Influence of age on the association between lifestyle factors and risk of hypertension

Background: Although hypertension is a highly prevalent disease in older populations, risk factors for developing hypertension have been studied primarily in younger cohorts. We sought to determine whether the strength of traditional hypertensive risk factors varied with age. Methods: We analyzed the prospective association between five modifiable risk factors and hypertension incidence among 78,590 initially nonhypertensive women of different ages in the Nurses' Health Study I cohort over 26 years. Results: Older age attenuated the association between incident hypertension and four of five risk factors associated with hypertension in younger women. Persons aged 50 years and younger who were low risk for all five risk factor behaviors had a hazard ratio (HR) for incident hypertension of 0.13 (95% confidence interval [CI], 0.03-0.52) compared with others in this age group. In women 61 and older, the HR was 0.62 (95% CI, 0.51-0.75). However, the hypothetical number needed to treat (the number of women needed to join the low-risk-factor group for a 10-year period to prevent one hypertension case) was similar between the age groups. Conclusion: The fraction of incident hypertension attributable to modifiable lifestyle factors decreases with age. Because the incidence of hypertension is higher in older persons, however, lifestyle modification would hypothetically prevent similar numbers of hypertension cases in younger and older populations. J Am Soc Hypertens 2012;6(4):284-290. (c) 2012 American Society of Hypertension. All rights reserved.