Klinisk institutt 2

Midtveisevaluering - Hilde Halland




Sex-differences in cardiac dysfunction in obesity – link to heart failure with preserved ejection fraction

The rapid increase in obesity is a major cause of the increasing incidence of heart failure. Women tend to develop heart failure despite normal left ventricular ejection fraction. This type of heart failure is particularly common in women with obesity, chronic hypertension or diabetes.

Subclinical cardiac dysfunction is known to be present long before clinical heart failure develops. The current project focuses on increasing the knowledge on prevalence and types of subclinical cardiac dysfunction in obese women and men, and how this can be detected in clinical practice.

In study 1 we measured cardiopulmonary function by recording peak oxygen uptake during a maximal exercise on a treadmill. This allowed for identification of fit and unfit participants. We then explored the association of fitness with the prevalences of major cardiovascular risk factors among overweight and obese women and men without known cardiovascular disease.

Surprisingly, we found that fitness was not associated with lower prevalences of major cardiovascular risk factors like hypertension, diabetes and metabolic syndrome.

Study 2 is on-going and explores subclinical cardiac structural changes in overweight and obese women and men. The preliminary analysis of clinical and echocardiographic data from 419 participants demonstrated that subclinical structural changes were found in the majority of participants (73% of women and 61% of men, p=0.012). Left atrium dilatation was the most prevalent type of subclinical cardiac dysfunction, occurring in 69% of the women and 54% of the men (p=0.002). Abnormal left ventricular geometry was less common and more prevalent among men (21% of women and 30% of men, p=0.043). In multivariable regression analysis, female sex was associated with a 2-fold higher prevalence of subclinical structural cardiac changes, in particular left atrium dilatation, while male sex was associated with a 2-fold higher prevalence of abnormal left ventricular geometry.

Study 3 will focus on the impact of concomitant hypertension on cardiac dysfunction in obesity.