The Triglycerides - Glucose Index: An independent predictor of late subclinical cardiotoxicity in adult survivors of childhood, adolescent and young adult cancer

Introduction The Triglycerides - Glucose index (TyG index) has been identified as a reliable alternative for estimating insulin resistance (IR). Numerous recent studies have provided strong statistical evidence suggesting that this index is associated with the development and prognosis of cardiovascular pathologies. Objectives The aim of this study was to investigate the predictive role of the TyG index on the decrease in left ventricular longitudinal global strain (GLS) assessed on two-dimensional echocardiography in asymptomatic adult survivors of childhood, adolescent and young adult cancer. Methods The study included patients aged 18 years and older, asymptomatic cardiovascular survivors of childhood, adolescent and young adult cancer treated with anthracyclines with or without mediastinal radiotherapy. Anthropometric characteristics, cardiovascular risk factors and cancer treatment-related characteristics were collected. The TyG index was calculated using the formula: ln [fasting triglycerides (mg/dl) × fasting glucose (mg/dl)/2]. GLS was assessed and expressed as an absolute value. A GLS equal to 17.3% was retained as the threshold value after calculation in a referent group matched to patients according to age and gender. Cardiac biomarkers GDF 15, ultra-sensitive troponin I and NT-proBNP levels were measured in addition to fasting blood glucose and lipid profiles. Multivariate analysis using linear regression was performed to identify associations between these different parameters. Results A total of 105 cancer survivors from childhood, adolescence and young adulthood were included. The sex ratio was 1.3. The mean age of the patients was 25 years, the mean time since completion of cancer treatment was 10.6 years, the mean cumulative doses of anthracyclines and mediastinal radiotherapy were successively 245.75 ± 75.14 mg/m2 and 34.6 ± 6.19 Gy. Mean GLS was 18.5 ± 2.83%, mean LVEF 60.6 ± 5.69%. None of the patients had any known diabetes or treatment to lower blood glucose or triglyceride levels. No patient had a history of cardiovascular disease. In the univariate study, the factors associated with lower GLS were patient age at recruitment (p = 0.03), mean time since completion of cancer treatment when this was greater than ten years (p = 0.005), dyslipidemia (p = 0.012), obesity (p = 0.037) and TyG (p = 0.037). In multivariate analysis, lower GLS was related to mean time since completion of cancer treatment (p = 0.015) and TyG index (p = 0.002). Conclusion Our results suggest that the TyG index, as a simple and inexpensive marker of insulin resistance, could help identify cancer survivors from childhood, adolescence and young adulthood who would be at risk of subclinical cardiac dysfunction. Prospective studies with larger numbers are needed to confirm these findings.