Role of Caveolin 1 (CAV-1) Deficiency in Response to Glucagon-like Peptide 1 (GLP-1) Receptor Agonist Treatment

Obesity is a chronic, multifactorial, and relapsing disease with an increasing prevalence that leads to insulin resistance, diabetes mellitus, hypertension, dyslipidemia, and cardiovascular diseases. Weight loss is known to improve metabolic and cardiovascular risk profiles. Although calorie restriction and increased physical activity represent the cornerstone of weight management treatment, clinical guidelines suggest adjunctive pharmacotherapy, particularly for adults with a BMI of 30 kg/m2 or greater or 27 kg/m2 or greater with coexisting conditions. Glucagon-like peptide 1 receptor agonists (GLP1 RAs) are highly effective in inducing weight loss in overweight and obese adults and have also been shown to improve cardiovascular outcomes. Elevated blood pressure (BP) is a well-known cardiovascular risk factor. Although GLP1 RAs improve insulin resistance, dyslipidemia, and type 2 diabetes, the beneficial effects of GLP1 RAs on BP are variable. This proposal's fundamental goal is to understand the mechanisms underlying this variable BP response to GLP1 RAs and investigate whether there is a variable response to weight loss.

Caveolin 1 is a protein on cell membrane that interacts with the GLP1 receptor and regulates its action. Our research laboratory previously demonstrated that a common polymorphism of the caveolin 1 (CAV1) gene (minor allele [C] at rs926198), which is associated with caveolin 1 deficiency, is strongly associated with higher BP and other components of the metabolic syndrome. This proposal will test the hypothesis that CAV-1 genotype will affect the CV and metabolic responses to treatment of overweight/obese individuals with a GLP-1 RA. Overall, demonstrating that a common variant in the CAV1 gene identifies the blood pressure and weight loss responses to GLP-1 RAs would be a very significant clinical outcome as GLP1 RAs use is rapidly increasing and would help lead to personalized therapy for obesity treatment.

Inclusion criteria

• Age ≥18 years, body mass index (BMI) ≥30.0 kg/m2 or ≥27.0 kg/m2 with the presence of at least one of the following weight-related comorbidities (treated or untreated): hypertension, prediabetes, dyslipidemia, obstructive sleep apnea,
• Normal screening laboratory values,
• Systolic BP < 160 mmHg and diastolic BP < 95 mmHg as determined from measurement during screening, using a random-zero device in the clinic and normal electrocardiogram, use of anti-hypertensive medications will be allowed except for mineralocorticoid receptor antagonists.

Exclusion criteria

• Diabetes mellitus,
• Treatment with a glucose-lowering agent(s) or anti-obesity medication within 90 days of screening,
• Treatment with a GLP-1 receptor agonist within 180 days,
• Current treatment with beta-blocker, or steroids,
• Pregnancy,
• Personal history of pancreatitis,
• Personal history of cholelithiasis,
• Previous surgical obesity treatment,
• Personal or first-degree relative(s) history of multiple endocrine neoplasia type 2 or medullary thyroid carcinoma,
• Medical illness other than hypertension, prediabetes, obstructive sleep apnea, or dyslipidemia,
• Alcohol intake >12 oz. per week,
• Tobacco, or recreational drug use