The role of telomere length and associated polymorphisms in type 2 diabetes in sub-Saharan African populations

Abstract

Telomeres are the capping repeats of eukaryotic chromosomes, which function in maintaining genome stability. With each successive cell replication, telomeres shorten until a critical threshold is reached and the cell undergoes apoptosis. States of heightened inflammation and oxidative stress accelerate the rate of telomere attrition as has been observed in non-communicable diseases such as type 2 diabetes. The prevalence of type 2 diabetes is rising, especially in low-to-middle income countries causing a significant health burden. Type 2 diabetes has previously been associated with a decrease in telomere length. The aim of this project was to determine the association between telomere length and type 2 diabetes in sub-Saharan African populations, and to explore the association of known telomere-associated variants in these African populations. A matched case-control association approach was used. Black male and female African adults, aged 40 years and above were studied: 836 (418 diabetic and 418 non-diabetic) for the telomere assay, and 770 (385 cases and 385 controls) for the genomic association study. A quantitative Real-Time polymerase chain reaction assay was used to measure telomere length. PLINK was used to explore the association of 28 previously identified SNP variants associated with telomere length between our selected cases and controls with age, sex, and BMI status, as potential confounders. The telomere length assay proved problematic as it resulted in high assay variability, non-specific amplification, primer-dimer formation, contamination of the “no sample negative control”, and non-amplification. In the genetic association study, none of the 28 variants previously associated with telomere length were associated with type 2 diabetes in this study.