Baseline urine pH is related to effective urine alkalization by short-term alkaline water supplementation: data from a self-controlled study in healthy Chinese volunteers following a systematic review and meta-analysis of literature.

Background: The outcomes of urine alkalization with alkaline water supplementation vary greatly across studies and therefore remain inconclusive, probably arising from differences in study design, ethnic group, and source of alkaline water, which needs further clarification. With a systematic review of literature, followed by an empirical observation among healthy Chinese volunteers, we aimed to investigate the outcomes of urine alkalization with alkaline water vs. daily drinking water, and whether these outcomes are intersected by certain factors such as gender and body mass index (BMI). Methods: We conducted a literature search of related studies on alkaline water supplementation and urine pH using the PubMed, Embase, Medline and Cochrane Library databases. The publication bias was assessed with inverted funnel plotting. Chi-square-based Q-test and I Results: Our systematic review of literature yielded limited data about the effect of alkaline water on urine pH. Despite an increase in urine pH after supplementation of alkaline water as indicated by the random-effect model, a high heterogeneity across the included studies (I Conclusions: Our meta-analysis and human subjects study revealed that alkaline water supplementation may be useful for urine alkalization, particularly in individuals with a lower urine pH. The outcomes seem not significantly pronounced in females, although more efforts warranted for validation. Short-term use of alkaline water is well-tolerated and not associated with over-alkalization of the urine.