TOPLINE:
Loneliness is associated with a higher risk of developing Parkinson’s disease (PD) across demographic groups and independent of other risk factors, data from nearly 500,000 U.K. adults suggest.
METHODOLOGY:
- Loneliness is associated with illness and death, including higher risk of neurodegenerative diseases, but no study has examined whether the association between loneliness and detrimental outcomes extends to PD.
- The current analysis included 491,603 U.K. Biobank participants (mean age, 56; 54% women) without a diagnosis of PD at baseline.
- Loneliness was assessed by a single question at baseline and incident PD was ascertained via health records over 15 years.
- Researchers assessed whether the association between loneliness and PD was moderated by age, sex, or genetic risk and whether the association was accounted for by sociodemographic factors; behavioral, mental, physical, or social factors; or genetic risk.
TAKEAWAY:
- Roughly 19% of the cohort reported being lonely. Compared with those who were not lonely, those who did report being lonely were slightly younger and were more likely to be women. They also had fewer resources, more health risk behaviors (current smoker and physically inactive), and worse physical and mental health.
- Over 15+ years of follow-up, 2,822 participants developed PD (incidence rate: 47 per 100,000 person-years). Compared with those who did not develop PD, those who did were older and more likely to be male, former smokers, have higher BMI and PD polygenetic risk score, and to have diabetes, hypertension, myocardial infarction or stroke, anxiety, or depression.
- In the primary analysis, individuals who reported being lonely had a higher risk for PD (hazard ratio, 1.37) – an association that remained after accounting for demographic and socioeconomic status, social isolation, PD polygenetic risk score, smoking, physical activity, BMI, diabetes, hypertension, stroke, myocardial infarction, depression, and having ever seen a psychiatrist (fully adjusted HR, 1.25).
- The association between loneliness and incident PD was not moderated by sex, age, or polygenetic risk score.
- Contrary to expectations for a prodromal syndrome, loneliness was not associated with incident PD in the first 5 years after baseline but was associated with PD risk in the subsequent 10 years of follow-up (HR, 1.32).
IN PRACTICE:
“Our findings complement other evidence that loneliness is a psychosocial determinant of health associated with increased risk of morbidity and mortality [and] supports recent calls for the protective and healing effects of personally meaningful social connection,” the authors write.
SOURCE:
The study, with first author Antonio Terracciano, PhD, of Florida State University College of Medicine, Tallahassee, was published online in JAMA Neurology.
LIMITATIONS:
This observational study could not determine causality or whether reverse causality could explain the association. Loneliness was assessed by a single yes/no question. PD diagnosis relied on hospital admission and death records and may have missed early PD diagnoses.
DISCLOSURES:
Funding for the study was provided by the National Institutes of Health and National Institute on Aging. The authors report no relevant financial relationships.
A version of this article first appeared on Medscape.com.