Renal Tubular Epithelial Subnuclear Vacuolization in Hypothermia and Diabetic Ketoacidosis—A Retrospective Autopsy Study

Abstract

Subnuclear vacuolization of the renal tubular epithelium refers to discrete lipid vacuoles displacing the nuclei toward the lumen. This phenomenon has been associated with conditions sharing fatal ketoacidosis as a common denominator. This retrospective study aimed to investigate renal tubular epithelial subnuclear vacuolization and other postmortem examination findings in fatal hypothermia and diabetic ketoacidosis (DKA) cases.Fourteen cases with hypothermia and 19 cases with DKA were included. More cases with DKA had focal or diffuse subnuclear vacuolization compared with hypothermia cases (89% vs 43%; P = 0.007). In 6 cases with DKA, formalin pigment was detected within subnuclear vacuoles, whereas no case with hypothermia had formalin pigment deposition. Comparative analyses of hypothermia and DKA cases revealed further differences: Vitreous beta-hydroxybutyrate was higher in the DKA group compared with the hypothermia group (P = 0.044), whereas blood ethanol concentrations were higher in the latter (P = 0.008). Hypothermia cases were older compared with the DKA cases (P = 0.022).When all cases were included in the statistical analysis, cases with subnuclear vacuolization had higher vitreous beta-hydroxybutyrate and blood ethanol concentrations (P = 0.029 and 0.023, respectively). The findings corroborate the results of previous studies suggesting a link between subnuclear vacuolization and increased levels of ketoacidosis.