Diabetes mellitus and bacteraemia: a comparative study between diabetic and non-diabetic patients

Abstract

Objectives: To compare the incidence, mortality, clinical characteristics and outcome between bacteraemias in diabetic and non-diabetic patients.

Methods: A prospective study of all adult patients with bacteraemia admitted to a large Spanish teaching hospital during six consecutive years (1984-1990); 152 were diabetics and 1488 non-diabetics.

Results: Rates per 1000 admissions when bacteraemic diabetic patients were compared with non-diabetics (p < 0.001) were respectively as follows: incidence 26.8/15.5, acquisition in the community 18.4/6.2, urinary tract source 8.7/2.2, and E. coli aetiology 8.9/3.4. Diabetes mellitus type II was found in 138 episodes. Glycosylated haemoglobin levels were 13 +/- 3%. Bacteraemia developed in association with hyperosmolar status in 14.5% of patients and with ketoacidosis in 5%. Patients in the diabetic group developed septic shock in 22% of the episodes, acute renal failure in 40%, superinfections in 22% and had an inappropriate empirical antibiotic treatment in 6%, vs 15.6%, 20%, 11% and 25% respectively of the non-diabetic bacteraemic patients (p < 0.05 for all comparisons). Overall mortality and bacteraemia-related mortality were similar in both groups. Multivariate analysis showed that the association with fatal diseases, shock and renal insufficiency negatively influenced the outcome of diabetic patients, while the nephro-urologic source and an appropriate therapy were accompanied by a better prognosis.

Conclusions: A higher incidence of bacteraemia, mainly of urinary source, community-acquired, and due to E. coli was found in the diabetic patients compared to non-diabetics. The common use of rapidly effective drugs for this predominant bacteraemia conditioned similar outcome and prognosis factors in both populations, in spite of the higher incidence of septic shock and acute renal failure in the diabetic population.