Canadian researchers have found that mice who engage in a single bout of intense exercise right before taking a dose of the antipsychotic drug olanzapine (Zyprexa) do not experience a drug-induced increase in blood sugar, a common side effect of the medication.
Olanzapine, commonly prescribed for schizophrenia, causes blood sugar levels to rise with each dose taken. If the findings translate to humans, schizophrenia patients may be able to ward off the weight gain and type 2 diabetes often caused by long-term use of the drug.
“Acute repeated spikes in blood sugar that you see with each dose of this drug have long-term impacts — and can predispose patients to the development of insulin-resistance Type 2 diabetes and cardiovascular disease,” said study author Dr. David Wright, associate professor in the Department of Human Health and Nutritional Sciences at the University of Guelph.
Patients typically take such drugs as olanzapine over a long period of time, potentially resulting in serious impacts on patients’ overall health, added Wright.
“If you look at the average life expectancy of an individual with schizophrenia versus someone in the general population, it’s a 20-year gap. If we can reduce the side effects associated with blood glucose levels, hopefully we can improve life expectancy and the overall quality of life,” he said.
And while clinicians often attempt to prevent higher blood glucose levels by prescribing anti-diabetic drugs, Wright said his lab is interested in exercise physiology and trying to figure out how exercise can improve glucose homeostasis.
“Cardiovascular disease is the leading cause of death in individuals that have schizophrenia,” said Wright. “And obviously not everything can be attributed to the metabolic effects of these drugs. But if we can look at the big picture and reduce these side effects, hopefully life expectancy and quality of life can be improved because once you go on these drugs you can’t really go off of them.”
For the study, Wright and PhD student Laura Castellani exercised mice by having them run until they reached exhaustion before giving them a dose of olanzapine. They found that the exercise prevented the rise in blood glucose levels that usually occurs when taking the medication.
However, the findings show that it must be intense exercise. When the tests were repeated with only moderate exercise similar to a fast jog, blood glucose levels still increased in mice because of the medication.
Although these findings are encouraging, Wright notes some challenges.
“Translating these findings to humans will be difficult, especially considering that patients taking anti-psychotics have a very low level of exercise adherence,” he said. “The next step is to see if we can identify the pathways that are activated during exercise so that we can perhaps target them pharmacologically or nutritionally.”
The findings are published in the journal Scientific Reports.
Source: University of Guelph