Nonesterified Fatty Acids and Hospitalizations Among Older Adults: The Cardiovascular Health Study

Abstract

Abstract Background We sought to determine associations between total serum concentrations of nonesterified fatty acids (NEFAs) and incident total and cause-specific hospitalizations in a community-living cohort of older adults. Methods We included 4715 participants in the Cardiovascular Health Study who had fasting total serum NEFA measured at the 1992/1993 clinic visit and were followed for a median of 12 years. We identified all inpatient admissions requiring at least an overnight hospitalization and used primary diagnostic codes to categorize cause-specific hospitalizations. We used Cox proportional hazards regression models to determine associations with time-to-first hospitalization and Poisson regression for the rate ratios (RRs) of hospitalizations and days hospitalized. Results We identified 21 339 hospitalizations during follow-up. In fully adjusted models, higher total NEFAs were significantly associated with higher risk of incident hospitalization (hazard ratio [HR] per SD [0.2 mEq/L] = 1.07, 95% confidence interval [CI] = 1.03–1.10, p < .001), number of hospitalizations (RR per SD = 1.04, 95% CI = 1.01–1.07, p = .01), and total number of days hospitalized (RR per SD = 1.06, 95% CI = 1.01–1.10, p = .01). Among hospitalization subtypes, higher NEFA was associated with higher likelihood of mental, neurologic, respiratory, and musculoskeletal causes of hospitalization. Among specific causes of hospitalization, higher NEFA was associated with diabetes, pneumonia, and gastrointestinal hemorrhage. Conclusions Higher fasting total serum NEFAs are associated with a broad array of causes of hospitalization among older adults. While some of these were expected, our results illustrate a possible utility of NEFAs as biomarkers for risk of hospitalization, and total days hospitalized, in older adults. Further research is needed to determine whether interventions based on NEFAs might be feasible.