Glucagon-like Peptide-1 Metabolism and Acute Neprilysin Inhibition

This study will test the hypothesis that neprilysin inhibition with sacubitril/valsartan will
increase endogenous glucagon-like peptide-1 (GLP-1) after a mixed meal compared to valsartan.
The primary statistical analysis will be within subject comparison (paired t-test or
nonparametric equivalent) of area under the curve intact GLP-1 after the meal during
sacubitril/valsartan compared to valsartan. Neprilysin inhibition may be a new drug target
for the treatment of type 2 diabetes by increasing intact GLP-1 and may be of particular
benefit to individuals with increased risk of hypoglycemia and cardiovascular disease.

Inclusion Criteria:

1. Men and women ages 18-80 years

2. Type 2 diabetes mellitus (T2DM) or pre-diabetes, controlled by diet alone or metformin
therapy and elevated blood pressure

1. Pre-diabetes is defined as fasting plasma glucose of 100-125 mg/dL, plasma
glucose of 140-199 mg/dL two hours after 75g oral glucose load, or hemoglobin A1C
5.7-6.4%. T2DM is defined as fasting plasma glucose of ≥126 mg/dL, plasma glucose
of ≥200 mg/dL two hours after 75g oral glucose load, or hemoglobin A1C ≥6.5%.

2. Elevated blood pressure is defined as systolic blood pressure (BP) ≥130 mmHg or
diastolic BP ≥80 mmHg on three occasions or therapy with antihypertensive
medication(s) for a minimum of three months.

3. For female subjects, the following conditions must be met:

1. Postmenopausal status for at least one year or

2. Status post-surgical sterilization, or

3. If childbearing potential, utilization of birth control (barrier methods,
abstinence, hormonal contraception, etc) and willingness to undergo regular beta
hCG monitoring prior to drug treatment and on each study day. (Valsartan is
pregnancy category D.)

Exclusion Criteria:

1. Type 1 diabetes

2. Poorly controlled T2DM, defined as hemoglobin A1C ≥8.7%

3. Use of anti-diabetic medications other than metformin for over 24 months prior to
initiation of the study.

4. Requiring the need for insulin therapy

5. Secondary hypertension

6. Severe hypertension requiring the use of more than two anti-hypertensive agents other
than a stable dose of diuretic or blood pressure > 180/110 mmHg

7. Subjects who have participated in a weight-reduction program during the last 6 months
and whose weight has increased or decreased more than 5 kg over the preceding 6 months

8. Pregnancy or breastfeeding

9. History of hypersensitivity or allergy to any of the study drugs, drugs of similar
chemical classes, angiotensin converting enzyme inhibitors, ARBs, or NEP inhibitors,
as well as known or suspected contraindications to the study drugs

10. History of angioedema

11. History of pancreatitis or known pancreatic lesions

12. Clinically significant gastrointestinal impairment that could interfere with drug
absorption

13. Significant cardiovascular disease such as myocardial infarction or cardiovascular
surgery or angioplasty within six months prior to enrollment, presence of angina
pectoris, arrhythmia with history of or risk of syncopal episodes or need for
antiarrhythmic therapy, congestive heart failure (LV hypertrophy and diastolic
dysfunction acceptable), deep vein thrombosis, pulmonary embolism, second- or
third-degree AV block, mitral valve stenosis, hypertrophic cardiomyopathy, or coronary
or carotid artery disease likely to require surgical or percutaneous intervention
within six months of screening

14. Impaired hepatic function (aspartate amino transaminase [AST] and/or alanine amino
transaminase [ALT] >3 x upper limit of normal range)

15. Impaired renal function (eGFR< 50mL/min/1.73m2 as determined by the MDRD equation)

16. History or presence of immunological or hematological disorders

17. Serum potassium >5.2 mmol/L at screening

18. History of serious neurologic disease such as cerebral hemorrhage, stroke, seizure, or
transient ischemic attack within six months

19. Hematocrit <35%

20. Diagnosis of asthma requiring use of inhaled beta agonist more than once a week

21. Clinically significant gastrointestinal impairment that could interfere with drug
absorption

22. Any underlying or acute disease requiring regular medication which could possibly pose
a threat to the subject or make implementation of the protocol or interpretation of
the study results difficult, such as arthritis treated with daily use of non-steroidal
anti-inflammatory drugs

23. Treatment with chronic systemic glucocorticoid therapy within the last year

24. Treatment with systemic glucocorticoid therapy acutely within six weeks prior to
enrollment

25. Treatment with lithium salts

26. History of alcohol or drug abuse

27. Treatment with anticoagulation

28. Treatment with any investigational drug in the one month preceding the study

29. Mental conditions rendering the subject unable to understand the nature, scope, and
possible consequences of the study

30. Inability to comply with the protocol, e.g., uncooperative attitude, inability to
return for follow-up visits, and unlikelihood of completing the study