A study conducted by Ruth Marrie, MD, PhD and her colleagues at the University of Manitoba in Winnipeg, Canada showed that obesity, diabetes, mental health problems, smoking, vascular, and joint problems could delay the diagnosis of multiple sclerosis (MS) by as long as 10 years.

The study, which was published in the October 29, 2008 issue of Neurology, found that the more medical problems a person had along with MS, the more severe their medical condition had become by the time they were finally diagnosed. People with vascular problems or obesity were one-and-a-half times as likely to be moderately disabled at the time of their MS diagnosis compared to people with MS who did not have weight or vascular problems. In addition, people with mental disorders or joint and muscle problems were twice as likely to be severely disabled at the time of their MS diagnosis compared to people without these conditions.

Dr. Marrie says that pre-existing medical problems can mask symptoms of a new disease and interfere with diagnosis of new conditions. Physicians need to be aware of this and pay close to new symptoms that develop in patients with pre-existing conditions.