Department of Clinical Sciences in Lund, Lund University, Lund, Sweden.
Department of Biobank Research, Umeå University, Umeå, Sweden.
Cancer Med. 2021 Feb;10(4):1431-1438. doi: 10.1002/cam4.3721. Epub 2021 Jan 16.
The relation between obesity, blood pressure (BP) and bladder cancer (BC) risk and mortality remains unclear, partially due to potential confounding by smoking, the strongest risk factor for BC, and not accounting for tumor stage and grade in such studies. We investigated body mass index (BMI) and BP in relation to BC risk by stage and grade, and BC-specific mortality, including separately among never-smokers aimed at minimizing confounding by smoking.
We analyzed 338,910 men from three Swedish cohorts, with 4895 incident BC's (940 among never-smokers) during follow-up. Cox regression was used to calculate hazard ratios (HR) and 95% confidence intervals adjusted for smoking status. HRs for BMI and BP were corrected for their regression dilution ratios, calculated from 280,456 individuals with 758,641 observations.
Body mass index was positively associated with non-muscle invasive BC (NMIBC, HR per 5 kg/m , 1.10 [1.02-1.19]) and NMIBC grade 3 (HR 1.17 [1.01-1.34]) in the full cohort, with similar effect sizes, albeit non-significant, among never-smokers. Systolic BP was positively associated with muscle-invasive BC (MIBC, HR per 10 mmHg, 1.25 [1.00-1.55]) and BC-specific mortality (HR 1.10 [1.01-1.20]) among never-smokers, with weaker and non-significant associations in the full cohort.
In an analyses of BMI, BP and BC risk by stage and grade among men, we found modest positive associations between BMI and NMIBC and NMIBC grade 3. SBP was positively associated with MIBC and BC-specific mortality in an analysis of never-smokers, which may reflect the association, un-confounded by smoking, also in a broader population.
肥胖、血压（BP）与膀胱癌（BC）风险和死亡率之间的关系仍不清楚，部分原因是由于吸烟的潜在混杂作用，吸烟是 BC 的最强危险因素，并且在这些研究中没有考虑肿瘤分期和分级。我们通过分期和分级研究了 BMI 和 BP 与 BC 风险的关系，以及 BC 特异性死亡率，包括针对从不吸烟者进行的单独分析，旨在最大限度地减少吸烟的混杂作用。
我们分析了来自三个瑞典队列的 338910 名男性，在随访期间有 4895 例膀胱癌（从不吸烟者中有 940 例）。使用 Cox 回归计算危险比（HR）和 95%置信区间，调整了吸烟状况。BMI 和 BP 的 HR 校正了其回归稀释比，从 280456 名个体的 758641 个观察值中计算得出。
在全队列中，BMI 与非肌肉浸润性膀胱癌（NMIBC，每 5kg/m ，HR1.10[1.02-1.19]）和 NMIBC 3 级（HR1.17[1.01-1.34]）呈正相关，且从不吸烟者的作用大小相似，尽管无统计学意义。在从不吸烟者中，收缩压与肌肉浸润性膀胱癌（MIBC，每 10mmHg，HR1.25[1.00-1.55]）和 BC 特异性死亡率（HR1.10[1.01-1.20]）呈正相关，而在全队列中关联较弱且无统计学意义。
在一项针对男性 BMI、BP 和 BC 风险的分期和分级分析中，我们发现 BMI 与 NMIBC 和 NMIBC 3 级之间存在适度的正相关。SBP 与 MIBC 和 BC 特异性死亡率在从不吸烟者的分析中呈正相关，这可能反映了在更广泛人群中不受吸烟混杂作用影响的关联。
