Incidence and risk factors for colorectal neoplasia in patients with oral squamous cell carcinoma.

AIM: Colorectal adenoma and cancer are not regarded as being associated with primary oral cancer. The aim of this study was to determine whether screening colonoscopy should be performed for patients with oral cancer in addition to the upper gastrointestinal endoscopic screening that is now routinely performed. METHOD: Between 2007 and 2013, 162 patients with oral squamous cell carcinoma were enrolled at Tokyo Dental College, Ichikawa General Hospital, and 136 individuals were assigned to colonoscopic surveillance. Advanced neoplasia was defined as an adenoma ≥ 10 mm, adenoma with villous histology or high-grade dysplasia regardless of size and invasive cancer. Associations between advanced neoplasia and clinical factors, including age, sex, body mass index, physical activity, smoking, alcohol consumption and oral cancer site and staging were determined. RESULTS: Advanced neoplasia, including five invasive cancers, was identified in 32 (23.5%) patients. An age- and sex-adjusted multivariate analysis revealed that smoking (Brinkmann index > 400; OR = 3.24, 95% CI = 1.28-8.18), alcohol consumption (lifetime pure ethanol consumption > 600 l; OR = 2.84, 95% CI = 1.18-6.79) and a diagnosis of cancer of the floor of the mouth (OR = 7.97, 95% CI = 2.49-25.46) were independent risk factors for advanced colorectal neoplasia. CONCLUSION: The prevalence of advanced colorectal neoplasia is unexpectedly high in patients with oral cancer. It should be recognized as a second primary tumour of oral cancer. Screening of oral cancer patients by colonoscopy should be routine practice, particularly among smokers and patients with a high intake of alcohol and cancer of the floor of the mouth.

Serum adiponectin and leptin levels are useful markers for prostate cancer screening after adjustments for age, obesity-related factors, and prostate volume.

AIM: Adiponectin and leptin, polypeptide hormones produced by adipocytes, have recently been reported to be associated with prostate cancer risk, though, the relationship remains poorly understood. We examined the association of adiponectin and leptin levels in serum with prostate cancer risk after adjustments for age, obesity-related factors, and prostate cancer risk. METHODS: Fifty-four prostate cancer patients and 70 control subjects provided blood sampled between 2008 and 2009. Using those, we determined serum adiponectin and leptin levels, and evaluated their relationships with prostate cancer risk after adjustments for age, obesity-related factors (body weight, body mass index, waist circumference), and prostate volume. Adipokine densities were calculated by dividing serum level with prostate volume. RESULTS: There were no differences for median serum adiponectin and leptin levels between the prostate cancer and benign control groups (P=0.22 and 0.78, respectively). Patients with levels of both adipokines in the highest quartile after adjustment for age had significantly higher risks of prostate cancer (adiponectin: odds ratio [OR] 2.79, P=0.014; leptin: OR 2.72, P=0.027). Patients with an adiponectin level greater than the median after adjustment for body weight also had a significantly elevated risk of prostate cancer (OR 2.22, P=0.031), whereas, those with a leptin level significantly greater than the median had a significantly lower risk (OR 0.46, P=0.027). Furthermore, median adiponectin density was significantly higher in the prostate cancer group than the benign group (P=0.0033). CONCLUSION: Serum adiponectin and leptin levels are useful markers for prostate cancer risk after adjustments for age, obesity-related factors, and prostate volume.

Lipopolysaccharide-induced murine lung injury results in long-term pulmonary changes and downregulation of angiogenic pathways.

Acute respiratory distress syndrome is the most severe form of acute lung injury (ALI) and is associated with significant mortality. Lipopolysaccharide (LPS)-induced injury is a valuable murine model of ALI but there is a paucity of data on lung regeneration and the role of angiogenic signaling involving vascular endothelial growth factor (VEGF). Eight-week-old male C57BL/6J mice were randomized to receive intratracheal instillation of either LPS or isovolumetric phosphate buffered saline as a vehicle control. Mice were observed at a single follow-up time-point that was either short-term (24 h or 4 days) or long-term (7 days or 4 weeks). On pulmonary function testing, LPS-treated mice had increased compliance at 4 weeks post-instillation, which correlated with decreased vascularization and with time-dependent, progressive decrease in alveolarization. Treadmill exercise tolerance testing demonstrated impaired performance at 24 h, 4 days and 4 weeks following LPS exposure. On lung protein analysis, LPS instillation decreased VEGF expression at up to 4 weeks, and decreased activation of its key receptor, VEGFR2 at 7 days and 4 weeks post-instillation. Together, these data provide insight on long-term pulmonary functional outcomes 4 weeks after ALI and identify angiogenic proteins as possible therapeutic targets following lung injury.

Mammalian transgenesis by intracytoplasmic sperm injection.

Coinjection of unfertilized mouse oocytes with sperm heads and exogenous DNA encoding either a green fluorescent protein (GFP) or beta-galactosidase reporter produced 64 to 94 percent transgene-expressing embryos, reflecting DNA-sperm head association before coinjection. Nonselective transfer to surrogate mothers of embryos in the GFP series generated about 20 percent offspring expressing the integrated transgene. These data indicate that exogenous DNA can reproducibly be delivered into an oocyte by microinjected spermatozoa and suggest an adaptable method of transgenesis.

Prevalence of the metabolic syndrome in kidney transplantation.

OBJECTIVES: We investigated the prevalence of the metabolic syndrome (MS) in kidney transplantation patients and assessed its development based on plasma adiponectin levels and the results of an oral glucose tolerance test (OGTT). METHODS: We performed a cross-sectional study of 94 recipients with stable graft function who underwent kidney transplantation between January 1999 and October 2008. The presence of MS was determined using National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATP III) criteria with body mass index (BMI) used in place of waist circumference. In addition, we measured plasma adiponectin level and performed a 75-g oral GTT. RESULTS: Fourteen (14.9 %) recipients suffered from MS for a mean period of 46.7 months (range, 1-106) after transplantation. BMI at the time of transplantation was significantly greater in the MS group (23.4 +/- 3.24 vs 20.1 +/- 2.50; P < .0001), whereas plasma adiponectin level was significantly lower (11.95 +/- 5.13 vs 17.71 +/- 8.47; P = .0158). The insulinogenic index values were similar, whereas the homeostatic model assessment of insulin resistance was greater in the MS group (2.598 +/- 1.918 vs 1.340 +/- 0.934; P = .0002). CONCLUSION: The level of adiponectin, which was lower in kidney transplant recipients who developed MS, was negatively correlated with insulin sensitivity. We concluded that a low adiponectin level may correlate with the prevalence of MS in kidney transplantation in association with impaired insulin sensitivity.

Stratified analyses for selecting appropriate target patients with diabetic peripheral neuropathy for long-term treatment with an aldose reductase inhibitor, epalrestat.

AIMS: The long-term efficacy of epalrestat, an aldose reductase inhibitor, in improving subjective symptoms and nerve function was comprehensively assessed to identify patients with diabetic peripheral neuropathy who responded to epalrestat treatment. METHODS: Stratified analyses were conducted on data from patients in the Aldose Reductase Inhibitor-Diabetes Complications Trial (ADCT). The ADCT included patients with diabetic peripheral neuropathy, median motor nerve conduction velocity > or = 40 m/s and with glycated haemoglobin (HbA(1c)) < or = 9.0%. Longitudinal data on HbA(1c) and subjective symptoms of the patients for 3 years were analysed (epalrestat n = 231, control subjects n = 273). Stratified analyses based on background variables (glycaemic control, grades of retinopathy or proteinuria) were performed to examine the relationship between subjective symptoms and nerve function. Multiple logistic regression analyses were conducted. RESULTS: Stratified subgroup analyses revealed significantly better efficacy of epalrestat in patients with good glycaemic control and less severe diabetic complications. In the control group, no improvement in nerve function was seen regardless of whether symptomatic benefit was obtained. In the epalrestat group, nerve function deteriorated less or improved in patients whose symptoms improved. The odds ratio of the efficacy of epalrestat vs. control subjects was approximately 2 : 1 (4 : 1 in patients with HbA(1c) < or = 7.0%). CONCLUSION: Our results suggest that epalrestat, an aldose reductase inhibitor, will provide a clinically significant means of preventing and treating diabetic neuropathy if used in appropriate patients.

Malignancy following kidney transplantation.

A cohort of 429 patients who received kidney grafts between 1973 and 2007 at our hospital was studied for the incidence and sites of malignancy. Sixty-two malignant diseases developed in 57 of 429 patients (13.3%). The cumulative incidences of malignancy increased markedly in the second and third posttransplantation decades. The overall rates were 1.8% at 5 years, 6.7% at 10 years, 12.5% at 15 years, 17.3% at 20 years, and 25.6% at 25 years. In the second and third posttransplantation decades, patients without malignancy showed significantly superior survival versus than those with cancer (P = .0002). Their survival rates were 83.4% versus 86.9% at 10 years and 63.1% versus 80.3% at 20 years, respectively. Skin cancer, renal cell carcinoma of the native kidney, hepatocellular carcinoma, posttransplantation lymphoproliferative disease, uterine cancer, and colorectal cancer were common in our series. The 5-year survival rates after the treatment of malignancy were better for skin cancer and renal cell carcinoma of the native kidney. Concerning the effects of immunosuppression, the tacrolimus-based group displayed a higher incidence among 3 groups (P = .0044).

Class II HLA Eplet Mismatch Is a Risk Factor for De Novo Donor-Specific Antibody Development and Antibody-mediated Rejection in Kidney Transplantation Recipients.

OBJECTIVES: We investigated the correlation between class II HLA epitope mismatch and antibody-mediated rejection (AMR) episodes in kidney transplant recipients. In patients with AMR, epitope mismatch was also examined for each class II HLA mismatch to determine development of de novo donor-specific antibodies (DSAs). METHODS: We conducted a retrospective study of 167 kidney recipients. The numbers of eplet mismatches were compared between those with (n = 12) and without (n = 155) AMR, and the numbers of eplet mismatches for each type of mismatch in class II HLA among the AMR patients was also compared. RESULTS: Twelve AMR episodes were diagnosed. The total number of eplet mismatches in AMR patients with either HLA-DR or HLA-DQ was greater than those in non-AMR patients (P = .0085 and P = .0041, respectively), though the incidence of HLA class II (DRB1 + DQB) mismatch was not significantly different between the groups (P = .095). The rate of non-AMR status in patients with ≥15 was lower than those with <15 HLA class II (DR or DQ) eplet mismatches (P = .0299 and P = .0128, respectively). Twelve AMR patients had 30 HLA-DRB1/3/4/5 and 32 HLA-DQA/B mismatches. In both HLA-DR and -DQ, de novo DSAs developed against HLAs in association with a greater number of eplet mismatches (P = .0046 and P = .0044, respectively). CONCLUSION: Class II HLA eplet mismatch is a risk factor for de novo DSA and AMR in kidney transplantation recipients. Furthermore, the number of HLA class II eplet mismatches has greater significance as a risk factor than the number of conventional HLA class II mismatches.

Severe Phlebitis Accompanying Vascular Rejection Type Acute T Cell-Mediated Rejection in Renal Transplantation.

PURPOSE: Renal transplant patients with vascular rejection type acute T cell-mediated rejection (ATCMR) grade II have a poor prognosis. Vascular lesions in those cases are thought to randomly occur, thus we searched for a novel pathological marker related to vascular rejection in kidney transplantation. METHODS: We determined pathological characteristics in 14 ATCMR grade II patients treated during an acute phase from 2004 to 2013. We then examined whether those findings appeared in transplant kidney biopsy specimens, except for cases of vascular rejection, in patients examined from 2010 to 2014. RESULTS: In 9 of the 14 ATCMR grade II patients, phlebitis was accompanied by inflammatory cells that formed polypoid projections in the venous lumen and partial disappearance of vascular endothelium. Further investigation showed those inflammatory cells to be T cells and macrophages. Histological findings revealed coexisting phlebitis in 2 of 13 patients with ATCMR grade I, 3 of 24 with borderline changes, and none with normal findings. Phlebitis occurred at a significantly greater rate than the other findings in cases of vascular rejection (P < .05). However, there was no significant difference in regard to graft survival between patients with and without phlebitis (P = .1829). CONCLUSION: Our results suggest severe phlebitis as a novel finding associated with the pathology of vascular rejection in patients with a renal allograft.

A carboxy-terminal truncation of human alpha-galactosidase A in a heterozygous female with Fabry disease and modification of the enzymatic activity by the carboxy-terminal domain. Increased, reduced, or absent enzyme activity depending on number of amino acid residues deleted.

Fabry disease is an X-linked disorder of glycosphingolipid metabolism caused by a deficiency of alpha-galactosidase A (alpha-Gal A). We identified a novel mutation of alpha-Gal A gene in a family with Fabry disease, which converted a tyrosine at codon 365 to a stop and resulted in a truncation of the carboxy (C) terminus by 65 amino acid (AA) residues. In a heterozygote of this family, although the mutant and normal alleles were equally transcribed in cultured fibroblasts, lymphocyte alpha-Gal A activity was approximately 30% of the normal control and severe clinical symptoms were apparent. COS-1 cells transfected with this mutant cDNA showed a complete loss of its enzymatic activity. Furthermore, those cotransfected with mutant and wildtype cDNAs showed a lower alpha-Gal A activity than those with wild type alone (approximately 30% of wild type alone), which suggested the dominant negative effect of this mutation and implied the importance of the C terminus for its activity. Thus, we generated mutant cDNAs with various deletion of the C terminus, and analyzed. Unexpectedly, alpha-Gal A activity was enhanced by up to sixfold compared with wild-type when from 2 to 10 AA residues were deleted. In contrast, deletion of 12 or more AA acid residues resulted in a complete loss of enzyme activity. Our data suggest that the C-terminal region of alpha-Gal A plays an important role in the regulation of its enzyme activity.

Kidney transplantation in patients receiving dialysis treatment for more than 10 years.

In the present single center study, we analyzed 277 kidney transplant patients (procedures performed between February 1984 and February 2006) to determine the impact of long-term dialysis on kidney transplant outcomes. Forty-four had been treated prior to renal transplantation with dialysis for more than 10 years (range, 10.0-32.5 years, average, 16.6 years; Group I), while the remaining 233 recipients showed an average end-stage renal disease period of 2.8 years (range, 0-9.8 years; Group II). There were no significant differences in patient survivals between the 2 groups: 97.3% vs 97.4% at 1 year; 85.7% vs 92.4% at 5 years; 85.7% vs 90.7% at 10 years (P = .2347). Five Group I patients died: 2 from infections, 2 from liver dysfunction, and 1 from cerebral bleeding. These causes of death were similar to those among Group II patients. Graft survival was not significantly different between the 2 groups: 95% vs 88.8% at 1 year; 75.5% vs 76.5% at 5 years; 75.5% vs 65.5% at 10 years (P = .6264). Our results suggested that dialysis treatment for more than 10 years did not have negative effects on posttransplantation patient and graft survival.

Retrospective study of the effects of cyclosporine in comparison with azathioprine on renal transplant recipients infected with hepatitis C virus.

A recent report noted that cyclosporine (CsA) inhibits replication of the hepatitis C virus (HCV) in vitro. Thus, CsA may be a superior immunosuppressant for renal transplant recipients infected with HCV. In the present retrospective study, we assessed whether CsA reduced the clinical impact of HCV infection among those patients. A total of 405 renal transplants were performed between 1973 and 2005, of whom we studied 189 who received CsA-based immunosuppression (CsA group) vs 108 who received an azathioprine-based regimen (AZA group). There were 44 HCVAb carriers and 145 noncarriers in the CsA group, and 41 carriers and 67 noncarriers in the AZA group. Our results showed that patient survival rate was significantly worse among HCVAb carriers than among noncarriers, as the overall survival rates were 82.9% and 90.9%, respectively, after 10 years and 71.5% and 85.7%, respectively, after 20 years (P = .0003). Patient survival rates were also significantly worse in HCVAb carriers than in noncarriers in both groups, which were 83.2% and 95.0%, respectively, after 10 years, and 74.7% and 88.8%, respectively, after 20 years (P = .0147) in the CsA group, and 82.9% and 83.6%, respectively, after 10 years and 70.7% and 80.6%, respectively, after 20 years (P = .0171) in the AZA group. Conversely, no significant difference was seen in patient survival rate for HCVAb carriers between the two groups (83.2% vs 82.9% at 10 years, and 74.7% vs 70.7% at 20 years, P = .8195). Our results confirmed that HCV infection has a negative impact on the long-term survival of renal transplant patients who receive either a CsA-based or an AZA-based regimen, suggesting that CsA does not have a positive impact on HCV carriers.

The development of Weinstein's noise sensitivity scale.

Many studies have shown the significant correlation between noise annoyance and noise sensitivity identified by Weinstein's noise sensitivity scale (WNS). However, the validity of the scale has not been sufficiently assessed. This study was designed to investigate the validity of each question in WNS and to develop a more valid noise sensitivity measurement scale. A questionnaire study was conducted in a residential area along trunk roads in Kusatsu, Japan, and 301 responses were collected. In this paper, noise sensitivity was defined as the factor that induced individual variability in reactions caused by noise exposure and that is not affected by the noise exposure. The relationship between noise exposure and answers to each question in WNS was investigated by multiple logistic regression analysis, and the influence of response bias on the score of WNS was examined. The results showed that WNS contained some questions that were inappropriately related to noise exposure level and that the score was affected by response bias. The reported correlation between annoyance and the score of WNS could be confounded by noise exposure and response bias. A noise sensitivity measurement scale named WNS-6B was newly developed, excluding the biased questions from the original WNS and applying binary coding to six-response options in order to reduce the response bias. WNS-6B seemed to be more appropriate to assess noise sensitivity than the original scale.

Role of alpha 2-adrenergic receptor in platelet activation during insulin-induced hypoglycemia in normal subjects.

The effects of alpha 2-adrenergic-receptor blocker mianserin on the responses of blood glucose, plasma beta-thromboglobulin (beta-TG), and various counterregulatory hormones to insulin-induced hypoglycemia were studied in nine healthy male subjects. The alpha 2-adrenoceptor-blocking action of mianserin was confirmed by its inhibitory effect on platelet activation in vitro. Mianserin was given orally 90 min before insulin injection; the same study without mianserin was performed on another day as the control study. The time courses of blood glucose and serum C-peptide (0, 20, 45, and 180 min after the insulin injection) were identical in both studies, indicating that mianserin has no effect on these parameters. However, a significant increase of beta-TG at 45 min after insulin injection was completely suppressed by the administration of mianserin (mean +/- SE, 68.5 +/- 6.0 vs. 28.8 +/- 7.6 ng/ml, n = 6, P less than .05). No significant differences were obtained between the two studies in the responses of plasma or serum catecholamines, cortisol, glucagon, growth hormone, thromboxane B2, and 6-ketoprostaglandin F1 alpha. These results suggest that epinephrine is responsible for some, if not all, of the beta-TG release from the platelets during insulin-induced hypoglycemia.

Impact of natural IRS-1 mutations on insulin signals: mutations of IRS-1 in the PTB domain and near SH2 protein binding sites result in impaired function at different steps of IRS-1 signaling.

Insulin receptor substrate-1 (IRS-1) is one of the major substrates of insulin receptor tyrosine kinase and mediates various insulin signals downstream. In this study, we have examined the impact of three natural IRS-1 mutations identified in NIDDM patients (G971R, P170R, and M209T) on insulin signaling. G971R is located near src homology 2 protein binding sites, and P170R and M209T are located in the phosphotyrosine binding domain of IRS-1. 32D-IR cells, stably overexpressing human insulin receptor, were transfected with wild-type human IRS-1 cDNA (WT) or three mutant IRS-1 cDNAs and analyzed. All the cell lines expressing mutant IRS-1 showed a significant reduction in [3H]thymidine incorporation compared with WT. Upon insulin stimulation, cells expressing G971R showed a 39% decrease (P < 0.005) in phosphatidylinositol 3-kinase (PI 3-kinase) activity, a 43% decrease (P < 0.01) in binding of the 85-kDa regulatory subunit of PI 3-kinase, and a 22% decrease (P < 0.05) in mitogen-activated protein kinase activity compared with those expressing WT. Cells expressing P170R and M209T showed slight but significant decreases in PI 3-kinase activity (17 and 14%, respectively; both P < 0.05) and in binding of p85 (22 and 16%, respectively; both P < 0.05) and a greater decrease in mitogen-activated protein kinase activity (41 and 43%, respectively; both P < 0.005) compared with WT. After insulin stimulation, cells expressing P170R and M209T showed significant decreases in IRS-1 phosphorylation (37 and 42%, respectively; both P < 0.05) and in IRS-1 binding to the insulin receptor (48 and 53%, respectively; P < 0.01) compared with WT. G971R showed no changes in IRS-1 phosphorylation and in IRS-1 binding to the insulin receptor compared with WT. These data suggest that the impaired mitogenic response of P170R and M209T was mainly due to reduced binding to the insulin receptor, whereas the impaired response of G971R was mainly due to reduced association with PI 3-kinase p85.

Cell-specific regulation of IRS-1 gene expression: role of E box and C/EBP binding site in HepG2 cells and CHO cells.

Insulin receptor substrate 1 (IRS-1) is one of the major substrates of insulin receptor tyrosine kinase and mediates multiple insulin signals downstream. We have previously shown that the levels of IRS-1 mRNA varied in different tissues. To elucidate the molecular mechanisms of the tissue specific regulation of IRS-1, we have studied the cis-acting elements and transacting factors in CHO and HepG2 cells. Using the chloramphenicol acetyltransferase (CAT) assay with the various deletion mutants of the IRS-1 promoter-CAT fusion plasmids, several regions responsible for positive or negative regulation in each cell line were identified. A region from -1645 to -1585 bp, which regulated expression negatively in CHO cells and positively in HepG2 cells, was further analyzed. Within this region a fragment from -1645 to -1605 bp upregulated the IRS-1 promoter only in HepG2 cells, whereas a fragment from -1605 to -1585 bp downregulated only in CHO cells. In the gel mobility shift assay, several nuclear proteins that bind to these fragments were detected, and among them, two nuclear proteins that bind to a potential E box (nucleotide [nt] -1635 to -1630) and two nuclear proteins that bind to a potential C/EBP binding site (nt -1599 to -1591) were identified in HepG2 and CHO cells, respectively. CAT assays using promoters mutated at the E box or at the C/EBP binding site revealed that these sequences were responsible for cell-specific regulation of the IRS-1 gene. We therefore concluded that the two nuclear proteins that bind to the E box regulate IRS-1 gene expression positively in HepG2 cells and the two nuclear proteins that bind to the C/EBP binding site regulate it negatively in CHO cells.

Creation and characterization of a mitochondrial DNA-depleted pancreatic beta-cell line: impaired insulin secretion induced by glucose, leucine, and sulfonylureas.

It has been proposed that mitochondrial oxidative phosphorylation in pancreatic beta-cells plays an important role in insulin secretion. To examine the impact of mitochondrial dysfunction on insulin secretion, we created a MIN6 cell line that depleted mitochondrial DNA (mtDNA) by treatment with ethidium bromide (EtBr), and studied the response of the cell line to various secretagogues. MIN6 cells cultured with 0.5 microg/ml EtBr for over 2 months (termed MIN6 deltamt cells) revealed a marked (>90%) decrease in mtDNA content and a lack of mRNAs encoded by mtDNA. MIN6 deltamt cells showed the defects of cytochrome c oxidase activity, glucose- and leucine-induced increase in cellular ATP content, and respiratory chain-driven ATP synthesis, suggesting that MIN6 deltamt cells lost oxidative phosphorylation activity due to the selective disruption of the subunits of respiratory chain enzymes encoded by mtDNA. MIN6 deltamt cells also showed a decrease in glucose utilization, suggesting the impairment of the glycolytic pathway as well. After stimulation with glucose and leucine, MIN6 deltamt cells showed no response in insulin secretion or intracellular free Ca2+ concentration ([Ca2+]i). On the other hand, arginine stimulated insulin secretion and an increase in [Ca2+]i in MIN6 deltamt cells as in MIN6 cells. Glibenclamide also stimulated insulin secretion and an increase in [Ca2+]i in both types of cells, but the responses of MIN6 deltamt cells were significantly lower than those of MIN6 cells. These results suggest the importance of ATP production in insulin secretion and an increase in [Ca2+]i, both induced by glucose and leucine. Moreover, mitochondrial function turns out to be not essential but important for the activation of sulfonylurea-induced insulin secretion.

Long-term results of the Kumamoto Study on optimal diabetes control in type 2 diabetic patients.

OBJECTIVE: To examine whether intensive glycemic control could decrease the frequency or severity of diabetic microvascular complications, an 8-year prospective study of Japanese patients with type 2 diabetes was performed. RESEARCH DESIGN AND METHODS: A total of 110 patients with type 2 diabetes (55 with no retinopathy [the primary prevention cohort] and 55 with simple retinopathy [the secondary intervention cohort]) were randomly assigned to multiple insulin injection therapy (MIT) groups and administered three or more daily insulin injections or assigned to conventional insulin injection therapy (CIT) groups and administered one or two daily intermediate-acting insulin injections. Worsening of microvascular complications was regularly assessed during 8 years. Two or more steps up in the 19 stages of the modified Early Treatment of Diabetic Retinopathy Study classification in retinopathy and one or more stages up among three stages in nephropathy (normoalbuminuria, microalbuminuria, and albuminuria) were defined as worsening of complications. RESULTS: In both primary prevention and secondary intervention cohorts, the cumulative percentages of worsening in retinopathy and nephropathy were significantly lower (P < 0.05) in the MIT group than in the CIT group. In neurological tests after 8 years, the MIT group showed significant improvement (P < 0.05) in the median nerve conduction velocities (motor and sensory nerves), whereas the CIT group showed significant deterioration (P < 0.05) in the nerve conduction velocities and vibration threshold. From this study, the glycemic threshold to prevent the onset and progression of diabetic microvascular complications was as follows: HbA1c < 6.5%, fasting blood glucose concentration < 110 mg/dl, and 2-h postprandial blood glucose concentration < 180 mg/dl. CONCLUSIONS: Intensive glycemic control can delay the onset and progression of the early stages of diabetic microvascular complications in Japanese patients with type 2 diabetes.