Introduction:
Nearly half of all smokers are hypertensive based on new guidelines issued in 2017. The objective of this study is to assess the excess risk and shortened life expectancy of smokers with 1) elevated blood pressure (120-129/<80), 2) stage 1 hypertension (130-139/80-89), and 3) stage 2 hypertension (≧140/≧90) compared to non-smokers with normal blood pressure <120/80 mmHg.

Methods:
A cohort, consisting of 422,771 adults, was recruited successively during routine health surveillance visits between 1996 and 2008 in Taiwan. Lifestyle information indicated on a questionnaire and results from fasting blood and other screening tests, including blood pressure measured while sitting, were repeatedly collected. Hazard ratios (HRs) were determined by the Cox regression method, and life expectancy was determined using the life table method.

Results:
One-quarter of the cohort participants were current smokers. Nearly half of the smokers (48%) were classified as hypertensive, with 14% having elevated blood pressure, 19% stage 1 and 16% stage 2 hypertension. The HR for cardiovascular disease (CVD) mortality was 1.41 for smokers with normal blood pressure, 1.45 for smokers with elevated blood pressure, 2.11 for smokers with stage 1 hypertension, and 4.92 for smokers with stage 2 hypertension, representing an average threefold increase compared to non-smokers with normal blood pressure. The HR for heart disease mortality was 1.43 for smokers with elevated blood pressure, 1.85 for smokers with stage 1 hypertension, and 3.56 for smokers with stage 2 hypertension. The HR for stroke mortality was 1.54 for smokers with elevated blood pressure, 2.98 for smokers with stage 1 hypertension, and 8.82 for smokers with stage 2 hypertension, representing a five-fold increase. Smoking shortened the life span by six years, and stage 2 hypertension shortened it by four years, representing a combined loss of life of 10 years. Elevated blood pressure alone did not increase mortality, when compared with normotensive (non)smokers (normal subjects).

Conclusions:
Smokers with hypertension have a three- to five-fold increase in CVD mortality, including mortality due to heart diseases and stroke. Life span shortened by five to six years for smokers and by 10 years for hypertensive smokers. Unfortunately, most smokers were unaware of their hypertension status, which could triple or quintuple their CVD mortality risks.