The aim of this study is to investigate the relationships between hypertension, hypertension medication and bladder cancer risk in a population-based case-control study conducted in Los Angeles. Non-Asians between the ages of 25 and 64 years with histologically confirmed bladder cancers diagnosed between 1987 and 1996 were identified through the Los Angeles County Cancer Surveillance Program. A total of 1,585 cases and their age-, gender-, and race-matched neighborhood controls were included in the analyses. Conditional logistic regression models were used to examine the relationship between history of hypertension, medication use, and bladder cancer risk. A history of hypertension was not related to bladder cancer; however, among hypertensive individuals, there was a significant difference in bladder cancer risk related to the use of diuretics or antihypertensive drugs (P for heterogeneity =0.004). Compared with individuals without hypertension, hypertensive individuals who regularly used diuretics/antihypertensives had a similar risk (odds ratio - OR, 1.06; 95% confidence interval -CI, 0.86-1.30), while untreated hypertensive subjects had a 35% reduction in risk (OR, 0.65; 95% CI, 0.48-0.88). A greater reduction in bladder cancer risk was observed among current smokers (OR, 0.43; 95% CI, 0.27-0.71) and carriers of GSTM1 null (homozygous absence) genotypes (OR, 0.43; 95% CI, 0.22-0.85). Similarly, among smokers with GSTM1 null genotype, levels of 4-aminobiphenyl-hemoglobin adducts were significantly lower among untreated hypertensive individuals (45.7 pg/g Hb) compared to individuals without hypertension (79.8 pg/g Hb) (P = 0.009). In conclusion, untreated hypertension was associated with a reduced risk of bladder cancer.

PMID: 20732908 [PubMed - as supplied by publisher] Source: National Library of Medicine.