目的:体重循环在人群中很常见。然而,目前尚不清楚体重循环的频率和幅度是否与肾癌风险相关,与体重指数(BMI)无关。
方法:一项前瞻性队列研究追踪了来自健康专业人员随访研究和护士健康研究(1992-2014)的85,562名参与者。在基线,参与者报告了过去4年中有意减重的频率和幅度.Cox比例风险模型用于估计风险比(HR)和95%置信区间(CI)。我们还对所有可用的观察性研究进行了荟萃分析,包括我们的两个队列。
结果:在22年的随访中,我们确定了441例肾癌病例.与非体重循环器(没有故意减肥的尝试)相比,在体重循环前调整BMI(合并多变量调整HR,1.78;95%CI,1.19,2.66)。体重循环后对达到的BMI的额外调整影响最小。按频率和幅度计算的体重循环与肾癌风险之间存在正趋势(P趋势=0.01)。此外,观察到的正相关并没有因循环者的亚型而异(例如,肥胖状态,减肥方法)。在荟萃分析中,我们发现体重循环与肾癌风险之间存在很强的正相关关系(体重循环者的相对风险与非循环器,1.51;95%CI,1.16,1.96;I2:52.2%;6项研究)。
结论:频繁的体重循环与肾癌风险增加有关,与BMI无关。我们的研究表明,体重循环可能是肾癌的重要危险因素。
OBJECTIVE: Weight cycling is common in populations. However, it is unclear whether frequency and magnitude of weight cycling is associated with kidney cancer risk, independent of body mass index (BMI).
METHODS: A prospective cohort
study followed 85,562 participants from Health Professionals Follow-up
Study and Nurses\' Health
Study (1992-2014). At baseline, participants reported frequency and magnitude of intentional weight loss in the past 4 years. Cox proportional hazard model was used to estimate hazard ratios (HR) and 95% confidence intervals (CI). We also conducted a meta-analysis of all available observational studies including our two cohorts.
RESULTS: During 22 years of follow-up, we identified 441 kidney cancer cases. Compared with non-weight cyclers (no attempt of intentional weight loss), severe cyclers (≥ 3 times of intentional weight loss of ≥ 4.5 kg) were at increased kidney cancer risk after adjusting for BMI before weight cycling (pooled multivariable-adjusted HR, 1.78; 95% CI, 1.19, 2.66). Additional adjustment for attained BMI after weight cycling had minimal influence. There was a positive trend between weight cycling by frequency and magnitude and kidney cancer risk (P-trend = 0.01). Moreover, the observed positive association did not differ by subtypes of cyclers (e.g., adiposity status, weight-loss methods). In the meta-analysis, we found a strong positive association between weight cycling and kidney cancer risk (summary relative risk for weight cyclers vs. non-cyclers, 1.51; 95% CI, 1.16, 1.96; I2: 52.2%; 6 studies).
CONCLUSIONS: Frequent substantial weight cycling was associated with increased risk of kidney cancer, independent of BMI. Our
study suggests that weight cycling may be an important risk factor for kidney cancer.