Relationship Between Cotinine-Verified Smoking Status and Incidence of Hypertension in 74,743 Korean Adults

Abstract

Background:The relationship between chronic smoking and hypertension (HTN) is inconclusive in previous studies, which were mainly based on self-reported smoking status. The aim of this study was to evaluate the association of cotinine-verified smoking status with incident HTN. Methods and Results:A total of 74,743 participants (43,104 men; age 38±5.4 years) were included in the study, with a mean follow-up period of 29 months. Individuals were divided into 4 groups on the basis of their cotinine-verified smoking status at baseline and at follow-up (never-smoking, new-smoking, former-smoking, and sustained-smoking). The incidence rate of HTN in the never-smoking, new-smoking, former-smoking, and sustained-smoking groups was 8.2%, 7.6%, 10.1%, and 8.7% for men and 1.8%, 2.5%, 1.5%, and 2.2% for women, respectively. In a multivariate Cox-hazard regression analysis adjusted for the variables with a univariate relationship, new-smoking and sustained-smoking had decreased relative risks (RRs) for incident HTN compared with never-smoking (RR [95% CI], 0.75 [0.58, 0.96] for new-smoking and 0.82 [0.74, 0.90] for sustained-smoking). Cotinine-verified current smoking at baseline was also inversely associated with incident HTN compared with cotinine-verified never-smoking at baseline (0.91 [0.84, 0.98]). These results remained significant only in men, although there was no sex interaction. Conclusions:This longitudinal study showed that cotinine-verified new-smoking and sustained-smoking decreased the risk for incident HTN, especially in men, compared with never-smoking.

Association of self‐reported and cotinine‐verified smoking status with incidence of metabolic syndrome in 47 379 Korean adults

“…According to the Society for Research on Nicotine and Tobacco (SRNT) 2002 recommendations, a urine cotinine cut‐off value of 50 ng/mL was used to distinguish smokers and non‐smokers . In a previous study, a cut‐off value of 50 ng/mL provided high sensitivity (84.8%) and specificity (98.2%) for distinguishing current from never smokers . Cotinine‐verified never smoking was defined as urinary cotinine concentrations <50 ng/mL, whereas cotinine‐verified current smoking was defined as urinary cotinine concentration ≥ 50 ng/mL.…”

“…The procedures for the anthropometric and laboratory measurements were the same as those described previously . Urine samples were collected from participants after they had stopped smoking for at least 10 hours.…”

“…The procedures for the anthropometric and laboratory measurements were the same as those described previously. [17][18][19] Urine samples were collected from participants after they had stopped smoking for at least 10 hours. Urinary cotinine concentration was measured with DRI Cotinine Assay (Microgenics, Fremont, California) using a modular P800 (Roche Diagnostics, Tokyo, Japan).…”

“…20 In a previous study, a cut-off value of 50 ng/mL provided high sensitivity (84.8%) and specificity (98.2%) for distinguishing current from never smokers. 19 Cotinine-verified never smoking was defined as urinary cotinine concentrations <50 ng/mL, whereas cotinine- verified current smoking was defined as urinary cotinine concentration ≥ 50 ng/mL. As reported previously, 19 individuals were divided into four groups based on cotinine-verified smoking status at baseline and follow-up: never smoking, new smoking, former smoking, and sustained smoking.…”

“…19 Cotinine-verified never smoking was defined as urinary cotinine concentrations <50 ng/mL, whereas cotinine- verified current smoking was defined as urinary cotinine concentration ≥ 50 ng/mL. As reported previously, 19 individuals were divided into four groups based on cotinine-verified smoking status at baseline and follow-up: never smoking, new smoking, former smoking, and sustained smoking. In addition, individuals were divided into four categories based on self-reported smoking status at baseline and follow-up, namely never smoking (no smoking at baseline and follow-up), new smoking (no smoking at baseline but smoking at follow-up), former smoking (smoking at baseline but having quit smoking by follow-up), and sustained smoking (smoking continuously at baseline and follow-up).…”