When researchers measured the levels of a molecule called CoQ in a range of samples, they found that there was less of it in body fat and muscle tissues that were resistant to insulin. A variety of different assays showed the same result; mouse and human samples, and research models were used in this study. When the investigators boosted the levels of CoQ, insulin resistance or pre-diabetes, in which blood sugar is abnormally high, was reversed. The work has been reported in eLife.
One author of the report, Dr. Daniel Fazakerley of the University of Sydney's School of Life and Environmental Science and Charles Perkins Centre noted that CoQ is critical to the conversion of nutrients like sugar and fat and into energy.
"CoQ is found in mitochondria, the power plants in the cells of our body, where it is required for the flow of electricity to the cell's 'motor' which is responsible for energy production," he explained. "Energy production can also generate reactive chemical species - often referred to as 'reactive oxygen species' or 'oxidants' - as by-products, which can be damaging to cells.
"Previous studies have shown that these oxidants can cause insulin resistance. Our study has found that lower mitochondrial CoQ enhanced oxidant formation by mitochondria. Importantly, by replenishing CoQ in mitochondria, either in cells or in animals, we were able to restore 'normal' mitochondrial oxidants and reverse insulin resistance."
The study supplies a missing link in the way we understand how changes in our diet lead to insulin resistance, said Professor David James, co-lead author and Leonard P. Ullmann Chair of Metabolic Systems Biology at the University of Sydney's Charles Perkins Centre.
"Eating a high fat, high sugar diet has long been known to be a major risk factor for obesity and pre-diabetes and our latest work brings us one step closer to understanding how and why," James explained.
"Replenishing CoQ could prove an invaluable preventive measure for insulin resistance- or pre-diabetes-linked diseases such as type 2 diabetes, cardiovascular disease, cancers, and dementia," added co-lead author Professor Roland Stocker from the Victor Chang Cardiac Research Institute and the University of New South Wales.
"However, oral CoQ supplements may not effectively restore mitochondrial CoQ due to its low absorption," Stocker stressed. "This work has provided an impetus for us to find alternate means of increasing CoQ in mitochondria to treat insulin resistance and pre-diabetes. If not an external supplement, perhaps we can stimulate the body to form more of the coenzyme itself - or find ways to prevent levels from lowering in the first place."
The video above from the Centers for Disease Control and Prevention has some information about how to reverse pre-diabetes.
Sources: AAAS/Eurekalert! Via University of Sydney, eLife