Unhealthy lifestyle plus genetic predisposition ups risk of mild cognitive impairment

In a cohort of older Chinese adults, unhealthy lifestyle habits contribute to a heightened risk of mild cognitive impairment and produce a synergistic effect with genetic risk, according to a study.

The study included 4,665 participants (mean age 67.9 years, 54.6 percent women) from the Tianjin Elderly Nutrition and Cognition (TENC) study. All participants were Chinese adults aged 60 years or older and who completed the neuropsychological assessments, general physical examinations, and a personal interview.

Researchers determined the participants’ lifestyle habits according to the Chinese Dietary Guidelines 2022, including healthy diet, regular physical activity, limited alcohol consumption, and no current smoking. The participants were then categorized according to their lifestyle habits: healthy and unhealthy (based on weighted standardized lifestyle score). Genetic risk was defined by the MTHFR TT genotype and APOE ε4, grouped into low and high genetic risk according to weighted standardized genetic risk score.

The main endpoint of newly diagnosed MCI, as determined using a modified version of Petersen criteria, was recorded in 653 participants (mean age 68.4 years, 40.9 women) over a median follow-up of 3.11 years.

Multivariable Cox proportional hazards analysis showed that the risk of MCI was elevated among participants with a low genetic risk and an unhealthy lifestyle (hazard ratio [HR], 3.01, 95 percent confidence interval [CI], 2.38–3.79), those with a high genetic risk and a healthy lifestyle (HR, 2.65, 95 percent CI, 2.03–3.44), and those with a high genetic risk and an unhealthy lifestyle (HR, 3.58, 95 percent CI, 2.73–4.69) as compared with participants with a low genetic risk and a healthy lifestyle.

A synergistic interaction was observed between lifestyle categories and genetic risk (β, 3.58, 95 percent CI, 2.73–4.69).