Could a quick insulin shot stop Steroid-Induced blood sugar spikes?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Age 40 to 80 years at consent. * Documented diagnosis of type 2 diabetes for at least 6 months. * HbA1c from 6.5% through 9.0% measured within 30 days before randomisation. * Symptomatic osteoarthritis of one knee for which the treating clinician has independently determined that an intra-articular corticosteroid injection is clinically indicated. * Planned administration of one intra-articular injection of triamcinolone acetonide crystalline suspension 40 mg into the index knee. * Diabetes managed without insulin, sulfonylureas or meglitinides. * Permitted glucose-lowering medications at stable doses for at least 30 days before randomisation. * Estimated glomerular filtration rate at least 45 mL/min/1.73 m² within 60 days before randomisation. * Capillary glucose from 90 through 250 mg/dL immediately before the injection. * Ability and willingness to perform scheduled capillary glucose testing, administer or receive subcutaneous insulin if assigned, follow hypoglycaemia instructions and remain contactable through day 7. * Ability to wear the study continuous glucose monitoring device and provide informed consent. Exclusion Criteria: * Type 1 diabetes, latent autoimmune diabetes in adults, pancreatogenic diabetes or another specific diabetes type requiring insulin. * Current basal, prandial, premixed or pump insulin treatment. * Current sulfonylurea or meglitinide treatment. * HbA1c below 6.5% or above 9.0%. * Capillary glucose below 90 mg/dL or above 250 mg/dL immediately before injection. * Fasting glucose above 250 mg/dL, random glucose above 300 mg/dL, clinically significant ketonaemia or hyperglycaemia requiring immediate treatment during screening. * Estimated glomerular filtration rate below 45 mL/min/1.73 m². * Severe hepatic impairment or another condition expected to materially alter insulin clearance or hypoglycaemia risk. * Level 3 hypoglycaemia requiring third-party assistance during the previous 6 months. * Documented impaired awareness of hypoglycaemia. * Pregnancy, planned pregnancy during study participation or breastfeeding. * Oral, intravenous or intramuscular corticosteroid use within 30 days before the study injection. * Any intra-articular, epidural, periarticular or soft-tissue corticosteroid injection within 30 days before the study injection. * Planned additional systemic or injected corticosteroid exposure before the day-7 assessment. * Acute febrile illness, active systemic infection or acute deterioration in health at screening or injection. * Suspected septic arthritis, infection over the injection site, prosthetic index knee, uncontrolled bleeding disorder or another contraindication to knee injection. * Known allergy or clinically significant hypersensitivity to triamcinolone acetonide, human NPH insulin, insulin aspart, protamine, lidocaine or required excipients. * Known allergy to continuous glucose monitoring adhesive or a skin condition preventing sensor use. * Cognitive, visual, physical or social limitation that would prevent safe glucose testing, insulin administration, hypoglycaemia treatment or study contact. * Participation in another interventional study likely to affect glucose or corticosteroid response. * Any condition that, in the investigator's documented judgement, makes participation unsafe for a reason not otherwise captured above.