Ketosis-prone diabetes--a new subgroup of patients with atypical type 1 and type 2 diabetes?

Genetics of diabetes

Diabetes mellitus is a complicated disease characterized by a complex interplay of genetic, epigenetic, and environmental variables. It is one of the world's fastest-growing diseases, with 783 million adults expected to be affected by 2045. Devastating macrovascular consequences (cerebrovascular disease, cardiovascular disease, and peripheral vascular disease) and microvascular complications (like retinopathy, nephropathy, and neuropathy) increase mortality, blindness, kidney failure, and overall quality of life in individuals with diabetes. Clinical risk factors and glycemic management alone cannot predict the development of vascular problems; multiple genetic investigations have revealed a clear hereditary component to both diabetes and its related complications. In the twenty-first century, technological advancements (genome-wide association studies, next-generation sequencing, and exome-sequencing) have led to the identification of genetic variants associated with diabetes, however, these variants can only explain a small proportion of the total heritability of the condition. In this review, we address some of the likely explanations for this "missing heritability", for diabetes such as the significance of uncommon variants, gene-environment interactions, and epigenetics. Current discoveries clinical value, management of diabetes, and future research directions are also discussed.

The phenotype of type 1 diabetes in sub-Saharan Africa

The phenotype of type 1 diabetes in Africa, especially sub-Saharan Africa, is poorly understood. Most previously conducted studies have suggested that type 1 diabetes may have a different phenotype from the classical form of the disease described in western literature. Making an accurate diagnosis of type 1 diabetes in Africa is challenging, given the predominance of atypical diabetes forms and limited resources. The peak age of onset of type 1 diabetes in sub-Saharan Africa seems to occur after 18-20 years. Multiple studies have reported lower rates of islet autoantibodies ranging from 20 to 60% amongst people with type 1 diabetes in African populations, lower than that reported in other populations. Some studies have reported much higher levels of retained endogenous insulin secretion than in type 1 diabetes elsewhere, with lower rates of type 1 diabetes genetic susceptibility and HLA haplotypes. The HLA DR3 appears to be the most predominant HLA haplotype amongst people with type 1 diabetes in sub-Saharan Africa than the HLA DR4 haplotype. Some type 1 diabetes studies in sub-Saharan Africa have been limited by small sample sizes and diverse methods employed. Robust studies close to diabetes onset are sparse. Large prospective studies with well-standardized methodologies in people at or close to diabetes diagnosis in different population groups will be paramount to provide further insight into the phenotype of type 1 diabetes in sub-Saharan Africa.

Stimulated UCPCR Levels Are Lower in People With Type 1 Diabetes Than in Other Diabetes Types in Sub-Saharan Africa: Results From a Preliminary Cross-Sectional Study

Background

The clinical utility of Urinary C-Peptide to Creatinine Ratio (UCPCR) is well understood in people with different types of diabetes in Caucasian populations, but studies are lacking in African populations. We, therefore, aimed to examine Urinary C-Peptide to Creatinine Ratio levels among groups of people with different types of diabetes in a sub-Saharan African population.

Methods

A total of 47 adults with diabetes; 10 with type 1 diabetes, 26 with type 2 diabetes, 11 with ketosis-prone diabetes, and 22 healthy control individuals, were recruited from Yaoundé Central Hospital in Cameroon. Fasting blood glucose and C-peptide were measured in venous blood and urine. Stimulated Urinary C-Peptide to Creatinine Ratio was determined in all subjects after ingestion of a standardized mixed meal. We compared the stimulated Urinary C-peptide to Creatinine Ration concentration in subjects with type 1 diabetes to the other groups.

Results

The basal C-peptide and HOMA-β were lower in T1D than in the T2D group [median 57 (34, 69) vs. 398 (335, 502) pmol/l; p ≤ 0.001] and [median 3.0 (1.63, 5.25) vs. 30.6 (17.94, 45.03); p < 0.001] respectively. Also, basal C-peptide and HOMA-β were lower in T1D than in those with KPD [median 57 (34, 69) vs. 330 (265, 478) pmol/l; p = 0.003] and [median 3.0 (1.63, 5.25) vs. 47.1 (16.2, 63.1), p = 0.001] respectively. Basal C-peptide was not different between participants with T2D and KPD; 398 (335, 502) vs. 330 (265, 478) pmol/l, p = 0.19. Stimulated UCPCR was lower in T1D compared to T2D, KPD and control participants; [median 0.29 (0.14, 0.68) vs. 0.89 (0.40, 1.69) nmol/moll; p = 0.009], [median 0.29 (0.14, 0.68) vs. 1.33 (0.84, 1.59) nmol/mol; p = 0.006] and [median 0.29 (0.14, 0.68) vs. 1.21 (0.85, 1.21) nmol/mol; p = 0.005] respectively. However, stimulated UCPCR was similar between the T2D and KPD study participants; 0.89 (0.40, 1.69) vs. 1.33 (0.84, 1.59) nmol/mol, p = 0.36.

Conclusions

Stimulated Urinary C-Peptide to Creatinine Ratio (UCPCR) is lower in participants with type 1 diabetes compared to those with other types of diabetes in this population. This means stimulated UCPCR could potentially differentiate type 1 diabetes from other diabetes types among people with diabetes in sub-Saharan Africa.

Adenosine monophosphate-activated protein kinase-based classification of diabetes pharmacotherapy

The current classification of both diabetes and antidiabetes medication is complex, preventing a treating physician from choosing the most appropriate treatment for an individual patient, sometimes resulting in patient-drug mismatch. We propose a novel, simple systematic classification of drugs, based on their effect on adenosine monophosphate-activated protein kinase (AMPK). AMPK is the master regular of energy metabolism, an energy sensor, activated when cellular energy levels are low, resulting in activation of catabolic process, and inactivation of anabolic process, having a beneficial effect on glycemia in diabetes. This listing of drugs makes it easier for students and practitioners to analyze drug profiles and match them with patient requirements. It also facilitates choice of rational combinations, with complementary modes of action. Drugs are classified as stimulators, inhibitors, mixed action, possible action, and no action on AMPK activity. Metformin and glitazones are pure stimulators of AMPK. Incretin-based therapies have a mixed action on AMPK. Sulfonylureas either inhibit AMPK or have no effect on AMPK. Glycemic efficacy of alpha-glucosidase inhibitors, sodium glucose co-transporter-2 inhibitor, colesevelam, and bromocriptine may also involve AMPK activation, which warrants further evaluation. Berberine, salicylates, and resveratrol are newer promising agents in the management of diabetes, having well-documented evidence of AMPK stimulation medicated glycemic efficacy. Hence, AMPK-based classification of antidiabetes medications provides a holistic unifying understanding of pharmacotherapy in diabetes. This classification is flexible with a scope for inclusion of promising agents of future.

Ketosis-Prone Type 2 Diabetes: A Case Series

Ketosis-prone type 2 diabetes ("Flatbush diabetes") carries features of both classical type 1 and type 2 diabetes and is highly prevalent in African populations. The disease, which is highly ketosis-prone, but neither chronically insulinopenic nor autoimmune, is discussed regarding pathogenesis, diagnosis and treatment from a patient case perspective.

DIABETIC KETOACIDOSIS: A COMMON DEBUT OF DIABETES AMONG AFRICAN AMERICANS WITH TYPE 2 DIABETES

OBJECTIVE

More than half of African Americans (AA) with a new diagnosis of diabetic ketoacidosis have clinical and metabolic features of type 2 diabetes during follow-up. This particular presentation of diabetes has been termed as ketosis-prone type 2 diabetes (KPDM) or atypical diabetes.

METHODS

We review the epidemiology, diagnosis, pathophysiology, and acute and long-term management of AA with KPDM and compare these similarities to patients with type 2 diabetes.

RESULTS

In contrast to the long-term insulin requirement of auto-immune type 1 diabetes, patients with KPDM are able to discontinue insulin after a few months of therapy and maintain acceptable glycemic control for many years on either diet or oral agents. Patients with KPDM have significant impairment of both insulin secretion and insulin action at presentation; however, at the time of near-normoglycemia remission, insulin secretion and action improve to levels similar to hyperglycemic patients with ketosis-resistant type 2 diabetes. In the long term, however, patients with KPDM have a decline in β-cell function similar to patients with type 2 diabetes. Recent studies indicate that treatment with metformin and dipeptidyl peptidase-4 inhibitors can prolong the period of near-normoglycemia remission for several years compared to placebo therapy.

CONCLUSION

KPDM is a unique but common presentation of newly diagnosed African Americans with type 2 diabetes.

ABBREVIATIONS

A(+/-) = auto-antibody positive/negative AA = African Americans DKA = diabetic ketoacidosis FFA = free fatty acids G6PD = glucose-6-phosphate dehydrogenase GAD-65 = 65-kDA glutamic acid decarboxylase HBA1c = glycated hemoglobin A1c HHV8 = human herpes virus 8 HLA = human leukocyte antigen KPDM = ketosis-prone type 2 diabetes.

The evolution of diabetic ketoacidosis: An update of its etiology, pathogenesis and management

The prognosis of diabetic ketoacidosis has undergone incredibly remarkable evolution since the discovery of insulin nearly a century ago. The incidence and economic burden of diabetic ketoacidosis have continued to rise but its mortality has decreased to less than 1% in good centers. Improved outcome is attributable to a better understanding of the pathophysiology of the disease and widespread application of treatment guidelines. In this review, we present the changes that have occurred over the years, highlighting the evidence behind the recommendations that have improved outcome. We begin with a discussion of the precipitants and pathogenesis of DKA as a prelude to understanding the rationale for the recommendations. A brief review of ketosis-prone type 2 diabetes, an update relating to the diagnosis of DKA and a future perspective are also provided.

Clinical profile of diabetic ketoacidosis in tertiary hospitals in China: a multicentre, clinic-based study

AIMS

To evaluate the clinical profile of patients with diabetic ketoacidosis in tertiary hospitals in China.

METHODS

A retrospective study of patients hospitalized with diabetic ketoacidosis between 2010 and 2012 was carried out in 15 tertiary hospitals around China. Clinical and laboratory data were collected. Patients were classified based on clinical diagnosis and treatment history. Groups were compared for differences in vital statistics and biochemical profiles at presentation.

RESULTS

The study comprised 643 patients with diabetic ketoacidosis: 308 patients (47.9%) with Type 1 diabetes, 294 patients (45.7%) with Type 2 diabetes and 41 patients (6.4%) with atypical diabetes. Three hundred and eighty-eight diabetic ketoacidosis episodes (60.3%) were in patients with known diabetes. The most common precipitating factor was infection (40.1%), followed by unknown causes (36.9%) and non-compliance with anti-diabetes treatment (16.8%). At presentation, gastrointestinal symptoms and dehydration were more common in the Type 1 diabetes group. For new-onset diabetes, only 74.4% and 55.9% of patients were evaluated for β-cell function and autoantibodies for classification. Only 67% of patients with diabetic ketoacidosis received appropriate fluid therapy and 56% patients with severe acidosis received bicarbonate therapy. The length of hospital stay was 10.0 (7.0-14.0) days. The mortality rate was 1.7%, and was much higher in Type 2 diabetes than that in Type 1 diabetes (3.2% vs. 0.4%, P < 0.01).

CONCLUSIONS

Type 2 and Type 1 diabetes contribute to a similar proportion of cases presenting with diabetic ketoacidosis in China. Admissions with diabetic ketoacidosis are still associated with significant mortality and prolonged hospitalization. The efficiency of diabetic ketoacidosis management needs to be improved by implementing the updated guidelines.

THE CLINICAL AND METABOLIC CHARACTERISTICS OF YOUNG-ONSET KETOSIS-PRONE TYPE 2 DIABETES IN CHINA

OBJECTIVE

To investigate the prevalence and clinical characteristics of ketosis-prone type 2 diabetes (KPD) in Chinese patients with young-onset diabetes.

METHODS

A total of 238 young diabetic patients were recruited from our inpatient department from January 1, 2012, to December 28, 2014. KPD was defined as diabetes without precipitating illness and with the presence of ketosis or diabetic ketoacidosis in the absence of autoantibodies at the time of diagnosis. We reviewed the clinical characteristics and disease progression of this group of patients.

RESULTS

Eighteen patients fulfilled the criteria for KPD, and the prevalence of patients with KPD was 7.6%. The mean (SD) age of the KPD group at the time of diagnosis of diabetes was 27.6 (4.85) years, and these patients were predominantly male (male to female ratio, 8:1) and had a high proportion of obesity and new-onset diabetes and a strong family history of diabetes. β-Cell function in the KPD group was intermediate between type 1 and type 2 diabetes. Patients with KPD had the highest levels of glycated hemoglobin, triglycerides, total cholesterol, and free fatty acids and the lowest levels of high-density lipoprotein. After 3 to 12 months of follow-up, 17 of 18 patients with KPD (94.4%) were able to discontinue insulin therapy, and 11 patients (61.1%) were managed with diet or exercise alone.

CONCLUSION

KPD patients accounted for 7.6% of the diabetic patients requiring admission to a large urban hospital in China, with an age of onset of diabetes of ≤35 years. These patients are more likely to be male, have abnormal lipid metabolism, and have more reversible β-cell dysfunction.

Acylation stimulating protein, complement C3 and lipid metabolism in ketosis-prone diabetic subjects

Background

Ketosis-prone diabetes (KPDM) is new-onset diabetic ketoacidosis without precipitating factors in non-type 1 diabetic patients; after management, some are withdrawn from exogenous insulin, although determining factors remain unclear.

Methods

Twenty KPDM patients and twelve type 1 diabetic patients (T1DM), evaluated at baseline, 12 and 24 months with/without insulin maintenance underwent a standardized mixed-meal tolerance test (MMTT) for 2 h.

Results

At baseline, triglyceride and C3 were higher during MMTT in KPDM vs. T1DM (p<0.0001) with no differences in non-esterified fatty acids (NEFA) while Acylation Stimulating Protein (ASP) tended to be higher. Within 12 months, 11 KPDM were withdrawn from insulin treatment (KPDM-ins), while 9 were maintained (KPDM+ins). NEFA was lower in KPDM-ins vs. KPDM+ins at baseline (p = 0.0006), 12 months (p<0.0001) and 24 months (p<0.0001) during MMTT. NEFA in KPDM-ins decreased over 30–120 minutes (p<0.05), but not in KPDM+ins. Overall, C3 was higher in KPDM-ins vs KPDM+ins at 12 months (p = 0.0081) and 24 months (p = 0.0019), while ASP was lower at baseline (p = 0.0024) and 12 months (p = 0.0281), with a decrease in ASP/C3 ratio.

Conclusions

Notwithstanding greater adiposity in KPDM-ins, greater NEFA decreases and lower ASP levels during MMTT suggest better insulin and ASP sensitivity in these patients.

Should diabetic ketosis without acidosis be included in ketosis-prone type 2 diabetes mellitus?

BACKGROUND

The incidence of ketosis-prone type 2 diabetes is very low except for people of sub-Saharan African origin and African Americans. However, there also are some type 2 diabetes patients with diabetic ketosis without acidosis (DKWA). We question whether DKWA should be included as a subtype of ketosis-prone type 2 diabetes mellitus and compared the clinical characteristics of DKWA and diabetic ketoacidosis (DKA) patients.

METHODS

The study population consisted of 594 consecutive unrelated Chinese inpatients with newly diagnosed type 2 diabetes. Demographic and clinical characteristics (age, gender, family history of diabetes, body mass index, blood pressure and plasma lipid parameters) were recorded. The patients were divided into ketosis-resistant diabetes (KRD), DKWA and DKA groups on the basis of urinary ketones, blood pH and bicarbonate levels. The blood glucose and c-peptide levels of the patients were also evaluated.

RESULTS

The prevalence of KRD, DKWA and DKA were 78.33%, 19.72% and 1.95%, respectively, in the study population. The clinical characteristics of patients with DKWA group patients were similar to those with DKA, except that DKA patients had higher blood glucose and deteriorated β cell function.

CONCLUSIONS

Diabetic ketosis without acidosis and DKA patients share similar clinical characteristics; DKWA should be considered ketosis-prone type 2 diabetes. Therefore, the prevalence of ketosis-prone type 2 diabetes might be underestimated.

Diabetic ketoacidosis and hyperglycemic hyperosmolar state

Diabetic ketoacidosis (DKA) and the hyperglycemic hyperosmolar state (HHS) are potentially fatal hyperglycemic crises that occur as acute complications of uncontrolled diabetes mellitus. The authors provide a review of the current epidemiology, precipitating factors, pathogenesis, clinical presentation, evaluation, and treatment of DKA and HHS. The discovery of insulin in 1921 changed the life expectancy of patients with diabetes mellitus dramatically. Today, almost a century later, DKA and HHS remain significant causes of morbidity and mortality across different countries, ages, races, and socioeconomic groups and a significant economic burden for society.

Pathogenesis of A⁻β⁺ ketosis-prone diabetes

A⁻β⁺ ketosis-prone diabetes (KPD) is an emerging syndrome of obesity, unprovoked ketoacidosis, reversible β-cell dysfunction, and near-normoglycemic remission. We combined metabolomics with targeted kinetic measurements to investigate its pathophysiology. Fasting plasma fatty acids, acylcarnitines, and amino acids were quantified in 20 KPD patients compared with 19 nondiabetic control subjects. Unique signatures in KPD--higher glutamate but lower glutamine and citrulline concentrations, increased β-hydroxybutyryl-carnitine, decreased isovaleryl-carnitine (a leucine catabolite), and decreased tricarboxylic acid (TCA) cycle intermediates--generated hypotheses that were tested through stable isotope/mass spectrometry protocols in nine new-onset, stable KPD patients compared with seven nondiabetic control subjects. Free fatty acid flux and acetyl CoA flux and oxidation were similar, but KPD had slower acetyl CoA conversion to β-hydroxybutyrate; higher fasting β-hydroxybutyrate concentration; slower β-hydroxybutyrate oxidation; faster leucine oxidative decarboxylation; accelerated glutamine conversion to glutamate without increase in glutamate carbon oxidation; and slower citrulline flux, with diminished glutamine amide-nitrogen transfer to citrulline. The confluence of metabolomic and kinetic data indicate a distinctive pathogenic sequence: impaired ketone oxidation and fatty acid utilization for energy, leading to accelerated leucine catabolism and transamination of α-ketoglutarate to glutamate, with impaired TCA anaplerosis of glutamate carbon. They highlight a novel process of defective energy production and ketosis in A⁻β⁺ KPD.

Ketosis-onset diabetes and ketosis-prone diabetes: same or not?

Objective. To compare clinical characteristics, immunological markers, and β -cell functions of 4 subgroups ("A β " classification system) of ketosis-onset diabetes and ketosis prone diabetes patients without known diabetes, presenting with ketosis or diabetic ketoacidosis (DKA) and admitted to our department from March 2011 to December 2011 in China, with 50 healthy persons as control group. Results. β -cell functional reserve was preserved in 63.52% of patients. In almost each subgroup (except A-   β - subgroup of ketosis prone group), male patients were more than female ones. The age of the majority of patients in ketosis prone group was older than that of ketosis-onset group, except A-   β - subgroup of ketosis prone group. The durations from the patient first time ketosis or DKA onset to admitting to the hospital have significant difference, which were much longer for the ketosis prone group except the A+ β + subgroup. BMI has no significant difference among subgroups. FPG of ketosis prone group was lower than that of A-   β + subgroup and A+ β + subgroup in ketosis-onset group. A-   β - subgroup and A+ β + subgroup of ketosis prone group have lower HbA1c than ketosis-onset group. Conclusions. Ketosis-onset diabetes and ketosis prone diabetes do not absolutely have the same clinical characteristics. Each subgroup shows different specialty.

Update on diagnosis, pathogenesis and management of ketosis-prone Type 2 diabetes mellitus

Diabetic ketoacidosis (DKA) has been considered a key clinical feature of Type 1 diabetes mellitus; however, increasing evidence indicates that DKA is also a common feature of Type 2 diabetes (T2DM). Many cases of DKA develop under stressful conditions such as trauma or infection but an increasing number of cases without precipitating cause have been reported in children and adults with T2DM. Such patients present with severe hyperglycemia and ketosis as in Type 1 diabetes mellitus but can discontinue insulin after a few months and maintain acceptable glycemic control on diet or oral agents. This subtype of diabetes has been referred to as ketosis-prone T2DM. In this article, we reviewed the literature on ketosis-prone T2DM and summarized the epidemiology, putative pathophysiology and approaches to management.

Family history of type 2 diabetes is increased in patients with type 1 diabetes

It has been suggested that type 1 (T1D) and type 2 diabetes (T2D) might share some susceptibility risk factors. A higher prevalence of T2D has been reported in families of Caucasian T1D children than in the general population, although data in adults and multiethnic groups is still lacking. Our goal was to compare the prevalence of T2D family history between adults with T1D from a multiethnic population and a non-diabetic control group. We performed a cross-sectional analysis of 145 adults with T1D and 141 healthy adults (control group) that included an interview and a review of the medical charts. Groups were matched for age, sex, ethnicity and body mass index (BMI). We found a higher prevalence of not only T1D but also T2D in first-degree relatives of patients than in controls (p<0.001 and p=0.042, respectively). These differences were not observed for second/third-degree relatives. When subjects were stratified according to their ethnicity, the higher frequency of T2D in FDR of patients than controls became more striking in non-white (p=0.002) and disappeared in white individuals (p=0.85). To conclude, the prevalence of T1D and T2D was higher in first-degree relatives of patients with T1D than of controls. The difference in T2D family history between patients and controls was specially striking among non-whites, which may represent a peculiarity of T1D in this group.

Thirty years of personal experience in hyperglycemic crises: diabetic ketoacidosis and hyperglycemic hyperosmolar state

CONTEXT

Diabetic ketoacidosis (DKA) and hyperglycemic hyperosmolar state (HHS) cause major morbidity and significant mortality in patients with diabetes mellitus. For more than 30 yr, our group, in a series of prospective, randomized clinical studies, has investigated the pathogenesis and evolving strategies of the treatment of hyperglycemic crises. This paper summarizes the results of these prospective studies on the management and pathophysiology of DKA.

SETTING

Our earliest studies evaluated the comparative efficacy of low-dose vs. pharmacological amounts of insulin and the use of low-dose therapy by various routes in adults and later in children. Subsequent studies evaluated phosphate and bicarbonate therapy, lipid metabolism, ketosis-prone type 2 patients, and use of rapid-acting insulin analogs as well as leptin status, cardiac risk factors, proinflammatory cytokines, and the mechanism of activation of T lymphocytes in hyperglycemic crises.

MAIN OUTCOME

The information garnered from these studies resulted in the creation of the 2001 American Diabetes Association (ADA) technical review on DKA and HHS as well as the ADA Position and Consensus Paper on the therapy for hyperglycemic crises.

CONCLUSIONS

Areas of future research include prospective randomized studies to do the following: 1) establish the efficacy of bicarbonate therapy in DKA for a pH less than 6.9; 2) establish the need for a bolus insulin dose in the initial therapy of DKA; 3) determine the pathophysiological mechanisms for the absence of ketosis in HHS; 4) investigate the reasons for elevated proinflammatory cytokines and cardiovascular risk factors; and 5) evaluate the efficacy and cost benefit of using sc regular insulin vs. more expensive insulin analogs on the general ward for the treatment of DKA.

Ketosis-prone type 2 diabetes: effect of hyperglycemia on beta-cell function and skeletal muscle insulin signaling

OBJECTIVE

To determine the underlying mechanism for the severe and transient beta-cell dysfunction and impaired insulin action in obese African American patients with ketosis-prone diabetes.

METHODS

The effect of sustained hyperglycemia (glucotoxicity) and increased free fatty acids (lipotoxicity) on beta-cell function was assessed by changes in insulin secretion during a 20-hour glucose (200 mg/m2 per minute) and a 48-hour Intralipid (40 mL/h) infusion, respectively. Insulin-activated signaling pathways and pattern of Akt-1 and Akt-2 expression and insulin-stimulated phosphorylation were analyzed in skeletal muscle biopsy specimens. Studies were performed in an obese African American woman within 48 hours after resolution of diabetic ketoacidosis and 1 week after discontinuation of insulin treatment.

RESULTS

Dextrose infusion rapidly increased C-peptide levels from a baseline of 3.2 ng/mL to a mean of 7.1 +/- 0.5 ng/mL during the first 8 hours of infusion; thereafter, C-peptide levels progressively declined. Lipid infusion was not associated with any deleterious effect on insulin and C-peptide secretion. Initial in vitro stimulation of muscle tissue with insulin resulted in a substantial and selectively decreased Akt-2 expression and insulin-stimulated phosphorylation on the serine residue. Improved metabolic control resulted in 70% greater Akt expression at near-normoglycemic remission in comparison with the period of hyperglycemia.

CONCLUSION

Hyperglycemia, but not increased free fatty acid levels, led to progressive beta-cell dysfunction and impaired insulin secretion. Hyperglycemia was also associated with diminished skeletal muscle Akt expression and phosphorylation in an African American woman with ketosis-prone diabetes, and this defect improved notably with aggressive insulin therapy. These results indicate the importance of glucose toxicity in the pathogenesis of ketosis-prone diabetes in obese African American patients.

Relato de caso: diabetes Flatbush - da cetoacidose ao tratamento não-farmacológico

Um subgrupo de pacientes, em sua maioria negros ou hispânicos e obesos, tem a cetoacidose diabética (CAD) como forma de apresentação de diabetes mellitus (DM), mas, devido à sua evolução clínica, posteriormente é classificado como DM tipo 2. Estes indivíduos têm pesquisa de auto-anticorpos anti-GAD, anti-IA2 e anti-insulina negativa, mas freqüentemente em associação com HLA classe II de risco para DM tipo 1 (DRB1*03 e/ou DRB1*04). Este subtipo peculiar de DM é denominado diabetes flatbush. Neste artigo, relatamos o caso de uma paciente de origem caucasiana com tais características, na qual foi possível retirada da insulinoterapia. Os possíveis fatores associados a esta evolução favorável serão discutidos.

Admissions for diabetic ketoacidosis in ethnic minority groups in a city hospital

Hospitalization for diabetic ketoacidosis (DKA) is increasing, perhaps due to the rising incidence of DKA in patients with type 2 diabetes mellitus (T2DM). Ethnic minority groups are at increased risk for T2DM. This study aimed at elucidating the characteristics of patients with ketosis-prone diabetes in a predominantly ethnic minority population. We performed a retrospective analysis of adults admitted with DKA at the Bronx Lebanon Hospital Center, Bronx, NY over 3 years. The patients were divided into cohorts based on type of diabetes and ethnicity. The cohorts were described and compared using statistical methods. We recorded 219 cases of DKA in 168 patients, 97% of whom were African American or Hispanic. Fifty-three (32%) patients had T2DM. New-onset diabetes, which was more common in T2DM (P < .0001), and African Americans (P = .008), occurred in 42 patients (25%). Readmission with DKA was more common in the Hispanic patients with type 1 diabetes mellitus (T1DM) (P = .0001). Type 2 diabetes mellitus was more prevalent in the African Americans (P = .04). Patients with T1DM had more severe acidosis than patients with T2DM (lower pH and bicarbonate and larger anion gap; P = .03, .02, and .005, respectively). Creatinine level was higher in patients with T2DM (P = .04) who were also less likely to have identifiable precipitating causes (P = .02). Hemoglobin A(1c) level was higher in patients with new-onset diabetes (P < .05), but did not differ between those with T1DM and T2DM. Mortality, which was 2%, occurred only in the African Americans with T2DM. We conclude that DKA is an important mode of initial presentation of T2DM, with new-onset T2DM accounting for about 60% of all new cases of DKA. African American patients with T2DM, in comparison with the Hispanic patients, are more susceptible to developing DKA. Diabetic ketoacidosis could occur in T2DM without any identifiable precipitant. The rising incidence of DKA may be attributable to its increasing occurrence in T2DM; therefore, measures aimed at primary prevention of T2DM are worthwhile.

Hyperglycemic crises in diabetes mellitus: diabetic ketoacidosis and hyperglycemic hyperosmolar state

Diabetic ketoacidosis (DKA) and hyperglycemic hyperosmolar state (HHS) potentially are fatal but largely preventable acute metabolic conditions of uncontrolled diabetes, the incidence of which continues to increase. Mortality from DKA has declined remarkably over the years because of better understanding of its pathophysiology and treatment. The mortality rate of HHS remains alarmingly high, however, owing to older age and mode of presentation of patients and associated comorbid conditions. DKA and HHS also are economically burdensome; therefore, any resources invested in their prevention would be rewarding.

Accuracy and predictive value of classification schemes for ketosis-prone diabetes

OBJECTIVE

Ketosis-prone diabetes (KPD) is an emerging, heterogeneous syndrome. A sound classification scheme for KPD is essential to guide clinical practice and pathophysiologic studies. Four schemes have been used and are based on immunologic criteria, immunologic criteria and insulin requirement, BMI, and immunologic criteria and beta-cell function (Abeta classification). The aim of the present study is to compare the four schemes for accuracy and predictive value in determining whether KPD patients have absent or preserved beta-cell function, which is a strong determinant of long-term insulin dependence and clinical phenotype.

RESEARCH DESIGN AND METHODS

Consecutive patients (n = 294) presenting with diabetic ketoacidosis and followed for 12-60 months were classified according to all four schemes. They were evaluated longitudinally for beta-cell autoimmunity, clinical and biochemical features, beta-cell function, and insulin dependence. beta-Cell function was defined by peak plasma C-peptide response to glucagon >or=1.5 ng/ml. The accuracy of each scheme to predict absent or preserved beta-cell function after 12 months of follow-up was tested using multiple statistical analyses.

RESULTS

The "Abeta" classification scheme was the most accurate overall, with a sensitivity and specificity of 99.4 and 95.9%, respectively, positive and negative likelihood ratios of 24.55 and 0.01, respectively, and an area under the receiver operator characteristic curve of 0.972.

CONCLUSIONS

The Abeta scheme has the highest accuracy and predictive value in classifying KPD patients with regard to clinical outcomes and pathophysiologic subtypes.

Diabetes mellitus in children and adolescents

Until recently, diabetes in children was virtually synonymous with type 1 diabetes mellitus, whereas type 2 diabetes was a disease of middle age and the elderly. Over the past 10-20 years, an alarming increase in the prevalence of type 2 diabetes has been reported from pediatric diabetes centers in North America and elsewhere in the world. Lifestyle factors responsible for the worldwide epidemic of overweight and obesity are responsible for the increase in the prevalence of type 2 diabetes in adults and children. This article briefly discusses the diagnosis and major types of diabetes in children but focuses on aspects of type 2 diabetes in children and adolescents, including demographics, pathophysiology, clinical presentation, screening, prevention and treatment. The identification of children at risk for type 2 diabetes and the implementation of community-wide preventive programs will be essential to reverse the tide. The availability of calorie dense "fast foods," candy, and sugared soft drinks must be restricted in schools and other venues frequented by children. Parents must limit the amount of time their children spend watching television and playing computer games. After-school programs that promote physical activity should be a priority of local and central governmental agencies. Prevention will only succeed if governments and local communities recognize that childhood obesity is an important public health problem and provide an environment that promotes changes in lifestyle that prevent and reverse obesity.

Improved glycemic control in subjects with atypical diabetes results from restored insulin secretion, but not improved insulin sensitivity

African-American subjects often present with hyperglycemic crisis (diabetic ketoacidosis or severe hyperglycemia), yet subsequently are treated without insulin. The pathophysiology of this unique condition is unknown. We hypothesized that recovery from atypical diabetes with intensive insulin therapy resulted from a reversal of a defect in beta-cell function and improved insulin sensitivity. We studied eight newly diagnosed, antibody-negative African-American subjects (age, 34-56 yr) who presented with hyperglycemic crisis. Subjects were studied at baseline after overnight glycemic control and again after 3 wk and 3 months of intensive insulin therapy. Insulin sensitivity (SI) was determined from an insulin-modified, frequently sampled i.v. glucose tolerance test, and insulin secretion was measured as the acute insulin response to glucose and to a glucagon stimulation test. Fructosamine and hemoglobin A1c declined significantly with intensive insulin therapy, and insulin requirements decreased over time. Both acute insulin response to glucose and the C peptide response to glucagon stimulation test improved by 3 wk (P = 0.02 vs. baseline), and improvements were maintained at 3 months (P = 0.02 vs. baseline). In contrast, the SI remained low throughout the study. We demonstrate that improved glycemic control correlates with a remarkable recovery of beta-cell function, but no change in SI.

PAX4 gene variations predispose to ketosis-prone diabetes

Ketosis-prone diabetes (KPD) is a rare form of type 2 diabetes, mostly observed in subjects of west African origin (west Africans and African-Americans), characterized by fulminant and phasic insulin dependence, but lacking markers of autoimmunity observed in type 1 diabetes. PAX4 is a transcription factor essential for the development of insulin-producing pancreatic beta-cells. Recently, a missense mutation (Arg121Trp) of PAX4 has been implicated in early and insulin deficient type 2 diabetes in Japanese subjects. The phenotype similarities between KPD and Japanese carriers of Arg121Trp have prompted us to investigate the role of PAX4 in KPD. We have screened 101 KPD subjects and we have found a new variant in the PAX4 gene (Arg133Trp), specific to the population of west African ancestry, and which predisposes to KPD under a recessive model. Homozygous Arg133Trp PAX4 carriers were found in 4% of subjects with KPD but not in 355 controls or 147 subjects with common type 2 or type 1 diabetes. In vitro, the Arg133Trp variant showed a decreased transcriptional repression of target gene promoters in an alpha-TC1.6 cell line. In addition, one KPD patient was heterozygous for a rare PAX4 variant (Arg37Trp) that was not found in controls and that showed a more severe biochemical phenotype than Arg133Trp. Clinical investigation of the homozygous Arg133Trp carriers and of the Arg37Trp carrier demonstrated a more severe alteration in insulin secretory reserve, during a glucagon-stimulation test, compared to other KPD subjects. Together these data provide the first evidence that ethnic-specific gene variants may contribute to the predisposition to this particular form of diabetes and suggest that KPD, like maturity onset diabetes of the young, is a rare, phenotypically defined but genetically heterogeneous form of type 2 diabetes.