Presence Of Microangiopathy Research Articles

Diabetic microangiopathy and urinary glycosaminoglycans.

Alterations in the metabolism of glycosaminoglycans (GAG) may play a role in the pathogenesis of diabetic-associated microangiopathy. Consequently, the relationship between diabetic nephropathy and retinopathy and urinary GAG distribution was assessed in 96 IDDM patients in comparison to 103 healthy controls. GAG concentration in 24h urine samples was determined by precipitation with cetylpyridinium chloride and potassium acetate in ethanol followed by a colorimetric test with carbazole. A marked difference (P = 0.0008) in urinary GAG excretion between patients (24.3 +/- 1.5 mg/24 h, mean +/- SEM) and controls (16.2 +/- 0.75 mg/24 h) could be detected. In patients with IDDM of longer duration, GAG excretion was increased (< or = 10 yr: 20.8 +/- 2.1 vs > 10 yr: 27.4 +/- 2.1 mg/24 h; P = 0.03). Furthermore, IDDM patients with class 4 nephropathy and retinopathy exhibited a markedly higher GAG excretion compared to those without nephropathy (33.1 +/- 3.0 vs 22.6 +/- 1.7 mg/24 h, P = 0.005) or retinopathy (29.7 +/- 2.8 vs 21.2 +/- 1.7 mg/24 h, P = 0.009). An increased urinary GAG concentration was detected in IDDM patients with albuminuria (> 300 mg/24 h: 29.9 +/- 3.3 vs < 30 mg/24 h: 23.0 +/- 1.7 mg/24 h; P = 0.048), proteinuria (> 0.5 g/24 h: 30.3 +/- 3.7 vs < 0.05 g/24 h: 22.7 +/- 1.6 mg/24 h) and in patients with augmented serum creatinine in comparison to those with normal values (> 0.12 mg/L: 34.9 +/- 2.3 vs < 0.12 mg/L: 22.4 +/- 1.6 mg/24 h; P = 0.01). The results demonstrate a close relationship renal GAG excretion and the presence of microangiopathy in IDDM patients.

Retinopathy in type 2 diabetes mellitus is associated with increased intima‐media thickness and endothelial dysfunction

Microangioathy and macroangiopathy in type 2 diabetes mellitus (T2DM) frequently coexist. Both types of vascular complications share traditional risk factors. It is not clear whether the presence of microangiopathy, such as diabetic retinopathy (DR), constitutes a predictor of atherosclerosis in T2DM. Here we described the search for the association between DR and intima-media thickness (IMT) in T2DM. We also compared endothelial function in subjects with and without DR. We examined 182 consecutive patients with T2DM for at least 5 years (mean age at examination 56.3 +/- 6.52 years). We assessed (i) IMT of carotid artery by ultrasound and (ii) endothelial function by flow-mediated dilatation (FMD) method as well as by measurement of concentrations of von Willebrand factor (vWF) and s-ICAM-1. All patients underwent ophthalmological examination. Statistical analysis included Student's, Mann-Whitney, chi-square, Fisher tests and multiple regression. DR was found in 71 (39.0%) subjects. IMT was higher in patients with DR than those without DR (0.87 mm vs. 0.79 mm, respectively, P = 0.0001). FMD was lower in the complication group than in subjects without DR (8.38% vs. 10.45%, respectively, P = 0.0023). Concentrations of s-ICAM-1 and vWF were not different between the groups. In multiple regression analysis, DR was among the predictors of increased IMT (P = 0.016) and decreased FMD (P = 0.002). We did not find a significant association of DR with vWF and s-ICAM-1 (P = 0.09 and P = 0.11, respectively). DR is associated with increased IMT and endothelial dysfunction in T2DM. Impaired endothelial function may be a common denominator of pathogenesis of microvascular complications and atherosclerosis in T2DM.

Serum adiponectin predicts all-cause mortality and end stage renal disease in patients with type I diabetes and diabetic nephropathy

Adiponectin levels are increased in patients with type I diabetes especially in the presence of microangiopathy. Here we determined the predictive value of serum adiponectin levels and 8 adiponectin gene polymorphisms for mortality, cardiovascular events and end-stage renal disease in type I diabetic patients. This prospective, observational follow-up study of type I diabetics consisted of 438 patients with overt diabetic nephropathy that were compared to 440 type I patients with normal albumin excretion. These two groups were followed an average of 8 years and generally matched for gender, age and duration of diabetes. Cox regression analysis of 373 patients showed a covariate-adjusted hazard ratio for all-cause mortality of 1.46 for a change of one standard deviation in log10 of serum adiponectin. There was no association with cardiovascular events; however, serum adiponectin levels predicted end stage renal disease in a covariate-adjusted analysis. Two of eight gene polymorphisms, found in the 878 patients, were associated with increased serum adiponectin levels but none of the polymorphisms were associated with a renal or cardiovascular outcome. These studies show that high serum adiponectin levels predict mortality and progression to end stage renal disease in type I diabetic patients.

Scleredema adultorum of Buschke: an under recognized skin complication of diabetes

Scleredema of Buschke or scleredema diabetorum is a skin complication of diabetes with deposits of collagen and aminoglycans in the dermis. This disease characterized by thickening and hardening of the skin, is usually localized in nape, back and shoulder areas. Consequences could be a decrease in motility of the shoulders and an impairment of respiratory function. Other possible complications are sleep apnoea syndrome and monoclonal gammapathy. Type 1 or type 2 diabetes may be associated with scleredema of Buschke in more than 50% of cases. Diabetes-related risk factors are long duration of the disease, presence of microangiopathy, overweight and need of insulin. Various specific treatments proposed in the literature are poorly validated. In most severe cases, radiation therapy may be useful.

Serum level of sialic acid (SA) and carbohydrate‐deficient transferrin (CDT) in type 2 diabetes mellitus with microvascular complications

Sialic acid (SA) is responsible for the composition of different isoforms of transferrin and is reported to be a marker of microvascular complications in type 2 diabetes mellitus. Therefore, we explored the serum concentration of SA, and the less sialylated isoforms of transferrin, termed carbohydrate-deficient transferrin (CDT), in relation to the presence of microvascular complications in type 2 diabetes mellitus. We studied 21 patients with type 2 diabetes with microangiopathy and 22 patients without complications who were hospitalized at a diabetic clinic. The prevalence of microvascular complications was based on clinical history, fundoscopy, and laboratory tests. Blood samples were taken for measurements of SA, CDT, total transferrin, glucose, HbA1c, fibrinogen, C-reactive protein (CRP), and indicators of renal dysfunction (i.e., creatinine, urea, albumin excretion rate (AER), and glomerular filtration rate (GFR)). A rise in serum SA and a decrease in CDT concentrations were observed in both diabetic groups with and without complications, and there were no differences between the two groups of patients. There was a statistically significant correlation between serum SA and CDT in diabetic subjects with microvascular complications, but not in patients without such complications. This proves that the serum changes in CDT and SA levels in the course of type 2 diabetes mellitus are associated with each other in the presence of microangiopathy.

Identificación del riesgo de pie diabético y factores asociados

Objectives To identify compliance with a protocol for the detection of diabetic foot in nursing consultations, as well as the risk of diabetic foot in the population studied, and to evaluate the association between diabetic foot and cardiovascular risk factors. Method We performed a multicenter, descriptive, cross-sectional, crossover study in three semiurban basic health areas in the region of Baix Empordà in Girona, Spain, with a population of 50056 inhabitants and a known prevalence of diabetes mellitus of 4.9% (2453 individuals). Men and women aged more than 14 years old with a diagnosis of diabetes mellitus of more than 6 months duration attended in the nursing consultations program in 2001 were studied. Statistical analysis consisted of univariate analysis and the chi-squared test. Results The protocol was applied in 30.2% of the population attended (625 out of 2069). Risk 1 of ulceration was found in 51.4%, risk 2 in 30.4%, risk 3 in 13.8% and risk 4 in 4.5%. Intermittent claudication (p < 0.001), hypertension (p < 0.003) and the presence of microangiopathy (p < 0.001) were directly associated with higher risk. Conclusions Every effort should be made to prevent and detect diabetic foot in patients with hypertension, claudication or microangiopathy. The application of the protocol should be increased.

Nephropathy, but not retinopathy, is associated with the development of heart disease in Type 1 diabetes: a 12‐year observation study of 462 patients

To study the occurrence of heart disease and death in Type 1 diabetic patients and evaluate whether presence of microangiopathy, i.e. nephropathy and retinopathy, was associated with the outcome. A 12-year observation study of 462 Type 1 diabetic patients without a previous history of heart disease at baseline who were treated under routine care in a hospital out-patient clinic. A total of 85 patients developed signs of heart disease, i.e. myocardial infarction (n = 41), angina (n = 23), and heart failure (n = 17) and 56 patients died. The mortality for patients without signs of heart disease during the observation period was 7.6% compared with 51% in patients with myocardial infarction (P < 0.001), 26% in patients with angina (P < 0.01) and 65% in patients with heart failure (P < 0.001). The relative risk for death was 9.0 (P < 0.001) and 2.5 (P < 0.05) times higher in patients with macroalbuminuria and microalbuminuria, respectively. The risk for cardiovascular death was 18.3 times (P < 0.001) higher in patients with macroalbuminuria compared with patients with normoalbuminuria. In patients with sight-threatening retinopathy, the relative risk for death was 7.0 times higher (P < 0.01) and the risk for coronary heart disease events 4.4 times higher (P < 0.05) compared with patients with no retinopathy. However, when retinopathy was adjusted for presence of macroalbuminuria, this association disappeared. This study shows a high incidence of heart disease in patients with Type 1 diabetes. The worse prognosis was seen in patients with sight-threatening retinopathy and macroalbuminuria and microalbuminuria at baseline. Macroalbuminuria and microalbuminuria were independently associated with a high risk for heart disease and death while the association with sight-threatening retinopathy only occurred in the presence of nephropathy.

Ocular disease in patients with TB and HIV presenting with fever in Malawi

To investigate ocular disease in Malawian patients with tuberculosis (TB) and HIV in presenting with fever, and to determine if indirect ophthalmoscopy is useful in the diagnosis of mycobacteraemia. A prospective study of all adult patients admitted with fever to Queen Elizabeth Central Hospital, Blantyre. All recruited patients had an ophthalmic examination, HIV tests, chest x-ray, sputum examinations, bacterial and mycobacterial blood cultures and malaria slide. 307 patients were recruited; 109 (36%) had TB, including 53 (17%) with mycobacteraemia; 255 (83%) had HIV and 191 (62%) had AIDS. Of the patients with TB 102 (94%) had HIV. Choroidal granulomas were found in four patients, all of whom had AIDS; three had disseminated TB with mycobacteraemia, and one had persistent fever but no other evidence of TB. Among the patients with AIDS, 32 (17%) had retinal microangiopathy manifest by cotton wool spots; one (0.5%) had signs of active cytomegalovirus (CMV) retinitis. The presence of microangiopathy was not related to TB. In Malawian patients with TB presenting acutely with fever, choroidal granulomas were found in 2.8%, and were concurrent with mycobacteraemia and AIDS. Ophthalmoscopy was not a useful aid in the diagnosis of mycobacteraemia. CMV retinitis is rarely seen in African AIDS patients. This may be due to mortality early in the disease course, or differences in race, HIV sub-type or co-morbidity.

Development of elderly diabetes burden scale for elderly patients with diabetes mellitus

Background: The purpose of the present paper was to validate an elderly diabetes burden scale (EDBS) and to assess its correlates in elderly patients with diabetes mellitus.Methods: Comprehensive questionnaires about both diabetes‐specific and non‐specific quality of life (QOL) were given by an interviewer to 455 elderly diabetic patients aged &gt; 65 years. To assess diabetes‐specific QOL, the EDBS was developed. The internal consistency and test–retest reliability of the EDBS were assessed. The validity of the EDBS was assessed with the correlation with the Philadelphia Geriatric Center morale scale, the mini‐mental state examination (MMSE) and diabetic complications, treatment of diabetes, hemoglobin (Hb) A1c, frequency of hypoglycemia, and socioeconomic factors.Results: Factor analysis of the 23 items on EDBS produced six reliable components (Cronbach's α): symptom burden (0.55), dietary restrictions (0.89), social burden (0.89), worry about diabetes (0.85), treatment dissatisfaction (0.85), and burden by tablets or insulin (0.77). It was found that the EDBS and its six subscales had good test–retest reliability (r = 0.94–0.99). However, the EDBS correlated significantly with the morale scale but not with MMSE, suggesting convergent and discriminant validity. The high scores of some subscales and total EDBS were significantly associated with high HbA1c level, frequency of hypoglycemia, and insulin therapy, showing construct validity. Multivariate analyses revealed that hyperglycemia, frequency of hypoglycemia, insulin treatment, the presence of microangiopathy, and low positive social support were independently associated with increased elderly diabetes burden scores.Conclusion: The EDBS is a simple but reliable and valid measure of diabetic‐specific QOL in elderly people with diabetes mellitus.

Relation of left ventricular hypertrophy to inflammation and albuminuria in adults with type 2 diabetes: the strong heart study.

To evaluate in adults with type 2 diabetes the extent to which the relation of left ventricular hypertrophy (LVH) to markers of systemic inflammation (fibrinogen and high-sensitivity C-reactive protein [hsCRP]) are affected by microangiopathy. We selected adults with type 2 diabetes using American Diabetes Association criteria from a population-based cohort, excluding those with medical history or electrocardiographic evidence of coronary heart disease or dialysis-dependent renal failure. LVH was assessed by echocardiogram. Of the 1299 eligible participants, 384 (29.6%) had LVH, which was associated with higher BMI, hsCRP, fibrinogen, and albuminuria in univariate analyses. After controlling for significant confounders, fibrinogen and albuminuria were higher in the presence of LVH (both P < 0.01), whereas hsCRP was not (P = 0.2), mostly because of the confounding effect of BMI. Adjustment for albuminuria abolished the relation of LVH to higher fibrinogen (P = 0.2). However, fibrinogen was significantly higher in participants with LVH among those without pathologic levels of albuminuria (<30 mg/g creatinuria), but not independent of BMI. Although hsCRP and fibrinogen were moderately correlated, fibrinogen, but not CRP, showed a significant relation with albuminuria. In adults with type 2 diabetes, echocardiographic LVH is associated with susceptibility to atherothrombosis and increased albuminuria, which is a marker of microangiopathy and endothelial dysfunction that appears in turn to be a relevant pathogenetic link between LVH and inflammation. However, in the absence of significant microalbuminuria, elevated BMI is a relevant pathogenetic factor in the relation of LVH to increased levels of markers of inflammation, potentially preceding development of significant albuminuria. In the presence of microangiopathy, we found that the atherothrombotic risk profile associated with LVH was independent of BMI and possibly reflected the association of LVH with a higher degree of endothelial dysfunction.

Variations of Ambulatory Blood Pressure With Position in Patients With Type 1 Diabetes

To study the influence of position changes on 24-h ambulatory blood pressure (ABP) in normotensive or mildly hypertensive normoalbuminuric patients with type 1 diabetes. A cross-sectional evaluation of patients was staged according to the duration of diabetes (DD) and the presence of microangiopathy. We recruited 37 patients (30 men and 7 women), aged 38 +/- 12 years, who were normotensive or mildly hypertensive (diastolic blood pressure [DBP] <105 mmHg) and free of antihypertensive treatment and microalbuminuria. They were included according to DD (group 1, <5 years; group 2, > or =10 years). An additional group of seven diabetic patients with microalbuminuria and mild untreated hypertension was also investigated. We recorded 24-h ambulatory blood pressure every 15 min with a position sensor, which allowed for the discrimination between standing or supine/sitting position in the patient. Mean daytime (10:00 A.M. to 8:00 P.M.) ABP in supine/sitting position did not significantly differ between groups 1 and 2. However, standing ambulatory systolic blood pressure (ASBP) and ambulatory DBP (ADBP) were significantly higher than supine/sitting ASBP and ADBP in group 1 (DeltaSBP 4 +/- 5, DeltaDPB 4 +/- 6 mmHg, P < 0.01) but not in group 2 (DeltaSBP 2 +/- 8, DeltaDBP 2 +/- 4 mmHg, P = NS). Patients free of microangiopathy presented with significantly higher ABP in standing position than in sitting/lying position, whereas patients with retinopathy and/or nephropathy exhibited no significant increase of ABP during standing. The monitoring of position during ambulatory measurement of blood pressure in type 1 diabetic patients shows different patterns in relation to disease duration and the presence of microangiopathy.

Pulmonary Function in Patients with Diabetes Mellitus

Pulmonary complications of diabetes mellitus have been poorly characterized. Although some authors have reported normal pulmonary function, others found abnormalities in lung volumes, pulmonary mechanics, and diffusing capacity. We studied pulmonary function in a group of patients with diabetes using a combined cardiopulmonary exercise test. Twenty-seven patients with diabetes aged 48 +/- 13 years participated in the study. Overall, forced vital capacity, forced expiratory volume in 1 second, and forced expiratory flow, midexpiratory phase, were within the predicted values, but the residual volume/total lung capacity ratio was slightly elevated. Comparison by diabetes type showed nonsignificant differences in forced expiratory volume in 1 second and forced expiratory flow, midexpiratory phase. Residual volume/total lung capacity ratio was significantly elevated in type 1 patients compared with type 2. Carbon monoxide diffusion capacity (DLCO) was normal in both groups. There was no correlation between the results on pulmonary function test and duration of disease, presence of microangiopathy, or glycemic control. The DLCO was significantly lower in patients with microangiopathic changes, but not when DLCO was corrected for alveolar volume. On the cardiopulmonary exercise test, maximal workload, maximum oxygen uptake, and maximal heart rate were less than predicted, whereas anaerobic threshold and ventilatory reserve were normal. No significant differences were noted in diabetes type, and there was no correlation between parameters of cardiopulmonary exercise test and the other variables. Spirometric values are preserved in patients with diabetes mellitus, and there are no defects in diffusing capacity. Cardiovascular factors may account for impaired physical performance. There is no need for routine screening of pulmonary function among diabetic patients.

Sural Nerve Pathology In Asymptomatic Minimally Neuropathic Diabetic Patients

12 diabetic patients aged 47.5 ± 9.4 yr., duration of diabetes (14.6 ± 10.3 yr.) and 15 control subjects were studied. In diabetic patients neuropathy symptom score =0, neuropathy deficit score = 4.5 + 0.7/30, vibration = 12.0 + 1.8 V, thermal perception (2.0 + 0.8°C), heart rate variation during deep breathing (17.8 + 2.3), 30:15 ratio (1.31 + 0.07) was normal. Baseline (n=12) and repeat neurophysiology (n=10) performed 8.7 + 0.6 years after sural nerve biopsy demonstrated normal values at baseline, with progression of neuropathy (peroneal motor nerve conduction velocity (ms−1) (42.3 + 2.9 v 39.4 +2.0), sural nerve conduction velocity (45.4 + 3.7 v 43.6 + 1.7). Myelinated fibre density, fibre and axonal area and g‐ratio were not significantly reduced. Teased fibre studies showed paranodal abnormalities (p &lt; 0.001), segmental demyelination (P &lt; 0.01) with remyelination (P &lt; 0.01) without axonal degeneration. Unassociated Schwann cell profile density (p &lt; 0.04) and axon density (P &lt; 0.001) were increased and axon diameter was decreased (P &lt; 0.007) with a shift of the size frequency distribution to the left (skewness‐ 0.89 v 0.64, P &lt; 0.03) suggestive of unmyelinated axonal atrophy/regeneration. Endoneurial capillary basement membrane thickening (P &lt; 0.006), endothelial cell hyperplasia (P &lt; 0.004) and luminal narrowing (P &lt; 0.007) occurred. Current measures of neuropathy are too insensitive to detect significant nerve fibre pathology. The presence of microangiopathy provides support for a microvascular basis of diabetic neuropathy.

Plasma Concentrations of a Novel, Adipose-Specific Protein, Adiponectin, in Type 2 Diabetic Patients

Adiponectin is a novel, adipose-specific protein abundantly present in the circulation, and it has antiatherogenic properties. We analyzed the plasma adiponectin concentrations in age- and body mass index (BMI)-matched nondiabetic and type 2 diabetic subjects with and without coronary artery disease (CAD). Plasma levels of adiponectin in the diabetic subjects without CAD were lower than those in nondiabetic subjects (6.6+/-0.4 versus 7.9+/-0.5 microg/mL in men, 7.6+/-0.7 versus 11.7+/-1.0 microg/mL in women; P<0.001). The plasma adiponectin concentrations of diabetic patients with CAD were lower than those of diabetic patients without CAD (4.0+/-0.4 versus 6.6+/-0.4 microg/mL, P<0.001 in men; 6.3+/-0.8 versus 7.6+/-0. 7 microg/mL in women). In contrast, plasma levels of leptin did not differ between diabetic patients with and without CAD. The presence of microangiopathy did not affect the plasma adiponectin levels in diabetic patients. Significant, univariate, inverse correlations were observed between adiponectin levels and fasting plasma insulin (r=-0.18, P<0.01) and glucose (r=-0.26, P<0.001) levels. In multivariate analysis, plasma insulin did not independently affect the plasma adiponectin levels. BMI, serum triglyceride concentration, and the presence of diabetes or CAD remained significantly related to plasma adiponectin concentrations. Weight reduction significantly elevated plasma adiponectin levels in the diabetic subjects as well as the nondiabetic subjects. These results suggest that the decreased plasma adiponectin concentrations in diabetes may be an indicator of macroangiopathy.

Increased levels of aldose reductase in peripheral mononuclear cells from type 2 diabetic patients with microangiopathy

Aldose reductase (AR) protein was measured in peripheral mononuclear cells (PMCs) from 55 patients with type 2 diabetes by a two-site ELISA using anti-human AR monoclonal antibody. AR levels did not correlate with age, duration of diabetes, and HbAlc. Furthermore, no significant differences were found in AR levels between the patients and healthy subjects. Thirty seven patients had at least one of diabetic microangiopathy; retinopathy, neuropathy, or nephropathy. AR levels were significantly higher in the patients with microangiopathy than in those without it (52.3±15.7 vs. 43.0±15.2 ng/10 6 cells, P<0.05). The patients with neuropathy had significantly higher AR levels than those without neuropathy (53.7±15.8 vs. 42.7±14.3 ng/10 6 cells, P<0.05). The same result applied to the patients with retinopathy (54.5±15.4 vs. 44.6±15.3 ng/10 6 cells, P<0.05). The AR levels in the patients with nephropathy tended to give a higher value than those without it. However, there were no significant differences between the two (53.9±3.6 vs. 46.4±2.6 ng/10 6 cells, NS). These results indicate that AR levels in PMCs from type 2 diabetic patients are associated with the presence of microangiopathy. The measurement of AR proteins in PMCs with this ELISA system is a useful tool for the clinical study of diabetic complications, and would increase our understanding of the pathogenesis of the disease.

Hemodynamic parameters and exercise tolerance in insulin- dependent diabetes mellitus

The problem of development of diabetic myocardiodystrophy is analyzed. Thirty-seven patients with type 1 diabetes running a grave course with various disease duration were examined. The major parameters of intracardiac hemodynamics were examined by echolocation; exercise tolerance was studied by bicycle ergometry. The data indicate the development of diastolic rigidity, reduced volume of leftventricular myocardium, and decreased stroke and minute output at the early stages of the disease. Bicycle ergometry showed reduced exercise tolerance. These changes were in direct proportion to disease duration, presence of microangiopathy, and compensation status. These parameters may appreciably improve in recovery of the disturbed metabolic processes with restoration of the age-specific norm in patients with not long disease standing. Hence, echolocation of the heart and bicycle ergometry may be regarded among the criteria of diabetes mellitus compensation.

Regional cerebral hypoperfusion in long-term Type 1 (insulin-dependent) diabetic patients

Captopril renography was utilized to assess the presence of angiotensin II dependent renovascular dysfunction in (1) 28 patients with mild to moderate essential hypertension (EH) with unimpaired renal function, and (2) 25 hypertensive patients with diabetic nephropathy (HDN). These studies were classified according to the diagnostic criteria outlined by the Working Party on Diagnostic Criteria of Renovascular Hypertension with Captopril Renography and the mean parenchymal transit time (MPTT) was used as an index for detecting the presence of angiotensin II dependent renal haemodynamic change. Patients with EH showed non-significant or non-specific alterations in the MPTT. Four patients in the HDN group showed a significant prolongation of MPTT in the presence of renin-angiotensin-aldosterone activation due to renal artery stenosis, and the other patients in this group showed a significant decrease in MPTT after captopril, consistent with increased blood flow and improved tubular transport function in the presence of microangiopathy only. We conclude that addition of MPTT to the standard diagnostic criteria of captopril renography may be helpful in predicting the beneficial or detrimental impact of angiotensin II inhibition treatment in HDN and in limiting the test protocol in EH to one post-captopril study.

Predictive value of captopril transit renography in essential hypertension and diabetic nephropathy

Summary Captopril renography was utilized to assess the presence of angiotensin II dependent renovascular dysfunction in (1) 28 patients with mild to moderate essential hypertension (EH) with unimpaired renal function, and (2) 25 hypertensive patients with diabetic nephropathy (HDN). The studies were classified according to the diagnostic criteria outlined by the Working Party on Diagnostic Criteria of Renovascular Hypertension with Captopril Renography and the mean parenchymal transit time (MPTT) was used as an index for detecting the presence of angiotensin II dependent renal haemodynamic change. Patients with EH showed non-significant or non-specific alterations in the MPTT. Four patients in the HDN group showed a significant prolongation of MPTT in the presence of renin-angiotensin-aldosterone activation due to renal artery stenosis, and the other patients in this group showed a significant decrease in MPTT after captopril, consistent with increased blood flow and improved tubular transport function in the presence of microangiopathy only. We conclude that addition of MPTT to the standard diagnostic criteria of captopril renography may be helpful in predicting the beneficial or detrimental impact of angiotensin II inhibition treatment in HDN and in limiting the test protocol in EH to one post-captopril study.

Impaired left ventricular systolic function during exercise in middle-aged insulin-dependent and noninsulin-dependent diabetic subjects without clinically evident cardiovascular disease

Equilibrium radionuclide angiocardiography was performed on 19 men and 17 women with insulindependent diabetes mellitus (IDDM) and on 24 men and 15 women with noninsulin-dependent diabetes mellitus (NIDDM) and on 24 male and 24 female control subjects aged 46 to 67 years. All were without clinically evident cardiovascular disease. No significant differences were found in left ventricular (LV) ejection fraction at rest between men with IDDM (56 ± 1%; mean ± standard error of the mean) or NIDDM (58 ± 1%) and control men (58 ± 1%), whereas LV ejection fraction was higher in women with IDDM (63 ± 1%; p < 0.01) and NIDDM (64 ± 2%; p < 0.01) than in control women (58 ± 1%). An abnormal LV ejection fraction response to dynamic exercise (an increase of <5% units or a decrease) was observed in 1 control man (4%), in 8 men with IDDM (42%, p < 0.01) and in 10 men with NIDDM (42%, p < 0.01). The respective figures were 4 (17%) for control women, 7 (44%, difference not significant) for women with IDDM and 10 (71%, p < 0.01) for women with NIDDM. Abnormal LV ejection fraction response to exercise in diabetic patients was not related to the metabolic control of diabetes, presence of microangiopathy or abnormalities in the autonomic nervous function. Myocardial perfusion scintigraphy performed in 18 diabetic patients in whom LV ejection fraction decreased during exercise showed a reversible perfusion defect in only 5 (28%). These results indicate that LV dysfunction on exercise may occur in both types of diabetic patients without any evidence of myocardial ischemia.

Effects of intravenous contrast media on cortical and medullary blood flow in the rat kidney.

The effect of slow intravenous infusion of contrast medium (CM) (1600 mg I/kg body weight) on cortical blood flow (BF) and medullary BF in rat kidneys was investigated by laser-Doppler flowmetry on either renal cortex or exposed renal papillas (inner medulla). The effect on cortical BF was evaluated after infusion of either ioxaglate, iohexol, or ioxithalamate. Mannitol and Ringer's solution were used as control substances. The effect on medullary BF was examined after infusion of either ioxaglate, iohexol, iopamidol, ioxithalamate, or mannitol. BF was measured continuously during a 30-minute control period and a 60-minute experimental period, starting with the CM infusion. Cortical BF was unchanged in the ioxaglate group and significantly increased in the iohexol, ioxithalamate, and mannitol groups (P less than .05). Medullary BF was moderately increased in the ioxaglate group (P less than .05) but moderately decreased in the groups that received iohexol, iopamidol, ioxithalamate, or mannitol (P less than .05). The reduction in medullary BF following infusion of the ratio 3.0 nonionic CM and of the ratio 1.5 ionic CM might be one contributory mechanism to the pathogenesis of CM nephropathy, especially in the presence of microangiopathy in the kidney.