Association of serum osmolality levels with all-cause mortality risk in patients with DKA

The purpose of this study was to investigate the relationship. between serum osmolality levels and 28-day mortality in patients with DKA. Data for this observational cohort study were obtained from the MIMIC-IV3.0 database. The participants were divided into five groups based on the serum osmolality quintiles. The primary outcome was 28-day mortality. We employed Cox proportional hazards regression analysis and threshold effect analysis to assess. the relationship between serum osmolality levels and 28-day mortality in patients with DKA. The study included 1026 patients; the mean age was 52 years, 55.0% were male. Our findings indicate that serum osmolality is associated with an increased risk of 28-day mortality, exhibiting a U-shaped relationship. Altered serum osmolality levels, whether lower or higher, are linked to a heightened risk of mortality. When osmolality < 306.8 mOsm/kg, the 28-day mortality risk decreased by 6.2% (HR 0.938, 95% CI 0.912-0.964) for every 1 mOsm/kg increase. At osmolality ≥ 306.8 mOsm/kg, there was a 3.7% (HR 1.037, 95% CI 1.030-1.045) increase in the 28-day mortality risk for every 1 mOsm/kg increase in osmolality. The risk of mortality was lower at osmolality of 284-299 mOsm/kg. A U-shaped correlation between initial serum osmolality and 28-. days all-cause mortality in patients with DKA was identified. These results underscore. serum osmolality's critical role in early mortality among patients with DKA.