Lipocalin-2 Deficiency Attenuates Insulin Resistance Associated With Aging and Obesity

duced from adipose tissue act in an autocrine and/or endocrine manner to perpetuate local inflammation and to induce periph-eral insulin resistance. The present study investigates whether lipocalin-2 deficiency or replenishment with this adipokine has any impact on systemic insulin sensitivity and the underlying mechanisms. METHODS AND RESULTS—Under conditions of aging or dietary-/genetic-induced obesity, lipocalin-2 knockout (Lcn2-KO) mice show significantly decreased fasting glucose and insulin levels and improved insulin sensitivity compared with their wild-type littermates. Despite enlarged fat mass, inflammation and the accumulation of lipid peroxidation products are signifi-cantly attenuated in the adipose tissues of Lcn2-KO mice. Adi-pose fatty acid composition of these mice varies significantly from that in wild-type animals. The amounts of arachidonic aci