Fibrinolysis in diabetes mellitus

In 198 diabetic patients of type I and type II and in 111 healthy persons of a control group the activity of fibrinolysis was investigated before and after a venous occlusion test of ten minutes. Spontaneous fibrinolysis was significantly diminished in diabetics of both types in comparison to the control group. A relationship to the degree of seriousness of retinopathy could not be identified in type I. The activity of fibrinolysis decreased in all test persons in old age. In diabetics patients of type II as well as in that age group being more than 56 years old there were smaller activities of fibrinolysis at higher stages of retinopathy. A negative linear correlation of this spontaneous activity of fibrinolysis could be found for the duration of the disease as well as for age. Different forms of diabetic therapy and the sex allowed no influence of the activity of fibrinolysis to be recognized. An increase of the activity of fibrinolysis after congestion could be established in diabetics as well as in the control group. After venous congestion the fibrinolytic activity showed no differences any longer in diabetics and in the control group, with age, duration of the disease and form of therapy being taken into consideration. Before and after venous congestion a negative linear correlation could be revealed between the activity of fibrinolysis and the height of blood sugar level. Therefore, the real blood sugar concentration should be taken into account in evaluating the fibrinolytic activity.     

Serum beta-glycosidases in diabetes mellitus

Levels of fasting blood glucose, serum beta-glucuronidase and beta-N-acetylglucosaminidase in 47 Libyan diabetic patients were determined. The respective mean values were 254.5 +/- 11 mg/dl, 74 +/- 5.7 Sigma units/ml and 171.8 +/- 25.5 microM PNP/dl. The mean body mass index and duration of diabetes of the patients were 30.5 +/- 0.91 kg/m2 and 7.5 +/- 1.16 years, respectively. Statistically significant correlations were found between fasting blood glucose and serum beta-glucuronidase levels (r = 0.65; p less than 0.001) and also between fasting blood glucose and beta-N-acetylglucosaminidase levels (r = 0.58; p less than 0.001). The activities of these two enzymes increase in serum with increasing fasting blood glucose levels. Patients with positive family history of diabetes have higher activities of these two enzymes than those without positive history of diabetes in the family. Patients with secondary complications have both enzymes elevated as compared with patients without secondary complications. Female patients have higher beta-N-acetylglucosaminidase activity and lower beta-glucuronidase activity than males. Age and duration of diabetes do not appear to have any effect on the activities of these enzymes.     

Platelet spreading in diabetes mellitus

In 162 test persons divided into healthy control persons and diabetics of type I and type II the thrombocyte spreading was investigated according to the method of Breddin. Age, sex, degree of seriousness of retinopathy, duration of diseases, present level of blood sugar and HbA1 concentration were taken into account. Spread thrombocyte forms were increasingly found in old age, in diabetics of both types and a close relation to the extent of retinopathy was evident. As diabetic retinopathy became evident and with growing degree of seriousness, spread forms of thrombocytes were increasingly found, so that the increased spreading capacity may be interpreted as a disturbed metabolic and blood vessel situation in diabetes mellitus.     

Comparison of prognosis for men with type 2 diabetes mellitus and men with cardiovascular disease

Background

People with type 2 diabetes mellitus are at high risk for cardiovascular disease. In some studies, the mortality rate among people with this condition has been equivalent to that among people with cardiovascular disease. We compared cardiovascular mortality between incident cases of diabetes and cardiovascular disease.

Methods

The study population was part of a random sample of 4376 men from Quebec, Canada, aged 35 to 64 years, who did not have cardiovascular disease in 1974 and who were followed until 1998. Three groups of incident cases were identified: diabetes without cardiovascular disease, first cardiovascular event (myocardial infarction, unstable angina or stroke) without diabetes, and both cardiovascular disease and diabetes. These cases were age-matched to a control group without diabetes or cardiovascular disease.

Results

During the 24-year follow-up period, new diabetes without cardiovascular disease was documented in 137 men. A first cardiovascular event without diabetes was documented in 527 men. Relative to the 627 controls, men with 1 of the 2 diseases of interest had higher cardiovascular mortality (age-adjusted relative risk [RR] 3.11, 95% confidence interval [CI] 1.96–4.92) for those with diabetes and 4.46 (95% CI 3.15–6.30) for those with cardiovascular disease). However, within the first 5 years after diagnosis, men with cardiovascular disease had higher cardiovascular mortality than men with diabetes (age-adjusted RR 2.03, 95% CI 1.01–4.08).

Interpretation

Men with isolated type 2 diabetes and men with isolated cardiovascular disease had similar cardiovascular mortality rates several years after initial diagnosis of either condition. These findings reinforce the need to prevent and optimally manage diabetes and cardiovascular disease.In 1971, type 2 diabetes mellitus was already considered an epidemic, affecting more than 170 million people worldwide.¹ In 2001, it was estimated that diabetes prevalence would increase by nearly 50% by the year 2010.¹ Epidemiologic studies performed in randomly sampled populations and initiated in the 1970s and 1980s have shown that diabetes increases the risk of all-cause death, as well as death due to cardiovascular disease and coronary artery disease.^2–23 In some studies,^12–17 but not all studies,^18–23 coronary or cardiovascular mortality among people with type 2 diabetes without previous cardiovascular disease was equivalent to that of people without diabetes who had had a first myocardial infarction or first cardiovascular event. Thus, there is controversy as to whether diabetes alone confers a risk of cardiovascular mortality similar to that associated with having had a first coronary or cardiovascular event. The differences in findings among various studies may be attributable to several factors such as age, sex, duration of diabetes and cardiovascular disease, ethnicity, cardiovascular risk factors and therapies. Furthermore, most studies used prevalent cases without considering the duration of cardiovascular disease or diabetes and did not exclude high-risk patients who had angina or intermittent claudication before the diagnoses of diabetes and cardiovascular disease.The rationale for undertaking the present study was the need for more information about the cardiovascular prognosis of men with type 2 diabetes relative to men with cardiovascular disease. We used incident instead of prevalent cases, without prior angina and without intermittent claudication. We speculated that the adverse prognosis associated with a diagnosis of diabetes would be similar to the prognosis associated with a diagnosis of cardiovascular disease over the long term but would be less similar over the short term. We formulated 2 hypotheses: first, that within the first few years after diagnosis, the risk of a fatal cardiovascular event would be higher among men with a first cardiovascular event and no diabetes than among men with type 2 diabetes and no cardiovascular disease; and second, that over the longer term, the risk of death within these 2 clinical subsets would tend toward equivalence.