The first investigation of leukocyte telomere length in Iranian subjects with morbid obesity

Morbid obesity can accelerate normal aging. Leukocyte Telomere Length (LTL) is a biomarker of aging which shows high variability in different ethnicities and has an association with body mass index. In this matched-pairs study, we examined LTL of 53 morbidly obese subjects (18‐65 years old, 85% women). Individuals with BMI> 40 kg/m2, who were candidate for bariatric surgery, and had a sibling from the same sex with age difference about ±5 years, were selected before surgery. By selecting siblings as controls, most important factors affecting LTL (age, genetic background, ethnicity, and sex) were highly adjusted for cases and controls. All siblings (17‐61 years old) were nonsmokers and clinically examined to have no sign of chronic infections, cancers, or cardiovascular diseases. LTL was measured by qPCR, based on relative standard curve method, using a mixture of 5 genomic DNA with different chronological ages as reference DNA, and K562 as quality control. Ratio of telomere quantity to single copy gene (albumin) quantity was calculated and normalized by K562 for each sample. Data analysis showed that LTL was negatively correlated with age in both cases (r= -0.163) and controls (r=-0.157). We compared LTL between 53 cases and 53 completely matched non-obese siblings by paired-samples T-test. Results showed that obese subjects have significantly shorter LTL than non‐obese individuals (P value=0.002). According to well matching criteria between obese and non-obese subjects, these results strongly suggest that high body mass index can cause shorter telomeres, and increase the incidence of age related disorders.