Hypertension, antihypertensive medication and risk of renal carcinoma in California seventh-day adventists

A longitudinal study of 34 198 non-Hispanic white California Seventh-day Adventists identified incident cases of renal carcinoma over six years of follow-up. The use of antihypertensive medications and self-reported hypertension had estimated age-sex adjusted incidence rate ratios of 4.51 and 2.90 respectively. These were relatively unchanged by stratifying on additional variables that may have been confounders. Cases diagnosed later during the follow-up period had the strongest association with hypertension, making the alternative explanation that the cancer may have caused the hypertension less likely. Being married in 1976 (amongst females at least) was also associated with a marked elevation of risk. Point estimates of effect suggested that frequent (≫3 week) consumption of fruit (RR=0.21) and salad vegetables (RR=0.34) may be protective for this cancer, although the 95% confidence interval did not quite exclude the null value.