Mitochondrial Dysfunction in Obesity‑Associated Insulin Resistance and Diabetes Progression

Mugisha Emmanuel K.

Faculty of Science and Technology Kampala International University Uganda

ABSTRACT

Mitochondria govern cellular energy, redox balance, and metabolite signaling across metabolic tissues. In obesity, chronic nutrient oversupply glucose, fatty acids, and branched‑chain amino acids forces mitochondria to operate outside their adaptive ranges, triggering bioenergetic inefficiency, oxidative stress, and maladaptive signaling that promote insulin resistance (IR) and accelerate type 2 diabetes (T2D). Key defects include substrate overload with incomplete fatty‑acid oxidation, electron transport chain (ETC) imbalance, altered TCA cycle anaplerosis/cataplerosis, and dysregulated mitochondrial dynamics (excess fission, impaired fusion), biogenesis (PGC‑1α axis suppression), and selective autophagy (mitophagy). Inter‑organelle communication deteriorates: mitochondria‑associated ER membranes (MAMs) mis‑handle Ca2+ and lipid trafficking, linking ER stress to impaired insulin action and β‑cell failure. Reactive oxygen species (ROS) and lipid peroxides, when sustained, inhibit insulin signaling nodes (IRS–PI3K–Akt), reprogram immune cells, and propagate “metaflammation.” Tissue context matters: adipose, liver, skeletal muscle, and pancreatic islets exhibit distinct mitochondrial vulnerabilities that converge on systemic dysglycemia. Therapeutically, exercise and caloric deficit restore mitochondrial quality control, while approved agents (metformin, SGLT2 inhibitors, incretin‑based therapies, TZDs) exert multi‑organ benefits that include improved mitochondrial efficiency or reduced substrate stress. Emerging strategies—NAD+ repletion, sirtuin/AMPK activation, redox modulators, mitophagy inducers, and safe thermogenic augmentation aim to correct root mitochondrial defects. Precision phenotyping with imaging and multi‑omics may identify mitochondrial endotypes that guide therapy choices. This review synthesizes mechanistic links between mitochondrial dysfunction and progression from obesity‑associated IR to T2D and outlines therapeutic opportunities to restore organelle health alongside glycemic control.

Keywords: mitochondria; insulin resistance; obesity; reactive oxygen species; mitophagy

CITE AS: Mugisha Emmanuel K. (2026). Mitochondrial Dysfunction in Obesity Associated Insulin Resistance and Diabetes Progression. RESEARCH INVENTION JOURNAL OF RESEARCH IN MEDICAL SCIENCES 5(1):62-68. https://doi.org/10.59298/RIJRMS/2026/516286