In obesity, adipose tissue macrophage infiltration promotes systemic insulin resistance. The key adipokine that is DECREASED in obesity and has insulin-sensitising, anti-inflammatory and atheroprotective properties is:

• A Leptin
• B Adiponectin ✓
• C Resistin
• D TNF-α

Explanation

Adiponectin is the most abundant adipokine and is paradoxically decreased in obesity despite increased adipose mass. It activates AMPK and PPAR-α in liver and muscle, enhancing fatty acid oxidation, suppressing gluconeogenesis and improving insulin sensitivity. It also has anti-inflammatory (suppresses NF-κB signalling, inhibits macrophage activation) and atheroprotective effects (inhibits foam cell formation, promotes reverse cholesterol transport). Leptin is increased in obesity (causing leptin resistance) and regulates satiety. Resistin promotes insulin resistance and is increased in obesity. TNF-α from adipose-resident macrophages promotes inflammation and insulin resistance.

Reference: Harper's Illustrated Biochemistry, 32nd ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.