The Association between Cardiometabolic Risk and Cognitive Function among Older Americans and Chinese.

BACKGROUND: Cardiometabolic risk (CMR) is associated with cognitive health, but the association can be affected by broader social, economic, and medical contexts. The US and China have very different developmental and epidemiological histories, and thus CMR among older people could be linked to cognitive function differently in the two countries.

METHODS: Cross-sectional and longitudinal OLS regression models were estimated for each country using nationally representative samples of populations over age 50: 7,430/4,474 Americans and 6,108/3,655 Chinese in the cross-sectional/longitudinal samples.

RESULTS: In the US, higher CMR is associated with worse cognitive function (b=-0.08, p<0.016). Longitudinally, CMR increase is associated with worse cognitive function at a marginally significant level (b=-0.10, p=0.055). No relationship between CMR level or change and cognitive function is observed in China. Higher education levels are linked to better cognitive function and slower cognitive decline in both countries. Unlike older Americans, relative to those with very low education levels, among older Chinese with the highest education level, a higher CMR links to better cognitive function (b=0.63, p=0.013) and slower cognitive decline (b=0.35, p=0.062); Nevertheless, a rapid increase in CMR is additionally harmful (b=-0.54, p=0.050) for cognitive function and may lead to faster cognitive decline (b=-0.35, p=0.079).

CONCLUSIONS: The significant relationship between CMR and cognitive function in the US suggests the importance of monitoring and controlling CMR factors at older ages. The insignificant relationship in China may be explained by the high CMR among those with high education levels, highlighting the need for improving cardiometabolic health through education and promoting healthy lifestyles.