The epidemic of type 2 diabetes (T2DM) is a public health problem that threatens to spiral out of control in the twenty-first
century. Early intervention can greatly mitigate the serious socioeconomic impact of the disease, driven largely by disabling
microvascular complications and cardiovascular disease. Obesity is at the core of the epidemic of T2DM, affecting 2/3 of adults
and reaching alarming rates in children in modern society. Our understanding of adipose tissue has evolved drastically in
the past decade being now viewed as a dynamic ‘endocrine organ’ responsible for the development or worsening of insulin resistance
and ‘lipotoxicity’ in obese individuals. ‘Lipotoxicity’ describes the damage that occurs when chronic energy supply exceeds
metabolic needs and lipid accumulates in tissues that would not normally store large amounts of lipid. In this setting, lipid
is redirected into harmful pathways of nonoxidative metabolism, with accumulation of toxic metabolites that activate inflammatory
pathways and eventually lead to apoptosis. It affects organs responsible for maintaining normal energy homeostasis, such as
the liver, skeletal muscle, and pancreatic beta-cells, but also the vascular bed. The ability of fatty acids to disrupt insulin
signaling and how the mitochondria adapts to chronic lipid overload are essential steps in understanding FFA-induced insulin
resistance and lipotoxicity across different tissues. Interventions that may prevent lipotoxicity in different target tissues,
but in particularpancreatic beta-cell lipotoxicity, such as exercise, weight loss, and/or pharmacological therapies such as
thiazolidinediones, hold the key to prevent diabetes in subjects genetically predisposed to T2DM and tackle the looming epidemic
of the coming century.
Keywords Type 2 diabetes mellitus – Obesity – Insulin resistance – Lipotoxicity – Free fatty acids – β-cell function – Fatty liver