Impact of telomere length alteration in chronic kidney disease patients of Pakistan: a case–control study and meta-analysis of 24,089 patients

Chronic kidney disease (CKD) is becoming a global health concern due to its rising prevalence owing to the complex interplay of environmental, genetic, and epigenetic factors. Leukocyte telomere length (LTL) is a potential indicator of biological age in age-related diseases. Our objective is to investigate the association between LTL and CKD in Pakistani population to systematically synthesize existing evidence by investigating previously reported studies. We conducted a case–control study (n = 166), aged 18–60 years. Relative LTL was measured using quantitative real-time PCR and expressed as telomere-to-single copy gene (T/S) ratios. Biochemical parameters and estimated glomerular filtration rate (eGFR) were assessed using standard methods. Multivariable linear regression adjusted for demographic and cardiometabolic factors was performed. A meta-analysis (11 studies, n = 24,089) were conducted. Our results revealed significant LTL attrition in CKD patients compared to controls with a moderate effect size. Correlational analysis revealed that LTL positively correlated with eGFR (p-value = 0.038) and negatively correlated with urea and creatinine (p < 0.05). After adjustment for age, sex, body mass index, diabetes, smoking, hypertension, and LDL cholesterol, CKD status remained independently associated with shorter LTL. Meta-analysis demonstrated an overall trend toward shorter telomeres in CKD, although substantial heterogeneity and evidence of small study effects were observed. Subgroup analysis in Asian populations showed a consistent but less robust association. LTL is associated with CKD, which may reflect systemic biological aging and disease burden rather than serving as a standalone clinical biomarker. Longitudinal studies are required to clarify causality and population-specific effects.