We start off with two news releases from the American College of Cardiology that are an education in themselves. The first is titled Diabetes Increases Risk of Death for Patients with Blocked arteries. In this news release the Studies of Left Ventricular Dysfunction (SOLVD) were discussed. They found that diabetes increased the risk of death for patients with heart failure. To see if this prediction held true no matter the cause of heart failure, researchers took another look at the data from SOLVD trial. The first step was to determine which patients had heart disease caused by blocked arteries that reduce blood and oxygen to the heart (ischemia) and which patients had heart disease caused by other factors. The researchers found that diabetes was strongly associated with an increased risk of dying in patients with ischemia. To make sure that ischemic patients weren’t sicker to begin with, they excluded diabetics, and found that patients with ischemic and non-ischemic disease had similar mortality rates. They concluded that diabetes interacts with ischemic heart disease to accelerate the progress of heart dysfunction.
The second news release dated June, 2002 is one that all of us with diabetes need to understand and is titled Physicians Rank Diabetes as Higher Risk Factor for Cardiovascular Disease than Smoking, New Survey Finds. The survey which was commissioned by the American Diabetes Association and the American College of Cardiology found that more than 90% of physicians surveyed reported that people with diabetes are “very” or “extremely’ likely to have a cardiovascular event. Although the physicians indicated that they routinely discuss reducing the risks for cardiovascular disease, they found that these patients are only moderately knowledgeable about their increased risks. Primary physicians and endocrinologists believe their patients perceive amputation and blindness as the greatest risks of diabetes. Research has shown that 68% of diabetics report that they are unaware of their increased risk of heart disease and stroke. Physicians cite “poor compliance” with lifestyle modifications and challenges with multiple drug regimes as a barrier for treating cardiovascular risk factors in diabetic patients. The ADA has a new educational program called Be Smart About Your Heart and the American College of Cardiology has a complementary outreach educational program to health care professionals via Make the Link.
Diabetes Care, 25:1919-1927,2002, has an article titled Effects of vitamin E on cardiovascular and microvascular outcomes in high-risk patients with diabetes by Eva Lon, MD, MSC et al. This Canadian study looked at the Heart Outcomes Prevention Evaluation (HOPE) trial which evaluated the effects of Vitamin E and of ramipril in patients at high risk of CV events. Patients were eligible for the study if they were 55 years or older and if they had CV disease or diabetes with at least one additional coronary risk factor. The study was designed to recruit a large number of people with diabetes, and the analyses of the effects of vitamin E in this group were preplanned. Patients were randomly allocated to daily treatment with 400 IU vitamin E and with 10 mg ramipril or their respective placebos and were followed for an average of 4.5 years.
The primary study outcome was the composite of myocardial infarction, stroke, or CV death. Secondary outcomes included mortality, hospitalizations for heart failure, hospitalizations for unstable angina, revascularizations, and overt nephropathy. The results, based on the 3,654 people with diabetes, were that Vitamin E had a neutral effect on the primary study outcome, on each component of the composite primary outcome, and on all predefined secondary outcomes. They concluded that daily administration of 400 IU vitamin E for an average of 4.5 years to middle-aged and elderly people with diabetes and CV disease/and or additional coronary risk factors(s) has no effect on CV outcomes or nephropathy.
Diabetes Care 25:2032-2036,2002 has an article titled Cardiac events in 735 type 2 diabetic patients who underwent screening for unknown asymptomatic coronary heart disease, 5-year follow-up from them Milan Study on atherosclerosis and diabetes (MiSAD) by Ezio Faglia, MD et al. This is a report on cardiac events in type 2 diabetic outpatients screened for unknown asymptomatic coronary heart disease and followed for 5 years. They looked at 925 subjects aged 40-65 who underwent an exercise treadmill test (ETT). If it was abnormal, the subjects then underwent an exercise scintigraphy. Of the 925 subjects, 735 were followed for 5 years and cardiac events were recorded. At the beginning of the study, 638 of the 735 followed subjects had normal ETT, 45 had abnormal EET with normal scintigraphy and 52 had abnormal EET and abnormal scintigraphy.
The 52 subjects in this last group underwent a cardiological and diabetological follow-up: the subjects with just abnormal ETT had a diabetological follow-up only. During the follow-ups, 42 cardiac events occurred:1 fatal myocardial infarction (MI), 20 nonfatal MI’s and 10 cases of angina in the 638 subjects with normal ETT; 1 fatal MI in the 45 subjects with normal scintigraphy; and 1 fatal MI and 9 cases of angina in the 52 subjects with abnormal scintigraphy. In all 52 subjects, all cardiac events were significantly more frequent, but the ratio of major (cardiac death and MI) to minor (angina) cardiac events was significantly lower. Scintigraphy abnormality, diabetes duration, and diabetic retinopathy were independent predictors of cardiac events. The researchers concluded that the low ratio of major to minor cardiac events in the positive scintigraphy group may suggest, although does not prove, that the screening program followed by appropriate management was effective for the reduction of risk of major cardiac events.
Diabetes 51:1959-1956,2002 has an article titled Lipoprotein subclasses and particle sizes and their relationship with coronary artery calcification in men and women with and without type 1 diabetes by Helen M. Colhoun et al. Type 1 diabetes is associated with increased atherosclerosis, especially in women, even though such patients often have an apparently normal lipid profile. This research examines whether lipoprotein particle sizes and subclasses differed between type 1 diabetic subjects ( n=194) and age-and sex-matched control subjects (n=195). They examined whether any abnormalities were of similar magnitude in men and women. The relationship of particle size to electron beam computer tomography-defined coronary artery calcification, a measure of atherosclerosis, was also examined. Proton nuclear magnetic resonance (NMR) spectroscopy was used to quantify VLDL, LDL, and HDL subclass levels and average particle size on fasting samples.
LDL size and subclass were similar in diabetic and nondiabetic men. In contrast, in women, diabetes was associated with less large and smaller LDL and a reduced LDL size. This effect of diabetes on LDL size in women compared to men was significant. Diabetes was associated with more large and less small HDL and, to a similar degree in both sexes, a higher HDL size. There were no definitive abnormalities in VLDL size. In nondiabetic subjects, lower average HDL particle size, lower LDL size, and higher VLDL size were significantly associated with coronary calcification. Thus, the HDL size differences with diabetes would be expected to be anti-atherogenic, and the LDL size differences pro-atherogenic. However, there was no clear relationship between particle size and calcification in diabetic subjects. The researchers concluded that in the general population NMR spectroscopy-derived particle size reveals important information about atherogenicity of lipoprotein profile. Type 1 diabetes is associated with differences in NMR-derived particle size, but their pathogenic significance is unclear.
Diabetes 51:3020-3024,2002 has an article titled Independent association of type 2 diabetes and coronary artery disease with myocardial insulin resistance by Patricia Iozzo, et al. Clustering of classical cardiovascular risk factors is insufficient to account for the excess coronary artery disease (CAD) of patients with diabetes, and chronic hyperglycemia and insulin resistance (IR) are the obvious culprits. Whole body and skeletal muscle IR is characteristic of people with type 2 diabetes but whether it extends to the normally contracting heart muscle is controversial. The researchers investigated whether type 2 diabetes is associated with myocardial IR independent of CAD in a case-control series of male nondiabetic and diabetic (type 1 and 2) patients with or with out angiographically documented CAD. Skeletal muscle glucose uptake was reduced in association with both CAD and type 2 diabetes. After looking at all of the data, the researchers concluded that type 2 diabetes is specifically associated with myocardial IR that is independent of and non-additive with angiographic CAD and proportional to skeletal muscle and whole-body IR.
Our final abstract is the one that sums up the reason for our sharing all of this information with you, our readers. The American Journal of Epidemiology 2002;156:929-935 has an article by Dr. Donna K. Arnett et al titled Some heart disease risk factors on the rise in the US. Heart disease and stroke are the first and third leading cause of death respectively in the US. To examine the trends and predict the future burden of cardiovascular disease, the researchers conducted four surveys of adults in Minneapolis-St. Paul. Each survey included 4,000-6,000 people. Over the course of the study, dietary fat consumption fell as did the proportion of people with high blood pressure and percentage of smokers. The number of people using medications to lower blood pressure and cut cholesterol also grew. But cholesterol and obesity climbed and people’s levels of activity fell. These findings suggest that the population burden of cardiovascular disease may increase in the future. The researchers suggested programs and strategies targeted to increased physical activity, reductions in body weight, plus improved diet and eating patterns.
BSP
