is increased in T2D and NAFLD independent of obesity but may be normalized by bariatric surgery, and that chronic treatment with GLP-1 reduces NEPa. Altered NEPa may therefore contribute to altered metabolism of GLP-1 in diabetes and following bariatric surgery. Whether liraglutide-induced reduction in NEPa contributes to its metabolic effects demands further investigation.
Presentation: Saturday, June 17, 2023