Plasma triglyceride level is an independent predictor of altered left ventricular relaxation

Diastolic dysfunction, manifested by impaired left ventricular (LV) relaxation, is prevalent among individuals with metabolic disorders. The objective of this study was to evaluate the extent to which plasma triglyceride (TG) levels are related to LV diastolic function.

A total of 424 subjects (age 49 +/- 12 years) had fasting plasma TG levels measured and underwent echocardiography for assessment of LV structure and function: LV ejection fraction and LV mass indexed to height (LVM/Ht(2.7)); transmitral inflow early diastolic peak velocity (E wave) and late diastolic peak velocity (A wave), and E wave to A wave ratio (E/A); deceleration time; and Doppler tissue imaging early diastolic myocardial velocity (EM), an index of LV relaxation.

All subjects had normal LV ejection fraction, 48% had hypertension, 16% had increased LVM/Ht(2.7), 11% had type 2 diabetes mellitus, 37% were obese, and 27% had hypertriglyceridemia (TG > 150 mg/dL). Univariate analysis showed significant relationships between TG level and E/A, deceleration time, and Em (P < or = .001 for all). After adjustment for potential confounders in multivariate models (eg, age, systolic blood pressure, and LVM/Ht(2.7)), TG levels remained predictive of E/A, deceleration time, and Em (P < or = .05, <.001, and < or =.0001, respectively). Stepwise multivariate analysis showed that after age and body mass index, the TG level was the next most predictive variable of Em.

Plasma TG levels show a strong relationship with impaired LV relaxation, an early marker of diastolic dysfunction in human beings. These findings support a hypothesis whereby elevated TG levels favor myocyte intracellular lipid accumulation, possibly leading to lipotoxic diastolic dysfunction.