Diagnosis Tends to Come Earlier for Those with More Education
People with Huntington’s disease who have had more formal education tend to be diagnosed earlier and have milder symptoms than those with less formal education, a new study indicates.
The study, “The effect of education on symptom onset and severity of Huntington’s disease,” was published in Movement Disorders Clinical Practice.
While the role of disease-causing mutations in affecting Huntington’s severity is well-established, little is known about how environmental and lifestyle factors, such as education, influence the course of Huntington’s. In the study, researchers at the University of Virginia and Virginia Commonwealth University analyzed data from a global patient registry, called Enroll-HD, to better understand how education affects the disease’s course.
“The primary objective of our study was to determine the effect of education on the age of onset of motor symptoms,” the researchers wrote. “Secondary objectives included determining the effect of education on the age of onset of depression, irritability, and cognitive impairment; and determining the effect of education on functional status after HD [Huntington’s disease] diagnosis.”
In total, the team assessed data for 4,537 people with Huntington’s, most of whom resided in Europe or North America. Based on education level, these patients were divided into three groups: 1,115 had completed only pre-secondary education, 1,491 had completed secondary education, and 1,931 had gone on to post-secondary education.
Statistical analyses were used to compare various disease-relevant measures between the three groups. These models revealed that individuals with more formal education tended to be significantly younger at diagnosis, and at the onset of motor symptoms, depression, irritability, and cognitive impairment.
“Our results show that HD participants with higher education level report earlier onset of participant-reported HD associated symptoms and have earlier age of HD diagnosis,” the researchers wrote.
“We suspect that these findings may be explained by increased self-awareness and/or insight and thus earlier recognition of mood, motor symptoms, irritability, and cognitive symptoms in more highly educated individuals,” the team added. “In the same way, earlier age of diagnosis in HD participants with higher education levels may arise from earlier recognition of symptoms and earlier evaluation by health care providers.”
Based on scores on the UHDRS (unified Huntington’s disease rating scale), patients with more formal education tended to have significantly less severe motor symptoms, as well as significantly greater functional ability. More education also was associated with better scores on multiple measures of cognition.
“Interestingly, and somewhat counter-intuitively, lower motor scores and better functional status were present in those with a higher level of education despite an earlier age of onset of motor, cognitive, and mood symptoms,” the researchers wrote. Lower motor scores on the UHDRS indicate better motor function.
The researchers posited several possible explanations for this finding: for example, it’s possible that these patients may have had milder symptoms simply because they were diagnosed and subsequently evaluated earlier in the course of their disease. It is also possible that education provides protection against Huntington’s symptoms by improving aspects of cognition or other processes, which the researchers said requires further investigation.
A limitation of this study is that socioeconomic status, which has a substantial effect on both education and health outcomes, was not available in the analyzed dataset.
Analyses of medication use showed high rates of chorea treatments among less-educated individuals, which “could suggest that healthcare access is not a significant factor influencing baseline motor symptoms, although this cannot be concluded with confidence given that this is an indirect measure of healthcare access,” the researchers wrote.