Perioperative glycaemic profiles in Aboriginal and Torres Strait Islander people with diabetes mellitus

AIMS: Diabetes mellitus is associated with perioperative dysglycaemia and post-operative complications. Aboriginal and Torres Strait Islander people have higher rates of diabetes mellitus and post-operative complications than non-Indigenous Australians, yet data on their perioperative glycaemic profiles are lacking. The aim of this study was therefore to comprehensively describe perioperative glycaemic profiles in Aboriginal and Torres Strait Islander people with diabetes mellitus. METHODS: We conducted a retrospective multicentre cohort study of 16,396 adults with diabetes mellitus undergoing surgery in South Australia (2018-2023). Patient demographics, comorbidities, anti-hyperglycaemic agents, glycated haemoglobin (HbA1c) levels, and perioperative blood glucose levels (BGL) were compared between Aboriginal and Torres Strait Islander people and non-Indigenous Australians using chi-squared tests for categorical data, and non-parametric tests for numerical data. RESULTS: Aboriginal and Torres Strait Islander people (n = 1065, 6.5% of the cohort) were younger (54.3 vs. 68.2 years, p < 0.001), more likely to be female (52.1% vs. 41.6%, p < 0.001), and experienced greater preoperative comorbidity (coronary artery disease: 26.8% vs. 14.8%, p < 0.001) (chronic kidney disease: 21.9% vs. 15.2%, p < 0.001) than non-Indigenous Australians. Although their pre-admission HbA1c was higher (68.5 mmol/L (8.4%) vs. 62.1 mmol/mol (7.8%), p < 0.001), their perioperative patient-day mean BGL (8.7 vs. 8.8 mmol/L, p = 0.032), glycaemic variability (coefficient of variation: 21.3% vs. 21.6%, p = 0.045) and perioperative glycaemic ratios (1.24 vs. 1.28, p = 0.382) were similar. However, higher rates of hypoglycaemia were observed amongst Aboriginal and Torres Strait Islander people (14.6% vs. 10.3%, p < 0.001), coinciding with greater inpatient use of sulphonylureas and insulin. CONCLUSIONS: Despite being 14 years younger and having greater preoperative comorbidity and higher HbA1c levels, Aboriginal and Torres Strait Islander people demonstrated higher rates of perioperative hypoglycaemia, but otherwise broadly comparable perioperative glycaemic profiles to their non-Indigenous Australian counterparts. Further research should ideally be Indigenous-led, and prospectively evaluate interventions to both reduce cumulative glycaemic burden and optimise perioperative glycaemia using modern diabetes technologies in Aboriginal and Torres Strait Islander people both with and without diabetes mellitus.