Reverse epidemiology of hypertension-mortality associations in hemodialysis patients: a long-term population-based study.
BACKGROUND
Although hypertension (HTN) is a predictor of mortality, recent data have questioned the link between baseline HTN and mortality in incident hemodialysis (HD) patients. We used Taiwan's National Health Insurance claim data (NHRI-NHIRD-99182) to investigate the association.


METHODS
In 1999, this longitudinal cohort study enrolled 5752 new HD patients. Follow-up began from the initiation of HD until death, the end of HD, or the end of 2008. A Kaplan-Meier survival analysis was done. Cox proportional hazard analysis was used to identify the risk factors for mortality.


RESULTS
The prevalence of baseline HTN was 75.47%. Patients with HTN had a higher prevalence of diabetic mellitus (DM) and cardiovascular diseases. The 1-, 5-, and 9-year cumulative survival rates were 95.5, 63.7 and 41.8% in patients with HTN, and 95.5, 71.0, and 52.0% in those without HTN (log-rank test: P <0.001). Multivariate analysis showed that patients with baseline HTN may have a higher survival rate (hazard ratio (HR) 0.901, 95% confidence interval (CI): 0.819-0.992). After stratification by age and DM, only elderly (≥65) patients without DM had a significantly higher survival rate (HR 0.769, 95% CI: 0.637-0.927). HTN predicts lower mortality with increasing age in patients with congestive heart failure (CHF) or coronary artery disease (CAD).


CONCLUSIONS
There is a reverse (counterintuitive) association between baseline HTN and mortality in elderly HD patients without DM and a clear tendency for a reverse association with increasing age in patients with CHF or CAD. Further study of the association between HTN and mortality in older HD patients may be warranted.
Department of Nephrology, Chi-Mei Medical Center, Tainan, Taiwan.
Chih-Chiang
CC
Chien
Chun-Sheng
CS
Yen
Jhi-Joung
JJ
Wang
Hung-An
HA
Chen
Ming-Ting
MT
Chou
Chin-Chen
CC
Chu
Chung-Ching
CC
Chio
Jyh-Chang
JC
Hwang
Hsien-Yi
HY
Wang
Yi-Hua
YH
Lu
Wei-Chih
WC
Kan
D000293:Adolescent; D000328:Adult; D000368:Aged; D015331:Cohort Studies; D015897:Comorbidity; D003324:Coronary Artery Disease / Q000453:epidemiology; D003920:Diabetes Mellitus / Q000401:mortality*; D005260:Female; D006333:Heart Failure / Q000453:epidemiology; D006801:Humans; D006973:Hypertension / Q000401:mortality*; D053208:Kaplan-Meier Estimate; D007676:Kidney Failure, Chronic / Q000401:mortality; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D006435:Renal Dialysis / Q000401:mortality*; D012307:Risk Factors; D015996:Survival Rate; D013624:Taiwan / Q000453:epidemiology