TY - JOUR
T1 - Temporal trends in cognitive function of older US adults associated with population changes in demographic and cardiovascular profiles
AU - Bancks, Michael
AU - Alonso, Alvaro
AU - Allen, Norrina
AU - Yaffe, Kristine
AU - Carnethon, Mercedes
N1 - Funding Information:
MB was supported by the National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health under Award Number T32HL069771 to conduct the current work while at Northwestern University in Chicago, Illinois, USA. AA was supported by the NHLBI of the National Institutes of Health under Award Number U01HL096902.
Funding Information:
Acknowledgements The authors thank the other investigators, the staff and the participants of the NHANES study for their valuable contributions. Contributors MB had full access to the data in this analysis. As such, he is the guarantor of this work, takes responsibility for the integrity of the data and the accuracy of the data analysis and affirms that the manuscript is an honest, accurate and transparent account of the study being reported. All authors made substantial intellectual contributions participating in creating and designing the study, analysing and interpreting the data and reviewing this manuscript. Funding MB was supported by the National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health under Award Number T32HL069771 to conduct the current work while at Northwestern University in Chicago, Illinois, USA. AA was supported by the NHLBI of the National Institutes of Health under Award Number U01HL096902.
Publisher Copyright:
© Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ.
PY - 2019/7/1
Y1 - 2019/7/1
N2 - Background Recent estimates suggest that dementia incidence is decreasing in the US possibly due to better management of cardiovascular disease (CVD) risk factors, but these studies lack repeated cross-sectional assessment among a representative US sample. Our objective was to assess temporal trends in cognitive performance in relation to CVD risk factors among older National Health and Nutrition Examination Survey (NHANES) participants. Methods We used repeated cross-sectional assessment of 5711 participants ≥60 years of age from four NHANES cycles: 1999-2000, 2001-2002, 2011-2012 and 2013-2014. Cognitive function was assessed during each cycle with the Digit Symbol Substitution Test (DSST). We estimated mean DSST score at each cycle and annual trend in DSST before and after adjustment for age, sex, race/ethnicity, education, smoking status, blood pressure, glucose status and body mass index. Results DSST scores was significantly higher for 2011-2012 (difference: 6.7, 95% CI 4.4 to 9.0) and 2013-2014 (difference: 6.2, 95% CI 4.0 to 8.5), but not 2001-2002 (difference: 2.3, 95% CI -0.01 to 4.6) as compared with 1999-2000 before adjustment. We observed a linear trend for higher annual DSST score before adjustment (DSST/year: 0.44, 95% CI 0.31 to 0.57) and after adjustment for age, sex, race/ethnicity, educational attainment and CVD risk factors (DSST/year: 0.17, 95% CI 0.08 to 0.26). Educational attainment was most strongly associated with the attenuation in the trend in cognitive function (77% of trend attenuation and 20% of variance in DSST). Conclusion Cognitive function is improving over time for US adults aged ≥60 years. These improvements are strongly associated with greater educational attainment and irrespective of the changing US demographic and cardiovascular health profiles.
AB - Background Recent estimates suggest that dementia incidence is decreasing in the US possibly due to better management of cardiovascular disease (CVD) risk factors, but these studies lack repeated cross-sectional assessment among a representative US sample. Our objective was to assess temporal trends in cognitive performance in relation to CVD risk factors among older National Health and Nutrition Examination Survey (NHANES) participants. Methods We used repeated cross-sectional assessment of 5711 participants ≥60 years of age from four NHANES cycles: 1999-2000, 2001-2002, 2011-2012 and 2013-2014. Cognitive function was assessed during each cycle with the Digit Symbol Substitution Test (DSST). We estimated mean DSST score at each cycle and annual trend in DSST before and after adjustment for age, sex, race/ethnicity, education, smoking status, blood pressure, glucose status and body mass index. Results DSST scores was significantly higher for 2011-2012 (difference: 6.7, 95% CI 4.4 to 9.0) and 2013-2014 (difference: 6.2, 95% CI 4.0 to 8.5), but not 2001-2002 (difference: 2.3, 95% CI -0.01 to 4.6) as compared with 1999-2000 before adjustment. We observed a linear trend for higher annual DSST score before adjustment (DSST/year: 0.44, 95% CI 0.31 to 0.57) and after adjustment for age, sex, race/ethnicity, educational attainment and CVD risk factors (DSST/year: 0.17, 95% CI 0.08 to 0.26). Educational attainment was most strongly associated with the attenuation in the trend in cognitive function (77% of trend attenuation and 20% of variance in DSST). Conclusion Cognitive function is improving over time for US adults aged ≥60 years. These improvements are strongly associated with greater educational attainment and irrespective of the changing US demographic and cardiovascular health profiles.
KW - cardiovascular disease risk factors
KW - cognition
KW - education
KW - epidemiological methods
UR - http://www.scopus.com/inward/record.url?scp=85063150616&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85063150616&partnerID=8YFLogxK
U2 - 10.1136/jech-2018-211985
DO - 10.1136/jech-2018-211985
M3 - Article
C2 - 30885985
AN - SCOPUS:85063150616
SN - 0143-005X
VL - 73
SP - 612
EP - 618
JO - Journal of Epidemiology and Community Health
JF - Journal of Epidemiology and Community Health
IS - 7
ER -
