Wenyan Zhao1, Faliang Gao2, Laidi Lv3, Xi Chen1. 1. Department of General Practice. 2. Department of Neurosurgery, Zhejiang Provincial People's Hospital, Affiliated People's Hospital, Hangzhou Medical College. 3. Department of General Practice, Hangzhou Zhaohui Jiedao Community Healthcare Center, Hangzhou, Zhejiang, China.
Abstract
OBJECTIVES: To investigate the interaction of hypertension and total plasma homocysteine (tHcy) levels on risk of all-cause and cardiovascular disease (CVD) mortality among middle-aged and older population. METHODS: This observational cohort study analyzed data from the National Health and Nutrition Examination Survey database (1999-2002 survey cycle). A generalized additive model (GAM) based on Cox proportional hazards models was applied to estimate the relationship of tHcy level with all-cause and CVD mortality. Stratification analyses by sex and renal function were performed. RESULTS: Among 5724 individuals aged 40-85, 704 (12.3%) died, with 339 CVD deaths after a median follow-up period of 5.58 years. Mean age was 60.7 ± 13.4 years (49.6% men). In the fully adjusted model, we found that per 1 μmol/l increment of plasma tHcy was associated with 8% increased risk of all-cause mortality and 7% increased risk of CVD mortality in hypertensive participants. The adjusted hazard ratio (95% CIs) for all-cause and CVD mortality were 1.08 (1.06-1.10) and 1.07 (1.04-1.10), respectively. There were pronounced interactive effects between hypertension and tHcy levels on risk of all-cause mortality (P for interaction = 0.031). CONCLUSION: Hypertension and tHcy levels can interactively affect the risk of all-cause mortality among middle-aged and older population. Conceivably, hypertension may further enhance the ability of elevated tHcy to provoke the risk of all-cause mortality.
OBJECTIVES: To investigate the interaction of hypertension and total plasma homocysteine (tHcy) levels on risk of all-cause and cardiovascular disease (CVD) mortality among middle-aged and older population. METHODS: This observational cohort study analyzed data from the National Health and Nutrition Examination Survey database (1999-2002 survey cycle). A generalized additive model (GAM) based on Cox proportional hazards models was applied to estimate the relationship of tHcy level with all-cause and CVD mortality. Stratification analyses by sex and renal function were performed. RESULTS: Among 5724 individuals aged 40-85, 704 (12.3%) died, with 339 CVD deaths after a median follow-up period of 5.58 years. Mean age was 60.7 ± 13.4 years (49.6% men). In the fully adjusted model, we found that per 1 μmol/l increment of plasma tHcy was associated with 8% increased risk of all-cause mortality and 7% increased risk of CVD mortality in hypertensive participants. The adjusted hazard ratio (95% CIs) for all-cause and CVD mortality were 1.08 (1.06-1.10) and 1.07 (1.04-1.10), respectively. There were pronounced interactive effects between hypertension and tHcy levels on risk of all-cause mortality (P for interaction = 0.031). CONCLUSION: Hypertension and tHcy levels can interactively affect the risk of all-cause mortality among middle-aged and older population. Conceivably, hypertension may further enhance the ability of elevated tHcy to provoke the risk of all-cause mortality.