Sitagliptin Effects on Arterial Vasculature and Inflammation in Obesity

• Status: Completed
• Trial end date: 2017-12-31
• Target enrollment: 0
• Participant gender: All

Summary

Abdominal obesity is a major risk factor for heart attack, stroke, peripheral vascular disease, dementia, cancer and Type 2 diabetes. The central hypothesis for this proposal is that pro-atherogenic mediators emanate from inflammation in deep subcutaneous adipose tissue (dSAT) that are released into the systemic circulation and damage the arterial vasculature. The investigators postulate that inflammation of dSAT, when quantified by macrophage phenotyping/enumeration will be a) closely linked with systemic levels of pro-atherogenic mediators and b) tightly associated with endothelial dysfunction and loss of central arterial elasticity, which are highly predictive of future cardiovascular disease (CVD) complications. These relationships provide the basis for macrophage-targeted therapy to reduce obesity-related inflammation and impaired arterial vasoreactivity. The investigators will evaluate a novel approach using a dipeptidyl peptidase 4 inhibitor (DPP4i) sitagliptin, which blocks signal transduction for monocyte/macrophage activation. Thus, in abdominally obese, 18-40 years-old adults without clinical CVD, the show study is expected to show that sitagliptin versus placebo will:

1. significantly improve early measures of arterial damage (brachial artery endothelial dysfunction and reduced carotid elasticity).

2. significantly attenuate inflammation in dSAT and local production of pro-inflammatory mediators in adipose tissue, which will be associated with decreases in systemic pro-atherogenic mediators that contribute to atherogenesis.

Since many obese persons fail to sustain weight loss by lifestyle interventions including diet and exercise, an important public health goal is to identify relatively safe alternative strategies that can be used pre-emptively in "asymptomatic" obese persons when arterial dysfunction and damage is still reversible before atherosclerosis progresses to serious CVD events.

• Phase: Phase 2
• Accepts Healthy Volunteers?: Accepts Healthy Volunteers

Details

• Lead Sponsor: University of Southern California
• Treatments: Sitagliptin Phosphate

Criteria

Inclusion Criteria:

• abdominal obesity (≥102cm for men and ≥88cm for women)

• impaired glucose tolerance with fasting plasma glucose 100-125 or HgbA1C 5.7-6.4%

• insulin resistance with HOMA-IR ≥3.0

• stable weight with no change >3% in prior 6 months

Exclusion Criteria:

• regular use of non-steroidal anti-inflammatory drug and unwilling to stop

• on statin or other anti-inflammatory medication or herbal remedy

• diabetes or clinically evident cardiovascular disease

• smoking daily or consuming >200g of alcohol daily

• active renal, hepatic, rheumatological or infectious disorder within 28 days