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Chronic elevations of blood glucose (hyperglycemia), blood pressure (hypertension), or both, are highly associated with mortality from cardiovascular diseases. In particular, both hyperglycemia and hypertension are directly linked to atherosclerosis (the formation of fatty cholesterol-containing plaques on the inner walls of arteries). The Framingham Heart Study was begun in 1948 with a sample of 5,209 men and women between the ages of 30 and 62 years who were followed biennially and monitored for the occurrence of any significant cardiovascular developments. Every other year, blood pressure and glucose levels were determined, blood chemistry analysis was performed, and data were obtained on a variety of clinical and life-style variables. Both hypertensive and hyperglycemic subjects were more likely to develop atherosclerosis. Diabetic patients were more likely to develop hypertension than nondiabetics, and hypertensive patients were more likely to develop diabetes (or glucose intolerance, a milder form of the disease) than normotensive subjects. It was found that hypertension, obesity, insulin resistance, hyperinsulinemia (high blood levels of insulin), hypertriglyceridemia (high blood levels of triglyceride fats), and hypercholesterolemia (high blood levels of cholesterol) tend to coexist. All of these factors promote the development of atherosclerosis; this may partly underlie the increased propensity of diabetic and hypertensive patients to develop this disease. Rational preventative measures should be undertaken in patients at risk for either condition, including weight reduction, a low-fat diet, and cessation of cigarette smoking. (Consumer Summary produced by Reliance Medical Information, Inc.)

The influence of uncontrolled blood glucose levels on the development of cardiovascular disease (CVD) is recognized, but not well-defined. A long-term study was designed to investigate the relationship between abnormally high blood glucose (hyperglycemia) and the onset of CVD. Data were derived from The Framingham study, in which every two years, since 1970, 1,382 men and 2,094 women between the ages of 45 and 85 years were examined. The subjects, who did not shown signs of CVD at the beginning of the study, were examined, evaluated, and reclassified. Classifications were made according to blood glucose levels and onset of CVD. Individuals receiving treatment for diabetes, or with abnormally low blood glucose were excluded from this analysis. Most previous long-term studies that consider numerous variables have investigated the effect of abnormal glucose levels in men, but not women. The results indicate that hypoglycemia is predictive of CVD, regardless of the presence of other risk factors such as smoking and high blood pressure, for women, but not for men. (Consumer Summary produced by Reliance Medical Information, Inc.)

Obesity and weight gain predispose people to high blood pressure, and both obesity and hypertension are separate risk factors for coronary artery disease, stroke, and other cardiovascular disease (CVD). Obesity leads to the development of conditions which are also risk factors, including higher blood levels of cholesterol and fat. This suggests that an individual with hypertension and obesity would be at higher risk than an individual with only hypertension. However, whether this is true is unclear in spite of several studies. Some have argued that hypertension in the obese is more benign. The relative risks of hypertension with or without coexisting obesity were examined in a study of 5,209 subjects over a period of 34 years. Among the subjects, only those who were initially free of CVD were studied, leaving 1,823 subjects (845 female). The risk of illness and death from CVD related to hypertension was similar in individuals of varying body mass index (BMI, a ratio of weight to height). When adjusted for age and smoking, the absolute risk of CVD was higher in hypertensive subjects with high BMIs. The results refute the notion that hypertension in obese subjects is less dangerous. Rather, the study concludes that hypertension is dangerous at any BMI, and weight reduction may decrease the cardiovascular risk of the hypertensive patient. (Consumer Summary produced by Reliance Medical Information, Inc.)

Coronary artery disease is associated with risk factors such as sex, age, smoking, high blood pressure, blood cholesterol levels, and weight. CAD tends to cluster within families, but the reason for this is unclear. It may be related to similar behavior patterns involving known risk factors, or genetic components such as blood pressure or cholesterol levels. A third alternative is that a family history of CAD is predictive of the risk for CAD independent of the other identified risk factors. The influence of a family history of CAD on identified risk factors was evaluated through a study of 2,740 women and 2,107 men in the Framingham Study. The results suggest that familial clustering is not due to similarity in known risk factors within the family. In addition, individuals who have a parent with the condition do not appear to be more susceptible to the effects of known risk factors. This suggests that the death of a parent from CAD may help to identify cases of CAD that occur among people who are otherwise considered to be at low risk. Further, modification of currently known risk factors may not decrease the risk associated with parental history of CAD, but will still decrease the overall risk for CAD. (Consumer Summary produced by Reliance Medical Information, Inc.)

The Framingham Study showed that diabetes increases the risk of cardiovascular disease and, in particular, disease of the coronary arteries that supply the heart. Factors that increase the risk of coronary disease occur in excess in diabetes. Impaired glucose tolerance, or the reduced ability of the tissues to use glucose, is a common characteristic of diabetes and contributes to an increased risk of coronary disease. Furthermore, diabetic patients may have increased thrombogenic factors, substances that promote the development of thrombi or blood clots. One such thrombogenic factor, fibrinogen, was shown to be important in the occurrence of cardiovascular disease. The role of impaired glucose tolerance and fibrinogen in the development of cardiovascular disease, particularly coronary disease, was assessed in 1,314 patients who were initially free of cardiovascular disease at the beginning of the Framingham study. Diabetes developed in 46 men and 43 women, and blood glucose levels greater than 120 milligrams per deciliter (mg/dL) were detected in 56 men and 53 women. Diabetes was a predisposing factor in 408 major cardiovascular disorders. Compared with nondiabetics, fibrinogen and triglyceride levels, blood pressure, and weight were greater and high density lipoprotein cholesterol was lower in diabetic patients. Although the ability of diabetes to increase the risk of cardiovascular disease is influenced by the presence of other risk factors, impaired glucose tolerance independently contributed to the risk of cardiovascular disease. Fibrinogen values increased with blood sugar levels, suggesting that the diabetic influence on cardiovascular disease may also be related to thrombogenic factors. (Consumer Summary produced by Reliance Medical Information, Inc.)

Two major risk factors for heart disease that often co-exist are hypertension, or high blood pressure, and hyperlipidemia, elevated blood lipids such as cholesterol and triglycerides. Both hypertension and hyperlipidemia should be corrected or minimized through medical treatment to prevent cardiovascular disease. The physician's best choice of medication when a patient first develops hypertension is currently a controversial topic. Some medications that lower blood pressure tend to raise blood lipids; diuretics and beta-blockers may have this effect in some patients. Alternative medications that have either a neutral or beneficial effect on lipid levels are those in the categories known as alpha-(sub 1)-blockers, ACE inhibitors, and calcium channel blockers. These drugs may be good choices for patients who have both hypertension and hyperlipidemia, and they tend to have few side effects. The selection of antihypertensive medication should also take into account the patient's age, race, and other medical conditions. Research has shown that certain classes of medication are more effective in blacks than whites or in elderly versus younger patients; guidelines for physicians are presented. (Consumer Summary produced by Reliance Medical Information, Inc.)

Previous studies have associated the development of cataracts in diabetics with a death rate of more than two times that of diabetics without cataracts. This paper explores whether this link can be associated with changes specific to the cardiovascular system. At the time of eye examination, 133 diabetic patients without cardiovascular involvement were observed. Of these, 57 had at least one cardiovascular event such as heart attack or stroke by the time of their most recent follow-up examination eight to ten years later. Statistical examination suggests that there is an increased risk of cardiovascular problems in diabetic persons with lens changes. Congestive heart failure and coronary artery disease (diseases of the vessels to the heart itself) were found. The authors conclude that lens changes in adult-onset diabetics are an early prognostic sign of mortality and appear to be a predictor of cardiovascular disease.

There is a fundamental, albeit poorly understood, link between the blood levels of the glucose-regulating hormone insulin and the regulation of blood pressure. In particular, high levels of insulin (hyperinsulinemia) are associated with high blood pressure (hypertension). The mechanism by which this linkage might be made remains unknown. Insulin enhances sodium retention, which would tend to raise blood pressure; effects of the hormone on smooth muscle or the kidneys may be involved, or there may some as yet undefined factor that causes increases in both insulin and blood pressure. In any case, both hyperinsulinemia and hypertension promote the formation of atherosclerosis, or fatty plaque deposits on the inner walls of blood vessels; both are also risk factors in the development of all major cardiovascular diseases including coronary artery disease, peripheral vascular disease, stroke, and cardiac failure. Both hyperinsulinemia and high blood pressure occur disproportionately in obese patients. It has been hypothesized that insulin resistance, or an insensitivity to the normal glucose-lowering effects of insulin, may be the common link between atherosclerosis, diabetes, obesity, hypertension, and thrombogenesis (the formation of arterial blood clots). It is particularly important to rapidly treat hypertension in diabetic patients; such treatment can delay the onset of numerous complications to which diabetics are particularly prone, including kidney dysfunction (nephropathy). (Consumer Summary produced by Reliance Medical Information, Inc.)