Introduction
metabolic and respiratory acid, Type 2 diabetes, CKD, diabetes
DIABETES, TYPE 2 DIABETES, TYPE 2 DIABETES, DIABETES
The serum bicarbonate concentration is a commonly measured surrogate marker of acid–base status in hospitalised and community-based patients. It is well recognised that both metabolic and respiratory acid–base derangements can affect the serum bicarbonate concentration and this complicates its clinical interpretation. Nevertheless, recent studies have identified serum bicarbonate as a marker of mortality risk that is independent of other predictive variables. There is evidence that a low serum bicarbonate concentration is independently associated with all-cause mortality in representative community-based individuals [Whether a low serum bicarbonate is an independent mortality risk factor among people with type 2 diabetes is uncertain. Type 2 diabetes is associated with an increased risk of CKD [Apparent discrepancies between studies and across patient groups may reflect differences in selection criteria, sample sizes and thus statistical power, and/or availability of clinically important covariates which may include the existence of other, more potent, mortality risk factors in people with diabetes. The aim of the present study was, therefore, to examine whether all-cause mortality is independently associated with serum bicarbonate concentration below the reference interval in a representative, well-characterised cohort of people with type 2 diabetes from the Fremantle Diabetes Study Phase II (FDS2). We also aimed to determine whether there are covariates of serum bicarbonate that modulate its relationship with mortality and help explain inconsistencies between previous published studies.