Sp050association of Hypertension With the Risk of Kidney Cancer: A Nationwide Population-Based Cohort Study

INTRODUCTION: Hypertension, obesity, smoking, and kidney disease are important risk factors for kidney cancer. However, the association between hypertension and the risk of kidney cancer has not been clearly elucidated in the general population. Thus, we investigated whether hypertension and blood pressure categories are associated with higher kidney cancer risk through a nationwide population-based study. METHODS: Using nationally representative data from the Korean National Health Insurance System, 9,746,445 participants who were free from kidney cancer between 2006 and 2009 were followed up until the end of 2016 to obtain data on cancer incidence. Participants were categorized by blood pressure and antihypertensive medication use as follows: normal (<120/80 mmHg), pre-hypertensive (120–139/80–89 mmHg), and hypertensive (≥140/90 mmHg), with or without antihypertensive medication. Cox proportional hazards models adjusted for age, sex, smoking, alcohol, regular exercise, income, body mass index, and diabetes were used to examine the association between hypertension and blood pressure categories and kidney cancer risk. RESULTS: Kidney cancer was noted in 11,083 (0.11%) of the participants during a medical follow-up duration of 8 years. Hypertension was associated with a higher risk of kidney cancer than was no hypertension (incidence, 30.0 vs 10.8 per 100,000 person-years; adjusted hazard ratio [HR], 1.637; 95% confidence interval, 1.572−1.705). Hypertensive participants taking medication had a higher cancer risk than did those without medication and pre-hypertensive patients (HR, 1.744 vs 1.249 vs 1.109, respectively). However, the risk of kidney cancer increased significantly with higher systolic or diastolic blood pressure in a dose-dependent manner, even after adjustment for antihypertensive medications. CONCLUSIONS: Hypertension was associated with an increased risk of kidney cancer than was normal blood pressure. Higher systolic and diastolic blood pressures were associated with an increased risk of kidney cancer. Screening and prevention of kidney cancer in hypertensive patients should be emphasized.