Fatigue is a predictor for cardiovascular outcomes in patients undergoing hemodialysis.
OBJECTIVE
Despite potential significance of fatigue and its underlying components in the occurrence of cardiovascular diseases, epidemiologic data showing the link are virtually limited. This study was designed to examine whether fatigue symptoms or fatigue's underlying components are a predictor for cardiovascular diseases in high-risk subjects with ESRD.


METHODS
788 volunteer patients under hemodialysis therapy (506 male, 282 female) completed the survey between October and November 2005, with the follow-up period up to 26 months to monitor occurrence of fatal or nonfatal cardiovascular events. The questionnaire consisted of 64 questions, and promax rotation analysis of the principal component method conceptualized eight fatigue-related factors: fatigue itself, anxiety and depression, loss of attention and memory, pain, overwork, autonomic imbalance, sleep problems, and infection.


RESULTS
14.7% of the patients showed fatigue scores higher than twice the SD of the mean for healthy volunteers. These highly fatigued patients exhibited a significantly higher risk for cardiovascular events (hazard ratio: 2.17; P < 0.01), with the relationship independent of the well-known risk factors, including age, diabetes, cardiovascular disease history, and inflammation and malnutrition markers. Moreover, comparisons of the risk in key subgroups showed that the risk of high fatigue score for cardiovascular events was more prominent in well-nourished patients, including lower age, absence of past cardiovascular diseases, higher serum albumin, and high non-HDL cholesterol.


CONCLUSIONS
Fatigue can be an important predictor for cardiovascular events in patients with ESRD, with the relationship independent of the nutritional or inflammatory status.
Koyama
Hidenori
H
Department of Metabolism, Endocrinology and Molecular Medicine, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka 545-8585, Japan. hidekoyama@med.osaka-cu.ac.jp
Fukuda
Sanae
S
Shoji
Tetsuo
T
Inaba
Masaaki
M
Tsujimoto
Yoshihiro
Y
Tabata
Tsutomu
T
Okuno
Senji
S
Yamakawa
Tomoyuki
T
Okada
Shigeki
S
Okamura
Mikio
M
Kuratsune
Hirohiko
H
Fujii
Hisako
H
Hirayama
Yoshinobu
Y
Watanabe
Yasuyoshi
Y
Nishizawa
Yoshiki
Y
D000368:Aged; D002318:Cardiovascular Diseases / Q000209:etiology* / Q000401:mortality; D016022:Case-Control Studies; D005221:Fatigue / Q000150:complications* / Q000175:diagnosis / Q000401:mortality; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D053208:Kaplan-Meier Estimate; D007676:Kidney Failure, Chronic / Q000150:complications / Q000401:mortality / Q000628:therapy*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D025341:Principal Component Analysis; D016016:Proportional Hazards Models; D006435:Renal Dialysis / Q000401:mortality; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D013997:Time Factors