Inflammation and functional decline in aging subjects from NHANES 2001 – 2010

Background: Higher systemic inflammation is associated with worse health outcomes for multiple co-morbidities. Inflammation has also been associated with functional and cognitive decline. We evaluated systemic inflammation in the geriatric population, as represented in the National Health and Nutrition Examination Survey (NHANES) 2001 through 2010, as a prediction tool for functional decline.  

Methods: C-reactive protein (mg/dL) was analyzed using quartiles developed from our dataset.  Functional decline utilized five following constructs: Activities of daily living (ADL): Eating, walking, dressing getting out of bed; Instrumental activities of daily living (IADL): Managing money, housekeeping, food preparation; Leisure and social activities (LSA): Attending social events, going out to movies, in-home leisure activities;  Lower extremity mobility (LEM): Walking for a quarter mile, walking up ten steps; General physical activities (GPA): Stooping, bending, standing, sitting, lifting, reaching, grasping. Logistic regression was performed for each type of decline utilizing CRP quartiles and adjusting for age and worse health than previous year.  Odd ratios are reported.

Results: The highest quartile (4^th quartile) of CRP was significant to < 0.0001: ADL: 1.82 (1.29 - 2.57); IADL: 2.06 (1.55 - 2.73); LSA: 2.65 (2.04 - 3.45); LEM: 3.33 (2.45 - 4.52); GPA: 2.66 (2.08 - 3.40).  The second and third quartiles of CRP were also significant for LEM and GPA.

Conclusion: Elderly subjects with higher level of systemic inflammation, as measured by CRP, had decreased function on evaluated scales. With further study, CRP may be a useful clinical tool to aid clinicians in predicting functional decline in elderly patients.