Physiological Determinants of Longevity in Centenarians in the Yoruba Ethnic Group: A Cross-Sectional Phenotypic and Metabolic Study in Ekiti and Osun States

Understanding the physiological phenotype of individuals who achieve exceptional longevity offers rare insights into the mechanisms that underpin biological resilience and decelerated ageing, yet no systematic characterisation of centenarians exists in any Nigerian ethnic group. This study investigated the physiological determinants of longevity in centenarians of Yoruba ethnicity in Ekiti and Osun States, South West Nigeria, making an original contribution to the emerging field of human longevity physiology in Africa. A phenotypic cross-sectional study enrolled 50 centenarians (aged 100 years and above), 80 octogenarians (aged 80 to 89), and 80 adults aged 60 to 69 as comparative reference groups. Physiological assessments included arterial stiffness by pulse wave velocity, autonomic function by heart rate variability, insulin sensitivity by homeostatic model assessment, inflammatory burden by high-sensitivity C-reactive protein and interleukin-6, telomere length from leukocyte DNA, mitochondrial DNA copy number, and lipid profile. Diet, sleep, and physical activity were characterised by structured interview. Multivariate logistic regression, latent class analysis, and discriminant analysis were applied. Results showed that centenarians had significantly lower pulse wave velocity than octogenarians of comparable sex and height, suggesting preserved vascular elasticity as a longevity signature. Insulin sensitivity was relatively maintained, and high-density lipoprotein cholesterol was significantly higher compared to octogenarians. Telomere length was longer and inflammatory markers lower than expected for age. Mitochondrial DNA copy number was elevated in centenarians. Traditional plant-based dietary patterns and sustained moderate physical activity characterised most centenarians. This study establishes the first physiological longevity phenotype data for any Nigerian ethnic group, contributing foundational knowledge. Keywords: longevity, centenarians, arterial stiffness, telomere length, Yoruba.