Frailty in elderly persons with essential tremor: A population-based study (NEDICES)

Background and purpose: Essential tremor (ET), one of the most prevalent neurological diseases, has been associated with a variety of comorbidities and, in some studies, a modest increase in risk of mortality. The mechanisms underlying this possible increased mortality have yet to be explored, although one possibility is increased frailty. Frailty has not been studied in ET, and our objective was to address this gap in knowledge. We hypothesized that frailty would be greater in ET cases than in controls. Methods: A 20-item frailty score assessed comorbid conditions, number of medications, and functional activity. The frailty score was compared in 237 non-demented elderly ET cases and 3903 non-demented age-matched controls from a population-based study in central Spain. Results: The frailty score was higher in ET cases than in controls (8.6±5.2 vs. 6.8±4.6, P<0.001). Stratifying the frailty score into quartiles and tertiles similarly revealed case-control differences (both P<0.001). The frailty score also increased with age (r=0.25, P<0.001), was higher in women than men (P=0.02), was correlated with subjective rating of health status (r=0.42, P<0.001), and was inversely correlated with body weight (r=-0.06, P<0.001) and hours/day that participants performed moderate or intensive physical activities (r=-0.16, P<0.001). Conclusion: Essential tremor cases had increased frailty compared to their counterparts without this disease. Whether this increased frailty is a contributor to the increased risk of mortality that has been observed in some studies is a question that deserves further scrutiny.