TOPLINE:

High blood lead level (BLL) was associated with an 87% increased prevalence of Alzheimer’s disease (AD) in middle-aged and older adults, but engaging in regular physical activity was associated with a 72% reduction in the prevalence, new research showed. 

METHODOLOGY:

• Researchers conducted a cross-sectional study using data from the 2007-2018 National Health and Nutrition Examination Survey for more than 13,000 individuals aged 45 or older (58% aged > 60 years, 50% women) with available BLL measurements and self-reported use of medications prescribed specifically for AD, such as rivastigmine, galantamine, donepezil, memantine, and gabapentin.
• BLLs were categorized as low, moderate, or high. Physical activity was assessed using the Global Physical Activity Questionnaire and categorized as no activity (0 metabolic equivalent task [MET]-min/wk), insufficient activity (1-599 MET-min/wk), or sufficient activity (≥ 600 MET-min/wk).
• Researchers assessed the associations of BLLs and levels of physical activity, alone and together, with the prevalence of AD.

TAKEAWAY:

• High BLL was associated with a significantly increased prevalence of AD compared with low BLL (adjusted odds ratio [OR], 1.87), with each one-unit increase in BLL linked to a 50% increase in prevalence (adjusted OR, 1.5; P < .05 for both).
• Engaging in sufficient and even insufficient physical activity was also associated with reduced AD prevalence (adjusted ORs, 0.28 and 0.59, respectively; P < .05 for both).
• Compared with the combination of no physical activity and a high BLL, combinations of sufficient exercise and high, moderate, or low BLLs were associated with 84%, 66%, and 76.5% reductions in AD prevalence, respectively.

IN PRACTICE:

“As far as we know, this is the first study demonstrating that the detrimental association of BLL with AD prevalence may be moderated by (physical activity),” highlighting the potential of exercise as a behavioral intervention, the investigators wrote.

SOURCE:

The study was led by Xiaosheng Dong, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, China. It was published online on November 10 in Alzheimer’s & Dementia.

LIMITATIONS:

The cross-sectional design prevented the establishment of a causal relationship. Levels of physical activity were assessed using a self-reported questionnaire, introducing potential recall bias. The diagnosis of AD was not validated by clinical assessment. Due to the small number of cases of AD, mild cognitive impairment could not be distinguished from AD. Additionally, the lack of data on resistance training prevented the exploration of different modalities of exercise. 

DISCLOSURES:

The study was funded by the Natural Science Foundation of Shandong Province, China Postdoctoral Science Foundation, Postdoctoral Innovation Project of Shandong Province, and National Science Foundation of China. The investigators reported having no relevant conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.