Associations of leukocyte telomere length with body anthropometric indices and weight change in Chinese women

OBJECTIVE: Telomeres are specialized chromatin structures essential for maintenance of chromosomal integrity and stability. Obesity has been proposed to be associated with telomere shortening; however, epidemiologic evidence has been conflicting. We conducted a study to evaluate the associations of telomere length with various anthropometric indices of general and abdominal obesity, as well as weight change. DESIGN AND METHODS: The study included 2,912 Chinese women ages 40–70 years. Monochrome multiplex quantitative PCR was applied to measure relative telomere length. ANOVA and the Dunnett test were used to compare log-transformed relative telomere length. Tests for linear trend were performed by entering the ordinal exposure as continuous parameters in the models. RESULTS: There is an inverse association between telomere length and body mass index (BMI) (P(trend) = 0.005), waist circumference (P(trend) = 0.004), waist-to-height ratio (WHtR) (P(trend) = 0.004), weight (P(trend) = 0.010), and hip circumference (P(trend) = 0.026), but not waist-to-hip ratio (WHR) (P(trend) = 0.116) or height (P(trend) = 0.675). Weight change since age 50 was further evaluated among women over age 55. Women who maintained their weight within ±5% since age 50, particularly within a normal range (BMI = 18.5–24.9 kg/m(2)), or reduced their weight from overweight (BMI = 25–29.9 kg/m(2)) or obesity (BMI ≥30 kg/m(2)) to normal range, had a longer mean of current telomere length than women who gained weight since age 50 (P(trend) = 0.025), particularly those who stayed in obesity or gained weight from normal range or overweight to obesity (P = 0.023). CONCLUSION: Our findings provide strong evidence supporting the hypothesis that telomere shortening is associated with obesity and that maintaining body weight within a normal range helps maintain telomere length.