High haemoglobin glycation index tied to telomere attrition

A negative association exists between haemoglobin glycation index (HGI) and telomere attrition, independent of HbA1c, according to a study. Tumour necrosis factor (TNF) α mediates the association between HGI and telomere length.

In this cross-sectional study, the authors enrolled 434 individuals with different glucose intolerances in a rural community and calculated the HGI as the difference between the measured and predicted HbA1c. Participants were categorized into tertiles of the HGI.

Polymerase chain reaction assay was used to determine the telomere length and mitochondrial DNA copy number (mtDNAcn). TNFα and interleukin (IL)-6, 8-oxo-2′-deoxyguanosine (8-oxo-dG), superoxide dismutase (SOD) activities, and glutathione reductase (GR) were also measured.

Participants in the high HGI group were older and had a shorter telomere length, higher levels of TNFα, SOD activities, and HbA1c. HGI was associated with telomere length (r, ‒0.25; p<0.001) and TNFα (r, 0.19; p<0.001) regardless of HbA1c levels. No association was noted between HGI and mtDNAcn.

Multiple linear regression analysis confirmed the independent relationship of HGI (β, –0.238, 95 percent confidence interval [CI], –0.430 to –0.046; p=0.015) and TNFα (β, –0.02, 95 percent CI, –0.030 to –0.014; p<0.001) with telomere length.

In ordinal logistic regression models, after controlling for confounding variables, the odds of a higher-level telomere length were 5.29-fold in the low HGI group (odds ratio [OR], 5.29, 95 percent CI, 2.45‒11.41; p<0.001) and 2.41-fold in the moderate HGI group (OR, 2.41, 95 percent CI, 1.35‒4.30; p=0.003) compared with the high HGI group.

On mediation analyses, TNFα accounted for 30.39 percent of the effects of the HGI on telomere length.