Am J Hypertens. 2020 Sep 24:hpaa152. doi: 10.1093/ajh/hpaa152. Online ahead of print.
BACKGROUND: Hypertension has been implicated as a smoking-related risk factor for cardiovascular disease but the dose-response relationship is incompletely described. Hispanics, who often have relatively light smoking exposures, have been understudied in this regard.
METHODS: We used data from a six-year follow up study of US Hispanic adults aged 18 to 76 to address the dose-response linking cigarette use with incident hypertension, which was defined by measured blood pressure above 140 / 90 mmHg or initiation of antihypertensive medications. Adjustment was performed for potential confounders and mediators, including urinary albumin-to-creatinine ratio which worsened over time among smokers.
RESULTS: Current smoking was associated with incident hypertension, with a threshold effect above five cumulative pack-years of smoking (versus never smokers, hazard ratio for hypertension [95% confidence interval] of 0.95 [0.67, 1.35] for 0-5 pack-years, 1.47 [1.05, 2.06] for 5-10 pack years, 1.40 [1.00, 1.96] for 10-20 pack years, and 1.34 [1.09, 1.66] for >= 20 pack-years, P = 0.037). In contrast to current smokers, former smokers did not appear to have increased risk of hypertension, even at the highest cumulative pack years of past exposure.
CONCLUSIONS: The results confirm that smoking constitutes a hypertension risk factor in Hispanic adults. A relatively modest cumulative dose of smoking, above 5 pack-years of exposure, raises risk of hypertension by over 30%. The increased hypertension risk was confined to current smokers, and did not increase further with higher pack-year levels. The lack of a smoking-hypertension association in former smokers underscores the value of smoking cessation.