Hemoglobin Glycation Index: A Novel Risk Factor for Incident Chronic Kidney Disease in an Apparently Healthy Population

CONTEXT

Chronic kidney disease (CKD) is a worldwide health problem. Recent literature has shown an association of hemoglobin glycation index (HGI) and CKD in patients with dysglycemia.

OBJECTIVE

The aim of this study was to reveal the impact of HGI as a predictor for incident CKD in the general population.

METHODS

CKD was defined as dipstick proteinuria or estimated glomerular rate (eGFR) < 60 mL/min/1.73 m2. Impact of HGI on incident CKD was assessed using the data from CKD-free health examinees (N = 23 467, 4.1% with diabetes) followed for a mean of 5.1 years: Cox proportional hazards model was employed with multivariate adjustment for age, systolic blood pressure, eGFR, fasting plasma glucose, body mass index, log[alanine aminotransferase], log[triglycerides], high-density lipoprotein cholesterol, platelet counts, smoking, and sex. Elevated level of HGI in subjects with CKD was ascertained after propensity score matching of another group of health examinees (N = 2580, 7.6% with diabetes).

RESULTS

In the former group, CKD developed in 2540 subjects and HGI was the second most robust predictor for CKD, following low eGFR. With adjustment for the 11 covariates, the hazard ratio of HGI (95% CI) for CKD was 1.293 (1.238 to 1.349) (P < .0001). The population attributable risk of HGI for CKD was 4.2%. In the latter group, among 708 subjects matched 1:1 for 9 covariates, HGI was significantly elevated in subjects with CKD (median [interquartile range] -0.208 [-0.504 to -0.156] vs -0.284 [-0.582 to 0.052], P = .03).

CONCLUSION

HGI was a novel risk factor for CKD in the general population.

P-610 Endoplasmic reticulum stress-induced Notch signaling stimulates cumulus-oocyte complex expansion in PCOS

Study question

Does endoplasmic reticulum (ER) stress and Notch signaling affect cumulus-oocyte complex (COC) expansion in pathophysiology of polycystic ovary syndrome (PCOS)?

Summary answer

Notch signaling is induced via activation of ER stress in granulosa cells (GCs) of PCOS and stimulates COC expansion that is abrogated by Notch inhibition.

What is known already

PCOS presents a variety of symptoms including ovarian dysfunction which is caused by various local factors in follicular microenvironment; among them, ER stress and following activation of unfolded protein response are critical, causing ovarian fibrosis, growth arrest of antral follicles and other ovarian dysfunctions. While Notch signaling pathway plays an important role of various ovarian functions such as ovarian development, follicle growth, luteinization and steroid hormone synthesis, the potential interaction between Notch signaling and ER stress in ovarian function is not determined.

Study design, size, duration

To examine expression levels of Notch signaling, ovaries and granulosa-lutein cells (GLCs) were collected from PCOS patients undergoing surgery or IVF. Human GLCs were collected from follicular fluid of IVF patients and cultured under ER-stressed condition. COCs obtained from PMSG-primed mice were subjected to examine the in vitro effects of ER stress activation and Notch inhibition on COC expansion. To examine the in vivo effects of Notch inhibition, dehydroepiandrosterone-induced PCOS mouse model was used.

Participants/materials, setting, methods

The expression levels of Notch signaling in ovaries and GLCs were investigated by immunohistochemistry and real time qPCR. To examine whether Notch signaling is activated by ER stress, human GLCs were incubated with ER stress inducer or inhibitor and ATF4 was knocked down by RNA interference. To investigate COC expansion level, murine COCs were cultured under ER stress condition with/without Notch signaling inhibitor. The COCs were collected from PCOS mice treated with/without Notch inhibitor.

Main results and the role of chance

We found that the expression levels of Notch2 and Hey2, a transcription factor activated by Notch signaling, were upregulated in GCs of antral follicles from PCOS patients and PCOS mice by using immunohistochemical analysis. Similarly, mRNA levels of these genes were higher in GLCs from PCOS patients than those from control patients. Notch signaling was induced in cultured human GLCs incubated with an ER stress inducer, tunicamycin; the effect was abrogated by incubation with an ER stress inhibitor, tauroursodeoxycholic acid (TUDCA), or knockdown of activating transcription factor 4 (ATF4, a transcription factor induced by ER stress). These findings suggest that Notch signaling is induced by ER stress via ATF4 pathway in human GCs. Measuring under a microscope, the area of expanded COCs was increased in cultured murine COCs incubated with tunicamycin, while this stimulatory effect of tunicamycin was abrogated by adding a Notch signaling inhibitor, DAPT. The area of expanded COCs obtained from PCOS model mice was increased compared to control mice, while administration of DAPT to these mice reduced the area. These results suggest that ER stress-induced Notch signaling stimulate COC expansion contributing PCOS pathophysiology.

Limitations, reasons for caution

COC expansion area was measured only in PCOS model mouse; it is unknown whether COC expansion is induced in PCOS patients. This point requires further investigation in PCOS patients.

Wider implications of the findings

Our findings suggest that ER stress-induced Notch signaling affects COC expansion, associated with ovulatory dysfunction in PCOS. The detailed understandings of PCOS pathophysiology may be beneficial for substantial clinical implications and inhibition of ER stress or Notch signaling may serve as a novel therapeutic approach for PCOS.

Trial registration number

This study was supported by Grants-in-Aid for Scientific Research from the Japan Society for the Promotion of Science (JSPS) (19k09749, 19k24045, 19k24021, 21k16808, 21j12871,), a grant from the Takeda Science Foundation, a grant from The Tokyo Society of Medical Science, a grant from The Japan Society of Fertility Preservation, and a grant from The Japan Society for Menopause and Women’s Health (JMWH) (a JMWH Bayer Grant).

Significance of mitral L wave to predict late recurrence of atrial fibrillation after radiofrequency catheter ablation

Background

Mitral L wave, prominent mid-diastolic filling wave in echocardiographic examinations, is associated with severe left ventricular diastolic dysfunction, and that has been reported to predict recurrent atrial fibrillation (AF) after cardioversion. However, association between mitral L wave and the outcome of AF after radiofrequency catheter ablation (RFCA) has not been established.

Objective

The aim of this study is to evaluate the predictive value of mitral L wave on AF recurrence after RFCA.

Methods

250 patients including 164 paroxysmal AF (65.6%) and 86 non-paroxysmal AF (34.4%) who received RFCA in single center from January 2015 to December 2016 were enrolled consecutively. Echocardiographic examinations before RFCA were recorded, and the mitral L wave was defined as a distinct mid-diastolic flow velocity with a peak velocity ≥20 cm/s following the E wave. Systematic follow-up was conducted after RFCA. Univariate and multivariate analyses were carried out to determine the factors predicting late recurrence of AF (LRAF) which means AF recurrence after 3 months. Enrolled patients were divided into groups with the L wave (L-group; n=57) or without the L wave (NL-group; n=193) based on the findings of echocardiographic examinations.

Results

During a follow-up of 35.0±17.6 months, the ratio of LRAF in the L-group was significantly higher than that in the NL-group (32 (56.1%) vs. 41 (21.2%), Hazard ratio [HR]: 3.55, 95% confidence interval [CI]: 2.33 - 5.42, p&lt;0.001). Among the clinical factors, presence of mitral L wave, BNP value, non-paroxysmal AF and moderate-severe mitral regurgitation were related to LRAF. A multivariate analysis using a Cox proportional hazard model found that presence of mitral L wave (HR: 2.67, 95% CI: 1.30 - 5.48, p=0.007) was significantly associated with LRAF.

Conclusion

This study revealed that mitral L wave predicts late recurrence of AF after RFCA.

Funding Acknowledgement

Type of funding sources: None.

P–632 Examination of temporal changes in phenotype and gut microbiome during the process of growth in polycystic ovary syndrome (PCOS) model induced by prenatal androgen exposure

Study question

From when do abnormality in gut microbiome and phenotypes of PCOS appear during the process of growth?

Summary answer

Reproductive phenotypes of PCOS appear from 6 weeks and metabolic phenotypes from 12 weeks onward. Alteration in gut microbiome appears as early as 4 weeks.

What is known already

The etiology of PCOS remains largely unknown, however PCOS is considered as a complex multigenic disorder with strong epigenetic and environmental influence. Previous studies have suggested that fetal over-exposure to androgens could be the main factor of the development of PCOS after birth. On the other hands, recent studies on both human and PCOS rodent models have demonstrated the association between PCOS and alteration of gut microbiome in adulthood. Furthermore, it was recently reported that gut microbiome in obese adolescent with PCOS is different from obese adolescent without PCOS.

Study design, size, duration

A rodent PCOS model induced by prenatal dehydroepiandrosterone (DHT) exposure was applied to this study. Phenotypes and gut microbiome were compared between PCOS model mice (n = 12/group) and control mice (n = 10/group) at each stage of growth; 4 weeks (prepuberty), 6 weeks (puberty), 8 weeks (adolescent), 12 weeks (young adult), and 16 weeks (adult). The determinants for PCOS phenotypes are onset of puberty, estrous cycle, morphology of ovaries, serum testosterone level, body weight, and insulin resistance.

Participants/materials, setting, methods

Pregnant dams were subcutaneously injected on days of 16, 17, and 18 of gestation with either sesame oil for control groups or sesame oil containing 250µg of DHT for prenatal DHT groups. The evaluation of PCOS phenotypes and gut microbiome in female offspring were performed at each stage of growth. For examination of gut microbiota, next generation sequencing and bioinformatics analysis of 16S rRNA genes were performed on DNA extracted from mouse fecal samples.

Main results and the role of chance

Prenatal DHT mice exhibited delayed puberty onset, disrupted estrous cycle, and significantly increased testosterone levels from 6 weeks onward. Significantly increased atretic antral follicles were observed in prenatal DHT mice at 6, 12, and 16 weeks. Prenatal DHT mice showed significantly decreased body weight at 4, 6, 8 weeks and increased body weight from 12 weeks onward. As for gut microbiome, alpha-diversity was significantly different between control and prenatal DHT mice from 8 weeks onward and beta-diversity was significantly different at 6 and 8 weeks. Altered composition of gut microbiota was observed as early as 4 weeks. At phylum level, Firmicutes are significantly increased in prenatal DHT mice at 4 and 8 weeks and decreased at 16 weeks. Actinobacteria phylum showed significant decrease at 6 and 8 weeks in prenatal DHT mice. At genus level, relative abundance of several bacterial taxa significantly differed between control and prenatal DHT mice; some taxa, such as Allobaculum, Adlercreutzia, Bilophila, Clostridium, Gemella, Gemmiger, Roseburia, Ruminococcus, Staphylococcus, and Sutterella, exhibited constant increase or decrease in prenatal DHT mice during the process of growth. Interestingly, Roseburia was never detected in prenatal DHT mice, while approximately half of control mice harbored Roseburia at 12 and 16 weeks.

Limitations, reasons for caution

It is not clearly determined whether alteration in gut microbiome is cause or result of PCOS development, although the changes in gut microbiome seemed to precede the appearance of typical PCOS phenotypes in the present study. Mouse model does not completely recapitulate human PCOS.

Wider implications of the findings: Our findings suggest that prenatal androgen exposure causes alteration of gut microbiome from pre-puberty onward, even before PCOS phenotypes become apparent. Intervention for girls at risk of PCOS with pre/pro-biotics may prevent them from developing PCOS in future.

Trial registration number

Not applicable

Development of glomerular hyperfiltration, a multiphasic phenomenon

The trajectory of glomerular filtration rate (GFR) in relation to glomerular hyperfiltration (GHF) has been unknown. It was evaluated retrospectively in 23,982 GHF-free health examinees who were followed for 2-10 yr (mean: 5.1 yr). GFR was estimated by the serum creatinine concentration, and GHF was defined as age- and sex-specific estimated GFR (eGFR) ≥ 95% of the Japanese general population. The temporal profile of eGFR was plotted in a GHF-centered way, which was fitted to a random coefficient linear mixed model. Of the 23,982 subjects, 797 and 23,185 subjects developed or did not develop GHF, respectively, so that they were termed as the GHF₍₊₎ and GHF_(-) groups. At baseline, median eGFR was significantly elevated in the GHF₍₊₎ group compared with in the GHF_(-) group: 94.1 versus 77.3 mL/min/1.73 m² (P < 0.001). Elevation of basal eGFR lasted for a mean (SD) of 3.3 (1.9) yr in the GHF₍₊₎ group; mean eGFR then rose to the GHF range, which was 108.5 mL/min/1.73 m². The eGFR decline after the peak was steeper in the GHF₍₊₎ group than in the GHF_(-) group: -0.984 versus -0.497 mL/min/1.73 m²/yr (P < 0.001). Baseline eGFR, but no other variable, well predicted incident GHF, with an area under the receiver operating characteristic curve of 0.87 (95% confidence interval: 0.86-0.88). In conclusion, GHF occurs as a chronic, multiphasic phenomenon: initially with a sustained GFR elevation for years, followed by a GFR surge to the GHF range, which was accompanied by accelerated GFR declining.

Electrocardiographic evaluation of depolarization and repolarization abnormalities in breast cancer patients with HER2-inhibitor related cardiac dysfunction

Background

The arrhythmic substrates of the myocardium such as depolarization and repolarization abnormalities are thought to reflect cardiac dysfunction prior to the morphologic left ventricular dysfunction. Activation time (AT), recovery time (RT) and T wave peek-end interval dispersion (Tpe-dispersion) are useful indicators of the arrhythmic substrate. We examined the appearance of depolarization and repolarization abnormalities in patients with cancer therapeutics-related cardiac dysfunction (CTRCD) using AT, RT and Tpe-dispersion.

Methods

We conducted a standardized case-control study of CTRCD with 40 patients who developed breast cancer and treated with trastuzumab (13 cases and 27 controls). We assessed the relation between electrocardiographic indexes, including AT, RT and corrected Tpe-dispersion, and CTRCD. QT intervals were measured by Fridericia method, and QT observer 3 software were used for the measurement of all electrocardiographic indexes.

Results

LVEF in case and control group were 45.7±8% and 69.2±6%, respectively. AT in aVR lead was significantly higher in case group compared with control (28.8±7ms vs 22.8±5ms, P=0.02). corrected Tpe-dispersion tended to be higher in case group than that of control group (43.2±19ms vs 31.9±10ms, P=0.06). QT dispersion and RT dispersion were not different between case and control group.

Conclusions

Our study demonstrated that AT in aVR may predict cardiac dysfunction in breast cancer patients with HER2-inhibitor related cardiac dysfunction. More detailed studies using other modalities which can detect depolarization and repolarization abnormalities, including ventricular late potentials and T wave alternans, are needed.

Funding Acknowledgement

Type of funding source: None

P93 The usefulness of dual cardiac autonomic nervous modulation assessment for prediction of mortality in patients with relatively preserved left ventricular ejection fraction

Background

Recent guidelines have stated that reduced left ventricular ejection fraction (LVEF) is the gold standard marker for identifying patients at risk for cardiac mortality. Although reduced LVEF identifies patients at an increased risk of cardiac arrest, sudden cardiac deaths (SCDs) occur considerably more often in patients with relatively preserved LVEF. Current guidelines on SCDs risk stratification do not adequately cover this general population pool. Heart rate variability (HRV) and heart rate turbulence (HRT) are non-invasive electrocardiography (ECG)-based techniques capable of providing relevant information on the cardiac autonomic nervous modulation. Although a large body of evidence about autonomic nervous modulation markers has been reported, the usefulness of HRV and HRT parameters for risk stratification in such patients with relatively preserved LVEF has not yet been elucidated.

Purpose

This study aimed to evaluate HRV and HRT parameters for predicting cardiac mortality in patients with structural heart disease (SHD), including ischemic heart disease, dilated cardiomyopathy and valvular heart disease, who have mid-range left ventricular dysfunction (LVD).

Methods

We prospectively enrolled 229 patients (187 men, age 63 ± 13 years) with SHD who have mid-range LVD (LVEF &gt; 40%). HRV and HRT parameters based on 24-hour ambulatory ECG recordings (Fukuda Denshi Co., Ltd., Tokyo, Japan) were evaluated as follows; SDNN, triangular index, high and low frequency HRV, turbulence onset and slope. The primary endpoint was all-cause mortality. Univariate and multivariate Cox regression analysis were used to assess the association between these cardiac autonomic nervous modulation and mortality.

Results

During a mean follow-up of 21 ± 11 months, all-cause mortality was seen in 11 (4.8%) patients. Univariate Cox regression analysis showed that reduced SDNN (&lt;50ms), reduced triangular index (&lt;20ms) and HRT category 2 were significantly associated with the primary endpoint (P &lt; 0.05). When HRT category 2 combined with reduced SDNN, Multivariate Cox regression analysis revealed that this combination more strongly associates with the primary endpoint (hazard ratio =7.91, 95%CI, 1.82-34.2; P = 0.006).

Conclusion

Dual cardiac autonomic nervous modulation assessment which combined HRT and HRV could be a superior technique to predict mortality in patients with relatively preserved LVEF.

P11 The difference in the serial change of indoxyl sulfate after catheter ablation among atrial fibrillation patients with or without chronic kidney disease

Introduction

It is well known that catheter ablation (CA) for patients with atrial fibrillation (AF) improves their renal function. However, the precise mechanism of improving a renal function, such as a transition of the uremic toxin is unclear.

Purpose

Indoxyl sulfate (IS), a protein-bound uremic toxin, induces chronic kidney disease (CKD) and AF. This study aimed to investigate the transition of serum IS level in the AF patients with and without CKD after CA.

Methods

A total of 138 consecutive AF patients who underwent CA and maintained sinus rhythm were prospectively enrolled (age 65.5 ± 10.7 years, paroxysmal AF 67.4%). Patients were divided into 4 groups (non-CKD/low-IS:68, non-CKD/high-IS:28, CKD/low-IS:13, CKD/high-IS:29). CKD was defined as CKD stage III (estimated glomerular filtration rate (eGFR) 30-60 ml/min/1.73m2), and high-IS was defined according to the mean of IS (IS≥1.1 μg/ml) before CA. Plasma IS levels and eGFR were determined before and at 1 year after CA. We evaluated the relationship between the IS and eGFR after CA among the 4 groups.

Results

CA significantly improved the eGFR in patients with CKD (from 50.2 ± 5.7 to 55.4 ± 10.8 ml/min/1.73m2, p &lt; 0.001). The serum IS level in the patients with non-CKD/high-IS was significantly decreased (from 1.7 ± 0.7 to 1.1 ± 0.6 μg/ml, p &lt; 0.001). However, the serum IS level in the patients with CKD/high-IS was not improved (from 1.9 ± 0.9 to 1.7 ± 0.7 μg/ml, p = 0.22) and significantly higher than that in the others (p &lt; 0.001), regardless of improving their eGFR (Figure). Furthermore, the multiple regression analysis revealed that the ΔIS, between before and after CA, was independent of eGFR.

Conclusion

The change of IS in the patients with CKD was significantly different from that in those without CKD. In the patients with CKD, CA improved their eGFR, however, the serum level of IS, a protein-bound uremic toxin, was not improved after CA.

Abstract P11 Figure. Serial Change of eGFR and IS

P6559Long-term follow-up and outcomes of patients with discontinuation of oral anticoagulant therapy after successful ablation procedures for atrial fibrillation

Background

Oral anticoagulant therapy (OAT) is effective for preventing strokes in atrial fibrillation (AF) patients. Currently, there is controversy regarding the discontinuation of OATs in patients with ablation procedures to eliminate AF.

Aim

We investigated the incidence of major bleeding and ischemic strokes/systemic embolisms in low-risk patients that discontinued OATs after successful AF ablation procedures.

Methods

Of 330 consecutive patients that underwent AF ablation procedures and were prescribed one of the direct oral anticoagulants or warfarin, 207 AF patients (158 men, mean age 61±11 years) who discontinued OATs three months after the procedure were enrolled. The average CHADS2 and HAS-BLED scores were 1.0±0.9 and 1.2±1.0, respectively, which meant that most patients had a low risk for strokes.

Results

During follow-up, 31 patients (15%) had recurrences of AF. Those patients underwent a re-ablation procedure and then re-discontinued their OATs three months after the session. During a 60±13 months follow-up, major bleeding was observed in five patients (2.4%) and was associated with a higher HAS-BLED score (2.2±0.4 vs. 1.1±1.0, P=0.027). In contrast, none of the patients experienced ischemic strokes/systemic embolisms.

Conclusions

This prospective study demonstrated that in patients with successful ablation procedures and low risk scores for AF management, OATs could be discontinued three months after the procedure. Unnecessary continuation of OATs may increase the incidence of major bleeding during the follow-up.

Prediabetes defined by the International Expert Committee as a risk for development of glomerular hyperfiltration

AIMS

To clarify if prediabetes defined by the International Expert Committee (Prediabetes_IEC) and/or the American Diabetes Society (Prediabetes_ADA) is a risk for incident glomerular hyperfiltration (GH).

METHODS

24,524 health examinees without diabetes, chronic kidney disease (CKD), GH and antihypertensive treatment at baseline, and repeated examinations at least twice during a mean of 5.3 years were retrospectively analysed. Diabetes was defined as fasting plasma glucose (FPG) ≥ 7.0 mmol/L and/or HbA_1c ≥ 47 mmol/mol, CKD by estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73 m² and/or dipstick-positive proteinuria, and GH by upper 95th eGFR in the Japanese adults. Prediabetes_IEC was diagnosed by "HbA_1c 42-46 mmol/mol and/or FPG 6.1-6.9 mmol/L", Prediabetes_ADA by "HbA_1c 39-46 mmol/mol and/or FPG 5.6-6.9 mmol/L", Prediabetes_ADA-IEC for the condition met the ADA but not the IEC prediabetes definition, and the ADA-normal glucose regulation (NGR_ADA) by both HbA_1c and FPG lower than Prediabetes_ADA. Risk of Prediabetes_IEC and Prediabetes_ADA for incident GH was examined by multivariate Cox proportional hazards model with seven covariates and probability of incident GH was calculated on the basis of it.

RESULTS

Prediabetes_IEC was a significant risk for incident GH [adjusted HR 1.91, 95% CI 1.32-2.71] but Prediabetes_ADA was not [adjusted HR 1.22, 95% CI 0.93-1.61]. The mean (SD) probability of incident GH was 2.3 (4.5)%, 1.0 (2.3)% and 1.0 (2.4)% for Prediabetes_IEC, Prediabetes_ADA-IEC and NGR_ADA, respectively: the former was significantly larger than the latter two which were not significantly different from each other.

CONCLUSIONS

Prediabetes_IEC was an independent risk for incident GH.

Elevated haemoglobin A1c but not fasting plasma glucose conveys risk of chronic kidney disease in non-diabetic individuals

AIMS

To compare impact of elevated HbA1c and fasting plasma glucose (FPG) on incident chronic kidney disease (CKD) in a non-diabetic cohort.

METHODS

Data from diabetes- and CKD-free 25,109 health examinees were retrospectively analysed with a mean observation period of 5.3 years. Prediabetes was diagnosed by the ADA and WHO criteria, and CKD by estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73 m² and/or dipstick proteinuria. Cox proportional hazards model was applied with sex, age, insulin sensitivity, systolic blood pressure, eGFR and serum alanine aminotransferase level as covariates.

RESULTS

For incident CKD (n = 2483), high HbA1c but not FPG was an independent risk: adjusted hazard ratio (AHR, 95%CI) for HbA1c 1% and FPG 1 mmol/L, 1.91 (1.70-2.16) and 0.85 (0.60-1.20), respectively. Prediabetes by the ADA and WHO criteria were both risk for CKD with AHR (95%CI), 1.21 (1.12-1.32) and 1.31 (1.16-1.48), respectively. Prediabetes diagnosed by 'elevated HbA1c irrespective of FPG', either by the ADA and the WHO definition, was a risk with AHR (95%CI), 1.48 (1.36-1.61) and 1.51 (1.31-1.74), respectively. In contrast, prediabetes diagnosed by 'raised FPG irrespective of HbA1c' was not a CKD risk.

CONCLUSIONS

Elevated HbA1c, but not FPG, identified CKD risk in non-diabetic individuals.

Reappraisal of attenuated insulin sensitivity in the evolution of non-alcoholic fatty liver disease

BACKGROUND/OBJECTIVES

It has been unknown if attenuated insulin sensitivity (Si) in non-alcoholic fatty liver disease (NAFLD) is a cause or a result. We examined the impact of attenuated Si on NAFLD evolution.

SUBJECTS/METHODS

We observed 4856 NAFLD- and diabetes-free participants for a mean 2.9 years. Si was indexed by single point insulin sensitivity estimator (SPISE = [600 × HDL-c^0.185]/[TG^0.2 × BMI^1.338]), correlating with 1/HOMA-IR in an independent cohort (n = 1537, Spearman rho = 0.519, P < 0.01). Fatty liver (FL) was diagnosed by ultrasonography and diabetes by fasting plasma glucose (FPG) ≥ 7 mmol/L and/or glycohemoglobin A1c ≥ 6.5%. Multinominal comparison was performed with incident FL (FL_w/oDM, n = 486), diabetes (DM_w/oFL, n = 171), and FL plus diabetes (FL/diabetes, n = 58) as targets; none of the above (n = 4,138) was the control. SPISE was taken as a predictor with adjustment for covariates. Trajectory of SPISE during the 5 years before development of each condition was also assessed.

RESULTS

With SPISE tertile 3 (>10.06) as the reference, tertile 1 (<8.07) was related to incident FL_w/oDM and FL/diabetes with OR (95% CI) 3.47 (2.60-4.63) and 1.78 (1.10-2.87), respectively, and tertile 2 (8.07-10.06) related to FL_w/oDM with OR (95% CI) 1.38 (1.03-1.85). Low SPISE was not significantly related to incident diabetes. At -5 years, SPISE was 12% (P < 0.05) and 13% (P < 0.01) lower in those developed FL_w/oDM and FL/diabetes, respectively, than the control. At year 0, SPISE in the two groups was 18% and 21% lower than the control, respectively (P < 0.01).

CONCLUSIONS

Attenuation of Si indexed by SPISE was a risk factor for NAFLD.

Type 2 Diabetes: When Does It Start?

Objective

We aimed to clarify the onset of diabetes.

Design

Data from 27,392 nondiabetic health examinees were retrospectively analyzed for a mean of 5.3 years. Trajectories of fasting plasma glucose (FPG), body mass index (BMI), and the single point insulin sensitivity (Si) estimator (SPISE), an index of Si, 10 years before diagnosis of prediabetes (PDM; n = 4781) or diabetes (n = 1061) were separately assessed by a mixed effects model. Diabetes and PDM were diagnosed by the American Diabetes Association definition on the basis of FPG and glycosylated hemoglobin A1c values.

Results

In individuals who developed diabetes, mean FPG and BMI were significantly higher (P < 0.01 each) and SPISE lower than those who did not at -10 years: FPG 101.5 mg/dL vs 94.5 mg/dL, BMI 24.0 kg/m² vs 22.7 kg/m², and SPISE 7.32 vs 8.34, P < 0.01 each. These measurements, in subjects who developed prediabetes, were slightly but definitely different from those who did not, already at -10 years: FPG 91.8 mg/dL vs 89.6 mg/dL, BMI 22.6 kg/m² vs 22.1 kg/m², and SPISE 8.44 vs 8.82, P < 0.01 each. In both cases, the differences were progressively greater toward year 0, the time of diabetes, or PDM diagnosis.

Conclusions

FPG was significantly elevated in those who developed diabetes at least 10 years before diagnosis of diabetes, and this was also the case in those who developed PDM. Glucose dysregulation precedes diagnosis of diabetes at least for 20 years.

Postchallenge hyperglycemia in subjects with low body weight: implication for small glucose volume

A hypothesis that postchallenge hyperglycemia in subjects with low body weight (BW) may be due, in part, to small glucose volume (G_V) was tested. We studied 11,411 nondiabetic subjects with a mean BW of 63.3 kg; 5,282 of them were followed for a mean of 5.3 yr. In another group of 1,537 nondiabetic subjects, insulin sensitivity, secretion, and a product of the two (index of whole body insulin action) were determined. Corrected 2 h-plasma glucose (2hPG_corr) during a 75-g oral glucose tolerance test in subjects with BW ≤ 59 kg was calculated as 2hPG_corr = δPG_2h · ECW/[16.1 (males) or 15.3 (females)] + fasting PG (FPG), where δPG_2h is plasma glucose increment in 2 h; ECW is extracellular water (surrogate of G_V); FPG is fasting plasma glucose; and 16.1 and 15.3 are ECW of men and women, respectively, with BW = 59 kg. Multivariate analyses for BW with adjustment for age, sex, and percent body fat were undertaken. BW was, across its entire range, positively correlated with FPG (P < 0.01). Whereas BW was correlated with 2hPG and δPG in a skewed J-shape, with inflections at around 60 kg (P for nonlinearity < 0.01 for each). Nonetheless, in those with BW ≤ 59 kg, insulin sensitivity, secretion, and action were unattenuated, and incident diabetes was less compared with heavier counterparts. BW was linearly correlated with 2hPG_corr, i.e., the J-shape correlation was mitigated by the correction. In conclusion, postchallenge hyperglycemia in low BW subjects is in part due to small G_V rather than impaired glucose metabolism.

Predictive models for conversion of prediabetes to diabetes

AIM

To clarify the natural course of prediabetes and develop predictive models for conversion to diabetes.

METHODS

A retrospective longitudinal study of 2105 adults with prediabetes was carried out with a mean observation period of 4.7years. Models were developed using multivariate logistic regression analysis and verified by 10-fold cross-validation. The relationship between [final BMI minus baseline BMI] (δBMI) and incident diabetes was analyzed post hoc by comparing the diabetes conversion rate for low (< -0.31kg/m²) and high δBMI (≥ -0.31kg/m²) subjects after matching the two groups for the covariates.

RESULTS

Diabetes developed in 252 (2.5%/year), and positive family history, male sex, higher systolic blood pressure, plasma glucose (fasting and 1h- and 2h-values during 75g OGTT), hemoglobin A1c (HbA1c) and alanine aminotransferase were significant, independent predictors for the conversion. By using a risk score (RS) that took account of all these variables, incident diabetes was predicted with an area under the ROC curve (95% CI) of 0.80 (0.70-0.87) and a specificity of prediction of 61.8% at 80% sensitivity. On division of the participants into high- (n=248), intermediate- (n=336) and low-risk (n=1521) populations, the conversion rates were 40.1%, 18.5% and 5.9%, respectively. The conversion rate was lower in subjects with low than high δBMI (9.2% vs 14.4%, p=0.003).

CONCLUSIONS

Prediabetes conversion to diabetes could be predicted with accuracy, and weight reduction during the observation was associated with lowered conversion rate.

Development of new diabetes risk scores on the basis of the current definition of diabetes in Japanese subjects [Rapid Communication]

To develop diabetes risk score (RS) based on the current definition of diabetes, we retrospectively analyzed consecutive 4,159 health examinees who were non-diabetic at baseline. Diabetes, diagnosed by fasting plasma glucose (FPG) ≥7.0 mmol/L, 2hPG ≥11.1 mmol/L and/or HbA1c ≥6.5% (48 mmol/mol), developed in 279 of them during the mean period of 4.9 years. A full RS (RS_Full), a RS without 2hPG (RS_-2hPG) and a non-invasive RS (RS_NI) were created on the basis of multivariate Cox proportional model by weighted grading based on hazard ratio in half the persons assigned. The RSs were verified in the remaining half of the participants. Positive family history (FH), male sex, smoking and higher age, systolic blood pressure (SBP), FPG, 2hPG and HbA1c were independent predictors for RS_Full. For RS_-2hPG, 7 independent predictors, exclusive of 2hPG and smoking but inclusive of elevated triglycerides (TG) comparing to RS_Full, were selected. FH, male sex, and higher age, SBP and HbA1c were independent predictors in RS_NI. In the validation cohort, C-statistic (95%CI) of RS_Full, RS_-2hPG and RS_NI were 0.80 (0.76-0.84), 0.75 (0.70-0.78) and 0.68 (0.63-0.72), respectively, which were significantly different from each other (P <0.01). Absolute percentage difference between predicted probability and observed diabetes were 1.9%, 0.7% and 0.9%, by the three scores, respectively, and not significantly different from each other. In conclusion, diabetes defined by the current criteria was predicted by the new diabetes risk scores with reasonable accuracy. Nonetheless, RS_Full with a postchallenge glucose value performed superior to RS_-2hPG and RS_NI.

Distribution of Water, Fat, and Metals in Normal Liver and in Liver Metastases Influencing Attenuation on Computed Tomography

The quantity of water, lipid and some metals was measured in autopsy specimens of 8 normal livers, 9 livers with fatty change, and in 12 livers with metastases of various origins. These parameters contribute to the CT number measured in the liver. Water played a major role in demonstration of liver metastases as a low-density area on CT. Other contributory factors include iron, magnesium and zinc. Lipid and calcium had no influence in this respect. Heavy accumulation of calcium in a metastatic lesion gives a high-density area on CT. However, even when a metastatic lesion was perceived on CT as a low-density area, the calcium content of the lesion was not always lower than that of the non-tumour region.

Primacy of lowered baseline glomerular filtration rate as a risk for incident chronic kidney disease: A longitudinal study in Japanese subjects

AIM

Risk profile for incident chronic kidney disease (CKD) in Japanese subjects has not been established. Our aim was to identify risk factors for CKD in Japanese.

METHODS

Consecutive 171 536 health examinees (median age 49 years and estimated glomerular filtration rate (eGFR) 78.2 mL/min per 1.73 m² ) without CKD were re-examined after a median period of 6.2 years. Results of Cox proportional hazards models in randomly assigned two thirds (Derivation cohort) were verified in the rest (Validation cohort). CKD was defined as eGFR <60 mL/min per 1.73 m² or positive dipstick proteinuria.

RESULTS

In the Derivation cohort, CKD developed in 1002 (5.8%) subjects. Seven variables such as lower eGFR, male gender, higher uric acid concentration, lower red cell count and higher age and systolic blood pressure were identified as significant risks for CKD, with lowered eGFR being an overwhelmingly strong risk: adjusted hazard ratio for those with the baseline eGFR <70 mL/min per 1.73 m² was as high as 90.1. Performance of prediction of CKD by the probability on the basis of the seven risk factors combined was only marginally preferable to eGFR alone. The area under the receiver operating characteristic curve (95% CI) for the prediction was 0.846 (0.826-0.864) and 0.822 (0.802-0.840) (P < 0.01), the kappa statistic was 0.263 and 0.250 (n.s.), and the mean absolute difference between "predicted probability" and "observed" CKD was 1.4% and 1.9% (P = 0.14) by the combined model and eGFR alone, respectively.

CONCLUSION

Seven risk factors for incident CKD were identified in Japanese health examinees. However, lowered baseline eGFR outweighed other risks to the degree that eGFR alone was suffice for CKD prediction.

Identification of proliferating human hepatic cells from human induced pluripotent stem cells

Mass-scale production of hepatocytes from human induced pluripotent stem cells (iPSCs) with functional properties of primary hepatocytes is of great value in clinical transplantation for liver failure as well as in facilitating drug development by predicting humanized drug metabolism profiles. In this report, we generated human hepatocyte-like cells from human iPSCs with the use of a stepwise protocol. Aiming at future clinical and industrial application, it is important to determine the suitable stage of iPSC-derived hepatic cells that possess high proliferative capacity to intensively expand the hepatic cells. Ki67 immunostaining showed that human iPSC-derived hepatic endoderm cells contained Ki67(+) cells at the highest level in the middle stage of hepatic differentiation, suggesting that the abundance of proliferating hepatic progenitor cells exists in this stage. Extensive expansion and differentiation of human iPSC-derived hepatic progenitors will provide future perspectives in transplantation therapy and drug development.

An Application of Thermoluminescence to Herbicide Studies

Thylakoids of genetically engineered species of Synechococcus PCC7942 were investigated by thermoluminescence (TL), polarographic and herbicide-binding studies. The results were as follows: 1) Deletion of either copy I or copy II/III of the psbA gene family resulted in modified oscillation patterns of flash induced TL and O2 evolution compared to wild type cells. 2) Replacement of Ser264 in psbA I by Ala or Gly inducing strong herbicide resistance leads to a downshift of the TL peak temperature of B-band by 10 C and alters the oscillation pattern of flash induced TL and O2 evolution significantly to exhibit a pattern with comparatively high O2 yield after the 2nd flash. Additional deletion of psbA II III does not lead to significant changes compared to the single mutated strains. 3) Contrary to Ser,M mutants, replacement of Phe255 by Tyr in psbA I alone, which also induces herbicide resistance, is not accompanied by- corresponding changes in TL peak temperature and/or oscillation pattern of flash-induced TL and O2 evolution. However, strongly altered properties are observed after additional deletion of psbA II/III. Based on these data it is inferred that expression of either psbA I or psbA II III genes only gives rise to PS II complexes slightly different in their function. Site-directed muta- genesis of psbA I gene modulates the expression ratio between copies I and II/III. The possible implications are discussed.

A New-Type Photosystem II Inhibitor which Blocks Electron Transport in Water-Oxidation System

The mode of action of three types of conjugated enamine compounds was investigated by means of thermoluminescence measurement. Cyanoacrylate and 2-(l-ethoxyethylam inom ethylidene)- 4-dodecyl-5,5-dim ethyl-cyclohexane-1,3-dione (ACm12) converted the B-band (30 °C) arising from S2QB - charge recombination to a downshifted 6 °C-band. This band was proved to be identical with the DCM U-induced Q-band (6 °C) arising from S2QA - recombination, indicating that these two compounds block QA to QB electron transport. 3-(1-dodecylam inopropyridene)-6- methyl-2H-pyran-2,4-dione (APp12 ), on the other hand, induced an abnormal band peaking at 15 °C between the Q-band and B-band. From the gradual downshift of its peak temperature in titration experiments, this band was assigned to arise from a modified S2QB - charge pair, in which the properties of either QB - or S2 is altered. The 15 °C-band showed normal oscillation during the first 2 flashes, but the oscillation was interrupted thereafter. Another therm oluminescence analysis by use of post flash low temperature illumination protocol revealed that APp12 affects neither QA to QB nor QB 2- to PQ electron transport, but specifically blocks S3 to S0 transition. These results indicate that APp12 is a new-type PS II inhibitor.

Role of squalene synthase in prostate cancer risk and the biological aggressiveness of human prostate cancer

BACKGROUND

We previously conducted a genome-wide linkage analysis of Japanese nuclear families affected with prostate cancer and showed that the susceptibility to prostate cancer was closely linked to D8S550 at 8p23. The role of farnesyl diphosphate farnesyltransferase (FDFT1), which is located under the peak marker D8S550 at 8p23, and squalene synthase, the enzyme encoded by FDFT1, in prostate cancer was studied.

METHODS

The association among common variants of FDFT1 with prostate cancer risk, the promoter activities of FDFT1 with different genotypes and the effects of inhibition of squalene synthase were studied, and the FDFT1 transcript levels of human prostate samples were quantified.

RESULTS

The A allele of rs2645429 was significantly associated with prostate cancer risk in a Japanese familial prostate cancer population. Rs2645429 was located in the promoter region of FDFT1, and the AA genotype showed significantly increased promoter activity. The knockdown of FDFT1 mRNA expression or squalene synthase inhibition led to a significant decrease in prostate cancer cell proliferation. Additionally, human prostate cancer specimens expressed significantly higher levels of FDFT1 mRNA compared with noncancerous specimens. Finally, aggressive cancers showed higher transcript levels.

CONCLUSIONS

FDFT1 and its encoded enzyme, squalene synthase, may play an important role in prostate cancer development and its aggressive phenotypes.

Skin biopsy is useful for the antemortem diagnosis of neuronal intranuclear inclusion disease

BACKGROUND

Neuronal intranuclear inclusion disease (NIID) is a progressive neurodegenerative disease characterized by eosinophilic hyaline intranuclear inclusions in neuronal and somatic cells. Because of the variety of clinical manifestations, antemortem diagnosis of NIID is difficult.

METHODS

Seven skin biopsy samples from patients with familial NIID were evaluated histochemically, and the results were compared with those of skin samples from normal control subjects and from patients with other neurologic diseases. We also examined skin biopsy samples from patients with NIID by electron microscopy.

RESULTS

In NIID skin biopsy samples, intranuclear inclusions were observed in adipocytes, fibroblasts, and sweat gland cells. These inclusions were stained with both anti-ubiquitin and anti-SUMO1 antibodies. Electron microscopy revealed that the features of the intranuclear inclusions in adipocytes, fibroblasts, and sweat gland cells were identical to those of neuronal cells. Approximately 10% of adipocytes showed intranuclear inclusions. No intranuclear inclusions were identified in the skin samples from normal control subjects and patients with other neurologic diseases.

CONCLUSIONS

Skin biopsy is an effective and less invasive antemortem diagnostic tool for NIID.

Preparing Titania Fibers and Their Photocatalytic Activity

Continuous titania fibers were prepared by a polytitanoxane precursor method. Polytitanoxane was synthesized through hydrolysis and polymerization reaction between partially chelated titanium isopropoxide and water without acid catalyst. Polytitanoxane, which was precipitated from an isopropanol solution by adding adequate amount of water to titanium isopropoxide, was then dried and dissolved in tetrahydrofuran. The concentrated viscous solution of polytitanoxane was considerably stable to further self-condensation and had good spinnability. The precursor fiber which was obtained by spinning the solution was calcined to form titania fibers.

Two types of titania fibers were obtained under different calcination conditions from the same precursor fiber; Dense fiber with high tensile strength of higher than 1 GPa, and porous fiber with high surface area of more than 10 m2/g.

Photocatalytic activity of those fibers was studied using the phenol mineralization reaction in water. The phenol degradation ability of high-surface-area titania fiber was almost the same as that of commercial titania powder for photocatalyst.

Single nucleotide polymorphism of TAG-1 influences IVIg responsiveness of Japanese patients with CIDP

OBJECTIVE

Chronic inflammatory demyelinating polyneuropathy (CIDP) is characterized by immune-mediated peripheral demyelination. Although corticosteroid, IV immunoglobulin (IVIg) and plasma exchange have been established as the most effective therapeutics, subpopulations of patients show little or no response to either of these therapies. In this study, we examined whether particular genetic factors influence the therapeutic responsiveness of patients with CIDP.

METHODS

One hundred Japanese patients categorized as responders or nonresponders to IVIg therapy participated in our study. We performed an association analysis with single nucleotide polymorphisms (SNPs) and haplotype studies between the IVIg responders and nonresponders.

RESULTS

Two separate SNPs, corresponding to TAG-1 (transient axonal glycoprotein 1) and CLEC10A (C-type lectin domain family 10, member A), showed strong significant differences between responders and nonresponders. Haplotype analysis of a series of expanded SNPs, from TAG-1 or CLEC10A, showed that only TAG-1 included a significant haplotype within 1 linkage disequilibrium block, which accommodates IVIg responsiveness. Diplotype analysis of TAG-1 also supported this observation.

CONCLUSIONS

Transient axonal glycoprotein 1 is a crucial molecule involved in IV immunoglobulin responsiveness in Japanese patients with chronic inflammatory demyelinating polyneuropathy.

[Off-pump coronary artery bypass grafting for angina pectoris with coronary artery aneurysm due to kawasaki disease: report of a case]

We report a 27-year-old woman who underwent off-pump coronary artery bypass grafting (OPCAB) for angina pectoris with coronary artery aneurysm due to Kawasaki disease. At the age of 3, she was diagnosed as Kawasaki disease with coronary artery aneurysms in the right coronary artery and the left anterior descending artery. She was medically followed-up since then Because an enlarged aneurysm and a stenotic lesion were recognized in the right coronary artery, operation was indicated. In operation, the right coronary artery was ligated at the inflow and the outflow of the aneurysm. OPCAB was also conducted with the right internal thoracic artery anastomosed to the right coronary artery. Postoperative course was uneventful, and she was discharged at the day 5 after operation. Revascularization using arterial grafts, especially the internal thoracic arteries, may be the choice for young patients to expect a good patency rate in the long-term.

[Off-pump coronary artery bypass grafting as standard operation; surgical strategies and results]

We report the clinical results of 799 cases of isolated coronary artery bypass grafting (CABG) performed during the recent 5 years. We performed off-pump CABG (OPCAB) as standard operation, in which arterial grafts were mainly used. The mean number of distal anastomoses was 3.6 +/- 1.4 per patient Four hundred and fifty-five cases (57.0%) were done only with arterial grafts. Bilateral internal thoracic arteries were used in 326 cases. The mean number of saphenous vein grafts was 1.6 +/- 0.8 per patient. Continuous hemodiafiltraion (CHDF) was performed in 22 cases (2.8%) postoperatively. Among the OPCAB cases, 10 cases (1.3%) were converted to on-pump CABG. There were 7 cases (0.9%) of hospital death. The mean length of postoperative hospital stay was 10.2 +/- 5.3 days. The ratio of the patients with left main trunk disease and that of the patients who required postoperative CHDF increased year by year. The mean length of postoperative hospital stay decreased every year, and the reduced length was 2.7 days in the 5 years (8.7+/- 3.6 days in 2007). It is expected that patients who have severe calcified lesions or who are on hemodialysis may increase in the near future. In such cases, CABG rather than percutaneous catheter intervention may be suitable for revascularization. Therefore, not only appropriate choice of treatment strategies, but also accurate surgical techniques may become more importance.

Metabolism of amyloid precursor protein in COS cells transfected with a beta-secretase candidate

Thimet oligopeptidase (TOP) is a thiol- andmetallo-dependent peptidase and has been shown to beone of the beta-secretase candidates. TOPexpressed in COS cells cleaved amyloid precursorprotein (APP) at the beta-secretase site, and wefound a proteolytic product of APP called secretedform of APP by beta-secretase (sAPPbeta) in theconditioned media. Here we demonstrate thatsAPPbeta was increased in conditioned media whenTOP was coexpressed in COS cells with APP and treatedwith an ADAM inhibitor SI-27. In addition, althoughTOP expressed in COS cell was localized at nuclei orGolgi apparatus, it exclusively colocalized at Golgiapparatus when APP was coexpressed with TOP.