A genome-wide association study (GWAS) was conducted in 2020 on self-reported walking pace using data from 450,967 individuals of European ancestry in the UK Biobank. The study categorized walking pace into three levels: slow, steady/average, and brisk. It utilized a linear mixed model that included age, sex, the type of genotyping array, and 20 principal components of ancestry. Rigorous quality control and analysis of over 10 million imputed variants led to the identification of 144 significant SNPs across 70 genomic regions. Some of the genes and SNPs are discussed below:
ADGRB2
The long name for the ADGRB2 gene is the Adhesion G Protein-Coupled Receptor B2 gene. In the context of walking pace, a genetic variant, rs12739999, in this gene was found to be associated with the walking speed. Although there is no mainstream research explicitly linking the function of ADGRB2 directly to walking speed, this gene could potentially influence this trait through its roles in the nervous system.
For example, a 2019 study of a consanguinous family showed a link between variants in the ADGRB3 gene, like the rs12739999, and cognitive impairments and ataxia. Ataxia is a condition characterized by a lack of muscle coordination that can affect various movements, such as walking, picking up objects, or speaking, making these activities appear clumsy or unsteady.
SLC39A8
The SLC39A8 gene encodes a member of the solute carrier family 39 (SLC39), which is involved in transporting divalent metal cations, such as zinc and manganese, across the cellular membrane. This gene plays a critical role in essential mineral homeostasis within the body. According to the 2020 GWAS, the most significant genetic signal (SNP rs13107325) related to self-reported walking pace was in the SLC39A8 gene.
DRD2
The DRD2 gene encodes for the dopamine receptor D2. This gene is crucial for the dopaminergic system in the brain, influencing behavior, reward, and motor control. The DRD2 SNP rs10750025 was found to influence walking pace in the 2020 GWAS.
The role of DRD2 in motor functions and coordination is a possible reason for its implication in walking pace. A 2018 randomized control trial showed that participants with the DRD2 Met/Met genotype significantly increased physical activity levels compared to those with lower dopamine signaling genotypes.Â
In addition to simple genetic polymorphisms, such as the SNPs, other types of DNA alterations can have an association with a trait. A very intriguing 2021 study investigated a causal relationship between walking pace and telomere length (LTL) measured in leukocytes, the white blood cells. Researchers used data from UK Biobank participants recruited between March 2006 and July 2010 and categorized self-reported walking pace as slow, steady/average, or brisk and measured LTL through qPCR assay. The analysis included 405,981 adults, showing that individuals who walked at a steady/average or brisk pace had significantly longer LTL than those who were slow. It indicated a likely causal relationship between a faster walking pace and longer LTL, suggesting that increased walking pace could causally influence LTL elongation. This finding supports the idea that the health benefits of brisk walking may be partly due to its impact on biological aging processes, as indicated by telomere length.
LifeDNA Fitness Report covers close to 100 genetic markers related to walking pace.