Growing evidence suggests that Parkinson's disease (PD) often starts with non-motor symptoms that precede diagnosis by several years. In the first study to examine patterns in the quality of life of Parkinson' disease patients prior to diagnosis, researchers have documented declines in physical and mental health, pain, and emotional health beginning several years before the onset of the disease and continuing thereafter. Their results are reported in the latest issue of Journal of Parkinson's Disease.
"We observed a decline in physical function in PD patients relative to their healthy counterparts beginning three years prior to diagnosis in men and seven and a half years prior to diagnosis in women," says lead investigator Natalia Palacios, PhD, Department of Nutrition, Harvard School of Public Health. "The decline continues at a rate that is five to seven times faster than the average yearly decline caused by normal aging in individuals without the disease."
The study included 51,350 male health professionals enrolled in the Health Professionals Follow Up Study (HPFS) and 121,701 female registered nurses enrolled in the Nurses' Health Study (NHS). In both ongoing studies, participants fill out biannual questionnaires about a variety of lifestyle characteristics and document the occurrence of major chronic disease. In the NHS study, questionnaires measured health-related quality of life in eight areas: physical functioning, role limitations due to physical problems, role limitations due to emotional problems, vitality, bodily pain, social functioning, mental health, and general health perceptions. In the HPFS, only physical functioning was assessed.