Immunogenetic analysis suggests different pathogenesis for obese and lean African-Americans with diabetic ketoacidosis

HLA-DRB1*08 allele may help to distinguish between type 1 diabetes mellitus and type 2 diabetes mellitus in Mexican children

BACKGROUND

It may be difficult to distinguish type 1 diabetes mellitus (T1DM) from type 2 diabetes mellitus (T2DM) in the pediatric population. Autoantibodies may help to differentiate both types of diabetes, but sometimes these are positive in patients with T2DM and negative in patients with T1DM. The human leukocyte antigen (HLA)-DR genotype has been associated with T1DM and with T2DM only in adults and in determined cases.

AIM

To determine the differences in HLA class II allele frequencies in Mexican children with T1DM and T2DM.

METHODS

We included 72 children with T1DM, 28 children with T2DM, and 99 healthy controls. All were Mexican, and diabetes was diagnosed according to the clinical and laboratory criteria established by the Expert Committee on the Diagnosis and Classification of Diabetes Mellitus. The HLA-DRB1 typing was performed using polymerase chain reaction-sequence-specific oligonucleotide probe and polymerase chain reaction sequence-specific primers.

RESULTS

We found an increased frequency of HLA-DRB1*08 and a decreased frequency of HLA-DRB1*04 in the group with T2DM vs. T1DM [p = 0.0001, odds ratio (OR) = 10.58, 95% confidence interval (CI) = 3-40.8 and p = 0.0006, OR = 0.24, 95% CI = 0.11-0.53, respectively]. No significant differences were found between HLA-DRB1 alleles in T2DM vs. controls. In the group with T1DM, there was a significantly increased frequency of the HLA-DR4 and HLA-DR3 alleles relative to controls (p = 0.0000001, OR = 3.59, 95% CI = 2.2-5.8 and p = 0.00009, OR = 4.66, 95% CI = 2.1-10.3, respectively).

CONCLUSION

There are significant differences in the HLA profile in Mexican children with T1DM and T2DM. HLA typing could play a role in the differentiation between both types of diabetes in this population.

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.

Presence of the metabolic syndrome distinguishes patients with ketosis-prone diabetes who have a Type 2 diabetic phenotype

OBJECTIVE

This study was designed to determine if patients with ketosis-prone diabetes could be distinguished clinically on the basis of features of the metabolic syndrome (MetS).

METHODS

Participants with ketosis-prone diabetes admitted to our institution during a 3-year period were studied. One hundred seventy-two patients from four ethnic backgrounds were divided into two groups: with or without MetS, as defined by the World Health Organization. Pearson's chi-square test or one-way ANOVA was used as appropriate to evaluate group differences.

RESULTS

Of the 172 patients, 74 (43%) had at least three characteristics of MetS (+MetS group), while 98 (57%) had less than three characteristics of MetS (-MetS group). The +MetS group had significantly higher beta-cell functional reserve as measured by the glucagon stimulation test [area under the curve (AUC) for C-peptide levels 19.50+/-2.26 compared with 8.66+/-1.66 ng/ml over 10 min; P=.0001]. A significantly higher proportion of patients in the +MetS group had preserved beta-cell functional reserve than in the -MetS group (70% compared with 30%; P<.00001). After 12 months of follow-up, +MetS patients had significantly lower HbA1c levels (8.3+/-0.4% compared with 9.8+/-0.4%; P=.01) and higher C-peptide/glucose ratios (2.01+/-0.28 compared with 1.14+/-0.21; P=.02) than the -MetS patients did.

CONCLUSIONS

Patients with ketosis-prone diabetes with the MetS are more likely to have features associated with Type 2 diabetes, despite having developed diabetic ketoacidosis (DKA), with better beta-cell functional reserve and glycemic control after the index DKA episode.

Pathophysiology of ketoacidosis in Type 2 diabetes mellitus

AIMS

Despite an increasing number of reports of ketoacidosis in populations with Type 2 diabetes mellitus, the pathophysiology of the ketoacidosis in these patients is unclear. We therefore tested the roles of three possible mechanisms: elevated stress hormones, increased free fatty acids (FFA), and suppressed insulin secretion.

METHODS

Forty-six patients who presented to the Emergency Department with decompensated diabetes (serum glucose > 22.2 mmol/l and/or ketoacid concentrations > or = 5 mmol/l), had blood sampled prior to insulin therapy. Three groups of subjects were studied: ketosis-prone Type 2 diabetes (KPDM2, n = 13) with ketoacidosis, non-ketosis-prone subjects with Type 2 diabetes (DM2, n = 15), and ketotic Type 1 diabetes (n = 18).

RESULTS

All three groups had similar mean plasma glucose concentrations. The degree of ketoacidosis (plasma ketoacids, bicarbonate and anion gap) in Type 1 and 2 subjects was similar. Mean levels of counterregulatory hormones (glucagon, growth hormone, cortisol, epinephrine, norepinephrine), and FFA were not significantly different in DM2 and KPDM2 patients. In contrast, plasma C-peptide concentrations were approximately three-fold lower in KPDM2 vs. non-ketotic DM2 subjects (P = 0.0001). Type 1 ketotic subjects had significantly higher growth hormone (P = 0.024) and FFA (P < 0.002) and lower glucagon levels (P < 0.02) than DM2.

CONCLUSIONS

At the time of hospital presentation, the predominant mechanism for ketosis in KPDM2 is likely to be greater insulinopenia.

Ethnic differences predicting ketonuria in patients with Type 2 diabetes

Ketonuria occurs more frequently than ketoacidosis does in patients with Type 2 diabetes and may portend serious future events. We studied the correlates of ketonuria among African American and Hispanic/Latino patients with Type 2 diabetes who did not have ketoacidosis.

METHODS

We performed a retrospective cross-sectional study of patients referred for diabetes education from the emergency department or the urgent care clinic of a large, public, urban hospital from 2001 until 2003. Eligible patients had newly diagnosed Type 2 diabetes or diabetes diagnosed within 15 years but without treatment for the previous 2 months. Using logistic regression analysis, we analyzed the predictors of ketonuria and assessed whether they varied by ethnic group.

RESULTS

Of 228 adult African American and Hispanic/Latino patients, 112 (49%) had ketonuria. Independent predictors of ketonuria were younger age (OR: 2.3), higher hemoglobin A(1c) (OR: 3.0), and a history of substance abuse (OR: 1.9) (for all: P<.05). Among Hispanic/Latino patients, ketonuria was also independently associated with low HDL-cholesterol (adjusted OR: 6.6; 95% CI: 2-20), but this relationship was not seen in African American patients.

CONCLUSIONS

Ketonuria is common among newly diagnosed or untreated patients with Type 2 diabetes in a public hospital serving a predominantly minority population. Some correlates of ketonuria differ among ethnic groups, suggesting potential ethnic differences in ketogenesis. Prospective identification and study of patients with ketonuria may have important implications for appropriate therapy, especially if it is shown that ketonuria is a predictor of symptomatic ketoacidosis.

Diabetic ketoacidosis: risk factors and management strategies

Diabetic ketoacidosis (DKA) is the most common hyperglycemic emergency in patients with diabetes mellitus. DKA most often occurs in patients with type 1 diabetes, but patients with type 2 diabetes are susceptible to DKA under stressful conditions, such as trauma, surgery, or infections. DKA is reported to be responsible for more than 100 000 hospital admissions per year in the US, and accounts for 4-9% of all hospital discharge summaries among patients with diabetes. Treatment of patients with DKA uses significant healthcare resources and accounts for 1 out of every 4 healthcare dollars spent on direct medical care for adult patients with type 1 diabetes in the US. Recent studies using standardized written guidelines for therapy have demonstrated a mortality rate of less than 5%, with higher mortality rates observed in elderly patients and those with concomitant life-threatening illnesses. Worldwide, infection is the most common precipitating cause for DKA, occurring in 30-50% of cases. Urinary tract infection and pneumonia account for the majority of infections. Other precipitating causes are intercurrent illnesses (i.e., surgery, trauma, myocardial ischemia, pancreatitis), psychological stress, and non-compliance with insulin therapy. The triad of uncontrolled hyperglycemia, metabolic acidosis and increased total body ketone concentration characterizes DKA. These metabolic derangements result from the combination of absolute or relative insulin deficiency and increased levels of counter-regulatory hormones (glucagon, catecholamines, cortisol, and growth hormone). Successful treatment of DKA requires frequent monitoring of patients, correction of hypovolemia and hyperglycemia, replacement of electrolyte losses, and careful search for the precipitating cause. Since the majority of DKA cases occur in patients with a known history of diabetes, this acute metabolic complication should be largely preventable through early detection, and by the education of patients, healthcare professionals, and the general public. The frequency of hospitalizations for DKA has been reduced following diabetes education programs, improved follow-up care, and access to medical advice. Novel approaches to patient education incorporating a variety of healthcare beliefs and socioeconomic issues are critical to an effective prevention program.

Predictors of glycaemic control in indigent patients presenting with diabetic ketoacidosis

AIM

To derive predictors of good glycaemic control in patients presenting with diabetic ketoacidosis (DKA) followed prospectively in a specialized clinic.

METHODS

One hundred and sixty-one adult patients were admitted during a 31-month period and followed for at least 12 months. After 1 year, the patients were classified into three groups: good control (GC) (HbA1c < or = 7%), intermediate control (IC) (HbA1c 7-9%) and poor control (PC) (HbA1c > 9%). Characteristics of patients in the three groups were compared both at baseline and during follow-up.

RESULTS

At 12 months, 36% of the patients were classified as GC, 27% as IC and 37% as PC. GC patients had higher fasting serum C-peptide levels 0.7 +/- 0.54 compared to 0.38 +/- 0.29 and 0.16 +/- 0.21 nmol/l, respectively, for the IC and PC patients (p < 0.0001). A higher proportion GC patient had a C-peptide level greater than 0.33 nmol/l than that for IC and PC patients (86, 61 and 19%, respectively; p < 0.0001). Exogenous insulin was safely discontinued in 50, 30 and 3% of patients, respectively, in the GC, IC and PC groups (p < 0.0001). Compliance with life-style interventions was higher in the GC than that in IC and PC patients (87, 41 and 5%, respectively; p < 0.0001). In the logistic regression analysis, predictors of good glycaemic control were having baseline fasting serum C-peptide value > or =0.33 mmol/l, OR: 3.01 (95% CI 1.07-8.55, p = 0.03) and compliance with life-style interventions OR 12.66 (95% CI 3.73-51.57, p = 0.0001).

CONCLUSION

Among adult patients with DKA, significant predictors of good glycaemic control are preserved beta-cell function and compliance with life-style modifications.

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.

Acquired non-type 1 diabetes in childhood: subtypes, diagnosis, and management

Over the past 30 years it has become apparent that not all diabetes presenting in childhood is autoimmune type 1. Increasingly type 2 diabetes, maturity onset diabetes of the young, iatrogenic diabetes, and rare syndromic forms of diabetes such as Wolfram's syndrome have been identified in children. This review is aimed at the general paediatrician looking after children with diabetes, and aims to provide an algorithm for assessment, investigation, and suggested management for the newly diagnosed child with suspected non-type 1 diabetes. This article will also be relevant to the child with atypical diabetes-that is, on low insulin doses outside the honeymoon period.

Ketosis-prone type 2 diabetes in patients of sub-Saharan African origin: clinical pathophysiology and natural history of beta-cell dysfunction and insulin resistance

Nonautoimmune ketosis-prone diabetic syndromes are increasingly frequent in nonwhite populations. We have characterized a cohort of patients of sub-Saharan African origin who had ketosis-prone type 2 diabetes (n = 111), type 1 diabetes (n = 21), and type 2 diabetes (n = 88) and were admitted to a hospital for management of uncontrolled diabetes. We compared epidemiological, clinical, and metabolic features at diabetes onset and measured insulin secretion (glucagon-stimulated C-peptide) and insulin action (short intravenous insulin tolerance test) during a 10-year follow-up. Ketosis-prone type 2 diabetes shows a strong male predominance, stronger family history, higher age and BMI, and more severe metabolic decompensation than type 1 diabetes. In ketosis-prone type 2 diabetes, discontinuation of insulin therapy with development of remission of insulin dependence is achieved in 76% of patients (non-insulin dependent), whereas only 24% of patients remain insulin dependent. During evolution, ketosis-prone type 2 diabetes exhibit specific beta-cell dysfunction features that distinguish it from type 1 and type 2 diabetes. The clinical course of non-insulin-dependent ketosis-prone type 2 diabetes is characterized by ketotic relapses followed or not by a new remission. Progressive hyperglycemia precedes and is a strong risk factor for ketotic relapses (hazard ratio 38). The probability for non-insulin-dependent ketosis-prone type 2 diabetes to relapse is 90% within 10 years, of whom approximately 50% will become definitively insulin dependent. Insulin sensitivity is decreased in equal proportion in both ketosis-prone type 2 diabetes and type 2 diabetes, but improves significantly in non-insulin-dependent ketosis-prone type 2 diabetes, only after correction of hyperglycemia. In conclusion, ketosis-prone type 2 diabetes can be distinguished from type 1 diabetes and classical type 2 diabetes by specific features of clinical pathophysiology and also by the natural history of beta-cell dysfunction and insulin resistance reflecting a propensity to glucose toxicity.

Ketosis-prone diabetes: dissection of a heterogeneous syndrome using an immunogenetic and beta-cell functional classification, prospective analysis, and clinical outcomes

Ketosis-prone diabetes is heterogeneous. Its causes could include novel beta-cell functional defects. To characterize such defects, 103 patients with diabetic ketoacidosis were evaluated for beta-cell autoimmunity and human leukocyte antigen (HLA) class II alleles, with longitudinal measurements of beta-cell function and biochemical and clinical parameters. They were classified into four A beta groups, based on the presence of glutamic acid decarboxylase (GAD)65, GAD67, or IA-2 autoantibodies (A+ or A-) and beta-cell functional reserve (beta+ or beta-). The group distribution was: 18 A+beta-, 23 A-beta-, 11 A+beta+, and 51 A-beta+. Collectively, the two beta- groups differed from the two beta+ groups in earlier onset and longer duration of diabetes, lower body mass index, less glycemic improvement, and persistent insulin requirement. HLA class II genotyping showed that the A-beta- group differed from the A+beta- group in having lower frequencies of two alleles strongly associated with autoimmune type 1 diabetes susceptibility: DQA*03 and DQB1*02. Similarly, the A-beta+ group differed from the A+beta+ group in having a lower frequency of DQB1*02. Ketosis-prone diabetes comprises at least four etiologically distinct syndromes separable by autoantibody status, HLA genotype, and beta-cell functional reserve. Novel, nonautoimmune causes of beta-cell dysfunction are likely to underlie the A-beta+ and A-beta- syndromes.

Economic impact of diabetic ketoacidosis in a multiethnic indigent population: analysis of costs based on the precipitating cause

OBJECTIVE

Diabetic ketoacidosis (DKA) is a common complication of diabetes. We analyzed the inpatient costs of treating DKA in a multiethnic, indigent population in Houston, Texas.

RESEARCH DESIGN AND METHODS

We measured the cost of resources utilized for all patients admitted to our hospital with DKA from 1 January to 31 December 1998. We also analyzed their medical records to determine the factors that precipitated the episode of DKA and then grouped them into three categories: acute illnesses, noncompliance with diabetes treatment, and new-onset diabetes. The data were analyzed by one-way ANOVA. The Tukey-Kramer procedure was used for post hoc multiple comparisons.

RESULTS

There were 167 admissions for DKA. The mean age was 40 +/- 13 years. The ethnic distribution was 49% African American, 32% Hispanic American, and 18% white. The total inhospital cost of treating DKA was $1,816,255. The mean cost per hospitalization was $10, 876 +/- 11,024. The frequency distribution by category of DKA-precipitating factor was 18% acute illness, 59% noncompliance, and 23% new onset. There were differences in mean cost of DKA associated with the three categories: $20,864 +/- 17,910 for acute illness, $11,863 +/- 8,701 for new onset, and $7,470 +/- 6,300 for noncompliance (P < 0.0001). The total cost for each category was $671,375 for acute illness, $694,082 for noncompliance, and $450,798 for new onset.

CONCLUSIONS

DKA is an expensive complication among indigent, multiethnic diabetic patients. Although the mean cost per admission was lowest for DKA precipitated by noncompliance, this causal category was responsible in sum for the greatest portion of the economic burden.

Diabetic ketoacidosis associated with Metabolife: a report of two cases

AIM

To describe two cases of diabetic ketoacidosis in newly diagnosed type 1- and type-2-diabetic individuals associated with Metabolife-356.

METHODS

We report the acute hospitalizations and clinical courses of two individuals with diabetic ketoacidosis taking Metabolife-356.

RESULTS

Both patients presented without a previous diagnosis of diabetes mellitus. One patient clinically has type 1 diabetes (positive islet cell antibodies and subnormal pancreatic beta cell function to glucagon stimulation) and is treated with insulin. The second patient, after 5 days of treatment with intravenous insulin of up to 25 units per hour, is now treated with oral medications. Several possible mechanisms may exist, including the increases in catecholamines and in blood glucose after ingestion of the ingredients of these supplements. Recent clinical trial data shows an increase in blood glucose (in non-diabetics) with these supplements despite significant weight loss at 8 weeks, although no association with diabetes mellitus has been shown in these closely monitored studies.

CONCLUSIONS

Although no precipitating factor of diabetic ketoacidosis was found in these individuals, the dietary supplement Metabolife cannot be established as a precipitant. However, patients with diabetes should take this supplement only after consultation with their health care provider, as stated on the product label. Most individuals using this supplement meet the current criteria for screening to detect undiagnosed diabetes mellitus and should consider these tests.

Metabolic and immunogenetic prediction of long-term insulin remission in African patients with atypical diabetes

AIMS

We aimed to characterize a cohort of 'atypical' diabetic patients of sub-Saharan African origin and to analyse possible determinants of long-term remission.

METHODS

Over 6 years, we studied the clinical and therapeutic profile of 42 consecutive patients undiagnosed or untreated prior to inclusion presenting with cardinal features of diabetes mellitus. We measured insulin secretion and sensitivity at inclusion. Immunogenetic (anti-GAD, anti-ICA and HLA class II) markers of Type 1 diabetes were compared with a 90-non-diabetic unrelated adult African population.

RESULTS

Twenty-one ketonuric patients (age 42 +/- 9 (sd) years; body mass index (BMI) 26 +/- 3 kg/m2) were initially insulin-treated (IT), and 21 non-ketonuric patients (age 38 +/- 8 years; BMI 26 +/- 5 kg/m2) had oral and/or diet therapy (NIT). Insulin could be discontinued in 47.6% (10/21) IT with adequate glycaemic control (HbA1c 6.7 +/- 1.3%), while insulin was secondarily started in 38.1% (8/21) NIT in expectation of better control. The initial basal (odds ratio (OR) 9.1, 95% confidence interval (CI) 1.3-64.4) and stimulated C-peptide (OR 8.17, 95% CI 1.5-44.1) were independently associated with remission. Insulin resistance was present in all the groups, more marked in the insulin-treated NIT. Anti-GAD antibodies and ICA were rare, but 38.1% IT vs. 1.1% controls had Type 1 diabetes HLA susceptibility haplotypes (P < 0.001) without significant difference between the subgroups.

CONCLUSION

Prolonged discontinuation of insulin is frequent in African diabetic patients initially presenting with signs of insulinopenia. In our patients, long-term insulin therapy was not associated with immunogenetic markers of Type 1 diabetes. The initial measure of insulin secretion seemed a good predictor of long-term remission.

Diabetic ketoacidosis and hyperglycemic hyperosmolar nonketotic syndrome

Diabetic ketoacidosis (DKA) and hyperglycemic hyperosmolar nonketotic syndrome (HHNS) are life-threatening acute metabolic complications of diabetes mellitus. Although there are some important differences, the pathophysiology, the presenting clinical challenge, and the treatment of these metabolic derangements are similar. Each of these complications can be seen in type 1 or type 2 diabetes, although DKA is usually seen in patients with type 1 diabetes and HHNS in patients with type 2 disease. The clinical management of these syndromes involves careful evaluation and correction of the metabolic and volume status of the patient, identification and treatment of precipitating and comorbid conditions, a smooth transition to a long-term treatment regimen, and a plan to prevent recurrence.