Declining cholesterol and mortality in a sample of older nursing home residents

OBJECTIVE: To examine the association between declining serum cholesterol and mortality in a sample of older nursing home residents. DESIGN: A retrospective cohort study. SETTING: A 203-bed nursing home. PARTICIPANTS: Persons aged 65 and older, resident in the nursing home on January 1, 1988, or admitted through December 31, 1989, were eligible (n = 185) for the study. Follow-up for mortality was conducted until June 30, 1991. Fifty-five survivors with two or more cholesterol levels recorded before January 1, 1990, and the 76 decedents with two or more recorded cholesterol levels constituted the analytic sample (71% of eligible subjects). OUTCOME MEASURE: Mortality of the nursing home residents. RESULTS: Cholesterol declined 31.1 mg/dL/yr (95% confidence interval [CI], 19.7 to 42.6) among decedents, versus 4.2 mg/dl/yr (95% CI, -4.9 to 13.2) among survivors. The association between cholesterol decline (absolute or relative rates) and mortality was examined using logistic regression controlling for age, sex, and tube feeding. Compared with a referrent group with no change or increase, declining cholesterol greater than 45 mg/dl/yr was accompanied by an adjusted relative odds for death of 6.2 (95% CI, 2.1 to 18.4); declining cholesterol greater than 20% per year was accompanied by an adjusted relative odds for death of 7.3 (95% CI, 2.4 to 22.2). Extreme declines greater than 20% per year occurred in 47% of decedents but in only 15% of survivors. CONCLUSION: Precipitously declining cholesterol appeared to be a marker for mortality in the sample and may help explain the low cholesterol-mortality association in older nursing home residents.