John Lighton, CEO of Las Vegas-based Sable Systems, spoke at the May 27th NevBio meeting about measuring metabolic rate. Lighton said that the measurement of metabolic rate can aid future medical and scientific developments in the areas of exercise and fitness, reperfusion injury, suspended animation, discovery science, and obesity and diabetes.
Sable Systems specializes in indirect calorimetry, the best way to determine human metabolic rate. Direct calorimetry, discovered by Antoine and Marie-Ann Lavoisier, is best for measuring the metabolic rates of smaller animals. To calculate metabolic rate, indirect caliometry measures the oxygen consumed and the CO2 produced by the subject. Studies in indirect calorimetry have revealed that there is a very small range between when the body is burning fat alone vs. when the body is burning carbs alone. If people want to lose weight, they must burn fat deposits in their body; if they are exercising at too high of an intensity, they are subsequently burning only carbs and not exercising in the correct way to lose weight.
Lighton also advocates the use of the fruit fly Drosophila to study reperfusion injury. Strokes are the most common reperfusion injuries, damage that occurs after tissue is cut off from oxygen and then re-exposed. He explained that the lack of oxygen is not the problem, but the reperfusion of oxygen is. 83% of Drosophila genes match human genes, and studying reperfusion in fruit flies makes for accurate and cheap ways to address this problem in humans. Scientists can also use fruit flies to study obesity and fat storage, aging and senescence, diabetes and insulin-related issues, gene expression, cell proliferation and apoptosis, stem cells, heart disease, and psychological disorders.
Metabolic rate measurements are also currently used in experiments in suspended animation at Roth Lab in Chapel Hill, North Carolina and the Hutchinson Cancer Research Institute in Seattle. Suspended animation is the slowing down of life processes, such as breathing and heartbeat, through external sources. Suspended animation is induced by adding hydrogen sulfide to air, to produce a semi-hiberation state. In this state, the body temperature and metabolic rate drop. Research is still being developed in suspended animation for humans. Suspended animation would be especially helpful on the battlefield in keeping soldiers alive longer until they can receive the appropriate medical care.
Discovery science in the area of metabolic rate is rapidly developing, exploring the speculative applications of respirometry and osteopathic manipulation. Commissioned scientific research for the Department of Defense, DARPA is exploring much of the open options in relation to metabolic rate.
Measuring metabolic rate is extremely relevant to today's obesity epidemic. These measurements can be used to combat the epidemic. For scientists to understand how fat storage is controlled, they must research animal models other than humans. To halt the epidemic, scientists need to determine the root causes and address biological solutions. Ability to measure the metabolic rate is a helpful tool for balancing energy intake against energy expenditure, better enabling scientists to explore options for slowing down this nation-wide epidemic.