Association of shorter telomeres with coronary artery disease in Indian subjects

Objective: Studies in white Caucasians have shown that telomere length, a marker of biological ageing, is shorter in individuals with coronary artery disease (CAD). South Asian Indians have a high prevalence of CAD, especially premature CAD. We examined the association of telomere length with CAD in Indian subjects. Design: Case-control. Setting: Mumbai, India. Subjects: 238 consecutive cases (aged 29-82 years), admitted to Cumballa Hill Hospital for coronary investigations or treatment and 238 control subjects (aged 30-87 years) from the same area without any clinical evidence of CAD. Methods: Mean leucocyte telomere length was measured using a PCR-based assay and expressed as a ratio (T/S ratio) of the telomere signal to that of a control single copy gene. Results: T/S ratio was significantly lower in CAD cases compared with controls (cases 1.21 (95% CI: 1.16 to1.26); controls 1.33 (1.28 to 1.38); P=0.0003), equivalent to approximately 166 base pairs. The difference remained significant after adjustment for other clinical characteristics (P=0.002). There were trends towards longer telomeres in vegetarian subjects compared with subjects on a mixed diet (vegetarians 1.31 (1.25 to 1.38); mixed 1.25 (1.18 to 1.33); P=0.088) and shorter telomeres in subjects with a positive family history for CAD (+ve FH 1.25 (1.18 to 1.32); -ve FH 1.31 (1.24 to 1.38); P=0.094). Conclusion: Subjects of Indian ethnicity with CAD have shorter telomeres than subjects without such a history. The finding provides further evidence that telomere biology is altered in subjects with coronary artery disease.