Human Intestinal Peptides Evaluation and Research

The HIPER-1 study is a single centre cross sectional study in which a total of 240 participants (in different metabolic states and surgical models) will receive an Oral Mixed Meal Tolerance Test (OMTT). At baseline and after 30, 60 and 120 minutes the PYY levels, GLP-1 levels, glucose and insulin sensitivity will be measured. The primary endpoint of the study will be the area under the GLP-1 and Peptide - YY curves and insulin sensitivity following the OMTT.

Obesity and type 2 diabetes mellitus (T2DM) are increasing worldwide, thus reaching pandemic proportions. Diet, exercise and medication remain the cornerstones of type 2 diabetes mellitus treatment. But, apart from studies demonstrating promising results in some of the developed countries; the long-term success rates of lifestyle and drug modifications are disappointing. In cases where classic strategies proved to be inadequate, broad type of gastrointestinal (GI) surgery methods offer new alternatives to treat obesity and T2DM. The variable levels of incretin stimulation (especially GLP-1) and improved glycaemic control in those with diabetes have been shown following various bariatric techniques.

Therefore, investigators aimed to analyze the levels of GLP-1 and Peptide YY hormones together with indices of insulin sensitivity in participants with various health conditions and in participants who underwent different surgical options including sleeve gastrectomy, minigastric bypass, sleeve gastrectomy with ileal transposition and sleeve gastrectomy with transit bipartition.

Eligibility Criteria:
For NON-SURGERY GROUPS

Inclusion Criteria:

1. GROUP NS-A: Healthy participants, no known disease, no previous surgery, HbA1c\<5.7%, BMI\<25 kg/m2 (n=30).

   GROUP NS-B: Obese diabetic, type 2 diabetes diagnosis longer than 3 years; BMI\>30 kg/m2 (n=30).

   GROUP NS-C: Non-obese diabetic, type 2 diabetes diagnosis longer than 3 years; BMI\<30 kg/m2 (n=30).

   GROUP NS-D: Obese non-diabetics, HbA1c\<5.7%, No signs and history of T2D, and BMI\>30 kg/m2 (n=30).
2. Preferably not on any kind of anti-diabetic drugs or will accept cessation of all anti-diabetic drugs 2 days prior to evaluation.
3. Absence of co-morbidities (dyslipidemia, hypertension, neuropathy, retinopathy, cardiovascular disease, stroke events or lower extremity amputation).
4. Possibility to participate to the quadruplicate measurement protocol.

Exclusion Criteria:

1. Anti insulin / islet antibody and glutamic acid decarboxylase antibody (antiGAD) positivity, plasma fasting C-peptide lesser than 1 ng/ml.
2. Liver cirrhosis, severe renal failure, collagen diseases, severe endocrinopathies, blindness.
3. Heart failure, acute myocardial infarction, stroke or transient ischemic attack, unstable angina pectoris.
4. History of malignancy or malignant neoplasm in place, severe inflammatory complications, neurological or cardiovascular in act.
5. Pregnancy
6. Any conditions that at the discretion of the head of the study can represent risk to the participant or could affect the protocol results.

For SURGERY GROUPS

Inclusion Criteria:

1. Type 2 Diabetic participants who underwent a sleeve gastrectomy, a mini-gastric bypass, a sleeve gastrectomy with ileal transposition or a sleeve gastrectomy with transit bipartition performed more than 6 months ago, but within the last 2 years, with steady weight profile.
2. Preferably not on any kind of anti-diabetic drugs or will accept cessation of all anti-diabetic drugs 2 days prior to evaluation.
3. Absence of or resolved co-morbidities (dyslipidemia, hypertension, neuropathy, retinopathy, cardiovascular disease, stroke events or lower extremity amputation).
4. Possibility to participate to the quadruplicate measurement protocol.

Exclusion Criteria:

1. Liver cirrhosis, severe renal failure, collagen diseases, severe endocrinopathies, blindness.
2. Heart failure, acute myocardial infarction, stroke or transient ischemic attack, unstable angina pectoris.
3. History of malignancy or malignant neoplasm in place, severe inflammatory complications, neurological or cardiovascular in act.
4. Pregnancy
5. Any conditions that at the discretion of the head of the study can represent risk to the participant or could affect the protocol results.