A narrative review on the possible causes of insulin resistance

Abstract

Insulin resistance is a multifactorial condition that significantly contributes to the development of type 2 diabetes, obesity and cardiovascular diseases. While traditionally linked to obesity and sedentary lifestyles, recent research reveals a more complex etiology involving behavioral, nutritional, endocrine, genetic, environmental, and cellular factors. This review explores both established and emerging contributors to insulin resistance including poor dietary habits, physical inactivity, chronic stress, circadian rhythm disruption and micronutrient deficiencies. Hormonal imbalances particularly involving cortisol, thyroid and sex hormones are examined for their impact on insulin signaling. Additionally, chronic inflammation, oxidative stress, mitochondrial dysfunction and endoplasmic reticulum stress are highlighted as key intracellular mechanisms reducing insulin sensitivity. The review also considers fewer known influences such as alterations in gut microbiota, exposure to endocrine disrupting chemicals, early developmental conditions and epigenetic changes. By integrating these diverse factors this paper aims to provide a comprehensive understanding of insulin resistance and its multifaceted origins.