Dietary therapy in heart failure with preserved ejection fraction and/or left ventricular diastolic dysfunction in patients with metabolic syndrome.

BACKGROUND: Heart failure is an ongoing epidemic of left ventricular (LV) dilatation and/or dysfunction due to the increasing prevalence of predisposing risk factors such as age, physical inactivity, (abdominal) obesity, and type-2-diabetes. Approximately half of these patients have diastolic heart failure (HFpEF). The prognosis of HFpEF is comparable to that of systolic heart failure, but without any known effective treatment. DIASTOLIC DYSFUNCTION: A biomathematically corrected diagnostic approach is presented that quantifies diastolic dysfunction via the predominant age dependency of LV diastolic function and unmasks (metabolic) risk factors, that are independent of age and, therefore, potential targets for therapy. Patients with HFpEF have reduced cardiac energy reserve that is frequently caused by insulin resistance. Consequently, HFpEF and/or LV diastolic dysfunction may be regarded as a cardiac manifestation of the metabolic syndrome (MetS). DIETARY THERAPY: Accordingly, a causal therapy for metabolically induced dysfunction aims at normalizing insulin sensitivity by improving postprandial glucose and lipid metabolism. The respective treatments include 1) weight loss induced by dietary energy restriction that is often not sustained long-term and 2) independent of weight loss, focus on carbohydrate modification in exchange for an increase in protein and fat, ideally combined with an aerobic exercise program. Hence, beneficial effects of different macronutrient compositions in the dietary therapy of the underlying MetS are discussed together with the most recently available publications and meta-analyses.
CONCLUSION: Modulation/restriction of carbohydrate intake normalizes postprandial hyperglycemic and insulinemic peaks and has been shown to improve all manifestations of the MetS and also to reduce cardiovascular risk.