Medication-Naïve Blood Pressure and Incident Cancers: Analysis of 2 Nationwide Population-Based Databases

BACKGROUND: Results of preceding studies on the relationship between blood pressure (BP) and cancers have been confounded due to individuals taking antihypertensive medications or shared risk factors. We assessed whether medication-naïve high BP is a risk factor for incident cancers. METHODS: This retrospective observational study included 1,388,331 individuals without a prior history of cancer and not taking antihypertensive medications enrolled in the JMDC Claims Database between 2005 and 2018. The primary outcome was 16 cancers. RESULTS: The median [interquartile range] age was 45 [40-52] years and 56.2% were men. Mean systolic BP (SBP) and diastolic BP (DBP) were 117.7 ± 15.8 and 72.8 ± 11.6 mm Hg. Multivariate Cox regression analysis demonstrated that SBP per 1-SD was associated with a higher incidence of thyroid (hazard ratio [HR]: 1.09, 95% confidence interval [CI]: 1.03-1.16), esophageal (HR: 1.15, 95% CI: 1.07-1.24), colorectal (HR: 1.04, 95% CI: 1.01-1.07), liver (HR: 1.11, 95% CI: 1.03-1.20), and kidney (HR: 1.22, 95% CI: 1.14-1.31) cancers, but with a lower incidence of stomach cancer (HR: 0.94, 95% CI: 0.91-0.98). These associations remained significant after adjustment for multiple testing. DBP was associated with higher incidences of thyroid, esophageal, colorectal, kidney, and corpus uteri cancers, but with a lower incidence of stomach cancer. The associations between SBP and incidences of thyroid, esophageal, colorectal, liver, and kidney cancers were confirmed in the Korean National Health Insurance Service database. CONCLUSIONS: Medication-naïve BP was associated with higher incidences of thyroid, esophageal, colorectal, liver, and kidney cancers. Uncovering the underlying mechanisms for our results may help identify novel therapeutic approach for hypertension and cancer.