Do high blood pressure and obesity contribute to kidney cancer?

This study investigated the impact of high blood pressure and obesity on the occurrence of kidney cancer.

The occurrence of kidney cancer is increasing globally among all age groups and races. Risk factors for kidney cancer include high blood pressure (hypertension), increased body weight and smoking. High blood pressure alone has been found to increase the risk for kidney cancer, and excess body weight is estimated to account for >25% of US kidney cancer cases.

Blood pressure may rise when there is a buildup of fatty deposits in the blood vessels and the heart is required to pump harder in order to allow blood to flow. However, few studies have examined the effect that both obesity and hypertension have together as risk factors for kidney cancer. 

This study examined the effect of hypertension and obesity as risk factors for kidney cancer both separately and together over 10.8 years among 156,774 racially diverse female participants. They also examined the effect of blood pressure on kidney cancer deaths for over 25 years among 353,340 men.

In the female study, systolic blood pressue (SBP) was measured. Systolic blood pressure is a measure of pressure in the arteries when the heart is beating, normally around 120 mmHg. SBP was categorized into 6 groups from <120 to >160 mmHg. Body mass index was also recorded as a measure of obesity for each participant. The study found that high SBP and large body mass index significantly increased the risk of kidney cancer.

In the male study, there were 906 deaths caused by kidey cancer after an average of 25 years among men, aged 35-57 years at screening. The study found that the risk of death from kidney cancer increased with increasing SBP with those who had a SBP of >160 mmHg being nearly twice as likely to develop kidney cancer compared with those who had a normals blood pressure of <120 mmHg. Risk of kidney cancer was also increased among cigarette smokers. 

This study suggested that both obesity and high blood pressure increase the risk of developing kidney cancer. Therefore, loosing excess weight and maintaing normal blood pressure may help prevent kidney cancer.  

Even though these studies had a long duration of 10-25 years, cancer may not develop until after this time. Therefore the effect of obesity and high blood pressure on kidney cancer may be even more significant than as shown in this study. 

If you or someone you know are obese or have high blood pressure, talk to a doctor about ways to lose weight and reduce blood pressure so as to reduce the risk of developing kidney cancer.