Insulin response
As previously outlined in Ranawana and Henry [13] and then
in Ranawana et al [14], blood samples for insulin determination
were obtained at the times mentioned above for GR. Using
finger-prick samples, 300 μL of capillary blood was collected at
each time point into Microvette collection tubes treated with
dipotassium EDTA (CB 300 K2E; Sarstedt Ltd, Leicester, UK) and
immediately stored in crushed ice. Microvette tubes were
centrifuged at 4000 rpm for 10 minutes (Centrifuge MC-6;
Sarstedt Ltd), and 120 μL of the supernatant plasma was
pipetted into Eppendorf tubes and frozen at −40°C. Upon
analysis, samples were defrosted and insulin concentrations
were determined by electrochemiluminescence immunoassay
using a reliable automated analyser (Cobas E411; Roche
Diagnostics, Burgess Hill, UK [15]. The unit of measurement
was μU/mL.