Impact of sex on microvascular reactivity in a murine model of diet-induced obesity and insulin resistance.

The association of obesity with cardiovascular disease is well established. However, the interplay of obesity and vascular dysfunction in peripheral tissues such as skeletal muscle, which plays a key in role metabolic homeostasis, requires further study. In particular, there is a paucity of data with regard to sex-differences. Therefore, using a murine model (C57BL/6) of high-fat diet-induced obesity and insulin resistance, we investigated changes in vascular function in gluteus maximus muscle of female and male mice. Diet-induced obesity resulted in alterations in microvascular function. Obese male mice displayed impaired vasoconstriction in second order arterioles compared to lean, male mice, whereas arterioles of obese, female mice displayed significant impairments of both vasodilation and vasoconstrictor responses compared to lean, female mice. Overall, this study identifies distinct differences in how obesity impacts the female and male murine response to skeletal muscle vascular function. This work advances our understanding of sex-specific risk of metabolic complications of obesity and indicates the need for expansion of this study as well as detailed investigation of sex-specific differences in obesity pathology in the future.