Serum cholesterol levels and in-hospital mortality in the elderly

Abstract

Purpose Although total cholesterol levels among middle-aged persons correlate with long-term mortality from all causes, this association remains controversial in older persons. We explored whether total cholesterol levels were independently associated with in-hospital mortality among elderly patients. Methods We analyzed data from a large collaborative observational study, the Italian Group of Pharmacoepidemiology in the Elderly (GIFA), which collected data on hospitalized patients. A total of 6984 patients aged 65 years or older who had been admitted to 81 participating medical centers during four survey periods (from 1993 to 1998) were enrolled. Patients were divided into four groups based on total cholesterol levels at hospital admission: <160 mg/dL (n = 2115), 160 to 199 mg/dL (n = 2210), 200 to 239 mg/dL (n = 1719), and ≥240 mg/dL (n = 940). Results Patients (mean [± SD] age, 78 ± 7 years) were hospitalized for an average of 15 ± 10 days. The mean total cholesterol level was 186 ± 49 mg/dL. A total of 202 patients died during hospitalization. Mortality was inversely related to cholesterol levels (<160 mg/dL: 5.2% [110/2115]; 160–199 mg/dL: 2.2% [49/2210]; 200–239 mg/dL: 1.6% [27/1719]; and ≥240 mg/dL: 1.7% [16/940]; P for linear trend <0.001). After adjustment for potential confounders (demographic characteristics, smoking, alcohol use, indicators of nutritional status, markers of frailty, and comorbid conditions), low cholesterol levels continued to be associated with in-hospital mortality. Compared with patients who had cholesterol levels <160 mg/dL, the odds ratios for in-hospital mortality were 0.49 (95% confidence interval [CI]: 0.34 to 0.70) for participants with cholesterol levels of 160 to 199 mg/dL, 0.41 (95% CI: 0.26 to 0.65) for those with cholesterol levels of 200 to 239 mg/dL, and 0.56 (95% CI: 0.32 to 0.98) for those with cholesterol levels ≥240 mg/dL. These estimates were similar after further adjustment for inflammatory markers and after excluding patients with liver disease. Conclusion Among older hospitalized adults, low serum cholesterol levels appear to be an independent predictor of short-term mortality.