Influence of pre-hypertension on all-cause and cardiovascular mortality: The Singapore Cardiovascular Cohort Study☆☆☆
Received 15 October 2007; received in revised form 16 January 2008; accepted 29 March 2008. published online 27 June 2008.
Abstract
Background
The effect of “pre-hypertension” (pre-HTN) itself, and in combination with other cardiovascular disease (CVD) risk factors in relation to mortality has not been assessed in Asian populations.
Methods
From three cross-sectional studies conducted in Singapore (baseline 1982–1995), 5830 persons were grouped into normotensive (NT), pre-HTN or hypertensive (HTN). Follow-up (median 12.0 yrs, IQR 12–19 yrs) was done by linkage to the National Death Register. Outcomes included all-cause and CVD (ischaemic heart disease (ICD-9 410–414) and cerebrovascular accidents (ICD-9 430–438)). Cox's proportional hazards model was used to obtain adjusted hazard ratios (HRs) for risk of mortality.
Results
After adjustment, pre-HTN was not associated with a statistically significant increased risk of all-cause or CVD mortality. However, an increased risk for all-cause and CVD mortality, in the presence of diabetes (adjusted HR 1.8; 95%CI 1.0–2.9 and 4.4; 95%CI 1.9–10.4), smoking (adjusted HR 2.2; 95%CI 1.3–3.5 and 4.9; 95%CI 1.8–13.3), and especially, pre-existing CVD (adjusted HR 3.1; 95%CI 1.5–6.4 and 9.3; 95%CI 3.3–25.9) was found.
Conclusions
Pre-HTN was not an independent risk factor for mortality. However an increased risk of mortality for pre-HTN in the presence of other CVD risk factors was observed. This finding supports current recommendations to screen for these risk factors in the pre-HTN Asian population.
cDepartment of Endocrinology, Singapore General Hospital, Singapore
Corresponding author. Community, Occupational and Family Medicine, Yong Loo Lin School of Medicine, MD3, National University of Singapore, 16 Medical Drive, Singapore 117597, Singapore. Tel.: +65 65164964; fax: +65 67791489.
☆ Source of funding: This study was supported by an unrestricted educational grant from Pfizer Pte Ltd (Singapore).
☆☆ Conflict(s) of interest/disclosure(s): None. Pfizer had no involvement in the data collection, analysis, interpretation of the data, writing of the manuscript, or decision to submit the paper for publication.
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