A hormone produced by fat cells may be a crucial link between the obesity and insulin resistance seen in people with type 2 diabetes, according to independent findings by researchers in Japan and the United States. The two groups reported their results in the August issue of Nature Medicine.
Expression of a protein called adiponectin or Acpr30 is reduced in obese mice and humans, prompting speculation that it may play a role in regulating energy balance and that a deficiency of the protein might be involved in the obesity-dependent development of diabetes. Investigators at the University of Tokyo confirmed this observation in two mouse models of type 2 diabetes and found that treating the mice with physiological doses of the protein decreased insulin resistance. In one mouse model that lacks adipose tissue (and thus has no adiponectin), insulin resistance was partially reversed by giving the mice a physiological dose of adiponectin or leptin (another protein secreted by fat cells) and completely reversed by giving both proteins.
Stephenson J. Obesity-Diabetes Link. JAMA. 2001;286(10):1167. doi:10.1001/jama.286.10.1167-JWM10009-4-1