Cephalic Phase Insulin Secretion and Capillary Recruitment in Healthy Men

Forty healthy volunteers will undergo two nailfold-videocapillaroscopy exams with a 10-minute interval between them, after an 10-h overnight fast in a temperature controlled room. The subjects will be randomized in two groups: one will receive a sensorial stimulus during the interval (stimulus group - SG) and the other will receive no stimulus (control group - CG). The sensorial stimulus will be a breakfast meal, with excellent presentation and aroma, composed by favorite food items previously related by the individual for this meal. The meal will not be offered for immediate intake, it will be placed in front of the volunteer for perception of the smell and taste.

Baseline microvascular parameters will be compared to the results after the interval. The investigators hypothesize that the SG will have greater capillary recruitment due to a possible effect of physiologically secreted insulin provoked by the sensorial stimulation (cephalic phase of insulin secretion).

• No Intervention: Control group
• Experimental: Sensorial Stimulus
  The sensorial stimulus will be a breakfast meal, with excellent presentation and aroma, composed by favorite food items previously related by the individual for this meal. The meal will not be offered for immediate intake, it will be placed in front of the volunteer for perception of the smell and taste, in order to trigger the cephalic phase of insulin secretion
  Intervention: Other: Breakfast tray

Inclusion Criteria:

• Healthy male volunteers
• Aged between 18 and 30 years
• BMI between 18.5 and 24.9 kg/m2

Exclusion Criteria:

• Diabetes mellitus, glucose intolerance or altered fasting glucose;
• Hypertension (Systolic pressure ≥ 130 mmHg and diastolic pressure ≥ 80 mmHg);
• HOMA-index ≥ 2.71
• Dyslipidemia
• Renal disease, coronary or peripheral vascular diseases, haematologic or hepatic diseases
• Smoking
• Chronic use of any medication