Définition
Insulin resistance is a condition in which cells become less responsive to insulin's signaling, requiring the pancreas to produce more insulin to maintain blood glucose control. It is the foundation of metabolic syndrome and drives accelerated biological aging in women.
Insulin is released by pancreatic beta cells in response to elevated blood glucose. Its primary function is to signal cells to take up glucose for energy production or storage — largely through translocation of GLUT4 transporters to the cell membrane in muscle and fat. In insulin resistance, this signal is blunted: cells require more insulin to achieve the same glucose uptake. The pancreas compensates with increased insulin output, producing hyperinsulinemia.
Chronically elevated insulin drives multiple adverse downstream effects: it promotes fat storage (particularly visceral fat), inhibits fat burning, promotes cellular proliferation, and — when pancreatic capacity eventually exhausts — allows blood glucose to rise unchecked. Insulin resistance appears on bloodwork years or decades before any formal diagnosis, making it a modifiable early-intervention target. Fasting insulin above 7 µIU/mL or HbA1c above 5.4% warrant attention, well before they cross standard clinical cutoffs.
In women, insulin resistance is strongly linked to cortisol (cortisol directly impairs insulin signaling), estrogen decline (estrogen supports insulin sensitivity in muscle tissue), and visceral fat accumulation (visceral adipocytes secrete inflammatory cytokines that blunt insulin signaling). The combination of declining estrogen, rising cortisol, and increasing visceral fat in perimenopause creates a perfect storm for insulin resistance development in the 40s.
The most effective interventions for improving insulin sensitivity: Zone 2 aerobic exercise (improves insulin receptor expression and GLUT4 translocation in muscle), strength training (increases muscle mass and glucose storage capacity), sleep optimization (a single night of poor sleep measurably impairs insulin sensitivity), time-restricted eating, post-meal walks, and dietary reduction of refined carbohydrates.
Guide associé
Cortisol and Weight Gain in Women
Lire le guide →
Ava Longevity · Built on the Ava Method · MMXXV