Yasuko Uchigata

High Incidence of Diabetic Nephropathy in Early-Onset Japanese NIDDM Patients: Risk analysis

OBJECTIVE Because early-onset Japanese NIDDM patients (diagnosed before age 30 years) can develop diabetic end-stage renal failure (ESRF) in their thirties, this study was performed to elucidate the incidence and determinants for the development of diabetic nephropathy. RESEARCH DESIGN AND METHODS The incidence of diabetic nephropathy and its relationship to baseline characteristics and long-term metabolic control were determined in 426 early-onset Japanese NIDDM patients who were followed for a mean of 6.8 years. RESULTS Of these 426 patients, 41 developed diabetic nephropathy manifested by persistent proteinuria (incidence rate [95%CI]/1,000 person-years; 14.1 [10.4–19.1]). Among patients whose mean HbA1c (measured by a high-performance chromatography method that is standardized and comparable to the one used in the Diabetes Control and Complications Trial study) was around 7% or less, few developed nephropathy. The incidence of nephropathy increased with increasing mean HbA1c level in a dose-dependent manner (χ2 trend = 49.9, P < 0.0001). Diastolic blood pressure and duration of diabetes at entry had significant predictive effects independent of metabolic control. CONCLUSIONS The incidence rate of diabetic nephropathy in early-onset Japanese NIDDM patients is potentially high, similar to or higher than that in Pima Indian NIDDM or Caucasian IDDM patients of comparable age. Diabetic nephropathy in NIDDM patients aged in their thirties or forties is likely to be an early feature that leads to ESRF, and this would contribute to the marked increase in the number of new patients with diabetic ESRF in Japan. NIDDM is a serious disease if near-normal glycemia is not achieved.

Existence of Early-Onset NIDDM Japanese Demonstrating Severe Diabetic Complications

OBJECTIVE To identify the clinical characteristics of early-onset NIDDM patients with severe diabetic complications. RESEARCH DESIGN AND METHODS The clinical cases of a large number of diabetic patients who visited a diabetes center within the period 1970–1990 were reviewed. Of a total of 16,842 diabetic patients, 1,065 (6.3%) had early-onset NIDDM (diabetes diagnosed before 30 years of age). These 1,065 patients were divided into two groups, those who developed proliferative retinopathy before the age of 35 (n = 135) and those who did not (n = 930). Development of proliferative retinopathy, nephropathy, renal failure, blindness, and atherosclerotic vascular disease were compared between the two groups. RESULTS The subgroup of 135 patients was characterized by poor glycemic control, often requiring insulin therapy and a higher familial prevalence of diabetes, and contained a greater proportion of women than the subgroup of 930 patients. Of the 135 patients, 99 (67%) developed proliferative retinopathy before the first visit. The 135 patients developed severe progressive complications in contrast to the 930 patients. A total of 81 patients (60%) developed diabetic nephropathy at a mean age of 31 years, 31 (23%) developed renal failure requiring dialysis at a mean age of 35 years, 32 (24%) became blind at a mean age of 32 years, and 14 (10%) developed atherosclerotic vascular disease at a mean age of 36 years. CONCLUSIONS Some Japanese early-onset NIDDM patients develop severe diabetic complications in their youth. Most of them had no symptoms nor regular treatment regarding diabetes until they were noticed to have developed severe diabetic complications. Although the relevant prevalence and the pathogenetic mechanism underlying the rapid onset of the complications remain to be determined, prolonged inadequate treatment of and familial predisposition to diabetes may be contributing factors. Careful diabetes care in the twenties, not only for IDDM but also for NIDDM patients, is warranted.

Serum levels of non-carboxymethyllysine advanced glycation endproducts are correlated to severity of microvascular complications in patients with Type 1 diabetes

We investigated whether serum levels of N-(carboxymethyl)lysine (CML), non-CML advanced glycation endproducts (AGEs), or pentosidine are associated with severity of diabetic microvascular complications in patients with Type 1 diabetes. Serum levels of CML, non-CML AGE, and pentosidine were measured by an enzyme-linked immunosorbent assay in 38 males and 47 females aged 31+/-8 years (mean+/-S.D.) with Type 1 diabetes for 18.7+/-7.0 years. There was a significant correlation between serum levels of CML or non-CML AGE and current HbA(1c) level (P<.01 and P<.05, respectively). The serum levels of non-CML AGE, but not CML or pentosidine, were significantly increased as normal renal status advanced to microalbuminuria, clinical nephropathy, and hemodialysis (P<.0001) and were positively correlated with urinary albumin excretion (UAE) in patients with Type 1 diabetes (P<.0001). A significant elevation of serum non-CML AGE was found in association with the severity of diabetic retinopathy (P<.0001). We found in the present study that CML levels were also increased in the stage of simple retinopathy, the early stage of clinically evident retinopathy (P<.05). Serum levels of non-CML AGE were significantly associated with the severity of diabetic nephropathy and retinopathy, suggesting a role of non-CML AGE in the progression of microvascular complications in patients with Type 1 diabetes. Since serum levels of CML were significantly increased in patients with simple retinopathy, CML may participate in the initiation of diabetic retinopathy.

Effect of Poly(ADP-ribose) Synthetase Inhibitor Administration to Rats Before and After Injection of Alloxan and Streptozotocin on Islet Proinsulin Synthesis

Nicotinamide (10 mmol/kg) and 3-aminobenzamide (1.25 mmol/kg), poly(ADP-ribose) synthetase inhibitors, were injected intravenously to rats either 30 min before the intravenous administration of 12 mg/kg alloxan or 50 mg/kg streptozotocin (“Pretreatment”) or 5 min after the administration (“posttreatment”). Fifteen minutes after the injection of the diabetogenic agents, pancreatic islets were isolated from the rats and proinsulin synthesis was determined. Proinsulin synthesis was decreased in islets from rats treated with alloxan or streptozotocin. Pretreatment with poly(ADP-ribose) synthetase inhibitors was found to protect against alloxan- or streptozotocin-induced decrease in proinsulin synthesis. By posttreatment with poly(ADP-ribose) synthetase inhibitors, streptozotocin-induced decrease in proinsulin synthesis was also significantly reversed, whereas the decrease induced by alloxan was not.

Strong association of insulin autoimmune syndrome with HLA-DR4

Insulin autoimmune syndrome is characterised by spontaneous hypoglycaemia without evidence of exogenous insulin administration, a high serum concentration of total immunoreactive insulin, and the presence of insulin autoantibodies in high titre. HLA typing of 27 patients with insulin autoimmune syndrome showed that all had DR4, which was present in only 43% of 51 healthy controls (odds ratio 72.1, p less than 2 x 10(-6), and 19 (70%) of the patients were positive for the allelic combination, Cw4, Bw62, and DR4. Analysis of the nucleotide sequences of the DRB1, DQA1, and DQB1 genes showed that all the patients had DRB1*0406, DQA1*0301, and DQB1*0302, compared with only 14% of the controls (odds ratio 281, p less than 1 x 10(-10). We conclude that the development of insulin autoimmune syndrome is associated with a strong genetic predisposition.

DNA strand breaks in pancreatic islets by invivo administration of alloxan or streptozotocin

Abstract Administration of diabetogenic doses of alloxan or streptozotocin to rats caused extensive DNA strand breaks in pancreatic islets. DNA of pancreatic exocrine cells was not affected by either alloxan or streptozotocin. hepatocyte DNA was fragmented by streptozotocin but not by alloxan. Intracellular NAD level was decreased in tissues whose DNA was fragmented. The results may raise a novel aspect concerning the mechanisms of action of the diabetogenic agents as well as concerning the organotropisms of the agents.

Allogeneic Transplantation of an Adipose-Derived Stem Cell Sheet Combined With Artificial Skin Accelerates Wound Healing in a Rat Wound Model of Type 2 Diabetes and Obesity

One of the most common complications of diabetes is diabetic foot ulcer. Diabetic ulcers do not heal easily due to diabetic neuropathy and reduced blood flow, and nonhealing ulcers may progress to gangrene, which necessitates amputation of the patient’s foot. This study attempted to develop a new cell-based therapy for nonhealing diabetic ulcers using a full-thickness skin defect in a rat model of type 2 diabetes and obesity. Allogeneic adipose-derived stem cells (ASCs) were harvested from the inguinal fat of normal rats, and ASC sheets were created using cell sheet technology and transplanted into full-thickness skin defects in Zucker diabetic fatty rats. The results indicate that the transplantation of ASC sheets combined with artificial skin accelerated wound healing and vascularization, with significant differences observed 2 weeks after treatment. The ASC sheets secreted large amounts of several angiogenic growth factors in vitro, and transplanted ASCs were observed in perivascular regions and incorporated into the newly constructed vessel structures in vivo. These results suggest that ASC sheets accelerate wound healing both directly and indirectly in this diabetic wound-healing model. In conclusion, allogeneic ASC sheets exhibit potential as a new therapeutic strategy for the treatment of diabetic ulcers.

Insulin autoimmune syndrome in Japan.

Since 1970, 197 patients with insulin autoimmune syndrome (IAS) showing severe spontaneous hypoglycemia have been reported in Japan. This is characterized by a high titer of anti-insulin autoantibodies without evidence of exogenous insulin administration. IAS is the third leading cause of spontaneous hypoglycemia in Japan, while only 21 cases have been reported in Europe and the United States. High levels of the extractable native human insulin and of the characteristic insulin autoantibodies in the sera of the IAS patients have been proved. Recently a significant association of HLA-DRB1*0406/DQA1*0301/DQB1*0302 with this syndrome has been found in the IAS patients in Japan.

Worldwide differences in the incidence of insulin autoimmune syndrome (Hirata disease) with respect to the evolution of HLA-DR4 alleles

The relationship between the geographic distribution of susceptibility genes to insulin autoimmune syndrome (IAS) and the incidence of insulin autoimmune syndrome was investigated in order to examine the distribution of the genetic background to susceptibility to certain diseases. The HLA-DR4 allele, DRB1*0406, is associated with increased susceptibility to IAS among Japanese, while the DRB1*0403 and DRB1*0407 alleles are not (the odds ratio of which are 1.6 and 1.1, respectively). The worldwide geographic distribution of the three DR*04 alleles showed that the distribution of DRB1*0403 encompassed that of DRB1*0406 and DRB1*0407. Taken together with the findings that Glu at position 74 in the DRB1 molecule is shared by the three DRB1*04 alleles, there are only a few differences between the DRB1 molecule-nucleotide sequences of DRB1*0403, DRB1*0406 and DRB1*0407, and that all the three DRB1*04 alleles are carried by the same class II haplotype, DQA1*0301/DQB1*0302, it may be considered that DRB1*0403 is the ancestral allele of DRB1*0406 and DRB1*0407. Therefore, populations with a higher prevalence of DRB1*0406 have a higher risk of developing IAS. The extremely low prevalence of IAS among Caucasians can be explained by the low prevalence of DRB1*0406 in this population. This is a good example of the association between the predisposition to risk of development of certain diseases and the evolution of susceptibility genes.

Arterial Stiffness Is Associated With Incident Albuminuria and Decreased Glomerular Filtration Rate in Type 2 Diabetic Patients

OBJECTIVE To investigate the association between aortic stiffness and incident albuminuria and the decline in estimated glomerular filtration rate (eGFR) in patients with type 2 diabetes. RESEARCH DESIGN AND METHODS We investigated 461 Japanese type 2 diabetic patients, comprising 199 women and 262 men, with a mean age of 59 ± 11 years. Patients were divided into two groups according to the median value of carotid-femoral pulse wave velocity (cf-PWV), which was used to evaluate aortic stiffness. The end point was defined as the transition from normo- to microalbuminuria or micro- to macroalbuminuria. The Cox proportional hazard model was used to calculate the hazard ratio (HR) and 95% CI. The correlation between cf-PWV and rate of change in eGFR was also determined by linear regression analysis. RESULTS The baseline mean (± SD) cf-PWV was 9.6 ± 2.4 m/s. During a median follow-up period of 5.9 years (range 0.3–8.6), progression of albuminuria was observed in 85 patients. The 5-year cumulative incidence of the end point in patients with cf-PWV below and above the median was 8.5 and 19.4%, respectively (P = 0.002, log-rank test). cf-PWV was significantly associated with incident albuminuria (HR 1.23, 95% CI 1.13–1.33, P < 0.001) by multivariate Cox regression analysis. A significant association between cf-PWV and annual change in eGFR was also suggested by multiple linear regression analysis (standardized estimate −0.095, P = 0.031). CONCLUSIONS Aortic stiffness is associated with incident albuminuria and the rate of decline in glomerular filtration rate in type 2 diabetic patients.