People taking long-acting pain killers for extended periods face a five-times greater risk of low testosterone, the male sex hormone, a new study says.

The study is the first to compare the use of short-acting opioids, which immediately release the drug, taken every four to six hours, and long-acting opioids, which slowly release the medication and are taken every eight to 12 hours.
The 81 men involved in the study were between 26 and 79 years old (median age 51) and were seen in the chronic-pain clinic at Kaiser Permanente`s Santa Rosa Medical Centre, California (KPSRMC), between January 2009 and June 2010, the Clinical Journal of Pain reports.

All of the participants had been on a stable dose of an opioid for at least three months, and none had a previous diagnosis of low testosterone. A larger retrospective study of more than 1,500 male pain patients is currently under way, according to a KPSRMC statement.

"There`s a large gap in the evidence base with regard to opioids," said Andrea Rubinstein from the departments of chronic pain and anesthesiology, KPSRMC.

"More safety and efficacy studies are needed. We need to know how we can prescribe these very useful medications in a way that brings the greatest benefits to our patients, without introducing additional risks."

Once prescribed primarily to cancer patients, the use of opioid-based medications such as oxycodone (Oxycontin) and hydrocodone (Vicodin) for treating chronic, non-cancer pain has increased dramatically in recent decades. An estimated 4.3 million Americans use opioids on a daily basis for pain.

"For years, doctors have been encouraged to prescribe long-acting opioids rather than short-acting opioids because we believed they were safer, had less abuse potential, and offered more consistent pain control, but no study has ever been able to support this practice," Rubinstein said.

A healthy young man should have testosterone levels between 300 and 800 nanograms per decilitre (ng/dL). Low testosterone, also known as hypogonadism, was defined as less than 250 ng/dL.

A decilitre is one-tenth of a litre.

Low testosterone levels have been linked with decreases in muscle mass, bone density (osteoporosis or osteopenia), cognition, mood, libido (sex drive) and general quality of life.

Seventy-four percent of the men on long-acting opioids had low testosterone levels, compared with 34 percent of the men using short-acting opioids.

After controlling for daily dosage and body mass index, the study found that the odds of having low testosterone were 4.78 times greater for men taking a long-acting opioid than a short-acting opioid.

Binge drinking interferes with the area of the brain that controls insulin regulation, which increases your risk of developing Type 2 diabetes, a new study has warned.

"Insulin resistance has emerged as a key metabolic defect leading to Type 2 diabetes and coronary artery disease (CAD)," said Christoph Buettner, MD, PhD, senior author of the study and Associate Professor of Medicine (Endocrinology, Diabetes and Bone Disease) at Mount Sinai.

"Someone who regularly binge drinks even once a week, over many years, may remain in an insulin resistant state for an extended period of time, potentially years," said Dr. Buettner.

Researchers in this study were able to show that it is alcohol`s effect on the brain - specifically the hypothalamus, the area that controls metabolism - that makes the body less able to process insulin.

The study was conducted on a group of rats, some of which were given alcohol over a three-day period to mimic binge drinking, while others received the same amount of sugar calories from other food sources. The rats who drank alcohol were then found to have higher concentrations of plasma insulin, an indicator of metabolic syndrome, which increases one`s risk for diabetes.

Researchers also identified inflammation occurring in the drinking rats` brains. When they inhibited the protein that causes inflammation in the hypothalamus, they were able to prevent insulin resistance.

Binge drinking is commonly defined as 4 drinks in a 2-hour span for women, or 5 for men.

The study was recently published in the journal Science Translational Medicine.