Forums » Open clinical » Diabetes » Chronic Hyperglycemia and Subclinical Myocardial Injury
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Chronic Hyperglycemia and Subclinical Myocardial Injury
posted at 29/1/2012 12:21 PM GMT
on bmj.com
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Posts: 142
First: 29/4/2011 Last: 14/5/2012 |
We have known for years that the macrovascular damage in type 2 diabetes begins years before microvascular disease occurs. Further we know that such damage is associated with glucose concentrations much lower than that associated with microvascular disease. Fully a quarter of patients admitted for an acute myocardial infarction have hyperglycemia, most with undiagnosed diabetes or pre-diabetes. However, there is not much clinical evidence available to document this process. Jonathan Rubin and his associates have looked at this issue from a unique perspective. They asked the question if chronic hyperglycemia were injurious to the heart might we not see evidence of such subclinical injury by looking at cardiac troponin T concentrations as a function of A1C? Lo and behold the answer was a resounding yes! ABSTRACT Objectives: The purpose of this study was to examine the association between hyperglycemia and subclinical myocardial injury in persons without clinically evident coronary heart disease (CHD). Background: Hyperglycemia is associated with an increased risk of cardiac events, but limited information is available on its relationship to subclinical myocardial damage. Elevated cardiac troponin T even below traditional detection levels can be detected by a novel high-sensitivity assay. Methods: We examined the association between baseline glycated hemoglobin (HbA1c) and high-sensitivity cardiac troponin T (hs-cTnT) in 9,661 participants free of CHD and heart failure in the ARIC (Atherosclerosis Risk in Communities) study. Multivariable logistic regression models characterized the association between clinical categories of HbA1c (<5.7%, 5.7% to 6.4%, and Results: Higher baseline values of HbA1c were associated in a graded fashion with elevated hs-cTnT (p for trend < 0.001). After adjusting for traditional risk factors, compared to persons with HbA1c <5.7%, the odds ratios of elevated hs-cTnT for persons with HbA1c 5.7% to 6.4% and Conclusions: Higher HbA1c is associated with elevated hs-cTnT among persons without clinically evident CHD, suggesting that hyperglycemia contributes to myocardial injury beyond its effects on development of clinical atherosclerotic coronary disease. Web citation http://content.onlinejacc.org/cgi/content/abstract/59/5/484 While, like coronary calcification scores, subclinical myocardial damage using troponin T concentrations may not yet be ready for prime time, this study does give additional assurance that mild hyperglycemia is more that “just a touch of sugar”.
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6.5%) and our primary outcome of elevated hs-cTnT (
14 ng/l).
6.5% were 1.26 (95% confidence interval: 1.01 to 1.56) and 1.97 (95% confidence interval: 1.44 to 2.70), respectively.|
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Just Another Observational Study at Least Potentially Biased.
posted at 12/2/2012 1:51 PM GMT
on bmj.com
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Posts: 367
First: 13/4/2011 Last: 16/5/2012 |
Hello Dr. Diabetes: I have read carefully this full article. So let´s get to the points: I understand that many diabetologists believe and overestimate the glucose toxicity theory. I do not belong to this group of physicians. We are on the fifth or sixth generation of Troponin essays. I see all the time in the general ICU patients with troponin levels above the 99 percentile (usually with troponins below 1). The majority have no major cardiac disease, mostly have severe sepsis, respiratory failure, multiple organ dysfunction. We never do PCI or thrombolyse these patients. All the recent large clinical trials do not show convincing evidence that trying to normalizing HBA1C is beneficial for diabetic cardiovascular disease complications like MI, Stroke, Heart Failure, amputations, or prolonging life. On the contrary, below a safety level of HBA1C there is a substantial risk for hypoglycaemias and even increased deaths! So, my conclusion is that the results of this cohort study, also with very complicated statistical tests, are probably biased with unindentified confounders. All Best, Joey
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Re: Chronic Hyperglycemia and Subclinical Myocardial Injury
posted at 13/2/2012 12:03 PM GMT
on bmj.com
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Posts: 446
First: 17/6/2011 Last: 15/5/2012 |
I agree with Joey R - it is possible to measure raised troponin levels in lots of clinical situations and sometimes it is difficult to see what the application of that result is. If we follow this study to the conclusion of protecting the heart from subclinical damage due to hyperglycaemia does that mean we lower blood glucose as aggressively as possible? This doesn't seem to fit with the rest of the data as Joey R says. Best sadian |
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Re: Chronic Hyperglycemia and Subclinical Myocardial Injury
posted at 15/2/2012 4:36 AM GMT
on bmj.com
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Posts: 12
First: 8/5/2009 Last: 15/2/2012 |
In Response to Chronic Hyperglycemia and Subclinical Myocardial Injury: We have known for years that the macrovascular damage in type 2 diabetes begins years before microvascular disease occurs. Further we know that such damage is associated with glucose concentrations much lower than that associated with microvascular disease. Fully a quarter of patients admitted for an acute myocardial infarction have hyperglycemia, most with undiagnosed diabetes or pre-diabetes. However, there is not much clinical evidence available to document this process. Jonathan Rubin and his associates have looked at this issue from a unique perspective. They asked the question if chronic hyperglycemia were injurious to the heart might we not see evidence of such subclinical injury by looking at cardiac troponin T concentrations as a function of A1C? Lo and behold the answer was a resounding yes! ABSTRACT Objectives: The purpose of this study was to examine the association between hyperglycemia and subclinical myocardial injury in persons without clinically evident coronary heart disease (CHD). Background: Hyperglycemia is associated with an increased risk of cardiac events, but limited information is available on its relationship to subclinical myocardial damage. Elevated cardiac troponin T even below traditional detection levels can be detected by a novel high-sensitivity assay. Methods: We examined the association between baseline glycated hemoglobin (HbA1c) and high-sensitivity cardiac troponin T (hs-cTnT) in 9,661 participants free of CHD and heart failure in the ARIC (Atherosclerosis Risk in Communities) study. Multivariable logistic regression models characterized the association between clinical categories of HbA1c (<5.7%, 5.7% to 6.4%, and 6.5%) and our primary outcome of elevated hs-cTnT ( 14 ng/l). Results: Higher baseline values of HbA1c were associated in a graded fashion with elevated hs-cTnT (p for trend < 0.001). After adjusting for traditional risk factors, compared to persons with HbA1c <5.7%, the odds ratios of elevated hs-cTnT for persons with HbA1c 5.7% to 6.4% and 6.5% were 1.26 (95% confidence interval: 1.01 to 1.56) and 1.97 (95% confidence interval: 1.44 to 2.70), respectively. Conclusions: Higher HbA1c is associated with elevated hs-cTnT among persons without clinically evident CHD, suggesting that hyperglycemia contributes to myocardial injury beyond its effects on development of clinical atherosclerotic coronary disease. Web citation http://content.onlinejacc.org/cgi/content/abstract/59/5/484 While, like coronary calcification scores, subclinical myocardial damage using troponin T concentrations may not yet be ready for prime time, this study does give additional assurance that mild hyperglycemia is more that “just a touch of sugar”. Posted by diabetesMD I agree with Diabetes MD- hyperglycaemia should be treated and not just passed off as 'a touch of sugar' . And first line treatment is diet and lifestyle changes. It's up to doctors to take the problem seriously and at least explore the patient's current diet and lifestyle to make appropriate suggestions.
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Re: Chronic Hyperglycemia and Subclinical Myocardial Injury
posted at 15/2/2012 10:10 PM GMT
on bmj.com
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Posts: 367
First: 13/4/2011 Last: 16/5/2012 |
Hello bee lin: With all my respect, I think you got the wrong perspective about this article. There is no evidence based on all the recent large clinical trials or meta-analysis that Hyperglycaemia should be intensively or aggressively treated in type 2 diabetics. The available evidence is that this approach induces more harm than clinical benefits. Comprehensive global cardiovascular risk reduction seems to be the strategy that works better for the prevention and treatment of diabetic complications. Besides that, Hyperglycaemia seeems to be at most a weak cardiovascular risk factor. and there is no evidence (from clinical trials) that small increases in high sensitivity troponin levels is an indication for an increased treatment of hyperglycaemia in type 2 diabetics. All Best, Joey |
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