Effect of vitamin B1 supplementation on blood creatinine and lactate levels and clinical outcomes in patients in intensive care units: a systematic review and meta-analysis of randomized controlled trials.

CONTEXT: The metabolic response to stress can deplete the remaining thiamine stores, leading to thiamine deficiency. OBJECTIVE: This study is the first meta-analysis of the effectiveness of thiamine supplementation on clinical and biochemical outcomes in adult patients admitted to the intensive care unit (ICU). DATA SOURCES: Scopus, PubMed, and Cochrane databases were searched to select studies up to 20 November 2022. STUDY SELECTION: Studies investigating the effect of thiamine supplementation on serum lactate and creatinine levels, the need for renal replacement therapy, length of ICU stay, and mortality rate in ICU patients were selected. DATA EXTRACTION: After excluding studies based on title and abstract screening, 2 independent investigators reviewed the full texts of the remaining articles. In the next step, a third investigator resolved any discrepancy in the article selection process. RESULTS: Of 1628 retrieved articles, 8 were selected for final analysis. This study showed that thiamine supplementation reduced the serum creatinine level (P = .03) compared with placebo. In addition, according to subgroup analysis, serum creatinine concentration was significantly lower in patients >60 years old (P < .00001). However, there was no statistically significant difference in the lactate level between the thiamine supplementation and placebo groups (P = .26). Thiamine supplementation did not decrease the risk of all-cause mortality (P = .71) or the need for renal replacement therapy (P = .14). The pooled results of eligible randomized controlled trials also showed that thiamine supplementation did not reduce the length of ICU stay in comparison to the placebo group (P = .39). CONCLUSION: This meta-analysis provides evidence that thiamine supplementation has a protective effect against blood creatinine increase in ICU patients. However, further high-quality trials are needed to discover the effect of thiamine supplementation on clinical and biochemical outcomes in ICU patients. SYSTEMATIC REVIEW REGISTRATION: PROSPERO no. CRD42023399710 (https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=399710).