Three-year change in inflammatory markers in elderly people and mortality: the Invecchiare in Chianti study.
OBJECTIVE
To describe changes in interleukin-6 (IL-6) and C-reactive protein (CRP) and to determine how changes are related to mortality in elderly people.


METHODS
Prospective cohort study.


METHODS
Two communities in the Tuscany region of Italy.


METHODS
Randomly selected residents aged 65 and older who participated in the first two waves of data collection (N=736).


METHODS
Two serum measurements of IL-6 and CRP taken 3 years apart. Mortality was observed for the 3 years after the second measurement; 79 deaths were observed in 2,079 person-years.


RESULTS
Correlations indicated marginal to moderate stability in IL-6 and CRP, with clinical categories remaining relatively stable over time. Baseline levels were not related to mortality between follow-up Years 3 and 6, but increases in IL-6 and CRP predicted 3- to 6-year mortality. Controlling for follow-up IL-6 and CRP attenuated the relationship between inflammatory changes and mortality, but increases in CRP continued to increase odds of mortality. After controlling for sociodemographic characteristics, biological risk factors, health behaviors, and disease at both times, increases in CRP, but not IL-6, were related to mortality. Odds of death were more than three times as great in subjects in whom any CRP increase was observed (odds ratio=3.10, 95% confidence interval=1.25-7.68) as in subjects with stable or declining CRP.


CONCLUSIONS
CRP and IL-6 levels within individuals vary over time, and increases in CRP are associated with greater mortality risk. Three-year changes in inflammatory markers are better predictors of mortality than baseline measures.
Alley
Dawn E
DE
Robert Wood Johnson Foundation Health and Society Scholars Program, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
Crimmins
Eileen
E
Bandeen-Roche
Karen
K
Guralnik
Jack
J
Ferrucci
Luigi
L
D000368:Aged; D000369:Aged, 80 and over; D002097:C-Reactive Protein / Q000378:metabolism*; D002908:Chronic Disease / Q000401:mortality*; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015850:Interleukin-6 / Q000097:blood*; D007558:Italy; D008297:Male; D016017:Odds Ratio; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012307:Risk Factors; D013223:Statistics as Topic; D016019:Survival Analysis
D015850:Interleukin-6; D002097:C-Reactive Protein