AbstractDiabetes Mellitus (DM) and insulin resistant (IR) are highly prevalent among heart failure (HF) patients. There is now increasing evidence to suggest a bidirectional relationship between IR and HF. DM and IR not only lead to heart failure, but heart failure can also lead to the development of DM or IR.
The degree of IR also correlates with the severity and mortality of CHF. The pathophysiology of IR in CHF has yet to be fully defined. Activation of sympathetic nervous system, abnormal regulation of adipocytokines systems, activation of inflammatory and coagulation cascade, accumulation of glycated products, endothelial dysfunction and hyperinsulinaemia are potential explanations of the development of IR in CHF. Additionally, it remains to be determined if IR is merely a marker reflecting the severity of CHF or whether it contributes to the disease in CHF. If IR is truly a culprit that worsens CHF, reversing IR may potentially be a new target for treatment in CHF, which may result in an improvement in symptoms and even mortality in patients with CHF. However, there are concerns over the use of certain insulin sensitizers, most notably, the thiazolidinediones (TZDs), which has been linked with increased risk of hospitalizations for CHF and concerns regarding its association with increased myocardial infarction. Despite previous concerns of lactic acidosis, there is now evidence that metformin may not only be safe but could potentially be useful in the setting of CHF. We have conducted a randomised double-blind, placebo-controlled trial testing the hypothesis of reversing IR with metformin in insulin-resistant CHF will have beneficial effects. If IR is a possible target for the treatment of CHF, what are the new and potential treatment modalities? We have now had better understandings of the adipocytokines systems, which may prove to be a therapeutic option to improve IR in CHF. AMP-activated protein kinase (AMPK) pathway has become the focus of research as a novel therapeutic target in cardio-metabolic disease. It has been shown to mediate, at least in part, the effects of a number of physiological and pharmacological factors that improve IR. It also exerts beneficial effects on the vasculature and the heart. There have been some new AMPK activators that are currently being tested in vivo setting or phase 1-2 trials, and the early results are somewhat promising.
Increased understandings and refreshed insights of IR and CHF have opened a new horizon and encouraged us to explore more therapeutics options in CHF.
|Date of Award||2013|
|Supervisor||Chim Lang (Supervisor)|
- Insulin resistance
- Heart failure