Decreased visfatin after exercise training correlates with improved glucose tolerance

Area of Science:

• Metabolic Health
• Endocrinology
• Exercise Physiology

Background:

• Visfatin (Nampt/pre-B-cell colony-enhancing factor) release from adipocytes is nutrient-responsive and linked to systemic nicotinamide adenine dinucleotide (NAD) biosynthesis and pancreatic beta-cell function.
• Visfatin's role in regulating insulin response requires further elucidation.

Purpose of the Study:

• To investigate the hypothesis that exercise training-induced reduction in insulin response to oral glucose load correlates with reduced plasma visfatin levels.
• To examine the relationship between changes in visfatin and metabolic parameters following exercise intervention.

Main Methods:

• Sixteen obese adults (mean age 65 years, BMI 33.4 kg/m²) underwent a 12-week supervised exercise program (5 days/week, 60 min/day at 85% HRmax).
• Visceral and subcutaneous adipose tissue were measured via computed tomography.
• A 2-hour, 75g oral glucose tolerance test and fasting plasma visfatin measurements (ELISA) were conducted before and after the intervention.

Main Results:

• Exercise training significantly increased cardiorespiratory fitness (VO2max) and reduced body weight, visceral adipose tissue (VAT), and subcutaneous adipose tissue (SAT).
• The area under the glucose and insulin response curves during the oral glucose tolerance test decreased significantly post-training.
• Plasma visfatin levels were significantly reduced post-intervention, with changes in visfatin correlating with changes in insulin and glucose area under the curve (AUC).

Conclusions:

• Exercise-induced reduction in plasma visfatin is likely attributed to weight loss and changes in body composition.
• The potential regulatory role of visfatin in mediating pancreatic insulin response to oral glucose warrants further investigation.