Renal arteriolar hyalinosis, not intimal thickening in large arteries, is associated with cardiovascular events in people with biopsy-proven diabetic nephropathy

AIMS

Diabetic nephropathy, a pathologically diagnosed microvascular complication of diabetes, is a strong risk factor for cardiovascular events, which mainly involve arteries larger than those affected in diabetic nephropathy. However, the association between diabetic nephropathy pathological findings and cardiovascular events has not been well studied. We aimed to investigate whether the pathological findings in diabetic nephropathy are closely associated with cardiovascular event development.

METHODS

This retrospective cohort study analysed 377 people with type 2 diabetes and biopsy-proven diabetic nephropathy, with a median follow-up of 5.9 years (interquartile range 2.0 to 13.5). We investigated how cardiovascular events were impacted by two vascular diabetic nephropathy lesions, namely arteriolar hyalinosis and arterial intimal thickening, and by glomerular and interstitial lesions.

RESULTS

Of the 377 people with diabetic nephropathy, 331 (88%) and 295 (78%) had arteriolar hyalinosis and arterial intimal thickening, respectively. During the entire follow-up period, those with arteriolar hyalinosis had higher cardiovascular event rates in the crude Kaplan-Meier analysis than those without these lesions (P = 0.005, log-rank test). When fully adjusted for clinically relevant confounders, arteriolar hyalinosis independently predicted cardiovascular events [hazard ratio (HR) 1.99; 95% confidence interval (CI) 1.12, 3.86], but we did not find any relationship between arterial intimal thickening and cardiovascular events (HR 0.89; 95% CI 0.60, 1.37). Additionally, neither glomerular nor interstitial lesions were independently associated with cardiovascular events in the fully adjusted model.

CONCLUSIONS

Arteriolar hyalinosis, but not intimal thickening of large arteries, was strongly associated with cardiovascular events in people with diabetic nephropathy.

Proposal for an Empirical Japanese Diet Score and the Japanese Diet Pyramid

A traditional Japanese diet (JD) has been widely regarded as healthy, contributing to longevity. The modern Japanese lifestyle has become markedly westernized, and it is speculated that the number of people who eat JD is decreasing. A simple evaluation of people with low adherence to JD will help improve dietary life. We developed a simple assessment tool that can capture JD, and examined factors associated with low adherence to JD. A total of 1458 subjects aged 18 to 84 years completed a brief self-administered diet history questionnaire. We constructed an empirical Japanese diet score (eJDS) consisting of 12 items from the common characteristics of a JD. In our participants, 47.7% of subjects reported low adherence to JD and only 11.1% demonstrated high adherence. In multivariate logistic regression analysis, younger age persons, physically inactive persons, and heavy drinkers were associated with low adherence to JD. Based on the cutoff values of eJDS, we proposed to create a Japanese diet pyramid that is easy to use visually. In conclusion, the eJDS and the Japanese diet pyramid will be useful tools for nutrition education and dietary guidance.

The World Health Organization's Healthy Diet Indicator and its associated factors: A cross-sectional study in central Kinki, Japan

The Healthy Diet Indicator (HDI), which is based on adherence to World Health Organization's (WHO) nutrition guidelines, is used worldwide. In 2015, the WHO updated the Fact Sheet for their recommended healthy diet. We investigated diet quality assessed by the updated HDI (HDI-2015) and factors related to adherence to this diet in a Japanese population. We conducted a cross-sectional study of 1370 participants from 8 workplaces, 1 college, and 2 communities. All participants completed a brief-type self-administered diet history questionnaire. The HDI-2015 assesses 7 components: fruits and vegetables, total fat, saturated fatty acid, polyunsaturated fatty acid, free sugar, dietary fiber, and potassium. Only 6.6% of subjects demonstrated high adherence to HDI-2015 (met ≥6 components), whereas 52.0% demonstrated moderate adherence (4-5 components), and 41.4% demonstrated low adherence (0-3 components). Male sex, older age, and regular physical activity were associated with higher adherence. The contemporary Japanese population has an overall low diet quality as evaluated by the updated HDI score. Improving adherence to healthier dietary patterns may promote better health in Japan.

Effect of Aspirin on Cancer Chemoprevention in Japanese Patients With Type 2 Diabetes: 10-Year Observational Follow-up of a Randomized Controlled Trial

OBJECTIVE

This study analyzed the efficacy of low-dose aspirin in cancer chemoprevention in patients with diabetes.

RESEARCH DESIGN AND METHODS

This study was a posttrial follow-up of the Japanese Primary Prevention of Atherosclerosis with Aspirin for Diabetes (JPAD) trial. Participants in the JPAD trial (2,536 Japanese patients with type 2 diabetes and without preexisting cardiovascular disease) were randomly allocated to receive aspirin (81 or 100 mg daily) or no aspirin. After that trial ended in 2008, we followed up with the participants until 2015, with no attempt to change the previously assigned therapy. The primary end point was total cancer incidence. We investigated the effect of low-dose aspirin on cancer incidence.

RESULTS

During the median follow-up period of 10.7 years, a total of 318 cancers occurred. The cancer incidence was not significantly different between the aspirin and no-aspirin groups (log-rank, P = 0.4; hazard ratio [HR], 0.92; 95% CI, 0.73-1.14; P = 0.4). In subgroup analyses, aspirin did not affect cancer incidence in men, women, or participants aged ≥65 years. However, it decreased cancer incidence in participants aged <65 years (log-rank, P = 0.05; HR, 0.67; 95% CI, 0.44-0.99; P = 0.048). After adjusting for sex, hemoglobin A_1c, smoking status, and administration of metformin and statins, aspirin significantly reduced cancer incidence in participants aged <65 years (adjusted HR, 0.66; 95% CI, 0.43-0.99; P = 0.04).

CONCLUSIONS

Low-dose aspirin did not reduce cancer incidence in Japanese patients with type 2 diabetes.

A cross-sectional study of the association between dynapenia and higher-level functional capacity in daily living in community-dwelling older adults in Japan

Background

There are many reports that dynapenia, sarcopenia and frailty each have associations with bodily function or with Instrumental Activities of Daily Living (IADL). However, studies that compare all three conditions and their effects on IADL are lacking. The purpose of this study is to examine associations of sarcopenia, frailty, and dynapenia with IADL.

Methods

Participants included 123 community-dwelling older adults (31 men, 92 women,) aged 65 years or older (75.0 ± 5.3 years) who were independent in IADL. In terms of physical function, measurements were performed for muscle mass, grip strength, walking speed, isometric knee extension strength, and unipedal standing. A questionnaire survey was carried out, the Tokyo Metropolitan Institute of Gerontology Index of Competence (TMIG-IC) was administered, and participants were asked about sense of fatigue and amount of activity.

Results

Dynapenia was associated with classifications of both frailty and sarcopenia. In addition, sarcopenia had a sensitivity and specificity for dynapenia of 33 and 89%, respectively. Frailty had a sensitivity and specificity for dynapenia of 17 and 98%, respectively. Dynapenia was a significant independent related factor for the TMIG-IC (β = −0.21, P < 0.05).

Conclusions

Dynapenia, more than sarcopenia or frailty, was related to difficulties with IADL; therefore, assessment of dynapenia should be given greater emphasis in evaluating the physical functioning of older adults.

Development of a Mediterranean diet score adapted to Japan and its relation to obesity risk

BACKGROUND

The Mediterranean diet (MD) is well known as a healthy diet that protects against several chronic diseases. However, there is no appropriate and easy index to assess adherence to the MD pattern in Japan.

OBJECTIVE

The aim of this study was to develop a novel instrument to measure MD adherence adapted to a Japanese diet and to examine its association with overweight/obesity risk.

METHODS

A cross-sectional nutritional survey provided the data for construction of a novel MD score. In total, 1,048 subjects who were employees and university students, aged 18-68 years (645 men and 403 women), completed a 58-item brief-type self-administered dietary history questionnaire. We constructed a Japanese-adapted MD score (jMD score) focusing on 13 components. Adherence to the jMD was categorized as low (score 0-4), moderate (5-7), or high (8-13).

RESULTS

Men had higher jMD scores than women, and adherence to the jMD score increased with age. Only 11.6% of subjects showed high adherence to the jMD, whereas 29.6% showed low adherence. A higher jMD adherence was associated with a higher intake of favorable nutrients with the exception of salt. The jMD adherence was significantly associated with a reduced likelihood of having overweight/obesity for the highest category compared with lowest category (odds ratio [OR] 0.50, 95% confidence interval [CI] 0.30-0.85, p-trend=0.017) after adjusting for age, sex, smoking, physical activity, alcohol intake, and hypertension. A two-point increment in jMD score was related to a reduced likelihood of having overweight/obesity with an odds ratio of 0.76 (95% CI 0.65-0.90, p=0.002).

CONCLUSIONS

Our novel jMD score confirmed reasonable associations with nutrient intakes, and higher MD adherence was associated with a lower prevalence of overweight/obesity.

Diet quality and adherence to a healthy diet in Japanese male workers with untreated hypertension

OBJECTIVES

As Japanese societies rapidly undergo westernisation, the prevalence of hypertension is increasing. We investigated the association between dietary quality and the prevalence of untreated hypertension in Japanese male workers.

DESIGN AND METHODS

We conducted a cross-sectional study of 433 male workers who completed a brief food frequency questionnaire. Adherence to the WHO-based Healthy Diet Indicator (HDI), the American Heart Association 2006 Diet and Lifestyle Recommendations, the Dietary Approaches to Stop Hypertension (DASH) diet, and Mediterranean-style diet was assessed using four adherence indexes (HDI score, AI-84 score, DASH score and MED score). Hypertension classes were classified into three categories: non-hypertension, untreated hypertension and treated hypertension (ie, taking antihypertensive medication).

RESULTS

The prevalence of untreated hypertension and treated hypertension was 22.4% and 8.5%, respectively. Patients with untreated hypertension had significantly lower HDI and AI-84 scores compared with non-hypertension. DASH and MED scores across the three hypertension classes were comparable. After adjusting for age, energy intake, smoking habit, alcohol drinking, physical activity and salt intake, a low adherence to HDI and a lowest quartile of AI-84 score were associated with a significantly higher prevalence of untreated hypertension, with an OR of 3.33 (95% CI 1.39 to 7.94, p=0.007) and 2.23 (1.09 to 4.53, p=0.027), respectively.

CONCLUSIONS

A lower dietary quality was associated with increased prevalence of untreated hypertension in Japanese male workers. Our findings support a potential beneficial impact of nutritional assessment using diet qualities.

Renal histological heterogeneity and functional progress in normoalbuminuric and microalbuminuric Japanese patients with type 2 diabetes

BACKGROUND AND OBJECTIVES

Renal histological injury patterns in type 2 diabetes are heterogeneous. We compared renal histological injury patterns using renal biopsy findings with renal function and followed up renal functional changes in normoalbuminuric and microalbuminuric patients with type 2 diabetes to determine whether renal function progresses according to injury patterns.

DESIGN SETTING PARTICIPANTS AND MEASUREMENTS

We examined 111 patients with type 2 diabetes with percutaneous renal biopsy (78 men, 52±11 years old, 59 normoalbuminuria, 52 microalbuminuria) and followed up 37 cases for 11 years. Light microscopy of tissues revealed renal injury patterns as: category I (CI), normal or near-normal structure; category II (CII), typical diabetic glomerulopathy; category III (CIII), atypical (disproportionately severe tubulointerstitial/vascular damage with no/mild glomerulopathy).

RESULTS

There were 29 CI, 62 CII, and 20 CIII patients. CII patients had a higher frequency of chronic kidney disease (CKD) G3-4, while the injury pattern distribution was not different among the albuminuria stages. The mean glomerular volume and volume fraction of cortical interstitium were larger than those of controls. The arteriolar hyalinosis index was larger in CII and CIII, while the percent global glomerular sclerosis was larger in CKD G3-4 compared with CKD G1-2. Renal function at follow-up was decreased in CII and CIII compared with the baseline estimated glomerular filtration rate (eGFR), while the GFR decline rate was faster in CII.

CONCLUSIONS

In normoalbuminuric and microalbuminuric patients with type 2 diabetes, loss of GFR could indicate typical diabetic glomerulosclerosis and a high frequency of global glomerular sclerosis. Urinary biomarkers identifying histological patterns of renal injury are necessary because GFR decline rates differed according to histological injury patterns.

Adherence index to the American Heart Association Diet and Lifestyle Recommendation is associated with the metabolic syndrome in Japanese male workers

BACKGROUND

As Japanese societies rapidly undergo Westernization, the prevalence of metabolic syndrome is increasing. We investigated the association between dietary habits and the prevalence of metabolic syndrome using a new adherence index to optimal dietary habits based on the American Heart Association Diet and Lifestyle Recommendation (AHA-DLR).

METHODS

We conducted a cross-sectional study of 503 male workers who completed a brief food frequency questionnaire. Adherence to the AHA-DLR was assessed using a 10-component adherence index (AI-84; a total possible score of 84 points). Metabolic syndrome was defined according to the most recently published harmonized criteria by the International Diabetes Federation in conjunction with the National Heart, Lung, and Blood Institute, American Heart Association, World Heart Federation, International Atherosclerosis Society, and International Association for the Study of Obesity.

RESULTS

The prevalence of metabolic syndrome was 26.6% and the AI-84 score ranged from 5 to 56 points. Subjects with metabolic syndrome had a significantly lower AI-84 score compared with those without (27.1 ± 9.1 vs. 28.9 ± 9.2, p=0.042). After adjusting for age, energy intake, smoking habit and physical activity, a higher AI-84 score was associated with a significantly lower prevalence of metabolic syndrome, with an odds ratio of 0.778 (95% CI 0.614-0.986, p=0.038) for each 10-point score increment.

CONCLUSIONS

A lower AI-84 score was associated with increased prevalence of metabolic syndrome. Our findings support a potential beneficial impact of nutritional assessment using adherence to the AHA-DLR for prevention of metabolic syndrome.

Aspirin reduces cerebrovascular events in type 2 diabetic patients with poorly controlled blood pressure. Subanalysis from the JPAD trial

BACKGROUND

There are few data that demonstrate a significant effect of aspirin therapy for diabetic patients. To clarify the effect of the primary prevention of aspirin therapy in diabetic patients, the relationship between blood pressure (BP) and the incidence of atherosclerotic events was investigated in participants in the Japanese primary prevention of atherosclerosis with aspirin for diabetes (JPAD) trial.

METHODS AND RESULTS

We divided the JPAD participants according to their systolic (SBP) and diastolic (DBP) BPs at enrollment (SBP ≥140 mmHg and/or DBP ≥90 mmHg: unattained group, SBP <140 mmHg and DBP <90 mmHg: attained group). The incidence of the primary atherosclerotic events, especially cerebrovascular events, was higher in the unattained group than in the attained group. The incidence of cerebrovascular events was higher in the unattained group than in the attained group in patients without aspirin therapy; however, the incidence of cerebrovascular events in the unattained group was as low as the incidence in the attained group in patients undergoing aspirin therapy. Cox proportional hazards analysis revealed that BP level was an independent predictor for cerebrovascular events in diabetic patients.

CONCLUSIONS

Aspirin therapy may reduce cerebrovascular events in diabetic patients with higher BP. Aspirin therapy could be an additional strategy as primary prevention for diabetic patients with higher BP.

Differential effect of low-dose aspirin for primary prevention of atherosclerotic events in diabetes management: a subanalysis of the JPAD trial

OBJECTIVE

Recent reports showed that low-dose aspirin was ineffective in the primary prevention of cardiovascular events in diabetic patients overall. We hypothesized that low-dose aspirin would be beneficial in patients receiving insulin therapy, as a high-risk group.

RESEARCH DESIGN AND METHODS

This study is a subanalysis of the Japanese Primary Prevention of Atherosclerosis With Aspirin for Diabetes (JPAD) trial-a randomized, controlled, open-label trial. We randomly assigned 2,539 patients with type 2 diabetes and no previous cardiovascular disease to the low-dose aspirin group (81 or 100 mg daily) or to the no-aspirin group. The median follow-up period was 4.4 years. We investigated the effect of low-dose aspirin on preventing atherosclerotic events in groups receiving different diabetes management.

RESULTS

At baseline, 326 patients were treated with insulin, 1,750 with oral hypoglycemic agents (OHAs), and 463 with diet alone. The insulin group had the longest history of diabetes, the worst glycemic control, and the highest prevalence of diabetic microangiopathies. The diet-alone group had the opposite characteristics. The incidence of atherosclerotic events was 26.6, 14.6, and 10.4 cases per 1,000 person-years in the insulin, OHA, and diet-alone groups, respectively. In the insulin and OHA groups, low-dose aspirin did not affect atherosclerotic events (insulin: hazard ratio [HR] 1.19 [95% CI 0.60-2.40]; OHA: HR 0.84 [0.57-1.24]). In the diet-alone group, low-dose aspirin significantly reduced atherosclerotic events, despite the lowest event rates (HR 0.21 [0.05-0.64]).

CONCLUSIONS

Low-dose aspirin reduced atherosclerotic events predominantly in the diet-alone group and not in the insulin or OHA groups.

Epithelial-mesenchymal transition as a potential explanation for podocyte depletion in diabetic nephropathy

BACKGROUND

Depletion of glomerular podocytes is an important feature of progressive diabetic nephropathy. Although the most plausible explanation for this podocyte depletion is detachment from the glomerular basement membrane after cellular apoptosis, the mechanism is unclear. Fibroblast-specific protein 1 (FSP1; encoded by the S100A4 gene) is a member of the S100 family of calcium-binding proteins and is constitutively expressed in the cytoplasm of tissue fibroblasts or epithelial cells converted into fibroblasts by means of epithelial-mesenchymal transition.

STUDY DESIGN

Retrospective cross-sectional analysis.

SETTINGS & PARTICIPANTS

109 patients with type 2 diabetes mellitus, of whom 43 (39%) underwent kidney biopsy.

PREDICTOR

Clinical stage (4 categories) and histological grade (5 categories) of diabetic nephropathy.

OUTCOME

FSP1 expression in podocytes in urine and glomeruli in kidney biopsy specimens.

MEASUREMENTS

Immunohistochemistry, real-time polymerase chain reaction, and in situ hybridization.

RESULTS

38 of 109 patients (35%) were normoalbuminuric, 16 (15%) had microalbuminuria, 8 (7%) had macroalbuminuria, and 47 (43%) had decreased kidney function. Approximately 95% of podocytes in urine sediment were not apoptotic, and 86% expressed FSP1. The number of FSP1-positive podocytes in urine sediment was significantly larger in patients with macroalbuminuria than in those with normoalbuminuria (P = 0.03). Intraglomerular expression of FSP1 occurred almost exclusively in podocytes from patients with diabetes, and the number of FSP1-positive podocytes was larger in glomeruli showing diffuse mesangiopathy than in those showing focal mesangiopathy (P = 0.01). The number also was larger in glomeruli with nodular lesions than in those without nodular lesions (P < 0.001). FSP1-positive podocytes selectively expressed Snail1 and integrin-linked kinase, a known trigger for epithelial-mesenchymal transition.

LIMITATIONS

Nonrepresentative study population.

CONCLUSIONS

These results suggest that the appearance of FSP1 in podocytes of patients with diabetes is associated with more severe clinical and pathological findings of diabetic nephropathy, perhaps because of induction of podocyte detachment through epithelial-mesenchymal transition-like phenomena.

Low-dose aspirin for primary prevention of atherosclerotic events in patients with type 2 diabetes: a randomized controlled trial

CONTEXT

Previous trials have investigated the effects of low-dose aspirin on primary prevention of cardiovascular events, but not in patients with type 2 diabetes.

OBJECTIVE

To examine the efficacy of low-dose aspirin for the primary prevention of atherosclerotic events in patients with type 2 diabetes.

DESIGN, SETTING, AND PARTICIPANTS

Multicenter, prospective, randomized, open-label, blinded, end-point trial conducted from December 2002 through April 2008 at 163 institutions throughout Japan, which enrolled 2539 patients with type 2 diabetes without a history of atherosclerotic disease and had a median follow-up of 4.37 years.

INTERVENTIONS

Patients were assigned to the low-dose aspirin group (81 or 100 mg per day) or the nonaspirin group.

MAIN OUTCOME MEASURES

Primary end points were atherosclerotic events, including fatal or nonfatal ischemic heart disease, fatal or nonfatal stroke, and peripheral arterial disease. Secondary end points included each primary end point and combinations of primary end points as well as death from any cause.

RESULTS

A total of 154 atherosclerotic events occurred: 68 in the aspirin group (13.6 per 1000 person-years) and 86 in the nonaspirin group (17.0 per 1000 person-years) (hazard ratio [HR], 0.80; 95% confidence interval [CI], 0.58-1.10; log-rank test, P = .16). The combined end point of fatal coronary events and fatal cerebrovascular events occurred in 1 patient (stroke) in the aspirin group and 10 patients (5 fatal myocardial infarctions and 5 fatal strokes) in the nonaspirin group (HR, 0.10; 95% CI, 0.01-0.79; P = .0037). A total of 34 patients in the aspirin group and 38 patients in the nonaspirin group died from any cause (HR, 0.90; 95% CI, 0.57-1.14; log-rank test, P = .67). The composite of hemorrhagic stroke and significant gastrointestinal bleeding was not significantly different between the aspirin and nonaspirin groups.

CONCLUSION

In this study of patients with type 2 diabetes, low-dose aspirin as primary prevention did not reduce the risk of cardiovascular events.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00110448.

Frailty, health-related quality of life and mental well-being in older adults with cardiometabolic risk factors

OBJECTIVE

Frailty is an emergent health-related problem in older adults. The aim of this study was to examine the health-related quality of life (HRQOL) and the effect of frailty in elderly patients with cardiometabolic risk factors.

METHODS

One-hundred and one patients 65 years or older responded to an HRQOL assessment using the World Health Organization Quality of Life (WHOQOL)-26 questionnaire. Frailty was assessed using two indices: the Hebrew Rehabilitation Center for Aged (HRCA) vulnerability index and the Vulnerable Elders Survey (VES) index. In addition, these patients completed self-rating questionnaires assessing mental well-being [the 28-item version of the General Health Questionnaire (GHQ-28)] and depression (Geriatric Depression Scale).

RESULTS

Based on the combination of HRCA and VES indices, 24 subjects (23.7%) met the criteria of frail. Persons > or = 75 years old and those with depressive mood or lower creatinine clearance had significantly lower WHOQOL-26 scores than their counterparts. Diabetes and macrovascular complications did not associate with the WHOQOL-26 scores. Compared with non-frail patients, the frail scored lower on the WHOQOL-26 questionnaire after adjusting for age, kidney dysfunction and depressive mood. Frail patients also reported significantly higher the GHQ-28 scores compared with non-frail patients.

CONCLUSIONS

Frail older adults had a significant lower HRQOL, as well as lower mental well-being, independent of age, diabetes, macrovascular complication, kidney dysfunction and depressed mood.

Surrogate markers of insulin resistance in assessing individuals with new categories “prehypertension” and “prediabetes”

BACKGROUND

There are few data on the impact of insulin resistance on the recently defined categories of prehypertension (PHT) and prediabetes (PDM). The aim of this study was to examine associations of surrogate markers of insulin resistance with PHT/PDM.

METHODS

Subjects included 554 individuals who underwent a 75-g oral glucose tolerance test (OGTT). They were classified into four groups using a severity score for high blood pressure and glucose tolerance. Insulin resistance was measured using the homeostasis model assessment of insulin resistance (HOMA-R) and three surrogate markers obtained from 75-g OGTT values (ISI-composite, Stumvoll index, and OGIS index).

RESULTS

HOMA-R increased significantly, but the other three surrogate indices decreased with increasing severity score. Of these markers, the OGIS index was mostly associated with prevalent PHT/PDM and the odds ratio for insulin resistance was 3.61 (95% CI 1.68-7.76, p=0.001) for subjects with either PHT or PDM and 29.98 (12.81-70.18, p<0.001) for subjects with both PHT and PDM.

CONCLUSIONS

PHT and PDM frequently coexist in relatively lean Japanese subjects. Decreased insulin sensitivity may contribute to the underlying status of PHT/PDM. Among the surrogate markers of insulin resistance, the OGIS index is the most sensitive for assessment of PHT/PDM status.

Utility of elevated 2-hour postload plasma glucose as an alternative to elevated fasting glucose as a criterion for the metabolic syndrome

We hypothesize that many persons with postchallenge hyperglycemia (PCH) but who do not meet the National Cholesterol Education Program (NCEP) criteria characterize a phenotype that is similar to the metabolic syndrome (MS) traits. Subjects included 725 Japanese who underwent a 75-g oral glucose tolerance test. If 2-hour plasma glucose of 7.8 mmol/L or higher was present, subjects with fasting glucose of less than 6.1 mmol/L could have one component of the MS (PCH-MS). Data obtained by the 75-g oral glucose tolerance test were used to calculate 3 insulin sensitivity indexes according to formulas proposed by Matsuda and DeFronzo (insulin sensitivity index composite), Stumvoll et al (Srumvoll index), and Mari et al (oral glucose insulin sensitivity index). Based on the PCH-MS and NCEP-MS criteria, 395 had neither PCH-MS nor NCEP-MS, 85 had PCH-MS, and 245 had NCEP-MS. Subjects with PCH-MS exhibited higher systolic blood pressure and triglyceride levels, lower high-density lipoprotein cholesterol levels, and lower insulin sensitivity than those who had neither PCH-MS nor NCEP-MS. A similar profile was observed when subjects with NCEP-MS were compared with those who had neither PCH-MS nor NCEP-MS. All 3 indexes of insulin sensitivity were significantly lower in subjects with PCH-MS than in those who had neither PCH-MS nor NCEP-MS, and approximately 66% of PCH-MS was in an insulin-resistant state. On the other hand, there was no statistical difference in the values between PCH-MS and NCEP-MS. Our data support the addition of abnormal 2-hour plasma glucose as a criterion for the MS, when fasting glucose is normal.

Fibroblast-specific protein 1 is a specific prognostic marker for renal survival in patients with IgAN

BACKGROUND

There is little direct evidence that fibroblasts are involved in the progression of the renal interstitial fibrosis in human glomerulonephritis. With the availability of a new specific marker for fibroblasts, we determined the presence of fibroblasts in kidneys with IgA nephropathy (IgAN) and correlated their numbers with various clinical parameters. In particular, we also prospectively asked if the number of fibroblasts in the renal interstitium correlates with prognosis.

METHODS

Cells positive for fibroblast-specific protein 1 (FSP1) were localized in renal biopsy specimens using immunohistochemistry with anti-FSP1 antibody. Clinical features were analyzed by one-way analysis of variance (ANOVA) with the Bonferroni correction. To assess the prognostic impact of the number of FSP1+ fibroblasts on renal survival in 142 patients with normal serum creatinine, the relationship between covariates to renal survival were evaluated univariately using the log-rank test and multivariately using Cox proportional hazards.

RESULTS

Fibroblasts identified by their expression of FSP1 accumulate in areas showing severe interstitial fibrosis. Some tubular epithelial cells undergoing epithelial-mesenchymal transition (EMT) in fibrotic areas also express FSP1. Numbers of FSP1+ fibroblasts directly correlate with serum creatinine (r = 0.74, P < 0.0001) and inversely correlate with estimated creatinine clearance (r = -0.54, P < 0.0001), and by multivariate analysis, the clinical factors influencing renal survival are urinary protein excretion [> or = 1.0 g/day, relative risk (RR) = 4.20, P= 0.032], hypertension (RR 5.85, P = 0.0027), and > or = 20 FSP1+ fibroblasts per high power field (HPF) (RR 7.39, P = 0.0015). Staining for FSP1+ fibroblasts is largely nonoverlapping with alpha-smooth muscle actin+ (alpha-SMA) cells in the interstitium.

CONCLUSION

The target protein FSP1 identifies human fibroblasts and tubular epithelium undergoing EMT, and distinguishes them from the diaspora of alpha-SMA+ vascular smooth muscle cells. FSP1+ fibroblasts are critically related to the progression of IgAN; consequently, staining FSP1 in renal biopsy specimens provides a valuable histologic index of progression.

New "pre-diabetes" category and the metabolic syndrome in Japanese

BACKGROUND

Recently, impaired fasting glucose (IFG) was redefined as fasting plasma glucose of 100-125 mg/dl, and individuals with IFG and/or impaired glucose tolerance (IGT) were referred to as having "pre-diabetes". However, there is a lack of data using the new definition of IFG and "pre-diabetes".

OBJECTIVE

The aim of this study was to examine associations of the metabolic syndrome components with the new "pre-diabetes" category in relatively lean Japanese.

METHODS

Six hundred and sixty-one Japanese study participants underwent a 75 g oral glucose tolerance test. They were classified into three groups-normal (n=225), pre-diabetes (n=308), and diabetes (n=128). The metabolic syndrome was defined according to the National Cholesterol Education Program Adult Treatment Panel III, as modified for waist circumference criteria by the Regional Office for the Western Pacific Region of WHO.

RESULTS

Prevalence of the metabolic syndrome in each group was 10.7%, 27.9%, and 53.9%, respectively. Of the metabolic syndrome components, the OR for prevalent pre-diabetes was 2.00 (95% CI, 1.73-2.31, p<0.001) for fasting glucose, 1.93 (95% CI, 1.54-2.42, p<0.001) for waist circumference, and 1.36 (95% CI, 1.10-1.68, p=0.005) for triglycerides. Similar associations were found in prevalent diabetes. Insulin resistance assessed using Stumvoll's index was significantly associated with both pre-diabetes and diabetes.

CONCLUSION

Pre-diabetes and the metabolic syndrome frequently coexist in relatively lean Japanese. This association seems to link with abdominal adiposity and insulin resistance.

Beta-cell function and insulin sensitivity contribute to the shape of plasma glucose curve during an oral glucose tolerance test in non-diabetic individuals

To clarify whether beta-cell function and/or insulin resistance contributes to the shape of plasma glucose curve during an oral glucose tolerance test (OGTT), we investigated 583 Japanese subjects with normal glucose tolerance (NGT, n = 306) or impaired glucose tolerance (IGT, n = 277). Each subject was subdivided into three shapes of plasma glucose curve as follows: monophasic pattern (M type), biphasic pattern (B type) and two peaks (T type). Homeostasis model assessment of insulin resistance, quantitative insulin sensitivity check index and insulinogenic index were assessed by plasma glucose and insulin concentrations obtained at fasting or during an OGTT. There was a greater proportion of M type in the IGT group (M = 80.9%, B = 15.5% and T = 3.6%), whereas the prevalence of B and T types was much higher in the NGT group (M = 66.6%, B = 26.5% and T = 6.9%). There were significant differences in the proportions of shape types between the NGT and IGT groups (p = 0.0006). Among the NGT category, insulin sensitivity was significantly higher in the B type than in the M type, and beta-cell function adjusted for insulin resistance was significantly higher in the B and T types than in the M type. Among the IGT category, no significant differences were seen among the three shape types with respect to insulin sensitivity, but the beta-cell function adjusted for insulin resistance was significantly lower in the M type than in the B and T types. In conclusion, both impaired insulin secretion and insulin resistance may contribute to the underlying mechanisms of the shape of plasma glucose curve in Japanese subjects.

Metabolic syndrome and new category 'pre-hypertension' in a Japanese population

OBJECTIVE

To examine whether insulin resistance and metabolic syndrome are associated with pre-hypertension, a new stage developed by the Joint National Committee on Prevention, Detection, Education and Treatment of High Blood Pressure (JNC-7).

PATIENTS AND METHODS

Subjects included 506 Japanese taking no anti-hypertensive medication. Subjects were divided into three groups according to blood pressure status using the JNC-7 criteria. Normotension (NTN) was defined as a Systolic Blood Pressure (SBP) < 120 mmHg and a Diastolic Blood Pressure (DBP) < 80 mmHg, pre-hypertension (PHT) as a SBP 120-139 mmHg or a DBP 80-89 mmHg and hypertension (HTN) as a SBP > or = 140 mmHg or a DBP > or = 90 mmHg. The metabolic syndrome was defined according to the National Cholesterol Education Program Adult Treatment Panel III as modified for waist circumference criteria by the Regional Office for the Western Pacific Region of WHO. Insulin sensitivity was assessed by plasma glucose and insulin concentrations obtained at fasting or during a 75 g oral glucose tolerance test.

RESULTS

There were no differences with respect to age, gender or glucose intolerance status among the three groups. The mean values of body mass index were similar between NTN and PHT, but were significantly higher in HTN than in other groups. The prevalence of the metabolic syndrome was 9.9% in NTN, 19.2% in PHT and 35.5% in HTN, respectively. The prevalence increased linearly with worsening of blood pressure status (p < 0.0001). An increase in the number of metabolic syndrome components (MS score) was also associated with a progress in blood pressure status. Even in the non-obese persons, the prevalence of the metabolic syndrome and the MS score increased linearly with worsening in blood pressure status. The homeostasis model assessment of insulin resistance (HOMA-R) was significantly higher in PHT and HTN than in NTN and increased significantly with worsening in blood pressure status. Furthermore, the quantitative insulin sensitivity check index (QUICKI) and the insulin sensitivity index proposed by Stumvoll et al. decreased significantly with worsening in blood pressure status.

CONCLUSIONS

The metabolic syndrome is prevalent even in the pre-hypertensive stage in a Japanese population and insulin resistance contributes to the underlying mechanisms of these abnormalities.

Insulin resistance and pancreatic beta-cell function in patients with hypertensive kidney disease

BACKGROUND

Insulin resistance and hyperinsulinaemia have been reported among patients with chronic renal failure. However, little is known concerning insulin sensitivity among patients with hypertensive kidney disease (HKD), especially in those with moderate or severe renal dysfunction.

METHODS

We examined and compared 30 patients with HKD, 30 normotensive patients with chronic kidney disease (CKD-NT), 30 normal controls and 30 patients with hypertension and normal renal function (HTN). Moderate and severe renal dysfunction were defined according to the K/DOQI definitions (estimated glomerular filtration rates between 15 and 59 ml/min per 1.73 m(2)). The homeostasis model assessment of insulin resistance (HOMA-R) and three surrogate indexes based on 75 g oral glucose tolerance test results were used to determine insulin sensitivity.

RESULTS

A trend to higher HOMA-R values in the HTN and HKD groups than in the other groups was noted, but the difference was not statistically significant. The insulin sensitivity index (ISI) proposed by Stumvoll et al. was significantly lower in the HTN, HKD and CKD-NT groups than in controls and was significantly lower in HKD than in the HTN and CKD-NT groups. The insulin sensitivity index proposed by Gutt et al. was significantly lower in HKD than in the control and HTN groups and showed a trend to being lower in HKD than in CKD-NT. The same patterns prevailed in the oral glucose ISI. We assumed that subjects whose ISI values decreased below the mean value minus 2-SD in the control group manifest apparent insulin resistance. According to this criterion, approximately 40% of HKD subjects were in an insulin-resistant state: only <10% of HTN subjects and approximately 10-30% of CKD-NT subjects were insulin resistant.

CONCLUSIONS

HKD with moderate to severe renal dysfunction is associated with insulin resistance.

Use of novel assays to indicate that O-esters and S-esters are produced by the same enzyme in brewing yeast

Ethanol- and methanethiol-dependent removal of acetyl-CoA by crude extracts of ale yeast has been monitored using a decrease in OD232. Activity has also been detected in these extracts after fractionation on polyacrylamide gels, in this case using a novel assay in which the coenzyme A produced in the reaction is linked via DCPIP reduction to color formation from nitroblue tetrazolium. Ethanol- and methanethiol-dependent activities migrate identically on such gels, and only one band of color formation was observed. Furthermore they displayed closely similar sensitivity to heating at 40 degrees C and 60 degrees C and pH optima, with activity maximal at pH 7.5. It is likely that a single enzyme is responsible for the formation of O-esters and S-esters in yeast. Initial kinetic studies indicate that methanethiol has higher affinity for the enzyme than has ethanol and a higher maximum velocity. However, the enzyme has a much lower Km for acetyl-CoA, suggesting that the alcohol or thiol substrate is the more likely substrate to be limiting.

Homeostasis model assessment of insulin resistance, quantitative insulin sensitivity check index, and oral glucose insulin sensitivity index in nonobese, nondiabetic subjects with high-normal blood pressure

To investigate the relationships between high-normal blood pressure (BP) and insulin resistance, we examined insulin sensitivity in 306 nonobese and nondiabetic Japanese subjects with various BP categories (optimal BP, normal BP, high-normal BP, and hypertension). Insulin sensitivity was measured from fasting plasma glucose and insulin values and those during a 75-g oral glucose tolerance test by five formulas: the homeostasis model assessment of insulin resistance (HOMA-R), the quantitative insulin sensitivity check index (QUICKI), the oral glucose insulin sensitivity (OGIS) index, and two insulin sensitivity indexes (ISI-composite and ISI-stumvoll). The HOMA-R was significantly higher, and the QUICKI was significantly lower in subjects with hypertension than in subjects with optimal BP. Both HOMA-R and QUICKI values showed that high-normal BP patients had a higher (but not significant) degree of insulin resistance than optimal BP patients. The OGIS index was significantly lower in subjects with high-normal BP or hypertension than in subjects with optimal BP. The ISI-composite was significantly lower in subjects with high-normal BP or hypertension than in subjects with optimal BP, and it was also significantly lower in subjects with hypertension than in subjects with normal BP. The ISI-stumvoll was significantly lower in subjects with high-normal BP or hypertension than in subjects with optimal BP. The OGIS index, ISI-composite, and ISI-stumvoll significantly decreased with increasing severity of BP status among the normotensive groups (optimal BP, normal BP, and high-normal BP). These findings indicate that insulin resistance is present even in the high-normal BP categories of nonobese and nondiabetic Japanese individuals.

Pancreatic beta-cell function and insulin sensitivity in japanese subjects with impaired glucose tolerance and newly diagnosed type 2 diabetes mellitus

To clarify whether pancreatic beta-cell function and/or insulin resistance contributes to development of glucose intolerance in Japanese subjects, we investigated 551 subjects who underwent a 75-g oral glucose tolerance test (OGTT). Subjects were divided into 3 groups: normal glucose tolerance (NGT, n = 238), impaired glucose tolerance (IGT, n = 211), and newly diagnosed type 2 diabetes mellitus (n = 102). The diabetics were subdivided into 3 subgroups as follows: diabetes with normal fasting glucose (fasting plasma glucose [FPG] < 110 mg/dL), diabetes with impaired fasting glucose (FPG 110 to 125 mg/dL), and diabetes with diabetic fasting glucose (FPG >or= 126 mg/dL). Insulinogenic index as early-phase insulin secretion, homeostasis model assessment (HOMA-beta and HOMA-resistance), and 4 different formulas of insulin sensitivity index were assessed by plasma glucose and insulin concentrations obtained at fasting or during a 75-g OGTT. Both early-phase insulin secretion and insulin sensitivity were low even in the IGT stage compared with NGT. The transition from IGT to diabetes was accompanied by a progressive deterioration of insulin reserve as well as insulin resistance. During the further progression in diabetes, insulinogenic index decreased additionally, whereas declines in insulin sensitivity were relatively small. In conclusion, both impaired insulin secretion and insulin resistance may contribute to the underlying mechanisms of glucose intolerance in Japanese subjects.

Validation of simple indices to assess insulin sensitivity and pancreatic Beta-cell function in patients with renal dysfunction

BACKGROUND/AIMS

Insulin resistance and hyperinsulinemia has been reported in patients with chronic renal failure. However, usefulness and validation of new indices for assessment to insulin sensitivity and pancreatic beta-cell function were unknown.

METHODS

We evaluated insulin sensitivity and pancreatic beta-cell function in 61 normal glucose tolerant (NGT) and 60 diabetic (DM) subjects; both groups were subdivided as normal renal function (NRF; C(cr) >/= 70 ml/min) and impaired renal function (IRF; C(cr) <70 ml/min). Insulin sensitivity were assessed by homeostasis model assessment of insulin resistance (HOMA-IR) and plasma glucose and insulin concentrations obtained at fasting or during a 75-gram oral glucose tolerance test (insulin sensitivity index), and pancreatic beta-cell function were assessed by insulinogenic index, first-phase insulin secretion index, and area under the response curve for plasma insulin (insulin-AUC(0-180)).

RESULTS

There was no evidence of insulin resistance in NGT-IRF group. No differences in both insulinogenic index and first-phase insulin secretion index between NGT-NRF and NGT-IRF, but these were significantly decreased in DM-NRF and DM-IRF. There were inverse linear correlations between the insulin sensitivity index and insulin-AUC(0-180) in patients with NGT and DM, respectively. These correlations were similarly robust in NRF subjects and IRF subjects.

CONCLUSIONS

New indices for assessment of insulin sensitivity and pancreatic beta-cell function calculated from plasma glucose and plasma insulin concentrations after OGTT are applicable for clinical use even in patients with renal dysfunction.

Oxidative DNA damage and tubulointerstitial injury in diabetic nephropathy

BACKGROUND

Oxidative stress is an important pathogenetic factor in underlying diabetic complications. Recently, 8-hydroxy-2'-deoxyguanosine (8-OHdG) has been reported to serve as a new sensitive biomarker of the oxidative DNA damage in vivo. We studied the relationship between oxidative DNA damage and tubulointerstitial injury in patients with diabetic nephropathy.

METHODS

Type 2 diabetic patients (n = 25) and healthy control subjects (n = 20) were studied. The urine concentrations of 8-OHdG were measured by a competitive ELISA. The severity of the glomerular changes was graded using Gellman's criteria, and the severity of the tubulointerstitial lesions was determined by a semiquantitative estimate of the space occupied by the fibrous tissue and/or interstitial infiltrates.

RESULTS

The urinary 8-OHdG excretion were significantly higher in the diabetics than in the healthy controls, and tended to increase with severity of the glomerular diffuse lesion, but it was not significant. The urinary 8-OHdG excretion significantly increased with severity of the tubulointerstitial lesion.

CONCLUSIONS

Oxidative stress may contribute to the progression of tubulointerstitial injury in patients with diabetic nephropathy.

Transferrinuria in type 2 diabetic patients with early nephropathy and tubulointerstitial injury

BACKGROUND: Transferrinuria is thought to be a marker for early stages of diabetic nephropathy. Transferrin has also been proposed as a mediator of tubular toxicity because the reabsorption of transferrin results in the release of reactive iron in proximal tubular cells, promoting the formation of hydroxyl radicals. We evaluated the role of urinary transferrin excretion in diabetic patients with early nephropathy by comparing tubulointerstitial injury in renal biopsy specimens. PATIENTS AND METHODS: 45 type 2 diabetic patients with normoalbuminuria (urinary albumin excretion <30 mg/24 h) or microalbuminuria (30-300 mg/24 h) were studied. All patients with microalbuminuria underwent renal biopsy, and the severity of the tubulo-interstitial lesions was determined by a semiquantitative estimate of interstitial fibrosis, tubular atrophy, and interstitial inflammatory infiltrates. Subjects were classified into group A (normoalbuminuria, n=25), group B (microalbuminuria without tubulointerstitial changes, n=11) or group C (microalbuminuria with tubulointerstitial changes, n=9). RESULTS: Urinary transferrin excretion (UTf), as well as UTf/creatinine clearance (Ccr), and transferrin clearance (CTf/Ccr), was significantly higher in groups B and C than in group A, and it was significantly higher in group C than in group B. There were no significant differences in urinary albumin excretion or mesangial expansion rate (MR% estimated by quantitative morphometric studies) between groups B and C. Although urinary beta2-microglobulin excretion was significantly higher in group C than in groups A and B, urinary N-acetyl-beta-D-glucosaminidase activity was significantly higher in groups B and C than in group A. CONCLUSIONS: Increased transferrinuria in the microalbuminuric stage may lead to the development of tubulointerstitial injuries in type 2 diabetic patients.

Validation of simple indices to assess insulin sensitivity based on the oral glucose tolerance test in the Japanese population

The homeostasis model assessment (HOMA) represents a simple index for evaluating insulin sensitivity, but clinical use is limited. Insulin sensitivity indices calculated from plasma glucose and plasma insulin concentrations after an oral glucose tolerant test (OGTT) have been proposed, but have not been validated in the Japanese population. We compared these indices with the euglycemic hyperinsulinemic clamp technique to evaluate the predicting insulin sensitivities in 77 Japanese subjects with varying degrees of glucose tolerance (normal glucose tolerance, n=40; impaired glucose tolerance, n=22; and type 2 diabetes mellitus, n=15). Insulin sensitivity was measured by the euglycemic hyperinsulinemic glucose clamp technique using an artificial pancreas, and expressed as the M-value. Weak inverse correlations existed between the HOMA index and M-values (r=-0.227, P=0.0468). An alternative index calculated by Matsuda's formula correlated with the M-value (r=0.450, P=0.0001). A second index calculated by Stumvoll's formula also correlated with the M-value (r=0.641, P=0.0001). Finally, a third index calculated by Gutt's formula also significantly correlated with the M-value (r=0.526, P=0.0001). All three indices are applicable for clinical use. The second index is the most sensitive measure of insulin sensitivity in the Japanese population.

Insulin secretion and sensitivity in non-obese and obese Japanese patients with coronary artery disease

In a cross-sectional study of 240 patients with angiographically documented coronary artery disease (CAD), we investigated whether obese and non-obese subjects differed as to the influence of insulin deficiency and insulin resistance on glucose intolerance and cardiovascular risk. Patients were classified according to a 75-g oral glucose tolerance test as having normal glucose tolerance (NGT), impaired glucose tolerance (IGT), or diabetes mellitus (DM). We defined obesity as a body mass index (BMI) exceeding 25 kg/m(2). Early phase insulin secretion (insulinogenic index) declined with worsening glucose intolerance in non-obese (tau = -.216, P <.001; Kendall's correlation coefficient) and obese subjects (tau = -.392, P <.001). Total insulin secretion was higher in obese subjects with NGT or IGT than in controls and decreased in association with worsening glucose intolerance in obese subjects (tau = -.239, P <.001). Insulin sensitivity was calculated by 3 proposed indices. The first of these decreased in association with worsening in glucose tolerance in non-obese subjects (tau = -.137, P <.01). The second showed such a pattern in both groups (non-obese, tau = -.407, P <.001; obese, tau = -.311, P <.001), as did the third (non-obese, tau = -.512, P <.001; obese, tau = -.488, P < 0.001). Because even prediabetic Japanese subjects with CAD showed a latent insulin secretion defect in response to a glucose load, as well as impaired insulin sensitivity, compensatory hyperinsulinemia is not a sensitive indicator of coronary risk.

Association of transforming growth factor-beta1 T29C polymorphism with the progression of diabetic nephropathy

Diabetes mellitus is a leading cause of end-stage renal disease in the Western world. Histologically, mesangial expansion with increased extracellular matrix protein is observed in patients with diabetic nephropathy. Because transforming growth factor (TGF)-beta promotes extracellular matrix production in response to high glucose, TGF-beta is considered to play a central role in the pathogenesis of diabetic nephropathy. We investigated the association of TGF-beta1 T29C polymorphism and the progression of diabetic nephropathy. Forty patients with type 2 diabetes mellitus were enrolled. All patients had had diabetes for more than 10 years. DNA was extracted from peripheral blood cells, and genotype was determined using real-time polymerase chain reaction method. Patients were classified into three groups according to genotype: TT, TC, and CC. Grade of diabetic nephropathy was determined using the amount of urinary excretion of albumin. Demographic characteristics of the patients with each genotype were not statistically different. No differences in the glycemic control and the mode of therapy were observed. Among patients with three genotypes, the severity of diabetic nephropathy was not statistically different. The patients with TT genotype tended to have a higher rate of progression of nephropathy; however, no statistically significant difference was observed among the three groups. Our results suggest that TGF-beta1 T29C polymorphism is not associated with the progression of diabetic nephropathy. Further studies are required to determine the exact role of this polymorphism in the progression of diabetic nephropathy.

Serum levels of advanced glycosylation end products in diabetic nephropathy

BACKGROUND/AIMS

Advanced glycosylation end products (AGEs) are important pathogenetic factors underlying diabetic complications. Recently, a highly reliable new enzyme-linked immunosorbent assay for these metabolites has been established. We used the assay to correlate AGEs in serum with renal function categories and histopathology in patients with diabetic nephropathy.

METHODS

Type 2 diabetic patients (n = 71) and healthy control subjects (n = 35) were studied. The diabetic subjects were divided into two groups: normal renal function and chronic renal failure not requiring dialysis. In renal biopsy specimens from 22 diabetic subjects with a normal renal function, the severity of glomerular lesions was assessed morphometrically in terms of the ratio of the area of periodic acid-Schiff stained mesangium to total glomerular area.

RESULTS

The serum AGE concentrations were higher in both undialyzed diabetic groups, especially in those with renal failure, than in the controls. The serum AGE concentrations increased with the severity of glomerular lesions (morphometric ratio under 15%, 2.85 +/- 0.73 mU/ml; 15-24%, 4.01 +/- 0.71 mU/ml; 25% or more, 5.12 +/- 0.64 mU/ml).

CONCLUSIONS

The serum AGE levels measured by the new enzyme-linked immunosorbent assay reflected the severity of glomerulopathy, and, therefore, it may be a clinically useful tool for assessing diabetic renal complications.

Advanced glycation end products in nondiabetic patients with coronary artery disease

OBJECTIVE

To investigate whether advanced glycation end products (AGEs) participate in the development of coronary artery disease (CAD) in nondiabetic and diabetic subjects.

RESEARCH DESIGN AND METHODS

Serum concentrations of AGEs were measured using a newly established enzyme-linked immunosorbent assay in 48 nondiabetic patients (normal glucose tolerance, n = 20; impaired glucose tolerance, n = 28) who received coronary angiography for the study of chest pain or suspected CAD. Insulin sensitivity was examined by the euglycemic-hyperinsulinemic glucose clamp technique and was estimated as the mean glucose infusion rate during the last 30 min of clamp time (M value).

RESULTS

Patients were classified into four groups based on the number of significantly stenosed vessels, defined as 0-, 1-, 2-, or 3-vessel disease. Serum concentrations of AGEs were significantly higher in nondiabetic subjects with CAD than in control subjects (2.42 +/- 0.65 vs. 1.96 +/- 0.40 mU/ml, P < 0.01) and significantly correlated with the number of significantly stenosed vessels (r = 0.678, P < 0.001). M values significantly inversely correlated with serum concentrations of AGEs (r = -0.490, P < 0.05). In multiple regression analysis, with the number of significantly stenosed vessels as the dependent variable, serum concentrations of AGEs, 2-h plasma glucose, and areas under the plasma glucose response curve were independently associated.

CONCLUSIONS

This pilot study indicates the relation between AGEs and the severity of CAD in nondiabetic patients. The measurement of serum AGE concentrations may be predictive of vascular damage.