Telomere Length Dynamics and Mitochondrial Function as Biomarkers of Biological Ageing in Adults with Metabolic Syndrome Across Multiple Nigerian Geopolitical Zones: A Multi-Site Cohort Study

Background: Biological ageing, indexed by telomere attrition and mitochondrial dysfunction, accelerates under conditions of chronic metabolic dysregulation. Metabolic syndrome, comprising central obesity, hypertension, dyslipidaemia, and insulin resistance, is rising across all Nigerian geopolitical zones but has never been examined in relation to molecular ageing biomarkers in a multi-site Nigerian cohort. This represents an original contribution to the ageing physiology literature. Objectives: This study aims to quantify leucocyte telomere length by quantitative PCR, assess mitochondrial oxidative phosphorylation capacity and mitochondrial DNA copy number in peripheral blood mononuclear cells, and examine their relationships with metabolic syndrome component severity and lifestyle determinants in a nationally representative sample across six geopolitical zones of Nigeria. Methods: Five hundred adults aged 40 to 70 years will be recruited from six tertiary hospitals, one per geopolitical zone. Metabolic syndrome will be classified using harmonised International Diabetes Federation criteria. Telomere length will be quantified by monochrome multiplex quantitative PCR. Mitochondrial respiration will be assessed by high-resolution respirometry using the Oroboros Oxygraph-2k. Structural equation modelling will examine direct and mediated pathways linking metabolic syndrome to biological ageing indices. Expected Outcomes: Greater metabolic syndrome burden is hypothesised to independently predict shorter telomere length and impaired mitochondrial oxidative phosphorylation, with central obesity as the dominant mediating component and significant north-south geopolitical zone differences in effect magnitude. Conclusion: This study will produce the first nationally distributed biological ageing dataset for Nigerian adults with metabolic syndrome. Keywords: telomere length, mitochondrial function, metabolic syndrome, biological ageing, multi-site Nigeria.