Updates on Computed Tomography Imaging in Aortic Aneurysms and Dissection

Computed tomography (CT) is a primary imaging modality for the diagnosis of aortic diseases, because of its minimal invasiveness and agility.

Prompt and accurate diagnosis is crucial especially for acute aortic diseases, and the guidelines for acute aortic dissection recommend the use of CT for initial diagnosis. For the follow-up observation of longstanding aortic diseases, the strategy of imaging management by CT must be different from that for emergency and acute phases.

In this review, we document the differences in characteristics and clinical course between aortic aneurysm and aortic dissection and explain the use of recent CT techniques in diagnosing short- and longstanding aortic diseases.

Chronic contained rupture of abdominal aortic aneurism complicated with aortic occlusion: a case report

Background

Chronic contained rupture is a subtype of an abdominal aortic aneurysm rupture. Its diagnosis is sometimes difficult due to lack of typical symptoms. We would like to report the challenge of diagnosing chronic contained rupture of abdominal aortic aneurysm with a retroperitoneal tumor.

Case presentation

A 60-year-old man reported perceived lower abdominal pain 7 months earlier that spontaneously remitted. A contrast-enhanced computed tomography (CT) indicated an abdominal aortic aneurysm and a mass lesion surrounding the abdominal aorta and iliac arteries. Fluorine-18-fluorodeoxyglucose positron emission tomography (FDG-PET) showed an increased accumulation of FDG in the margin of the lesion, indicating a retroperitoneal tumor. A CT-guided biopsy revealed only retroperitoneal fibrous tissue with chronic inflammation. We were thus unable to reach a definitive diagnosis. At 1 month after the initial examination, intermittent claudication was newly observed. A follow-up contrast-enhanced CT scan revealed abdominal aortic occlusion. Mass resection and bypass surgery were performed for diagnosis and treatment. Intraoperative and pathological findings led to the diagnosis of chronic contained rupture of an abdominal aortic aneurysm. The patient was discharged 19 days after surgery.

Conclusion

The mass peripheral to the abdominal aorta should be considered the possibility not only of tumor but also of chronic contained rupture of an abdominal aortic aneurysm.

Usefulness of transesophageal echocardiography in diagnosis of hemolytic anemia post total aortic arch replacement using the elephant trunk technique

We report a rare case of a patient with hemolytic anemia who underwent emergency total arch replacement using the elephant trunk technique for type A acute aortic dissection 3 years earlier. The 78-year-old woman was referred to our hospital for diagnosis of the cause of the hemolytic anemia, which required twice weekly blood transfusion. Although contrast-enhanced computed tomography could not provide sufficient information, transesophageal echocardiography (TEE) revealed graft flection with high velocity. After percutaneous balloon dilatation, the hemolytic anemia improved and follow-up TEE showed no re-stenosis of the dilatation site.

Influence of daily alcohol consumption on serum adiponectin levels in men

BACKGROUND

The risk of cardiovascular diseases is lower among moderate alcohol drinkers than among both nondrinkers and heavy drinkers. However, factors that can account for the U-shaped or J-shaped relationship between daily alcohol consumption and incident cardiovascular diseases remain obscure.

PURPOSE

The present cross-sectional study investigated the relationship between alcohol consumption and serum adiponectin levels.

METHOD

Total adiponectin was measured in 527 males participating in health check-up programs (age range 40-86 years, mean 60.5 years). Based on questionnaire responses, alcohol intake was categorized into three groups: none or occasional (A1); <50 g/day and ≥3 days/week (A2); and ≥50 g/day and ≥3 days/week (A3).

RESULTS

No significant differences in adiponectin levels were observed among the three alcohol consumption groups of subjects without the metabolic syndrome (MetS). In subjects with the MetS, the adiponectin level was significantly higher in the A2 (moderate drinker) group than in both the A1 and A3 groups. MetS subjects in group A2 had higher HDL-C levels than those in A1, but levels in group A3 were not significantly different from those in group A2.

CONCLUSION

An increased adiponectin level in moderate alcohol drinkers who have MetS may contribute to the U-shaped relationship between alcohol consumption and risk of cardiovascular events, in addition to the involvement of HDL-C.

Factors related to long-term prognosis in medically treated type B aortic dissection: a physical predisposing factor

AIM

In medically treated patients with Stanford type B aortic dissection, it has been shown that the state of the dissecting aorta in the acute phase predicts the prognosis. The present study examined other crucial factors, including physical characteristics, related to the long-term prognosis in type B aortic dissection.

METHODS

Two hundred and two patients with type B aortic dissection who were discharged alive with medical treatment in the acute phase (mean age 66.5 years, range 29-90 years, 160 males) were followed.

RESULTS

During the mean follow-up period of 4.9 years (ranging up to 12.2 years), 37 all-cause deaths were confirmed. A surgical procedure related to aortic dissection was performed in 8, and re-dissection occurred in 3. The survival rate at 5 years after onset was 82%. On Cox regression analysis, increased height (greater than the median value) was significantly associated with all-cause death and the composite aortic event when adjusted by age and sex (hazard ratio [HR]=2.22, 95%confidence interval [CI] 1.15-4.83, P=0.021, and HR=4.53, 95%CI 1.26-16.35, P=0.021, respectively). Patients with coexisting true aortic aneurysms also had a higher risk than those without (composite aortic events, HR=3.63, 95%CI 1.41-9.35, P=0.008).

CONCLUSION

More strict management in the chronic phase is needed in taller patients as well as patients with coexisting true aortic aneurysms. This common physical predisposing feature may also assist in making the decision for earlier surgical intervention to the affected aorta.

Reduction of both beta cell death and alpha cell proliferation by dipeptidyl peptidase-4 inhibition in a streptozotocin-induced model of diabetes in mice

AIMS/HYPOTHESIS

Incretins stimulate insulin secretion in a glucose-dependent manner but also promote pancreatic beta cell protection. Dipeptidyl peptidase-4 (DPP-4) inhibitors are a new glucose-lowering treatment that blocks incretin degradation by DPP-4. We assessed whether DPP-4 inhibition suppresses the progression to hyperglycaemia in a low-dose streptozotocin (STZ)-induced diabetic mouse model, and then investigated how DPP-4 inhibition affects islet function and morphology.

METHODS

The DPP-4 inhibitor, des-fluoro-sitagliptin (SITA), was administered to mice during and after STZ injections, and in some mice also before STZ.

RESULTS

In control mice, STZ resulted in hyperglycaemia associated with impaired insulin secretion and excess glucagon secretion. In SITA-treated STZ mice, these metabolic abnormalities were improved, particularly when SITA administration was initiated before STZ injections. We observed beta cell loss and dramatic alpha cell expansion associated with decreased insulin content and increased glucagon content after STZ administration. In SITA-treated mice, islet architecture and insulin content were preserved, and no significant increase in glucagon content was observed. After STZ exposure, beta cell apoptosis increased before hyperglycaemia, and SITA treatment reduced the number of apoptotic beta cells. Interestingly, alpha cell proliferation was observed in non-treated mice after STZ injection, but the proliferation was not observed in SITA-treated mice.

CONCLUSIONS/INTERPRETATION

Our results suggest that the ability of DPP-4 inhibition to suppress the progression to STZ-induced hyperglycaemia involves both alleviation of beta cell death and alpha cell proliferation.

[Strategies for prevention from spinal cord ischemia during thoracic endovascular aortic repair]

Spinal cord ischemia (SCI) is one of the most serious complications in patients who undergo thoracic endovascular aortic repair (TEVAR). The incidence of SCI after TEVAR has been supposed to be lower than the one after traditional open surgical repair. However, not a few cases regarding SCI after TEVAR have been reported recently. Since the detailed mechanism of the SCI is still not fully understood, preventive strategies against SCI including preoperative identification of critical segmental artery (CSA) applying the artery of Adamkiewicz, preservation of the CSA, motor evoked potential (MEP) monitoring, and cerebrospinal fluid (CSF) drainage are routinely performed during TEVAR in our practice.

Association between metabolic syndrome and carotid atherosclerosis: relevance of combined criteria including the serum adiponectin level for the general population

OBJECTIVE

The association between carotid atherosclerosis and the metabolic syndrome (MetS) was analyzed in the general population. The usefulness of the inclusion of the serum adiponectin concentration in the MetS criteria for the detection of atherosclerosis was also examined.

PATIENTS AND METHODS

The 825 participants of a comprehensive health checkup who underwent carotid ultrasonography and the measurement of serum adiponectin levels were studied.

RESULTS

The carotid plaque score (PLS) was significantly higher in the MetS group than in the non-MetS group in women, but not in men. In women, a significantly higher odds ratios was obtained for MetS, in terms of the current waist circumference criterion, and a high PLS (fourth quartile) (OR=2.64, p=0.040). In men, however, a waist circumference of around 85 cm did not reflect high a PLS, and even when the waist circumference criterion was varied, the odds ratio did not increase. When the waist circumference was replaced by hypoadiponectinemia in the current MetS criteria, the odds ratio was significantly increased in men (OR=1.82, p=0.032).

CONCLUSION

The current MetS criteria seem appropriate for women. In men, there was no significant evidence for the validity of the inclusion of the waist circumference criterion as an essential component. Incorporating hypoadiponectinemia into the current criteria would be useful for the early detection of atherosclerosis in men.

Chronic kidney disease is associated with increased carotid artery stiffness without morphological changes in participants of health check-up programs

BACKGROUND AND METHODS

Patients with chronic kidney disease (CKD) show a much higher risk of cardiovascular disease. However, the mechanisms underlying this association and the impact of CKD on behaviors of the vascular walls have not been fully clarified. Using ultrasonography, this study investigated associations of CKD (estimated glomerular filtration rate <60 ml/min/1.73 m(2) and/or presence of proteinuria) with both elasticity (stiffness β index) of the carotid artery and intimal atherosclerotic changes in participants of health check-up programs (n=3406, 63% men; mean age, 58.8 years).

RESULTS

Stiffness β was significantly higher in CKD subjects (7.49 ± 0.14) than in non-CKD subjects (6.87 ± 0.05, P<0.001). This significant difference was maintained in a multiple adjusted model including conventional risk factors such as hypertension, diabetes mellitus, dyslipidemia, smoking and obesity (7.20 ± 0.14 vs. 6.91 ± 0.05, P=0.043). No significant differences in intima-media complex thickness or plaque score were seen between CKD and non-CKD subjects.

CONCLUSION

In participants of health check-up programs, CKD was associated with increased carotid arterial stiffness without intimal disease, independently of conventional risk factors. These findings indicate that CKD may predispose the carotid arteries to earlier development of arteriosclerosis, characterized by increased arterial stiffness.

Low-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio as a useful marker for early-stage carotid atherosclerosis

A higher ratio of low-density lipoprotein cholesterol (LDL-C) to high-density lipoprotein cholesterol (HDL-C) is associated with a greater risk of cardiovascular events in patients with coronary heart disease. However, the role of this lipid index during early-stage atherosclerosis has not yet been established. This study investigated relationships between LDL-C/HDL-C ratio and carotid plaque score as assessed by ultrasonography in 825 subjects from the general population (527 men, 298 women; mean age, 60.5 years). To identify factors strongly associated with plaque score, stepwise multiple regression analysis was performed using various clinical variables including conventional lipid indices. In both sexes, increased LDL-C/HDL-C ratio was associated with increased plaque score (men: beta = 0.132, P = .001; women: beta = 0.150, P = .012). This association was maintained in men with normal LDL-C level (<140 mg/dL). The highest quartile of LDL-C/HDL-C ratio (>2.9 in men, >2.6 in women) showed significantly increased plaque score even when adjusted by factors included in the final model of stepwise analysis (P = .007 in men, P = .033 in women). No association was seen between LDL-C and plaque score in the multivariate-adjusted model. These findings indicate that increased LDL-C/HDL-C ratio may also be associated with initiation of atherosclerosis. Assessment of this lipid ratio may thus facilitate early management of atherosclerotic risks better rather than assessment of LDL-C alone.

Efficacy of low-dose hydrochlorothiazide in combination with telmisartan on early morning blood pressure in uncontrolled hypertensive patients

Hypertensive patients whose BP was uncontrolled despite the use of antihypertensive agents, including an ARB (candesartan 8 mg/day or valsartan 80 mg/day), were enrolled. The patients were randomly assigned to combination therapy with telmisartan 40 mg/day (changed from current ARB) and hydrochlorothiazide (HCTZ) 12.5 mg/day (T + H, n = 32) or to no change in their current drug regimen (CTL, n = 32). The observation period was 12 weeks. The office and home BPs were significantly reduced in the T + H compared to those in the CTL. A sufficient and long-acting BP lowering effect, as reflected in decreased early morning BP, was obtained with the combination of low-dose HCTZ and telmisartan without apparent metabolic deterioration.

Effects of telmisartan on adiponectin levels and body weight in hypertensive patients with glucose intolerance

Few studies have analyzed intraclass differences in angiotensin II receptor blockers (ARBs) with respect to antidiabetic or metabolic effects. We designed a prospective randomized study to compare a peroxisome proliferator-activated receptor-gamma (PPARgamma)-activating ARB with a nonactivating ARB to delineate the effects on metabolic factors associated with cardiovascular disease. Subjects initially comprised 153 hypertensive patients (72 men, 81 women; mean age, 67.9 +/- 7.8 years) with diagnosed glucose intolerance on the glucose loading test. Patients were randomly assigned to receive 6-month administration of telmisartan 47.0 mg/d (TEL) or candesartan 8.4 mg/d (CAN), or to have no change in drug regimen (control group, CTL). Fasting plasma glucose level was significantly reduced in TEL (n = 46) compared with CTL (n = 47) (percentage of change from baseline, -1.7% vs +2.2%; P = .045). Percentage of increase in adiponectin was significantly larger in TEL than in CTL (+10.5% vs +2.2%, P = .025), but not significantly larger in CAN (n = 44) than in CTL (+4.9% vs +2.2%; P = .13). Percentage of decrease in body weight from baseline was significantly enhanced in TEL compared with CTL (-2.2% vs -0.8%, P = .023) and CAN (-2.2% vs -0.3%, P = .007). Telmisartan decreased body weight while increasing serum adiponectin levels in hypertensive patients with glucose intolerance. Candesartan did not achieve similar improvements in these patients. Among ARBs, telmisartan may have a larger impact on obesity-related diseases that can lead to cardiovascular disorders.

Increased carotid artery stiffness without atherosclerotic change in patients with aortic dissection

The arterial properties and pathogenesis of aortic dissection remain obscure. To examine the arterial properties of patients with aortic dissection, the authors studied the ultrasonographic characteristics of the carotid artery in patients with an aortic dissection (AD, n = 86), and compared these findings with data of patients suffering from arteriosclerosis obliterans (ASO, n = 151), coronary artery disease (CAD, n = 163), and with healthy controls (HC, n = 77). Atherosclerotic intimal changes, such as intima-media thickness (IMT) and plaque formation, were milder in AD than in ASO or CAD (IMT: 0.83 +/- 0.16 vs 0.93 +/- 0.20/0.86 +/- 0.17 mm, p < 0.05; plaque number: 0.6 +/- 1.1 vs 2.7 +/- 2.4/2.5 +/- 2.1, p <0.05). Luminal diameter in AD, ASO, and CAD was significantly higher than in HC. The luminal distensibility in AD was decreased compared with HC but was the same as in ASO and CAD. Intra-AD group analysis showed that in patients with an intramural hematoma (IMH) or a dissection with a thrombosed false lumen (TLF) the IMT was higher than in patients with a classic dissection. In addition, plaque formation was more severe in AD patients with a coexisting abdominal aortic aneurysm (AAA). Reduced distensibility without severe intimal disease was found in AD. These findings suggest that patients with AD may have several arterial alterations, including structural abnormalities. Patients with IMH, TFL, or coexisting AAA may differ from patients who have a classic type of dissection or who do not have AAA, in terms of arterial characteristics including intimal disease and wall elastic property, and the initiating cause of the dissection.

Angiotensin AT(1) receptor antagonism normalizes retinal blood flow and acetylcholine-induced vasodilatation in normotensive diabetic rats

AIMS/HYPOTHESIS

The renin angiotensin system is emerging as a potential therapeutic target for diabetic retinopathy. This study examines the effects of angiotensin-converting-enzyme inhibition by captopril and angiotensin AT(1) receptor antagonism using candesartan-cilexetil on retinal blood flow and acetylcholine-stimulated vasodilatation in normotensive diabetic rats.

METHODS

Non-diabetic or streptozotocin-induced diabetic rats were treated for 2 weeks with captopril (100 mg/kg/day) or candesartan cilexetil (2 mg/kg/day). Retinal haemodynamics were measured using video fluorescein angiography. Effects of exogenous acetylcholine on retinal haemodynamics were examined following intravitreal injection. Total retinal diacylglycerol was labelled using diacylglycerol kinase, separated by thin-layer chromatography, and quantified using autoradiography.

RESULTS

Diabetic rats had prolonged retinal mean circulation time and decreased retinal blood flow compared with non-diabetic rats. Treatment of diabetic rats with either captopril or candesartan blocked the development of these blood flow abnormalities. Intravitreal injection of acetylcholine (10(-5) mol/l) in non-diabetic rats increased retinal blood flow by 53.9+/-22.0% relative to baseline whereas this response to acetylcholine was blunted in diabetic rats (4.4+/-19.6%, p<0.001). Candesartan treatment of diabetic rats restored the acetylcholine-stimulated retinal blood flow response to 60.0+/-18.7% compared with a 56.2+20.1% response in candesartan-treated non-diabetic rats. Total retinal diacylglycerol levels were increased in diabetic rats (3.75+/-0.98 nmol/mg, p<0.05) compared with non-diabetic rats (2.13+/-0.25 nmol/mg) and candesartan-treatment of diabetic rats normalized diacylglycerol levels (2.10+/-0.25 nmol/mg, p<0.05).

CONCLUSION/INTERPRETATION

This report provides evidence that angiotensin-converting enzyme inhibition and AT(1) receptor antagonism ameliorates retinal haemodynamic dysfunctions in normotensive diabetic rats.

Chichibabin indolizine synthesis revisited: synthesis of indolizinones by solvolysis of 4-alkoxycarbonyl-3-oxotetrahydroquinolizinium ylides

Solvolysis of 4-alkoxycarbonyl-(or 4-acyl)-3-oxo-1,2,3,4-tetrahydroquinolizinium ylides (1-4) was studied and three types of reactions were found to proceed competitively. Thus, alcoholysis afforded the Chichibabin rearrangement products, 2,3-dihydro-2-indolizinones (5-8), solvolysis in trifluoroethanol or in aqueous methanol caused ring opening (and subsequent ester cleavage) to 2-alkoxycarbonylethylpyridinium-1-acetates 10, 15, and 16, and hydrolysis resulted in ring opening to 1-alkoxycarbonylmethylpyridinium-2-propionates 11 or 13 (and subsequently to 12 or 14). Characteristically, all the types of reactions proceeded significantly faster with t-butoxycarbonyl substituted ylides than with smaller alkoxycarbonyl substituted ones. The general mechanism for the solvolysis, involving a ketene intermediate, is proposed based on kinetic measurements.

Tetrahydroquinolizinium ylides: preparation and 1,3-dipolar cycloaddition

By the Cu(II)-catalyzed reaction of 2-(4-diazo-3-oxoalkyl)pyridines (2), 4-alkoxycarbonyl (or 4-acyl)-3-oxo-1,2,3,4-tetrahydroquinolizinium ylides (3) were obtained in high yields. From the cycloaddition reaction of 3 with acetylenic esters (propynoates or acetylenedicarboxylates) the labile [2 + 3] cycloadducts, 3-oxo-3H-2a,4,5,8a-tetrahydropyrrolo[2,1,5-de]quinolizine-2a-carboxylates (8 or 12), were identified, which further reacted with DMAD (dimethyl acetylenedicarboxylate) to afford azocine derivatives (15 or 16) and produced pyrrolodihydroquinolizines (9 or 20) by dealkoxycarbonylation.

Downregulation of the voltage-dependent calcium channel (VDCC) beta-subunit mRNAs in pancreatic islets of type 2 diabetic rats

The present study was undertaken to determine whether altered expression of the VDCC beta-subunits in pancreatic beta-cells could play a role in the changes in beta-cell sensitivity to glucose that occur with diabetes. Application of competitive RT-PCR procedure revealed that in normal Wistar rats, LETO and prediabetic OLETF rats, the beta(2)-subunit mRNA levels were 60-200-fold greater than the levels for the beta(3)-subunit. These findings suggest that the beta(2)-subunit as well as the beta-cell type VDCC1 alpha(1)-subunit may be the predominant form of the VDCC expressed in pancreatic beta-cells. The levels of mRNA encoding the beta-subunits and the beta-cell type alpha(1)-subunit as well as insulin were significantly reduced in diabetic rats. Perfusion experiments revealed that diabetic rats showed the higher basal insulin secretion and profoundly impaired insulin secretory responses to glucose compared with non-diabetic rats. Alternatively, impaired insulin secretory responses to glucose in high dose glucose-infused rats were recovered partly with the elevation of mRNA levels of the VDCC beta(2)- and beta(3)-subunits as well as the alpha(1)-subunit by the treatment with diazoxide. Thus, considering the possibility that the most striking effect of the VDCC alpha(1) beta-subunit coexpression in pancreatic beta-cells might occur on activation kinetics like the skeletal muscle, the impairment of further activation of the VDCCs to acute glucose challenge caused by the reduced expressions of the alpha(1) beta-subunits mRNAs in type 2 diabetic animals might be at least partly associated with the alterations in beta-cell sensitivity to glucose.

Detection of the association between a deletion polymorphism in the gene encoding angiotensin I-converting enzyme and advanced diabetic retinopathy

We investigated the relationship between advanced diabetic retinopathy (ADR) and an angiotensin-converting enzyme (ACE) gene polymorphism in subjects with type 2 diabetes and ADR, pre-proliferative (PrePDR) or proliferative diabetic retinopathy (PDR) without overt nephropathy. Polymerase chain reactions were used to detect insertion/deletion (I/D) polymorphisms of the ACE gene. There was no difference in the frequency of II, ID, or DD genotypes, or of I and D alleles among subjects with type 2 diabetes without diabetic retinopathy (NDR) or with simple diabetic retinopathy (SDR) and non-diabetic controls. There was also no difference in the frequency of ACE genotypes among subjects with type 2 diabetes with NDR, or SDR and ADR. However, the frequency of the ACE DD genotype in ADR was significantly higher than that in controls (chi(2)=6.64, P=0.036). On the other hand, the frequency of the D allele in ADR was significantly higher than that in controls (chi(2)=6.33, P=0.012), NDR (chi(2)=4.18, P=0.041) and SDR (chi(2)=4. 89, P=0.027), respectively. These results indicate a significant relationship between the presence of the D allele polymorphism in the ACE gene and ADR in Japanese subjects with type 2 diabetes and no overt nephropathy.

Increased levels of advanced glycosylation end products in the kidney and liver from spontaneously diabetic Chinese hamsters determined by immunochemical assay

Increased levels of advanced glycosylation end products (AGEs) have been reported in tissues in association with diabetes mellitus. Thus, we measured tissue AGE levels and detected an accumulation of AGEs in the kidney and liver from spontaneously diabetic Chinese hamsters (CHAD) to determine the relationship between AGEs and diabetes mellitus. Diabetic CHAD aged 12 to 13 months were studied together with age-matched nondiabetic CHAD. We used an AGE-specific noncompetitive enzyme-linked immunosorbent assay (ELISA) with polyclonal anti-AGE-bovine serum albumin (BSA) antibody to measure tissue AGE levels. The samples extracted from the kidney and liver obtained from diabetic and nondiabetic CHAD reacted with anti-AGE-BSA antibody. When the absorbance of standard AGE-BSA (0.1 microg/mL) was expressed as 1 U, AGE levels in the kidney and liver from diabetic CHAD were significantly increased as compared with nondiabetic CHAD (kidney, 0.26 +/- 0.05 v 0.10 +/- 0.03 U/microg protein, P< .01; liver, 0.20 +/- 0.03 v 0.09 +/- 0.02 U/microg protein, P< .01). Positive AGE staining was observed in the renal cortex, especially in the tubules of diabetic CHAD, but little AGE staining was observed in the glomerulus by the immunohistochemical study. AGE staining was diffuse in the hepatocytes. These AGE levels were significantly correlated with fasting plasma glucose and glycated hemoglobin (P < .01, respectively). In conclusion, we have confirmed that AGE structures were expressed in the kidney and liver from CHAD, and these AGE levels were increased in diabetic CHAD. AGE staining was observed in the renal tubules and hepatocytes. Tissue AGE levels were positively correlated with glycemic control in CHAD.

Relationship between autofluorescence and advanced glycation end products in diabetic lenses

Autofluorescence and advanced glycation end product (AGE) levels were measured in the lenses of 9 diabetic Chinese hamsters and 6 age-matched controls. Lens autofluorescence also was measured in 37 diabetic patients and 14 age-matched controls. Lens autofluorescence values were measured noninvasively with a lens measurement system using color filters with peak transmission at 365- and 434-nm wavelengths (excitation and emission, respectively) that are characteristic of AGE fluorescence. The peak lens autofluorescence level was used as the lens autofluorescence value, and the mean lens autofluorescence values from both eyes of each subject were used for statistical analysis. The AGE levels in one lens from each hamster were measured by noncompetitive enzyme-linked immunosorbent assay with a polyclonal anti-AGE antibody. We found a 2.2 times increase of the mean lens autofluorescence value of diabetic hamsters in comparison with that of controls (P<0.01). We also found a 1.5 times increase of the mean AGE level from the lenses of diabetic hamsters in comparison with that of controls (P<0.01). Moreover, a statistically significant positive correlation between the AGE level and autofluorescence value in the same lenses was observed in all hamsters (rho=0.58, P<0.05). In human subjects, we found a 1.4 times increase of the mean lens autofluorescence value of diabetic patients in comparison with that of age-matched controls (P<0.01). Our results suggest that non invasive measurement of lens autofluorescence may be a guide to AGE levels in lenses.

Increased frequency of apolipoprotein epsilon 2 allele in non-insulin dependent diabetic (NIDDM) patients with nephropathy

The genetic polymorphism of apolipoprotein E (epsilon 2, epsilon 3 and epsilon 4) is associated with lipid abnormalities. It has been suggested that lipid abnormalities may contribute to the development and progression of kidney diseases, including diabetic nephropathy. Thus, in this study we compared the apo E allele frequencies among 146 non-insulin-dependent diabetic (NIDDM) patients with nephropathy, 135 NIDDM patients without nephropathy and 576 of the general Japanese population. The epsilon 2 allele frequency was significantly higher in diabetic patients with nephropathy (7.2%) and with renal failure (9.7%) than in diabetic patients without nephropathy (2.6%) and in the general Japanese population (3.7%). It is concluded that there is a possibility that the epsilon 2 allele is associated with nephropathy in NIDDM.