Michael D. Jensen, M.D.
Michael D. Jensen, M.D.
Dr. Jensen and his lab study the effects of obesity and how body fat and body-fat distribution influences health. The regulated uptake, storage and release of fatty acids from adipose tissue play a major role in determining the health effects of body fat.
This involves measuring the systemic and regional free fatty acid release in order to relate these factors to organ and tissue function. It also measures the uptake of fatty acids into muscle, liver and adipose tissue in order to determine whether preferential uptake of fat can predispose to obesity or a specific body fat distribution. The cellular fate(s) of fatty acids and the cell processes responsible for these steps can be assessed. The long-term goal is to understand the regulation of body fat and body fat distribution in hopes of developing novel approaches to improve the health of humans affected by obesity/excess fat.
What causes people to gain abdominal fat and why does abdominal fat predispose to diabetes and cardiovascular disease? Dr. Jensen is working to better understand how people store fat in their abdomen vs. hips and thighs as well as why people who preferentially gain abdominal fat are predisposed to diabetes.
Whether one gains or loses fat in one body region vs. another is determined by how well the fat cells in those regions take up and release fat compared to other fat cells, as well as how many fat cell there are and whether new fat cells are being created. Excess release of fatty acids from fat cells can cause metabolic dysfunction in tissue such as muscle, liver and pancreas. Dr. Jensen's team has developed approaches to measure the relative efficiency of fat storage and release in different body fat depots, whether people create new fat cells or lose old ones, and how fatty acids released from fat cells is metabolized by muscle and liver tissue.
Human studies involve: long-term feeding experiments; the use of isotope dilution techniques to measure free fatty acid and triglyceride fatty turnover; blood flow measurements; body composition measurements; exercise studies; indirect calorimetry to measure energy expenditure; doubly labeled water; ELIZA, Western blotting, real-time PCR and tissue enzyme activity measures to understand tissue function. To gain tissue for the latter measurements we routinely perform adipose tissue and muscle biopsies. Dr. Jensen's lab has recently developed PET tracers to study fatty acid metabolism in humans.
Significance to patient care
By understanding the constitutional, genetic and environmental factors that regulate body fat distribution and tissue fatty acid metabolism we hope to provide insights into potential novel therapeutic options to prevent/treat insulin resistance and Type 2 diabetes.
Dr. Jensen research into regulation of fat metabolism will help prevent and improve quality-of-life for patients with obesity, insulin resistance and lipid disorders.
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