Synergism between smoking and vital exhaustion in the risk of ischemic stroke: evidence from the ARIC study.
OBJECTIVE
To examine the synergism between vital exhaustion and cigarette smoking in producing ischemic stroke. Vital exhaustion (VE), a state characterized by unusual fatigue, irritability, and feelings of demoralization, is measured by the Maastricht questionnaire (MQ), a 21-item inventory of symptoms.


METHODS
The Atherosclerosis Risk in Communities (ARIC) Study is an ongoing cohort study, initiated in 1987. The MQ was administered at the second follow-up visit (1990-1992), and participants were subsequently followed for an average of 6.27 years. Four US communities (Minneapolis, Minnesota; Washington County, Maryland; Forsyth County, North Carolina; and Jackson, Mississippi). 13,066 participants aged 48 to 67 years at baseline (Visit 2) with no history of stroke. Validated hospitalized ischemic stroke.


RESULTS
During the follow-up period, there were 202 incident ischemic strokes. After multivariate adjustment, current smoking, and high VE were independent risk factors for incident stroke: (smoking vs. non-smoking HR=1.76, p < 0.01; high VE vs. low VE HR=1.94, p < 0.01). For persons with both VE and smoking vs. persons with neither, HR=2.71 (p < 0.001). The proportion of stroke disease burden due to VE and smoking that could be attributed to their interaction was 81 to 93 percent.


CONCLUSIONS
The combination of cigarette smoking and VE is synergistic in the production of stroke.
Schwartz
Skai W
SW
Department of Epidemiology and Biostatistics, College of Public Health, University of South Florida, Tampa, FL 33612, USA. sschwartz@hsc.usf.edu
Carlucci
Cheryl
C
Chambless
Lloyd E
LE
Rosamond
Wayne D
WD
D000368:Aged; D002545:Brain Ischemia / Q000453:epidemiology* / Q000209:etiology; D015987:Effect Modifier, Epidemiologic; D005221:Fatigue / Q000150:complications* / Q000503:physiopathology; D005260:Female; D006801:Humans; D015994:Incidence; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011336:Probability; D018570:Risk Assessment; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects* / Q000503:physiopathology; D020521:Stroke / Q000453:epidemiology* / Q000209:etiology; D011795:Surveys and Questionnaires; D014481:United States / Q000453:epidemiology