Insulin Resistance Influences the Impact of Hypertension on Left Ventricular Diastolic Dysfunction in a Community Sample.

BACKGROUND: Although obesity-associated metabolic abnormalities (insulin resistance-IR) may not play as marked a role in determining left ventricular (LV) diastolic dysfunction (DD) as hypertension, the impact of combinations of these risk factors on DD is unknown.

HYPOTHESIS: We hypothesized that IR influences the impact of hypertension on DD.

METHODS: In 704 randomly selected participants from a community sample with a high prevalence of hypertension (50.6%) and obesity (46.5%), we determined adiposity indices, IR from the homeostasis model (HOMA-IR) and LV diastolic function using standard echocardiographic techniques.

RESULTS: HOMA-IR was independently associated with lateral wall e' and E/e' (p<0.05 to p<0.005) as well as a diagnosis of DD (p<0.02). Importantly however, an enhanced relationship between HOMA-IR and E/e' in hypertensives (n=356, partial r=0.15, p<0.005) as compared to normotensives (n=348, partial r=0.02 p=0.75) was noted. Consequently, as compared to normotensives, with adjustments for confounders, hypertension was independently associated with DD only in those with the highest tertile of HOMA-IR (Odds ratio=2.65, 95% confidence interval=1.29 to 5.42, p<0.01), whilst in those with the lowest tertile of HOMA-IR, hypertension failed to show a higher prevalence of DD (p=0.22).

CONCLUSIONS: Insulin resistance enhances the impact of hypertension on LV DD. Thus DD is more likely to occur with the combination of hypertension and IR.