Associations between serum total bilirubin levels and functional dependence in the elderly.
BACKGROUND
Many studies support the role of bilirubin as a cytoprotector in chronic inflammatory diseases, such as stroke and atherosclerosis.


OBJECTIVE
To investigate the relationship between serum total bilirubin levels and functional dependence in older adults.


METHODS
Data from the National Health and Nutrition Examination Survey (1999-2002) pertaining to 2235 old adults were analysed. All participants had given a household interview, providing information of five major domains on self-reported functional status (activities of daily living, instrumental activities of daily living, leisure and social activities, lower extremity mobility and general physical activities), had completed serum total bilirubin measurement, and a questionnaire regarding personal health. Poor performance was defined as experiencing difficulty with one or more items in a given domain. Functional dependence was defined as having three or more poor performances in the five major domains. Multiple logistic regression was performed together with quartile-based stratified odds ratio (OR) comparison and trend tests.


RESULTS
The OR of functional dependence for each standard deviation increment in the serum total bilirubin level was 0.56 (P = 0.002). After additional adjustment, the inverse association remained essentially unchanged. In quartile-based analysis, participants with higher quartiles of serum total bilirubin tended to have lower ORs of functional dependence. The trends of lower likelihood of functional dependence across increasing quartiles of the serum total bilirubin level were statistically significant (P < 0.05 for all trends).


CONCLUSIONS
Higher serum total bilirubin levels were associated with lower likelihood of functional dependence in older adults.
Department of Family and Community Medicine, Tri-Service General Hospital, Taipei, Taiwan; School of Medicine, National Defense Medical Center, Taipei, Taiwan.
T W
TW
Kao
C H
CH
Chou
C C
CC
Wang
C C
CC
Chou
J
J
Hu
W L
WL
Chen
D000203:Activities of Daily Living; D000368:Aged; D000369:Aged, 80 and over; D001663:Bilirubin / Q000097:blood* / Q000737:chemistry; D003430:Cross-Sectional Studies; D059026:Diagnostic Self Evaluation; D005260:Female; D006184:Habits; D006306:Health Surveys; D006801:Humans; D006932:Hyperbilirubinemia / Q000453:epidemiology; D057187:Independent Living; D007249:Inflammation / Q000097:blood; D008297:Male; D008875:Middle Aged; D009017:Morbidity; D009043:Motor Activity; D010084:Oxidation-Reduction; D012919:Social Behavior; D011795:Surveys and Questionnaires; D014481:United States / Q000453:epidemiology
D001663:Bilirubin