Early Symptoms Affecting Quality of Life May Predate Parkinson’s Disease Diagnosis

Parkinson's Disease (PD) is a brain disorder that causes tremors and difficulty with movement and walking, and most commonly affects people over the age of 50.  Natalia Palacios, from Harvard School of Public Health (Massachusetts, USA), and colleagues studied data collected on 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.  The researchers identified 454 men and 414 women with PD in the two cohorts. At 7.5 years prior to diagnosis, physical function among PD cases, in both men and women, was comparable to that in the overall cohort. A decline began approximately 3 years prior to diagnosis in men and approximately 7.5 years prior to diagnosis in women. Physical function continued to decline thereafter at a rate of 1.43 and 2.35 points per year in men and women, respectively. In comparison, the average yearly decline in individuals without PD was 0.23 in men and 0.42 in women. Other measures of quality of life, available only in women, declined in a similar pattern.  The study authors conclude that: "the quality of life in [Parkinson's Disease] patients begins to decline years before the diagnosis.”