Glycaemic control, smoking habits and diabetes duration affect the extrinsic fibrinolytic system in type I diabetic patients but microangiopathy does not

Current smoking status may be associated with overt albuminuria in female patients with type 1 diabetes mellitus: a cross-sectional study

BACKGROUND

There are very few clinical reports that have compared the association between cigarette smoking and microangiopathy in Asian patients with type 1 diabetes mellitus (T1DM). The objective of this study was to assess the relationships between urinary protein concentrations and smoking and gender-based risk factors among patients with T1DM.

METHODS

A cross-sectional study of 259 patients with T1DM (men/women = 90/169; mean age, 50.7 years) who visited our hospital for more than 1 year between October 2010 and April 2011 was conducted. Participants completed a questionnaire about their smoking habits. Patient characteristics included gender, age, body mass index, blood pressure, hemoglobin A1c, lipid parameters, and microangiopathy. Diabetic nephropathy (DN) was categorized as normoalbuminuria (NA), microalbuminuria (MA), or overt albuminuria (OA) on the basis of the following urinary albumin/creatinine ratio (ACR) levels: NA, ACR levels less than 30 mg/g creatinine (Cr); MA, ACR levels between 30 and 299 mg/g Cr; and OA, ACR levels over 300 mg/g Cr.

RESULTS

The percentages of current nonsmokers and current smokers with T1DM were 73.0% (n = 189) and 27.0% (n = 70), respectively. In addition, the percentage of males was higher than that of females (52.2% versus 13.6%) in the current smoking population. The percentage of DN was 61.8% (n = 160) in patients with NA, 21.6% (n = 56) in patients with MA, and 16.6% (n = 43) in patients with OA. The percentage of males among OA patients was also higher than that of females (24.4% versus 12.4%). However, current smoking status was associated with OA in females with T1DM only [unadjusted odds ratio (OR), 4.13; 95% confidence interval (CI), 1.45-11.73, P < 0.01; multivariate-adjusted OR, 5.41; 95% CI, 1.69-17.30, P < 0.01].

CONCLUSIONS

Based on our results in this cross-sectional study of Asian patients with T1DM, smoking might be a risk factor for OA among female patients. Further research is needed of these gender-specific results.

Do plasminogen activator inhibitor (PAI-1) or tissue plasminogen activator PAI-1 complexes predict complications in Type 1 diabetes: the Pittsburgh Epidemiology of Diabetes Complications Study

AIMS

To examine the predictive power of plasminogen activator inhibitor-1 (PAI-1) and the complexes it forms with tissue plasminogen activator (tPA-PAI-1) for the two major Type 1 diabetes (T1D) complications (coronary artery disease (CAD) and overt nephropathy) in the context of standard risk factors.

METHODS

Observational prospective study of 454 participants with childhood onset (< 17 years) T1D, aged 18+ years at baseline. PAI-1 and tPA-PAI-1 were determined using ELISA methodology. Follow-up (6 years) was limited to 382 individuals for CAD and 294 individuals for overt nephropathy, after excluding baseline cases. Total, HDL and LDL-cholesterol, triglycerides, HbA1, blood pressure, body mass index (BMI), waist-hip ratio (WHR), leucocyte count, Beck depression score and fibrinogen were also examined.

RESULTS

The 56 incident cases of CAD had marginally lower PAI-1 and higher tPA-PAI-1 levels compared with those free of CAD. However, marginally higher PAI-1 and significantly higher tPA-PAI-1 (P = 0.04) levels were seen in those who developed nephropathy. After controlling for age, both PAI-1 and tPA-PAI-1 showed significant negative correlations with HDL-cholesterol, and positive correlations with triglycerides, WHR, HbA1 and fibrinogen. tPA-PAI-1 was also positively correlated with total and LDL-cholesterol. In multivariate analyses, neither PAI-1 nor tPA-PAI-1 was an independent predictor of CAD or overt nephropathy.

CONCLUSIONS

These results suggest little association between PAI-1 and later CAD in patients with T1D. However, tPA-PAI-1 complexes may be involved in the pathogenesis of overt nephropathy.

Smoking and mortality among women with type 2 diabetes: The Nurses' Health Study cohort

OBJECTIVE

To assess the relationship between cigarette smoking and mortality among women with type 2 diabetes in the Nurses' Health Study cohort.

RESEARCH DESIGN AND METHODS

The Nurses' Health Study, a prospective cohort of U.S. female registered nurses, included 7,401 women with type 2 diabetes diagnosed at baseline or during follow-up from 1976 to 1996. Total and cause-specific mortality of these diabetic women were the outcomes of interest.

RESULTS

We documented 724 deaths during 20 years of follow-up (67,420 person-years) among women with type 2 diabetes. In multivariate analyses, adjusting for age, history of high blood pressure and high cholesterol, and other cardiovascular risk factors, compared with never smokers, the RRs of mortality were 1.31 (95% CI 1.11-1.55) for past smokers, 1.43 (0.96-2.14) for current smokers of 1-14 cigarettes/day, 1.64 (1.24-2.17) for current smokers of 15-34 cigarettes/day, and 2.19 (1.32-3.65) for current smokers of > or =35 cigarettes/day (P for trend = 0.0002). Women with type 2 diabetes who had stopped smoking for > or =10 years had a mortality RR of 1.11 (0.92-1.35) compared with diabetic women who were never smokers.

CONCLUSIONS

Cigarette smoking is associated in a dose-response manner with an increased mortality among women with type 2 diabetes. Furthermore, quitting smoking appears to decrease this excess risk substantially. Diabetes patients should be strongly advised against smoking.

Legg-Calvé-Perthes disease and passive smoking

We carried out a case-control study with 90 patients with Legg-Calvé-Perthes disease (LCPD) and 183 normal children, as controls, selected at random to determine whether the condition of passive smoking is related to the disease. Seventy-one of 90 of the LCPD group (78.9%) were passive smokers. Only 79 of 183 (43.2%) in the control group were passive smokers (p = 0.00000). We did not find any statistical relationship between passive smoking and evolution of the condition (p = 0.42883), Catterall extension (p = 0.60544), final Stulberg result (p = 0.53201), or presence of sequelae (p = 0.53256). We also could not find any statistical difference between ages (p = 0.18). The odds ratio was 5.3203 (95% confidence interval 2.92-9.69). The association between LCPD and passive smoking, after controlling for age and gender, became significant (p = 0.0000). Thus the risk of LCPD in passive smoking children is more than five times higher than in children who are not exposed to smoke. It seems that passive smoking is a factor directly or indirectly associated with LCPD.

The association of fibrinolysis and hyperlipidaemia with quantitative sensory tests in an epidemiological study of Swedish type 1 diabetic patients

Serum levels of cholesterol, HDL-cholesterol, triglycerides, lipoprotein Lp(a), and the fibrinolysis factors tPA (tissue plasminogen activator) and PAI-1 activity (plasminogen activator inhibitor) were compared with sensory thresholds for vibration, electrical current perception, and pain in a population-based study comprising 239 patients with diabetes mellitus Type 1, aged 15-50 years. Univariate regression analyses (n = 180) showed significant correlations between elevated sensory thresholds and age, duration of diabetes, serum cholesterol and triglycerides, and HbA1c. In multivariate regression analysis, age, duration of diabetes, height, and serum triglycerides showed significant independent associations with five or six of the six measured sensory threshold variables. In addition there was a significant association between increased thresholds for vibration and Lp(a) levels. Thus, increased sensory thresholds for vibration, current perception, and pain in patients with Type 1 diabetes are associated with increased serum triglyceride levels, and Lp(a) levels are associated with increased threshold for vibration. Fibrinolytic activity is unrelated to these measures of nerve function in Type 1 diabetic patients.

Endurance physical activity, diet and fibrinolysis

The impact of long-term, heavy exercise on recently established cardiovascular/thromboembolic risk factors of the fibrinolytic system, tissue plasminogen activator (tPA) and plasminogen activator inhibitor (PAI-1) in relation to food composition was studied. Twenty healthy men, aged 18-55 years participated in a 14-day skiing tour through the Swedish mountains, carrying a pack load of 30 kg, and spending each night in self-dug igloos (ambient temp -10 degrees to -25 degrees C), and were randomized to 2 food regimens having 30 or 40 energy percent of fat. Individual records were kept of all consumed food. Citrated plasma was obtained before and after 1 and 2 weeks of exercise: tPA release was assessed by a 10 min venous occlusion (VO) test. At baseline, daily dietary fiber intake correlated negatively with PAI-1 activity. Already after the first week of the skiing tour there were significant drops in PAI-1 activities, cholesterol and triglycerides. The tPA mass concentrations also dropped, both before and after VO, but tPA activities were unchanged, as were von Willebrand factor (vWF) levels. These changes were related mainly to the expenditure of energy, calculated from the food consumption, and appeared to be mediated through changed insulin sensitivity and decreased body fat mass. The energy percent of fat in the food had no differential impact. The effects receded a few weeks after cessation of the endurance exercise. Thus, endurance physical activity improves the fibrinolytic risk factor profile by reducing PAI-1 while leaving tPA activity unaffected, independently of food composition. A low dietary fiber intake appears to be associated with higher PAI-1 activities at baseline.

Changes in fibrinolytic parameters in male patients with type 2 (non-insulin-dependent) diabetes mellitus

We examined changes in fibrinolytic parameters in male patients with diabetes mellitus (DM) and controls. DM patients were divided into three groups: patients without retinopathy, patients with simple retinopathy, and patients with proliferative retinopathy. Plasma levels of t-PA (tissue plasminogen activator) and t-PA-PAI-1 (plasminogen activator inhibitor-1) complex increased with increase in age, but those of PAI-1 (total and free) did not change in controls. On the other hand plasma levels of PAI-1 decreased with increase in age in DM patients. Plasma levels of t-PA, t-PA-PAI-1 complex, free and total PAI-1 increased with increase in body mass index in controls, but no significant changes were shown in these parameters in DM patients. When compared with controls, plasma levels of t-PA, t-PA-PAI-1 complex and PAI-1 were lower in DM patients. Plasma levels of UK (urokinase) and Lp(a) were higher in DM patients. ELT (euglobulin clot lysis time) was significantly shorter in DM patients than in controls. Patients without retinopathy showed increased fibrinolytic activities compared with those with retinopathy due to the increased levels of t-PA in plasma. These results seem to indicate that blood vessels release larger amounts of t-PA at the early stage of DM, then release being impaired at its advance stage. It is also suggested that the regulatory control mechanisms of fibrinolytic activity associated with mechanisms of fibrinolytic activity associated with change in age and body mass index are different between patients with DM and normal people.

The status of PAI-1 as a risk factor for arterial and thrombotic disease: a review

Plasminogen activator inhibitor-1 (PAI-1) is a rapid inhibitor of tissue plasminogen (tPA) in vivo. Evidence suggests that the level of plasma PAI-1 activity is responsible for the regulation of the whole fibrinolytic process through this tPA/PAI-1 interaction. Levels of PAI-1 have therefore emerged as a candidate for a thrombotic risk factor. Recent epidemiological data supports the view that high plasma levels of PAI-1 may be important in the pathogenesis of arterial and thrombotic disease. These data are reviewed and their significance discussed. PAI-1 expression has been shown to be regulated by many different factors in vitro and the relevance of these data to in vivo physiology is addressed. The current knowledge of the biochemistry, expression and genetics of PAI-1 is also presented and the significance of this to disease pathogenesis is discussed.

Fibrinolytic parameters and lipoprotein (a) levels in plasma of patients with coronary artery disease

Fibrinolysis and lipid disturbances have been considered as independent risk factors for coronary artery disease. Besides this, lipoprotein(a), which is characterized by its homology with plasminogen may interfere with the fibrinolytic function. To evaluate the eventual correlation between fibrinolytic parameters, lipoprotein (a) and other risk factors, 46 patients with coronary artery disease (34 with chronic angina pectoris and 12 with myocardial infarction) were studied. Increased basal values of t-PA antigen (8.2 and 6.6 vs. 4.2 ng/ml) but decreased response after stimulus (2.2 and 1.8 vs. 3.8 ng/ml) and increased levels of lipoprotein(a) (24.7 and 35.9 vs. 10.5 mg/dl) were the most relevant differences between coronary artery disease patients and controls. No correlation between lipoprotein(a) and fibrinolytic parameters was found. Therefore plasma concentration of the main plasma fibrinolytic parameters and lipoprotein(a) seem to be unrelated though the relevance of this interaction at a local level needs to be studied.

Activation of coagulation in diabetes mellitus in relation to the presence of vascular complications

To examine the relationship between diabetic vascular disease and haemostasis, a set of sensitive assays has been used to assess in vivo activation of coagulation in 62 diabetic patients (41 Type 1 and 21 Type 2), aged 19-68 years, who had been screened for the presence of complications. Fibrinopeptide A, an index of thrombin activity, was significantly increased in diabetic patients compared with control subjects (p less than 0.05), in both plasma (with complications mean 8.04 +/- 11.87 (+/- SD); without complications 7.21 +/- 10.13; control subjects 2.11 +/- 1.40 micrograms l-1) and urine (with complications mean 1.48 +/- 0.74; without complications 1.35 +/- 0.62; control subjects 0.98 +/- 0.39 micrograms l-1). Activated factor VII (VIIa ratio 1.21 +/- 0.39; 1.13 +/- 0.23; 1.01 +/- 0.11) and fibrinogen (3.15 +/- 0.59; 3.11 +/- 0.69; 2.70 +/- 0.57 g l-1) were also elevated in diabetic patients with and without complications (VIIa p less than 0.05, fibrinogen p less than 0.01). The only difference between Type 1 and Type 2 patients was in fibrin degradation products (Type 1 0.28 +/- 0.18; Type 2 0.40 +/- 0.18 mg l-1, p less than 0.01). Plasma levels of fibrin degradation products were elevated in diabetic patients (p less than 0.05 vs control subjects), and correlated with age (r = 0.44, p less than 0.01) but were unrelated to the presence of complications. There were no significant differences in any coagulation variables between diabetic patients with and without complications.(ABSTRACT TRUNCATED AT 250 WORDS)

Hypo-fibrinolysis in patients with hypertension and elevated cholesterol

To test the hypothesis that increased blood pressure and hyperlipidaemia result in changes in the fibrinolytic system, 84 subjects with both hypertension and elevated serum cholesterol levels (the high risk group) were compared with 55 controls matched with respect to age, sex and body mass index (BMI). Plasminogen activator inhibitor (PAI-1), and tissue plasminogen activator (tPA) antigen and activity were measured before and after venous occlusion. In the high risk group, tPA activity was significantly lower both before and after venous occlusion and PAI-1 levels were significantly higher. In a multivariate analysis the triglyceride levels, diastolic blood pressure and cholesterol levels were independently associated with the PAI-1 levels. Diastolic blood pressure was independently and inversely associated with resting tPA activity. We conclude that patients with hypertension and hyperlipidaemia have a reduced activity of the fibrinolytic system, an effect which is unrelated to differences in age, sex, smoking or BMI.

Effects of doxazosin and atenolol on the fibrinolytic system in patients with hypertension and elevated serum cholesterol

Disturbances in the fibrinolytic system have been associated with cardiovascular disease and its risk factors. In the present study the effects of an alpha 1-adrenoceptor inhibitor (doxazosin) and a selective beta-adrenoceptor blocker (atenolol) on the fibrinolytic system have been evaluated. Eighty four subjects with previously untreated mild to moderate hypertension and elevated serum cholesterol were randomized to receive atenolol or doxazosin in a double-blind study over 6 months. Tissue plasminogen activator(tPA) and plasminogen activator inhibitor (PAI-1) were measured in citrated plasma samples before and after venous occlusion before and at the end of the study period. tPA activity after venous occlusion and tPA capacity were significantly increased after doxazosin as compared to pretreatment values. The fibrinolytic variables did not change in the atenolol group. Thus, doxazosin but not atenolol, improved the activity of the fibrinolytic system in patients with hypertension and an elevated serum cholesterol level. This effect of doxazosin warrants consideration when selecting a first-line antihypertensive drug.

How accurate is the smoking history in newly diagnosed diabetic patients?

A smoking history was obtained from 94 consecutive newly diagnosed diabetic patients referred to an adult diabetic clinic. The smoking load was measured using urinary cotinine/creatinine ratios (COT/Cr). Fifty-six patients (60%) claimed to be non-smokers, but COT/Cr suggested active smoking in five of these. The patients who admitted to smoking were given standardised anti-smoking advice. At 3 months, 32 smoking patients were reviewed and 21 (66%) claimed to have reduced or stopped smoking. However, the median COT/Cr in the 32 patients showed no significant reduction (11.15 vs. 9.30 micrograms/mg). Urinary COT/Cr indicated that 6 patients had stopped smoking (median COT/Cr 6.98 fell to 0.97 micrograms/mg), but several patients had a marked rise in COT/Cr, demonstrating that their smoking habit had increased considerably. Therefore the smoking history obtained from new diabetic patients can be very misleading. An objective measure of smoking habits in the initial assessment and follow-up of diabetes may be worthwhile. Anti-smoking counselling at diagnosis of diabetes may persuade some smokers to stop.

Plasma levels of endothelial-derived haemostatic factors in autoimmune thrombocytopenia and haemolytic anaemia

The endothelial cell-synthesized haemostatic factors tissue plasminogen activator (tPA), plasminogen activator inhibitor (PAI) and von Willebrand factor (vWF) were assayed in a cross-sectional study of patients with immune thrombocytopenia (ITP) (n = 12) and autoimmune haemolytic anaemia (AIHA) (n = 3), and compared with a simultaneously selected contrast group of other hospitalized patients with obscure blood cytopenia at the time of sampling. All three factors were grossly elevated in both the study group and the contrast group. In the autoimmune patient group, the three haemostatic variables were significantly correlated with orosomucoid levels, demonstrating the acute-phase nature of the increased levels of vWF, tPA and PAI. These findings support the view that haemostatic factors of the vessel wall are implicated in the pathophysiology of a wide spectrum of diseases.

A study of patients with diabetes mellitus (type 1) and end-stage renal failure: tobacco usage may increase risk of nephropathy and death

Thirty-four consecutive patients with diabetes mellitus as a plausible cause of end-stage renal failure were investigated with regard to outcome and tobacco consumption. The mean duration of diabetes was 25.5 years. Thirty-one of the patients had used tobacco regularly for at least 5 years. For 28 patients it was possible to calculate the intake of tobacco as the daily mean and the total consumption (expressed as pack years). The time period (in years) between initiation of tobacco usage and onset of persistent proteinuria, as an early indicator of diabetic nephropathy, was shorter if the daily consumption of tobacco was higher (P less than 0.01) and the total consumption (pack years) in these patients was lower (P less than 0.05). There was an increased risk of early death (P less than 0.01) in patients who were currently smokers when they were uraemic (predialysis), on dialysis or had kidney grafts, compared to those who had never used tobacco or who were ex-smokers. In conclusion, it appears to be important for insulin-dependent diabetic patients to avoid tobacco usage and for current smokers to give up the habit in order to reduce the risk of diabetic nephropathy and early death.

Reduced plasminogen activator inhibitor activity in high consumers of fruits, vegetables and root vegetables

We studied a cross-sectional sample of 260 subjects aged 30-60 years, in order to assess the relation between food intake habits and factors of the fibrinolytic system. Plasma samples of tissue plasminogen activator (tPA) antigen, and plasminogen activator inhibitor (PAI-1) activity were obtained for the assay. The dietary pattern was determined using a food frequency questionnaire, according to which the subjects were grouped as high, low or medium consumers. The subjects who were high consumers of fruit, vegetables, and root vegetables showed the lowest levels of PAI-1, those who were low consumers had the highest levels, whereas the medium consumers showed intermediate values. The tPA levels did not differ between the three groups, and there were no significant differences in other variables that covaried with PAI-1 levels, such as age, anthropometric variables, or serum lipid levels, which could confound the PAI-1/food pattern relationship. The data, which show that a frequent intake of fruit, vegetables, and root vegetables--foodstuffs rich in vitamin C and fibre--is associated with lower PAI-1 levels, are consistent with increased activity of the fibrinolytic system and thus a reduced risk of thromboembolic and cardiovascular disease in subjects who exhibit this food intake pattern.