Population-based study of baseline ethanol consumption and risk of incident essential tremor.
BACKGROUND
Recent postmortem studies have demonstrated pathological changes, including Purkinje cell loss, in the cerebellum in essential tremor (ET). Toxic exposures that compromise cerebellar tissue could lower the threshold for developing ET. Ethanol is a well-established cerebellar toxin, resulting in Purkinje cell loss.


OBJECTIVE
To test whether higher baseline ethanol consumption is a risk factor for the subsequent development of incident ET.


METHODS
Lifetime ethanol consumption was assessed at baseline (1994-1995) in a prospective, population-based study in central Spain of 3285 elderly participants, 76 of whom developed incident ET by follow-up (1997-1998).


RESULTS
In a Cox proportional hazards model adjusting for cigarette pack-years, depressive symptoms and community, the baseline number of drink-years was marginally associated with a higher risk of incident ET (relative risk, RR = 1.003, p = 0.059). In an adjusted Cox model, the highest baseline drink-year quartile doubled the risk of incident ET (RR = 2.29, p = 0.018), while other quartiles were associated with more modest elevations in risk (RR(3rd quartile) = 1.82 (p = 0.10), RR(2nd quartile) = 1.75 (p = 0.10), RR(1st quartile) = 1.43 (p = 0.34) vs non-drinkers (RR = 1.00)). With each higher drink-year quartile, the risk of incident ET increased an average of 23% (p = 0.01, test for trend).


CONCLUSIONS
Higher levels of chronic ethanol consumption increased the risk of developing ET. Ethanol is often used for symptomatic relief; studies should explore whether higher consumption levels are a continued source of underlying cerebellar neurotoxicity in patients who already manifest this disease.
Louis
E D
ED
GH Sergievsky Center, Columbia University, New York, NY 10032, USA. EDL2@columbia.edu
Benito-León
J
J
Bermejo-Pareja
F
F
D000368:Aged; D000428:Alcohol Drinking / Q000453:epidemiology*; D003863:Depression / Q000150:complications / Q000453:epidemiology; D020329:Essential Tremor / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008019:Life Style; D008297:Male; D011153:Population; D016016:Proportional Hazards Models; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology; D012959:Socioeconomic Factors; D013030:Spain / Q000453:epidemiology; D011795:Surveys and Questionnaires