One- and five-year risk of death and cardiovascular complications for hospitalized patients with hyperglycemia without diagnosed diabetes: an observational study.

Background — Hyperglycemia is recognized as an important threat to the health of patients, independent of diabetes status. However, no long-term follow-up study of patients with in-hospital elevated glucose without diabetes has been conducted. 

Objective — To compare 1- and 5-year risk of death and cardiovascular (CV) complications in patients with a diagnosis of diabetes versus those without a diabetes diagnosis 

Design — Retrospective cohort study. 

Methods — Risk of all-cause death and CV complications (acute myocardial infarction [AMI], congestive heart failure [CHF], cardiovascular disease [CVD], peripheral vascular disease [PVD], and end-stage renal disease [ESRD]) in those diagnosed with diabetes versus those with different glycemia categories was determined using competing risk models.

Settings/Patients — All adult patients from a tertiary hospital discharged alive between 1996 and 2008 from any service except psychiatry or obstetrics. 

Results — Compared to patients with diagnosed diabetes, patients with peak serum glucose level >200 mg/dL had significantly higher 1-year risk (hazard ratio [HR]: 1.31, 95% confidence interval [CI]: 1.20-1.43) and 5-year risk (HR: 1.13, 95% CI: 1.06-1.22) of death but a decreased 1-year risk of hospitalization for CHF (HR: 0.71, 95% CI: 0.62-0.81), PVD (HR: 0.20, 95% CI: 0.18-0.24), or ESRD (HR: 0.73, 95% CI: 0.6-0.89). There was no risk difference for AMI (HR: 0.96, 95% CI: 0.78-1.18) or CVD (HR: 0.79, 95% CI: 0.61-1.0).

Conclusions — Although it is unclear whether hospitalized patients with elevated peak serum glucose have early diabetes or their hyperglycemia reflects hospital stress or another comorbidity, in-hospital hyperglycemia is an important clinical indicator, carrying a higher 1- and 5-year mortality risk than those with diagnosed diabetes.