High incidence of diabetic nephropathy in early-onset Japanese NIDDM patients. Risk analysis

Comparisons of the outcomes on control, type of management and complications status in early onset and late onset type 2 diabetes in Asia

OBJECTIVE

To describe the clinical characteristics and chronic diabetic complications in early (EOD) and late onset type 2 diabetes mellitus (LOD) in Asia.

RESEARCH DESIGN AND METHODS

Retrospective collection of information (basic patient data, treatment received for diabetes, hypertension, dyslipidaemia, clinical measurements, complications, life-style management, etc.) on paper form and prospective collection of blood samples for HbA(1c) assessment were performed. Means, proportions and associated factors were analyzed using non-parametric and logistic regression.

RESULTS

The frequency of EOD (<30 years) varies in different Asian countries (0.4-5.3%). Overweight (BMI>or=23 kg/m2) was common in both EOD (60%) and LOD (66%). EOD was characterized by significantly higher levels of HbA(1c) (median 8.9% versus 7.9%) and FPG (median 9.8 mmol/L versus 8.3 mmol/L) but hypertension was less common (43% versus 59%). Lipid profiles (cholesterol and triglycerides) were similar between both groups of patients. Cataract was more common in LOD and was associated with onset age and diabetes duration whereas an increase in frequency of advanced eye disease, retinopathy and history of photocoagulation was found in EOD cohort.

CONCLUSIONS

In addition to diabetic control and duration of the disease, the onset age conferred risk to certain subsets of chronic complications in type 2 diabetes population.

Type 2 diabetes mellitus in youth: the complete picture to date

Type 2 diabetes mellitus is a heterogeneous condition in which the clinical manifestation of hyperglycemia is a reflection of the impaired balance between insulin sensitivity and insulin secretion. Clinical experience and research in youth type 2 diabetes mellitus are in an early stage because of the relative novelty of the condition in pediatrics. This article discusses the amassed information in type 2 diabetes mellitus of youth to date with respect to the epidemiology, pathophysiology, risk factors, clinical presentation, screening, and management strategies.

Heterogeneity of early-onset and ketosis-resistant diabetes in Korean subjects--is it possible to determine cut-off age of early-onset type 2 diabetes?

OBJECTIVE

To investigate the heterogeneity of early-onset and ketosis-resistant diabetes and to define a not-arbitrary cut-off age for early-onset diabetes based on its clinical and metabolic characteristics, and diabetes complications.

METHODS

We classified 1015 early-onset diabetes subjects aged 21-40 into four groups (group I, age at diagnosis 21-25 years; group II, 26-30; group III, 31-35; group IV, 36-40). Familial and diabetic history, statue of insulin secretion, metabolic parameters, and diabetes complications were analyzed.

RESULTS

No significant difference in family history or the rate of diabetic complication was found in the four groups. Subjects with a 21 to a 25-year-old diabetes onset had the lowest serum C-peptide levels, with 50% of the cumulative 24-h urine C-peptide levels of the other three groups (p<0.0001). This group also had the lowest prevalence of hyperlipidemia and arterial hypertension (p<0.01 and <0.0001, respectively). Group III was found to have a higher prevalence of insulin insufficiency and hypertension than group IV.

CONCLUSION

Our data based on insulin secretory function and metabolic factors might suggest that a cut-off age of 26 years might be warranted in Korean patients. Korean early-onset type 2 diabetes patients tend to be non-obese and insulin secretory dysfunction.

The factors affecting glycemic control in Japanese adolescents with type 2 diabetes mellitus

The factors affecting glycemic control were examined using HbA(1C) as an index in a total of 22 patients with type 2 diabetes mellitus whose ages at onset were less than 18 years old. As a result, the presence or absence of the following cases were considered possible factors for significant exacerbation of glycemic control: diabetic microangiopathy; school phobia or nonworking situation; drug therapy; use of more than two kinds of oral hypoglycemic agents (OHAs) or insulin for the drug therapy cases. No improvement in glycemic control could be achieved even by increasing the number of OHAs for co-administration or by insulin use unless dietary/exercise therapy, a basic therapeutic option, was adequately performed.

Trends in incidence of end-stage renal disease in Japan, 1983-2000: age-adjusted and age-specific rates by gender and cause

BACKGROUND

Trends in age-adjusted or age-specific incidence rates of end-stage renal disease (ESRD) have never been examined in Japan, a major ESRD epidemic area.

METHODS

A nationwide registry has provided the number of ESRD patients commencing maintenance renal replacement therapy for time period from 1983 to 2000. We computed gender- and age-specific incidence rates of ESRD over 2-year periods, in total or by cause. Age-adjusted incidence rates were calculated using the 1985 Model Population of Japan as the standard.

RESULTS

Causes of ESRD in 1999-2000 were, in order of decreasing frequency, diabetic nephropathy, chronic glomerulonephritis, unknown causes, nephrosclerosis and polycystic kidney disease in men, and chronic glomerulonephritis, diabetic nephropathy, unknown causes, nephrosclerosis and polycystic kidney disease in women. The age-adjusted all-cause incidence of ESRD increased until 1995-1996, but has since levelled off in both genders. The age-adjusted rate for diabetic nephropathy has been rapidly increasing, while that for chronic glomerulonephritis has decreased since 1995-1996. The former rate exceeded the latter in 1997-1998 in men. All-cause ESRD has rapidly increased in the eighties age group, whereas the increase slowed down in younger age groups in the late 1990s. The rate for diabetic nephropathy has linearly risen in almost every age group in men, whereas it began to level off in women aged 40-59 years at about 1995. For chronic glomerulonephritis, the rate had already started to decline in the mid-1980s in those aged <45 years. The rate of nephrosclerosis has been increasing independently of age.

CONCLUSIONS

The present study shows changes in the epidemiological features of the incidence of ESRD in Japan from 1983 to 2000.

Age, body mass index and Type 2 diabetes-associations modified by ethnicity

AIMS/HYPOTHESIS

The aim of this study was to assess the effect of ethnicity on the association between age and body mass index as well as the prevalence of diabetes.

METHODS

We selected population-based studies carried out after 1980 in the DECODE/A studies representing different ethnic groups: 11 European, 1 Maltese, 3 Indian, 2 Chinese and 3 Japanese surveys. The total numbers of subjects were 14,240 men and 15,129 women who were 30 to 89 years of age. Diabetes was diagnosed according to the 1999 World Health Organization criteria based on a standard 75 g OGTT. Sex-specific prevalence of diabetes by age and BMI was stratified by ethnic group, in particular the interaction of ethnicity on the associations between age/BMI and the prevalence of diabetes.

RESULTS

The prevalence of diabetes was higher in studies from India and Malta compared to Japan, China, and the rest of Europe. The association between BMI and diabetes, adjusted for age, showed noticeable differences between the ethnic groups with an increase in prevalence starting at a BMI between 15 and 20 kg/m(2) in the Maltese and Indian populations compared to 25 kg/m(2 )in Europeans.

CONCLUSION/INTERPRETATION

The effect of BMI on the age-adjusted prevalence of Type 2 diabetes was modified by ethnicity with considerably lower thresholds in Indian and Maltese subjects compared to those from the rest of Europe. This difference should be reflected in national and international recommendations regarding "optimal" BMI.

Progression to overt nephropathy in type 2 diabetes: the Casale Monferrato Study

OBJECTIVE

The first sign of diabetic nephropathy is microalbuminuria, but its predictive role of progression to overt nephropathy in type 2 diabetes has not yet been clarified. The aims of this study were to assess during 7 years of follow-up the incidence rate of overt nephropathy and the predictive role of microalbuminuria and other baseline variables (blood pressure, lipids, fibrinogen, uric acid, smoking, and HbA(1c) cumulative average during follow-up).

RESEARCH DESIGN AND METHODS

A prospective population-based study was performed in Casale Monferrato, Italy, including 1,253 type 2 diabetic patients recruited at baseline (1991-1992), 765 with normoalbuminuria (albumin excretion rate [AER] <20 microg/min) and 488 with microalbuminuria (AER 20-200 microg/min). All measurements were centralized. A nested case-control study within the cohort was performed, selecting four control subjects, frequency matched for age and attained individual time of follow-up with each case. Conditional regression analysis was performed to assess variables independently associated with risk of progression to overt nephropathy.

RESULTS

Of 1,253 total patients, 1,103 (88.0%) were included in the follow-up examination (median 5.33 years); their age and duration of disease at baseline were 68.4 +/- 10.5 years and 10.4 +/- 6.6 years, respectively. Cases of overt nephropathy were 202, giving an incidence rate of 37.0/1,000 person-years (95% CI 32.3-42.6). In conditional logistic regression analyses, microalbuminuria provided a 42% increased risk with respect to normoalbuminuria (95% CI 0.98-2.06), independently of duration of diabetes, hypertension, and systolic blood pressure. Other variables independently associated with progression to overt nephropathy were HbA(1c) cumulative average (P = 0.002), apolipoprotein B (P = 0.013), fibrinogen (P = 0.02), and HDL cholesterol (P = 0.03).

CONCLUSIONS

Of type 2 diabetic patients, 3.7% progress every year to overt nephropathy. Microalbuminuria is associated with a 42% increased risk of progression to overt nephropathy. Other independent predictors are HbA(1c), HDL cholesterol, apolipoprotein B, and fibrinogen.

Lessons learned from young-onset diabetes in China

The prevalence of young-onset diabetes is rapidly rising in China. Young-onset diabetes is etiologically and phenotypically heterogeneous. Thirty percent to 50% of these patients have insulin secretory failure owing to autoimmune or monogenic or other yet to be identified forms of diabetes. Others have a strong family history of diabetes and exhibit features of the metabolic syndrome. Management of these young patients poses major diagnostic and therapeutic challenges, which require a multidisciplinary and holistic approach to ensure that these subjects are identified early and managed appropriately. Understanding the molecular basis of diabetes in these subjects may also eventually lead to improvement in diagnosis, classification, and treatment.

Treatment of diabetic nephropathy in its early stages

Diabetic nephropathy is one of the most frequent causes of end-stage renal disease (ESRD), and, in recent years, the number of diabetic patients entering renal replacement therapy has dramatically increased. The magnitude of the problem has led to numerous efforts to identify preventive and therapeutic strategies. In normoalbuminuric patients, optimal glycemic control (HbA(1c) lower than 7.5%) plays a fundamental role in the primary prevention of ESRD [weighted mean relative risk reduction (RRR) approximately 37% for metabolic control versus trivial renoprotection for intensive anti-hypertensive therapy or ACE-inhibitors (ACE-I)]. In the microalbuminuric stage, strict glycemic control probably reduces the incidence of overt nephropathy (weighted mean RRR approximately 50%), while blood pressure levels below 130/80 mmHg are recommended according to the average blood pressure levels obtained in various studies. In normotensive patients, ACE-I markedly reduce the development of overt nephropathy almost regardless of blood pressure levels; in hypertensive patients, ACE-I are less clearly active (weighted mean RRR approximately 23% versus other drugs), whereas angiotensin-receptor blockers (ARB) appear strikingly renoprotective. Once overt proteinuria appears, it is uncertain whether glycemic control affects the progression of nephropathy. In type 1 diabetes, various anti-hypertensive treatments, mainly ACE-I, are effective in slowing down the progression of nephropathy; in type 2 diabetes, two recent studies demonstrate that ARB are superior to conventional therapy or calcium channel blockers (CCB). In clinical practice, pharmacological tools are not always used to the best benefit of the patients. Therefore, clinicians and patients need to be educated regarding the renoprotection of drugs inhibiting the renin-angiotensin system (RAS) and the overwhelming importance of achieving target blood pressure.

Barriers to the treatment of adolescent type 2 diabetes--a survey of provider perceptions

OBJECTIVE

Type 2 diabetes mellitus (T2DM) is increasingly common among children and adolescents. However, achievement of good metabolic control has been difficult in this population. The aim of this study was to survey pediatric endocrine and diabetes specialists regarding the issues they consider to be barriers to successful treatment of adolescent T2DM.

METHODS

An electronic questionnaire was administered to 220 physicians and nurses attending a conference on pediatric diabetology in 2001.

RESULTS

The issues that were most strongly perceived as barriers to successful treatment of adolescents with T2DM were prevalence of high-risk lifestyle in other family members (98%), lack of immediate risk to life reducing patient motivation (89%), lack of guidelines regarding optimal treatment (73%), prevalence of behavioral and/or psychiatric disorders (71%), and cultural/language barriers (65%). The survey also revealed that in the majority of clinics, T2DM education programs were not designed specifically for type 2 patients nor delivered by a specifically trained education team. Furthermore, despite the fact that cultural and ethnic differences were identified as important barries to care, educational materials designed for particular racial and cultural groups were used in only 37% of the clinics.

CONCLUSIONS

This survey identifies a number of areas perceived by clinicians to be significant barriers to successful treatment of T2DM in adolescent patients. Given the multiple challenges identified by the survey, programs addressed specifically to the characteristics of adolescents with T2DM will be necessary, including materials appropriate to the developmental stage and ethnic background of patients.

Pharmacokinetics of nateglinide in renally impaired diabetic patients

Treatment of hyperglycemia in patients with diabetes mellitus and renal insufficiency is complicated by altered pharmacokinetics of hypoglycemic agents. This study evaluated the pharmacokinetic profile and safety of nateglinide, an amino acid derivative that improves early phase insulin secretion and reduces mealtime glucose excursions. This open-label, single-dose, two-center study included patients (mean age = 57 +/- 10 years) with type 1 or 2 diabetes with impaired renal function (IRF) (n = 10) or with renal failure undergoing hemodialysis (n = 10). Both groups were compared with age-, sex-, height-, and weight-matched healthy controls (n = 20). All participants received a single 120-mg dose of nateglinide immediately before breakfast. Pharmacokinetic and safety evaluations were undertaken up to 48 hours postdose. All 40 subjects completed the study. Plasma nateglinide concentrations increased rapidly in patients undergoing dialysis and matched healthy subjects (tmax = 0.95 vs. 0.78 h, respectively) and was comparable with patients with IRF and matched healthy subjects (tmax = 0.80 vs. 0.65 h, respectively). There were no statistically significant differences for Cmax or AUC0-t between the groups. Nateglinide was eliminated rapidly in all groups (t1/2 = 1.9-2.8 h). There was no correlation between the level of renal function and systemic exposure. There was a low extent of renal excretion of nateglinide in healthy subjects (11%) and diabetic patients with IRF (3%). Nateglinide was well tolerated. These data suggest that nateglinide is suitable for use in diabetic patients with IRF or with renal failure undergoing dialysis. Given the comparable absorption and elimination profiles of nateglinide in renally impaired and healthy subjects, no dose adjustment appears necessary in the renally impaired.

Increasing incidence of type 2 diabetes in children and adolescents: treatment considerations

The emerging public health problem of type 2 diabetes in youth reflects increasing rates of childhood obesity. As in adults, type 2 diabetes in children is part of the insulin resistance syndrome that includes hypertension, dyslipidemia and other atherosclerosis risk factors, and hyperandrogenism seen as premature adrenarche and polycystic ovary syndrome. Studies in children document risk factors for type 2 diabetes and associated cardiovascular risk factors, including obesity, family history, diabetic gestation, and underweight or overweight for gestational age. Genetically determined insulin resistance, or limited beta-cell reserve, has been demonstrated in high risk individuals. This genetic background, considered advantageous in a feast and famine existence (the thrifty genotype), is rendered detrimental with abundant food and physical inactivity, a lifestyle demonstrated to be typical of families of children with type 2 diabetes. Case finding in high risk individuals who are asymptomatic may be an appropriate response to the public health challenge of type 2 diabetes in children, because risk factors for cardiovascular disease are already present at the time of diagnosis. Treatment is dictated by the degree of metabolic derangement and symptoms. The only data on the use of oral hypoglycemic agents in children has been with metformin. Prevention efforts will require community and government involvement to reduce obesity and increase physical activity in the child, as well as adult, population.

Diabetes mellitus--a special medical challenge from a Chinese perspective

As we enter the new millennium, Asia is being hit by an epidemic of diabetes and its related diseases. The rising prevalence of young onset diabetes which is closely associated with obesity and genetic factors as well as the increased propensity to develop kidney disease are special challenges in the management of Chinese diabetic patients. Although diabetic patients have earlier mortality and increased risks for micro and macrovascular complications, there is strong evidence that these devastating complications can be largely prevented by patient education, periodic assessments and use of appropriate therapeutic agents to optimize metabolic control and improve cardiovascular risk factors. However, a multidisciplinary approach is often required to deliver these complex disease management protocols. Hence, it is not surprising that large scale studies often revealed substandard diabetes management in both the hospital and community settings. This is often due to a combination of factors such as non-adherence to recommended guidelines both by patients and doctors as well as the 'non-urgent' and 'silent nature' of diabetes and its complications. To minimize the impacts of diabetes on quality of life, society productivity and utilization of health care resources, concerted efforts between health care professionals and public bodies are urgently needed to increase awareness, improve standards of care and develop better diagnostics and treatment modalities.

Familial early-onset type 2 diabetes in Chinese patients: obesity and genetics have more significant roles than autoimmunity

OBJECTIVE

We examined the prevalence of different forms of diabetes in Hong Kong Chinese patients with familial early-onset type 2 diabetes and compared their clinical features with patients with familial late-onset type 2 diabetes.

RESEARCH DESIGN AND METHODS

A total of 145 young patients with early-onset diabetes (age and age at diagnosis < or = 40 years) and a family history of diabetes were studied. They were screened for mutations in the genes encoding glucokinase, hepatocyte nuclear factor (HNF)-4alpha, and HNF-1alpha. The mitochondrial DNA A-->G at nucleotide 3243 (mt3243) and amyLin S20G mutations were studied, and antibodies to GAD (anti-GADs) were also examined.

RESULTS

The prevalence of putative diabetogenic gene mutations and autoimmune markers were 4% for glucokinase, 0% for HNF-4alpha, 5% for HNF-1alpha, 3% for mt3243, 2% for amylin 520G, and 4% for anti-GAD. Compared with late-onset patients, the patients with early-onset diabetes had a higher prevalence of a parental history of diabetes and were generally more obese. When classified by obesity indexes (BMI and waist circumference), the obese patients, especially those with early-onset diabetes, had a clustering of cardiovascular risk factors and increased rates of retinopathy and albuminuria. CONCLUSIONS; Genetic factors (up to 14%) and obesity (55%) play more significant roles than autoimmunity (4%) in familial type 2 diabetes in young Chinese patients. The significance of obesity-related genes and other gene-gene and gene-environment interactions in these young patients remains to be determined.

Higher incidence of diabetic nephropathy in type 2 than in type 1 diabetes in early-onset diabetes in Japan

BACKGROUND

Whether the type of diabetes, race, and year and age of diagnosis affect the incidence of diabetic vascular complications is unknown. That both type 1 and type 2 diabetes occur in the young Japanese population prompted us to investigate whether the type of diabetes and the year of diagnosis are related to the incidence of nephropathy.

METHODS

Of the 17,256 diabetic patients who visited the outpatient clinic at our diabetes center between 1965 and 1990, 1578 (9.1%) had early-onset diabetes (diagnosed before the age of 30); of these, 620 (39%) had type 1, and 958 (61%) had type 2 diabetes. The incidence of nephropathy was analyzed in the patients according to postpubertal duration and year of diagnosis.

RESULTS

The cumulative incidence of nephropathy after 30 years of postpubertal diabetes was significantly higher (P < 0.0001) in type 2 diabetic patients (44.4%, 95% CI, 37.0 to 51.8%) than in type 1 diabetic patients (20.2%, 95% CI, 14.9 to 25.8%). The incidence of nephropathy among type 1 diabetic patients has declined during the past two decades, whereas it has not among type 2 diabetic patients. The rate ratio for type 2 diabetic patients diagnosed between 1980 and 1984 relative to type 1 diabetic patients diagnosed in the same period was 2.74 (95% CI, 1. 17 to 6.41).

CONCLUSIONS

The incidence of nephropathy has declined in Japanese patients with type 1 but not in those with type 2 diabetes. In young Japanese patients, because of the higher incidence of nephropathy in type 2 diabetes and the higher prevalence of type 2 than type 1 diabetes, type 2 diabetes is likely the major cause of diabetic nephropathy.