Clinical trial NCT03178019: DPP4 Activity, Microvascular Reactivity and Inflammation
Official title: Dipeptidyl Peptidase 4 (DPP4) Activity and Its Associations With Endothelial Dysfunction, Inflammatory and Metabolic Markers, Heart Rate and Blood Pressure Variability, and Measures of Adiposity in Subjects With Different Grades of Glucose Tolerance
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Overweight
Pre Diabetes
Diabetes Mellitus Type 2 Without Complication
Lead sponsor: Rio de Janeiro State University
Sponsor class: OTHER
First posted: 2017-06-06
Enrollment: 52
Sex: ALL
Minimum age (years): 18
Maximum age (years): 50
Standard ages: ADULT
Accepts healthy volunteers: yes
Observational model: OTHER
Time perspective: CROSS_SECTIONAL
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Men and women aged between 18 and 50 years, BMI ≥ 25.0 kg/m², with different degrees of glucose tolerance, and living in the state of Rio de Janeiro (Brazil).

Brief summary: Dipeptidyl peptidase 4 (DPP4) is a serine exopeptidase able to inactivate various oligopeptides involved in inflammation, immunity and vascular function. Our aim was to investigate the associations between constitutive levels of DPP4 activity and inflammatory biomarkers, skin microvascular reactivity, gut peptides, insulin resistance indexes, heart rate and blood pressure variability, and measures of adiposity in subjects with different grades of glucose tolerance.

Detailed description: Dipeptidyl peptidase 4 (DPP4), also known as adenosine deaminase binding protein or cluster of differentiation 26 (CD26), is a serine exopeptidase able to inactivate various oligopeptides composed of proline, hydroxyproline, or alanine as the penultimate residue. In recent years, DPP4 has received attention due to its ability to rapidly inactivate the main incretins secreted by the gastrointestinal tract: glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP). As its own name already says, incretins enhance insulin secretion in a glucose-dependent fashion, but also suppress or modulate glucagon secretion. Since it was demonstrated that type 2 diabetes mellitus (T2D) have incretin deficiency and hyperglucagonemia on its physiopathology, gliptins emerged as a new class of drugs for the treatment of this disease, acting through the inhibition of DPP4 and consequently ameliorating these defects.

DPP4 not only inactivate incretins but also a number of cytokines, chemokines, and neuropeptides involved in inflammation, immunity and vascular function. Furthermore, evidence from in vitro and in vivo studies, including clinical ones in T2D, suggested that gliptins' inhibition of DPP4 was associated with reduction of inflammatory biomarkers and also attenuation of endothelial dysfunction and atherogenesis, possibly through regulation of the DPP4 substrates.

There is a paucity of studies that associate the constitutive levels of DPP4 activity (i.e., outside the context of pharmacological inhibition of the enzyme) with markers of inflammation and endothelial function, specially tested on skin microcirculation. We hypothesized that constitutive levels of DPP4 activity might be directly associated to inflammation and inversely correlated with skin blood flux and one or more components of vasomotion (suggesting an association with endothelial disfunction) even in the absence of diabetes. Our aim was to investigate the associations between constitutive levels of DPP4 activity and inflammatory biomarkers, skin microvascular reactivity, gut peptides, insulin resistance indexes, heart rate and blood pressure variability, and measures of adiposity in subjects with different grades of glucose tolerance.

Eligibility criteria: Inclusion Criteria:

* BMI ≥ 25.0 kg/m²
* Any degree of glucose tolerance

Exclusion Criteria:

* BMI \< 25.0 kg/m²
* Uncontrolled chronic diseases, such as arterial hypertension
* Smoking
* Severe alcoholism
* Moderate to severe chronic kidney disease, heart failure, chronic lung disease, and chronic liver disease
* Fasting serum triglycerides \> 400 mg/dl
* Fasting serum cholesterol \> 300 mg/dl
* Pregnancy and breastfeeding
* Women in the climacteric period
* Individuals who undergo bariatric surgery
* Acute disease at the time of sampling
* Initiation of statin or change in its dose within 60 days
* Use of aspirin and/or fluconazole within 10 days prior to the exams

Primary outcomes:
measure: Intergroup analysis of the associations between DPP4 activity and skin microvascular reactivity
timeFrame: 63 minutes
measure: Intergroup analysis of the associations between DPP4 activity and markers of inflammation
timeFrame: 63 minutes
Secondary outcomes:
measure: Intergroup analysis of the associations between DPP4 activity and biochemical parameters
timeFrame: 63 minutes
measure: Intergroup analysis of the associations between DPP4 activity and insulin resistance indexes, heart rate and blood pressure variability, and measures of adiposity
timeFrame: Baseline evaluation
Other outcomes:
Locations:
Study officials:
affiliation: State University of Rio de Janeiro
name: Wellington S Silva Júnior, MD
role: PRINCIPAL_INVESTIGATOR
References: