OBJECTIVE To investigate the prevalence of plasma vitamin B1 deficiency in patients with sepsis and analyze the relationship between plasma vitamin B1 levels and lactic acidosis.

METHODS A total of 40 patients with sepsis and 42 patients with sepsis shock admitted to the intensive care unit (ICU) of General Hospital of Ningxia Medical University from Nov. 2020 to Nov. 2022 were selected as the study objects. Volunteers matched by age, gender and body mass index (BMI) were selected as the healthy group. Data on gender, age, BMI, underlying diseases, sequential organ failure assessment (SOFA) score, acute physiology and chronic health evaluation (APACHE) Ⅱ score, infection site, duration of mechanical ventilation and ICU length of stay were collected. Laboratory tests including blood routine, electrolytes, blood lactate (Lac), alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood urea nitrogen (BUN) and serum creatinine (Scr) were performed in both groups. Plasma samples from both disease group and the healthy group were collected. High-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was used to measure plasma thiamine (vitamin B1) levels in the disease group on the first, third and fifth days, respectively, as well as in the healthy group.

RESULTS On the first day of admission, both the sepsis group and the septic shock group exhibited vitamin B1 deficiency. Specifically, 6 cases of vitamin B1 deficiency were observed in the patients with sepsis, while 8 cases of vitamin B1 deficiency were noted in the patients with septic shock (P=0.640). By the third and fifth days, the proportions of vitamin B1 deficiency in the sepsis group were 22.50% and 42.50%, respectively, whereas in the septic shock group, these proportions were high at 26.19% and 54.76%, with a statistically significant difference (P < 0.05). On the fifth day, in the normal liver function group, vitamin B1 levels showed a negative correlation with lactate (r =-0.590, P=0.005), whereas in the abnormal liver function group, vitamin B1 levels were positively correlated with lactate (r =0.678, P=0.017). The patients in the septic shock group had low K⁺ and ALB levels (2.60±0.42) mmol/L and (24.56±5.78) g/L, respectivelycompared to those in the sepsis group (P < 0.05).

CONCLUSIONS Plasma vitamin B1 deficiency is prevalent among patients with sepsis. Changes in plasma vitamin B1 levels are closely associated with blood lactate levels in these patients.