274280 Association between C-reactive protein levels and mortality risk in older workers and non-workers

Wednesday, October 31, 2012

Diana Kachan, BS , Epidemiology and Public Health, University of Miami, Miller School of Medicine, Miami, FL
Tainya C. Clarke, MPH, MS , Department of Epidemiology & Public Health, University of Miami, Miller School of Medicine, Miami, FL
Alberto Caban-Martinez, PhD, DO, MPH, CPH , Epidemiology and Public Health, University of Miami, Miller School of Medicine, Miami, FL
Lora E. Fleming, MD, PhD , European Centre for Environment and Human Health, University of Exeter Medical School, Truro, United Kingdom
Sharon L. Christ, PhD , College of Health and Human Sciences, Purdue University, West Lafayette, IN
William G. LeBlanc, PhD , Department of Epidemiology & Public Health, University of Miami Miller School of Medicine - NIOSH Research Group, Miami, FL
Kristopher L. Arheart, EdD , Department of Epidemiology & Public Health, University of Miami Miller School of Medicine - NIOSH Research Group, Miami, FL
Peter Muennig, MD, MPH , Department of Health Policy and Management, Columbia University, New York, NY
Stacey L. Tannenbaum, PhD, RD, LD/N , Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL
Manuel A. Ocasio, BA , Department of Epidemiology & Public Health, University of Miami Miller School of Medicine, Miami, FL
David J. Lee, PhD , Epidemiology and Public Health, University of Miami, Miller School of Medicine, Miami, FL
Objectives: The positive effects of employment on older worker mortality can be attenuated by various health and environment-related factors. C-reactive protein (CRP) is a non-specific indicator of inflammation exposure. We compared mortality risk in older workers and non-workers across measured levels of CRP. Methods: Using pooled 1988-1994 National Health and Nutrition Examination Survey III data with mortality follow-up through 2006 from the National Death Index, age-adjusted mortality rates for U.S. individuals aged >=65 years were examined. Hazard ratios were calculated for workers and non-workers by CRP levels: 1) low (<0.33 mg/dL); 2) high (>=0.33 mg/dL). Results were adjusted for race/ethnicity, health status, age, and gender. Results: Classification of 3,618 participants aged 65+ was: 1) low-CRP non-workers (n=1,900); 2) high-CRP non-workers (n=1,252); 3) low-CRP workers (n=309); and 4) high-CRP workers (n=157). We identified 2,596 deaths. Compared to the low-CRP non-workers group, the high-CRP non-workers individuals were at highest risk of mortality (Hazard Ratio: 1.18; 95% Confidence Interval: 1.051.31), and low-CRP workers were at lowest risk (0.57; 0.44-0.73). High-CRP workers were not significantly different from either non-worker group; however they were at higher risk of mortality compared to low-CRP workers (1.75; 1.22-2.51). Higher risk was also associated with male gender (1.62; 1.56-1.69), fair/poor health (1.58; 1.38-1.80), and white non-Hispanic race/ethnicity (1.34; 1.06-1.69). Conclusions: Employment at an older age was associated with lower mortality risk for low CRP levels, but not for high CRP levels. CRP can be used as a non-invasive way to monitor mortality risk across older population groups.

Learning Areas:
Epidemiology
Occupational health and safety

Learning Objectives:
1. Examine differences in mortality risk among individuals aged 65+ by employment status and exposure levels. 2. Identify demographic characteristics associated with increased mortality risk within the study population. 3. Discuss the relationship between high and low CRP levels and mortality for older workers and non-workers.

Keywords: Aging, Workforce

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: because I am a PhD student mentored by a group of occupational epidemiologists
Any relevant financial relationships? No

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.