J Glob Health. 2023 Oct 20;13:04094. doi: 10.7189/jogh.13.04094.
The association between tea consumption and chronic kidney disease (CKD) remained inconsistent. We aimed to evaluate the association of tea consumption with new-onset CKD and examine the effects of common additives (milk and sweeteners) and genetic variations in caffeine metabolism on the association.
176 038 and 3104 participants free of CKD at baseline in the United Kingdom Biobank (UK Biobank) and Coronary Artery Risk Development in Young Adults (CARDIA) study were included, respectively. Dietary information was collected using 24-hour dietary recall questionnaires. The study outcome was new-onset CKD.
In the UK Biobank, during a median follow-up of 12.13 years, 3535 (2.01%) participants developed CKD. Compared with tea non-consumers, the risk of new-onset CKD was significantly lower in unsweetened tea consumers (hazard ratio (HR) = 0.84, 95% confidence interval (CI) = 0.76-0.93), but not in sweetened tea consumers (HR = 0.96, 95% CI = 0.85-1.08), regardless of whether milk was added to tea. Accordingly, relative to tea non-consumers, the adjusted HRs (95% CIs) of new-onset CKD for participants who reported drinking unsweetened tea 1.5 or fewer, >1.5 to 2.5, >2.5 to 3.5, >3.5 to 4.5, and >4.5 drinks/d were HR = 0.86, 95% CI = 0.75-0.99; HR = 0.88, 95% CI = 0.78-1.00; HR = 0.83, 95% CI = 0.73-0.94; HR = 0.83, 95% CI = 0.72-0.95; and HR = 0.86, 95% CI = 0.75-0.99. Moreover, the association of unsweetened tea consumption with new-onset CKD was stronger among those with faster genetically predicted caffeine metabolism levels, although the interaction was insignificant (P-value interaction = 0.768). Consistently, in the CARDIA study, compared with tea non-consumers, a significantly lower risk of new-onset CKD was found in unsweetened tea consumers (HR = 0.80, 95% CI = 0.65-0.98) but not in sweetened tea consumers (HR = 0.97, 95% CI = 0.70-1.34).
Compared with tea non-consumers, consumption of unsweetened tea, but not sweetened tea, was significantly associated with a lower risk of new-onset CKD, regardless of whether milk was added.
饮茶与慢性肾脏病（CKD）之间的关联仍不一致。我们旨在评估饮茶与新发 CKD 的关联，并研究常见添加剂（牛奶和甜味剂）和咖啡因代谢的遗传变异对该关联的影响。
英国生物库（UK Biobank）和冠状动脉风险发展在年轻人（CARDIA）研究中分别纳入了 176038 名和 3104 名基线时无 CKD 的参与者。使用 24 小时膳食回忆问卷收集饮食信息。研究结局为新发 CKD。
在 UK Biobank 中，中位随访 12.13 年后，3535 名（2.01%）参与者发生 CKD。与不饮茶者相比，不添加甜味剂的茶饮用者新发 CKD 的风险显著降低（风险比（HR）=0.84，95%置信区间（CI）=0.76-0.93），但添加甜味剂的茶饮用者（HR=0.96，95%CI=0.85-1.08）并非如此，无论是否添加牛奶。相应地，与不饮茶者相比，报告饮用不添加甜味剂的茶 1.5 杯或更少、>1.5 至 2.5 杯、>2.5 至 3.5 杯、>3.5 至 4.5 杯和>4.5 杯/天的参与者新发 CKD 的调整 HR（95%CI）分别为 HR=0.86，95%CI=0.75-0.99；HR=0.88，95%CI=0.78-1.00；HR=0.83，95%CI=0.73-0.94；HR=0.83，95%CI=0.72-0.95；和 HR=0.86，95%CI=0.75-0.99。此外，尽管交互作用无统计学意义（P 值交互作用=0.768），但在咖啡因代谢水平预测较快的人群中，不添加甜味剂的茶饮用与新发 CKD 的关联更强。同样，在 CARDIA 研究中，与不饮茶者相比，不添加甜味剂的茶饮用者新发 CKD 的风险显著降低（HR=0.80，95%CI=0.65-0.98），而添加甜味剂的茶饮用者（HR=0.97，95%CI=0.70-1.34）则不然。
与不饮茶者相比，无论是否添加牛奶，饮用不添加甜味剂的茶与新发 CKD 的风险降低显著相关，但饮用添加甜味剂的茶则不然。
