Long-term Burden of Higher Body Mass Index from Childhood and Adult Hypertension Are Linked Through Triglyceride-Glucose Index: A 30-year prospective cohort study

Background: The triglyceride-glucose (TyG) index was regarded as a simple surrogate marker of insulin resistance (IR). It is confirmed that IR was significantly associated with hypertension, and obesity was the risk factor for IR and hypertension. Mediation of the association between body mass index (BMI) and risk for hypertension through the TyG index seems plausible but has not been investigated. Methods The longitudinal study cohort consisted of 1,553 individuals (869 for male), who had been examined 4 or more times for BMI from childhood, with a follow-up period of 30 years. Total area under the curve (AUCt) and incremental AUC (AUCi) were calculated as the long-term burden and trend of BMI. The TyG index was calculated as ln [fasting triglyceride (mg/dl) × fasting plasma glucose (mg/dl)/2]. Results In multivariable-adjusted logistic regression models, BMI AUCt and BMI AUCi were significantly associated with the risk of adult hypertension, both without (RR = 1.30 for BMI AUCt; 1.31 for BMI AUCi) and with (RR = 1.25 for BMI AUCt; 1.26 for BMI AUCi) the inclusion of TyG index as a covariate. Importantly, mediation analysis showed that the TyG index mediated the BMI AUCt-SBP association (19.3%), the BMI AUCt-DBP association (22.7%), the BMI AUCi-SBP association (18.5%) and BMI AUCi-DBP association (21.3%). Furthermore, the TyG index showed significant mediation effects of 15.9% on the BMI AUCt-hypertension association and 14.9% on the BMI AUCi-hypertension association. Conclusions These findings suggest that the cumulative burden of BMI originating in childhood significantly increases the risk of hypertension in midlife, and the TyG index plays an important mediation role in this association. We emphasize that early weight management has the potential to reduce the burden of hypertension caused by insulin resistance.