Research | On the Frontier of Diabetes Research

Research | On the Frontier of Diabetes Research
Zhenqi Liu, MD, Chief of Endocrinology & Metabolism

Dr. Zhenqi Liu, chief of the Division of Endocrinology and Metabolism, currently has a three-year grant (2011-2013) from Novo Nordisk to support clinical research focusing on insulin action and resistance in type 2 diabetes. He shared some insights into his research, and its potential to impact patient care.

Q: What area of diabetes research does your project cover?  What role will this particular project play in preventing, treating and/or curing diabetes?

Patients with type 2 diabetes are prone to cardiovascular diseases such as heart attack, heart failure, stroke and kidney failure, and have a decreased response to insulin–a condition called insulin resistance. The underlying mechanisms for this remain unclear.

Both the small blood vessels and skeletal muscle have been implicated in the development of cardiovascular complications in diabetic patients. Insulin acts on the skeletal muscle to stimulate glucose use [uptake?]. In order for insulin to act on the skeletal muscle, however, it must be delivered to the muscle first. It is in the small blood vessels in muscle where insulin passes through the vessel wall to reach muscle cells. Expansion of the small blood vessels increases the delivery of insulin, together with oxygen and nutrients to the skeletal muscle. It is unclear whether in the insulin resistant states that expansion of the small blood vessel volume would increase insulin sensitivity by increasing insulin delivery to the muscle.

Diabetes is associated with many biochemical abnormalities which are capable of causing insulin resistance and abnormal vascular function in the skeletal muscle. In this study, we are examining whether selective activation of a hormone receptor, called angiotensin II type 2 receptors, increases insulin sensitivity in the muscle by increasing muscle small blood vessel volume and insulin delivery in the insulin-resistant states. We use a state-of-the-art technique called contrast-enhanced ultrasound (CEU) to non-invasively measure small blood vessel volume in the human skeletal muscle. Results from these studies are shedding light on our understanding of the relationship between type 2 diabetes, insulin resistance, and cardiovascular complications in humans, and open a whole new avenue for future mechanistic, diagnostic and therapeutic studies.

Q: If a person with diabetes were to ask you how your project will help them in the future, how would you respond?

This research is providing a better understanding of the underlying mechanisms of insulin resistance and microvascular complications, which in turn will facilitate future development of therapeutic agents to protect tissues from ischemic injury and decrease the associated morbidity and mortality, especially in patients with diabetes.

Q: Why is it important for you, personally, to become involved in diabetes research?  What role will this award play in your research efforts?

I am a board-certified endocrinologist and have a strong interest in diabetes. In my practice, more than 50% of my patients have diabetes and many of them have diabetes-related complications, including coronary artery disease. It is thus very important for me to become actively involved in diabetes research to better serve my patients. This award provides extremely important momentum for my research efforts by providing both financial resources and protected research time. It also helps me generate more data for future funding applications in diabetes research.

Q: Where do you see the future of diabetes research headed?

As we develop a better understanding of the molecular and cellular mechanisms of diabetes, the future of diabetes research will focus on applying these insights to the clinical setting and, in particular, seeking a cure for diabetes.