To identify the prevalence of tight glycaemic control in elderly patients with type 2 diabetes mellitus and characterise the population at risk for hypoglycaemia.
A retrospective observational study was performed over 6 months, January to June 2015 at Acute Medical Unit, Princess Alexandra Hospital. Chart review of diabetic patients over the age of 65 was performed to compare the demographics of patients with poor glycaemic control and /or hypoglycaemia with those having adequate control.
A total of 294 patients were reviewed with male:female ratio of nearly 1:1 and mean age of 77 years. Nearly 60% were on hypoglycaemic agents and one-fourth on insulin. Around one-fourth had very tight glycaemic control with HbA1c of <6.5%. In all, 42 patients had in-hospital hypoglycaemia. Half of these patients did not have their diabetic medication reviewed and nearly one-fourth died within 12 months.
Patient characteristics were analysed using Pearson’s chi-square. In-patient documented hypoglycaemia (BSL<4mmol/L) was more likely to be associated with increasing burden of co-morbidities (p=0.002), chronic kidney disease (p=0.029), microvascular complications (p=0.02) and recurrent hospital admissions (p=0.037). There was a three-fold increased risk of mortality in this group (p=0.005, OR 3.05, CI 1.36-6.80). Increasing age had more stringent BSL control and higher usage of sulfonylureas +/- insulin which may prove to be counterproductive (p=0.006, p=0.046). Surprisingly, HbA1c was not a good predictor of hypoglycaemia and complications in this cohort. Patients on sulfonylureas and insulin were approximately twice as likely to develop hypoglycaemia (p<0.001). Multiple logistic regression was performed to develop a predictive scoring system for in-patient hypoglycaemia.
Overtreatment of type 2 diabetes mellitus in elderly patients is prevalent and less recognised as well as under-reported resulting in frailty, disability and poor outcomes. A conservative approach to glycaemic targets in frail older people may be worthwhile.