Diabetic cardiomyopathy
This article or section possibly contains synthesis of material which does not verifiably mention or relate to the main topic. (March 2020) |
Diabetic cardiomyopathy | |
---|---|
Universal blue circle symbol for diabetes.[1] | |
Specialty | Cardiology |
Diabetic cardiomyopathy is a disorder of the
Signs and symptoms
One particularity of diabetic cardiomyopathy is the long latent phase, during which the disease progresses but is completely asymptomatic. In most cases, diabetic cardiomyopathy is detected with concomitant
Pathophysiology
Defects in cellular processes such as
While it has been evident for a long time that the complications seen in diabetes are related to the hyperglycemia associated to it, several factors have been implicated in the pathogenesis of the disease. Etiologically, four main causes are responsible for the development of heart failure in diabetic cardiomyopathy: microangiopathy and related endothelial dysfunction, autonomic neuropathy, metabolic alterations that include abnormal glucose use and increased fatty acid oxidation, generation and accumulation of free radicals, and alterations in ion homeostasis, especially calcium transients.[citation needed] Additional effects include inflammation and upregulation of local angiotensin systems.
Diabetic cardiomyopathy may be associated with restrictive (
Microangiopathy
Microangiopathy can be characterized as subendothelial and endothelial fibrosis in the coronary microvasculature of the heart. This endothelial dysfunction leads to impaired myocardial blood flow reserve as evidence by echocardiography.[10] About 50% of diabetics with diabetic cardiomyopathy show pathologic evidence for microangiopathy such as sub-endothelial and endothelial fibrosis, compared to only 21% of non-diabetic heart failure patients.[11] Over the years, several hypotheses were postulated to explain the endothelial dysfunction observed in diabetes. It was hypothesized that the extracellular hyperglycemia leads to an intracellular hyperglycemia in cells unable to regulate their glucose uptake, most predominantly, endothelial cells. Indeed, while
Autonomic neuropathy
While the heart can function without help from the nervous system, it is highly innervated with autonomic nerves, regulating the heart beat according to demand in a fast manner, prior to hormonal release. The autonomic innervations of the myocardium in diabetic cardiomyopathy are altered and contribute to myocardial dysfunction. Unlike the brain, the peripheral nervous system does not benefit from a barrier protecting it from the circulating levels of glucose. Just like endothelial cells, nerve cells cannot regulate their glucose uptake and suffer the same type of damages listed above. Therefore, the diabetic heart shows clear denervation as the pathology progresses. This denervation correlates with echocardiographic evidence of diastolic dysfunction and results in a decline of survival in patients with diabetes from 85% to 44%. Other causes of denervation are ischemia from microvascular disease and thus appear following the development of microangiopathy.[citation needed]
Inflammation
Diabetes is associated with increased inflammation, which is mediated by generation of abnormal fatty acids, AGEs and other mechanisms.[19] The resulting cytokine profile promotes hypertrophy and apoptosis of cardiomyocytes, abnormal calcium signaling, impaired myocardial contractility and myocardial fibrosis.[20] Additionally, it may lead to microvascular dysfunction, either directly or via endothelial damage, thereby promoting myocardial ischemia.[21]
Diagnosis
Diagnostic approaches for diabetic cardiomyopathy include echocardiography, cardiac MRI investigations, Multi‐slice computed tomography (MsCT), and nuclear imaging.[22] Potential risks of the investigation (e.g. exposure to radiation) and diagnostic utility should be weighed for an optimised personalised procedure.[22]
Treatment
At present, there is no effective specific treatment available for diabetic cardiomyopathy.[23]
Treatment rationale centers around intense glycemic control through diet and preferential use of certain medications in diabetic patients at high risk for developing cardiovascular disease or heart failure. A rationale for therapeutic decision making in individuals with coexistent diabetes mellitus and HF is less clear because there is a possibility that additional factors beyond glycemia might contribute to the increased HF risk in diabetes mellitus.
As with most other heart diseases,
References
- ^ "Diabetes Blue Circle Symbol". International Diabetes Federation. 17 March 2006. Archived from the original on 5 August 2007.
- ^ PMID 24882754.}
- PMID 15094099.
- S2CID 9488917.
- PMID 16959587.
- PMID 3275682.
- PMID 15573141.
- S2CID 41710519.
- PMID 25888006.
- PMID 16606865.
- PMID 4263660.
- ^ PMID 11050244.
- S2CID 624220.
- PMID 9604860.
- PMID 8040253.
- PMID 9293394.
- S2CID 10939325.
- S2CID 9772677.
- PMID 33791873.
- PMID 35308180.
- PMID 32080423.
- ^ PMID 28231848.
- PMID 30425649.}
- ^ PMID 30605420.
- PMID 17468147.
- PMID 12742294.