, according to what investigators say is the most comprehensive study in the nation of temporal trends in Parkinson’s disease mortality.
“The reason behind the rising death rates from Parkinson’s disease is not clear at present and warrants further investigation,” Wei Bao, MD, PhD, associate professor in the department of epidemiology at the University of Iowa College of Public Health, in Iowa City, said in an interview. “We know that people are living longer and the general population is getting older, but that doesn’t fully explain the increase we saw in the death rate in people with Parkinson’s disease,” Dr. Bao added in a statement.
“Understanding why more people are dying from this disease is critical if we are going to reverse the trend,” Dr. Bao said.
The study was published online Oct. 27 in Neurology.
Long-term data
The researchers used data from the National Vital Statistics System to determine national trends in Parkinson’s disease mortality overall and in several key subgroups. The analyses included 479,059 people who died of Parkinson’s disease between 1999 and 2019.
Over the 21-year period, the age-adjusted mortality from Parkinson’s disease rose from 5.4 per 100,000 in 1999 to 8.8 per 100,000 in 2019. The average annual percent change (APC) was 2.4% for the entire period.
During the study period, the number of deaths from Parkinson’s disease more than doubled, from 14,593 to 35,311.
The death rate from Parkinson’s disease increased significantly across all age groups. The average APC was 5.0% among adults younger than 65 years, 1.9% among those aged 65-74 years, 2.2% among those 75-84 years, and 2.7% among those 85 and older.
The death rate increased in both men and women, but age-adjusted Parkinson’s disease mortality was twice as high in men as in women. The researchers say one possible explanation for the sex difference is estrogen, which leads to higher dopamine levels in areas of the brain that control motor responses and may protect women from Parkinson’s disease.
The study also showed that White people are more likely to die from Parkinson’s disease than persons of other racial and ethnic groups. In 2019, the death rate per 100,000 was 9.7 for Whites, 6.5 for Hispanics, and 4.7 for non-Hispanic Blacks.
Previous studies have shown that compared with White people, Black and Hispanic people are less likely to see a neurologist, owing to socioeconomic barriers. This suggests that White people may be more likely to receive a Parkinson’s disease diagnosis, the researchers noted.
“It’s important to continue to evaluate long-term trends in Parkinson’s death rates,” Dr. Bao said.
“This can inform future research that may help pinpoint why more people are dying of the disease. Also, updating vital statistics about Parkinson’s death rates may be used for priority setting and financing of health care and policy,” Dr. Bao added.