Association of corrected QT interval with body mass index, and the impact of this association on mortality: Results from the Third National Health and Nutrition Examination Survey

Summary Background Both QT interval and body mass index (BMI) are independently associated with mortality. Those with higher BMI have longer QT, although evidence is inconsistent. The joint association of QT and BMI with mortality merits investigation. Objective To examine the association of QT with BMI, and to examine the joint association of QT and BMI with all-cause and cardiovascular mortality. Methods We followed 4036 participants from NHANES III for a median of 14.7 years. Weighted sample was divided into 4 categories by BMI as: 18.5–24.9, 25–29.9, 30–34.9 and ≥35, and 2 categories by corrected QT interval (QTc) as: normal (