Researchers call for routine testing of blood glucose in elderly
Researchers have discovered a strong link between high, undiagnosed blood glucose in non-diabetic patients and increased hospital death rates in a study of patients in Spain and Italy. Presented in the International Journal of Clinical Practice (IJCP), the findings suggest that blood glucose levels in hospitalised elderly patients should be tested routinely. Routine testing would allow high-risk patients to be identified and given intensive therapy to reduce their risk of death.
After examining 808 hospitalised elderly patients, researchers found that 25% of the undiagnosed diabetic patients had high blood glucose levels. The Spanish team looked at 447 patients admitted to a geriatric unit, while the Italian team studied 361 patients aged over 60 who were admitted to an internal medicine department. They discovered that when they excluded the 206 patients already diagnosed with diabetes, a quarter of the remaining 602 patients had a fasting glucose level of 126 milligrams per decilitre (mg/dl) or more, which is the threshold used to diagnose the disease; just under a fifth of them had levels exceeding 180 mg/dl.
Mortality rates in patients with a fasting glucose level of less than 126 mg/dl was just over 8% for the total sample and the patients admitted without a diagnosis of diabetes. But when the researchers looked at the undiagnosed patients whose fasting glucose levels were 126 mg/dl to 180mg/dl, the death rate rose to 18% and, in patients whose levels exceeded 180mg/dl, the rate increased to 31%. These levels were much higher than the 14% and 23% for diabetic patients with fasting glucose levels exceeding 126 mg/dl and 180 mg/dl respectively.
'Our study shows a high mortality rate and short hospital survival in non-diabetic elderly patients with a high baseline fasting glucose level of more than 180 mg/dl,' says co-author Professor Fabio Monzani from the Department of Internal Medicine at the University of Pisa in Italy. He points out that the study 'underlined the importance of testing elderly patients for fasting glucose levels on admission to hospital for acute illnesses and suggested that a blood glucose level of 180 mg/dl or less might be an appropriate target in people who have not been diagnosed with diabetes'.
Professor Monzani says the findings 'should help us to identify those patients at high risk during hospitalisation, so that they can be offered intensive therapy to reduce their risk of death and improve their prognosis'.
The average age of the total cohort was 84 years and 57% were female. Although there were significant variations between the reasons why patients has been admitted to hospital in the two cohorts, the five most common reasons for hospital admission were the same in both the Spanish and Italian groups. These were congestive heart failure (19%), respiratory tract infection (12.5%), acute cerebrovascular disease (12%), exacerbation of chronic obstructive pulmonary disease (9%) and cancer (8%).
Meanwhile, hospital stays averaged 10.5 days for the total cohort and the average time from admission to death was 11.3 days. The Italian internal medicine cohort had a lower death rate — 8% versus 14% — and lower average hospital stay — 9 days versus 12 days — than the Spanish geriatric group, but the intervals from admission to death were similar in both groups.