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

Type 1 diabetes in low and middle-income countries - Tanzania a streak of hope

INTRODUCTION

In several of the Low and Middle Income countries , many patients with Type 1 diabetes (T1D) are most probably not diagnosed at all which may contribute to their low incidence. As an example of a country with low income and poor resources, we have chosen to study T1D in children/young people in Tanzania.

METHODS

Analyses of casebooks and statistics at several Tanzanian hospitals treating young patients with insulin dependent diabetes, usually Type 1 diabetes, and collection of information from different organisations such a Tanzanian Diabetes Association, Life for a Child, Changing Diabetes in Children and World Diabetes Foundation.

RESULTS

The incidence in several areas is low. However, a lot of data are often missing at studied clinics and therefore the incidence might be higher, and with increased awareness in recent years the number of patients has increased many-folds. Most patients present with typical symptoms and signs of T1D, and a high proportion with plausible ketoacidosis , although this proportion has decreased from about 90% to about 40% in recent decades. Many patients have poor blood glucose control, and complications often develop already after short diabetes duration. In recent years resources have increased, awareness has increased and diabetes clinics started where staff has got training.

CONCLUSIONS

There are problems with diabetes care in Tanzania but several facts give hope for the future.

When Sugar Reaches the Liver: Phenotypes of Patients with Diabetes and NAFLD

Type 2 diabetes mellitus (T2DM) and non-alcoholic fatty liver disease (NAFLD) have been traditionally linked to one another. Recent studies suggest that NAFLD may be increasingly common in other types of diabetes such as type 1 diabetes (T1DM) and less frequently ketone-prone and Maturity-onset Diabetes of the Young (MODY) diabetes. In this review, we address the relationship between hyperglycemia and insulin resistance and the onset and progression of NAFLD. In addition, despite the high rate of patients with T2DM and other diabetes phenotypes that can alter liver metabolism and consequently develop steatosis, fibrosis, and cirrhosis, NALFD screening is not still implemented in the daily care routine. Incorporating a clinical algorithm created around a simple, non-invasive, cost-effective model would identify high-risk patients. The principle behind managing these patients is to improve insulin resistance and hyperglycemia states with lifestyle changes, weight loss, and new drug therapies.

Long-term changes in carbohydrate tolerance, insulin secretion and action in African-American patients with obesity and history of hyperglycemic crises

INTRODUCTION

Many African-Americans (AA) with obesity with newly diagnosed diabetes presenting with diabetic ketoacidosis (DKA) or severe hyperglycemia (SH) discontinue insulin therapy and achieve near-normoglycemia remission (hemoglobin A1c (HbA1c) <7%, fasting blood glucose (FBG) <130 mg/dL) and able to be managed on oral antidiabetic agents (OAD) during follow-up. Using combined data from two randomized controlled trials, we assessed long-term carbohydrate tolerance and changes in insulin sensitivity and insulin secretion.

RESEARCH DESIGN AND METHODS

Seventy-five participants with DKA (n=33) and SH (n=42) underwent 2-hour 75 g oral glucose tolerance test (OGTT) after insulin discontinuation and every 6 months until hyperglycemia relapse (FBG ≥130 mg/dL, HbA1c >7% or two random BG ≥180 mg/dL) while treated with OAD (metformin, sitagliptin or pioglitazone) or placebo. Glucose tolerance status was defined as per the American Diabetes Association. Sensitivity index (S_i) was calculated by oral minimal model, insulin secretion as the incremental area under the curve of insulin (IncreAUC_i) and disposition index (DI) as S_i×IncreAUC_i.

RESULTS

During remission, OGTT showed normal glucose tolerance (NGT) (n=9 (12%)), prediabetes (n=34 (45%)) and diabetes (n=32 (43%)). DI and S_i were higher in patients with NGT versus prediabetes versus diabetes (p<0.001), while IncreAUC_i was not significantly different among NGT, prediabetes and diabetes (p=0.14). Achieving NGT status did not prolong near-normoglycemia remission. OAD treatment significantly prolonged hyperglycemia relapse-free survival (log-rank p=0.0012) compared with placebo and was associated with lower hyperglycemia relapse (HR: 0.45, 95% CI: (0.21 to 0.96), p=0.04).

CONCLUSIONS

In AA patients with obesity with history of DKA and SH, near-normoglycemia remission is associated with improved insulin secretion and action with half of patients achieving NGT or prediabetes, and only half having diabetes on OGTT. NGT and prediabetes on OGTT were not associated with prolonged hyperglycemia relapse-free survival.

TRIAL REGISTRATION NUMBER

NCT01099618, NCT00426413.

Evaluation and management of ketosis-prone diabetes

INTRODUCTION

Patients presenting with diabetic ketoacidosis (DKA) who lack the classic phenotype of autoimmune type 1 diabetes have become increasingly identified in recent decades. This has led to the recognition of heterogeneous syndromes of 'ketosis-prone diabetes' (KPD). Evaluation and optimal management of KPD differs from that of 'typical' type 1 or type 2 diabetes. Awareness of these differences and a systematic approach to diagnosis and treatment can improve glycemic control and prevent both acute and chronic complications of diabetes.

AREAS COVERED

This article reviews the Aß classification scheme ('A' for autoantibody status and 'ß' for beta cell functional reserve) which accurately delineates subgroups of KPD, and addresses the relevance of defining these subgroups for clinical outcomes and long-term insulin dependence. Subsequently, the detailed evaluation and management of KPD patients after their index DKA episode is described.

EXPERT COMMENTARY

Among patients presenting with DKA, it is important to diagnose specific subgroups of KPD and not assume that they represent exclusively patients with autoimmune type 1 diabetes. The Aß classification is an accurate aid to diagnosis, and permits optimal management of the subgroups (e.g., insulin treatment for the ß- subgroups; follow-up testing and a range of treatment options for the ß+ subgroups).

EADSG Guidelines: Insulin Therapy in Diabetes

A diagnosis of diabetes or hyperglycemia should be confirmed prior to ordering, dispensing, or administering insulin (A). Insulin is the primary treatment in all patients with type 1 diabetes mellitus (T1DM) (A). Typically, patients with T1DM will require initiation with multiple daily injections at the time of diagnosis. This is usually short-acting insulin or rapid-acting insulin analogue given 0 to 15 min before meals together with one or more daily separate injections of intermediate or long-acting insulin. Two or three premixed insulin injections per day may be used (A). The target glycated hemoglobin A1c (HbA1c) for all children with T1DM, including preschool children, is recommended to be < 7.5% (< 58 mmol/mol). The target is chosen aiming at minimizing hyperglycemia, severe hypoglycemia, hypoglycemic unawareness, and reducing the likelihood of development of long-term complications (B). For patients prone to glycemic variability, glycemic control is best evaluated by a combination of results with self-monitoring of blood glucose (SMBG) (B). Indications for exogenous insulin therapy in patients with type 2 diabetes mellitus (T2DM) include acute illness or surgery, pregnancy, glucose toxicity, contraindications to or failure to achieve goals with oral antidiabetic medications, and a need for flexible therapy (B). In T2DM patients, with regards to achieving glycemic goals, insulin is considered alone or in combination with oral agents when HbA1c is ≥ 7.5% (≥ 58 mmol/mol); and is essential for treatment in those with HbA1c ≥ 10% (≥ 86 mmol/mol), when diet, physical activity, and other antihyperglycemic agents have been optimally used (B). The preferred method of insulin initiation in T2DM is to begin by adding a long-acting (basal) insulin or once-daily premixed/co-formulation insulin or twice-daily premixed insulin, alone or in combination with glucagon-like peptide-1 receptor agonist (GLP-1 RA) or in combination with other oral antidiabetic drugs (OADs) (B). If the desired glucose targets are not met, rapid-acting or short-acting (bolus or prandial) insulin can be added at mealtime to control the expected postprandial raise in glucose. An insulin regimen should be adopted and individualized but should, to the extent possible, closely resemble a natural physiologic state and avoid, to the extent possible, wide fluctuating glucose levels (C). Blood glucose monitoring is an integral part of effective insulin therapy and should not be omitted in the patient's care plan. Fasting plasma glucose (FPG) values should be used to titrate basal insulin, whereas both FPG and postprandial glucose (PPG) values should be used to titrate mealtime insulin (B). Metformin combined with insulin is associated with decreased weight gain, lower insulin dose, and less hypoglycemia when compared with insulin alone (C). Oral medications should not be abruptly discontinued when starting insulin therapy because of the risk of rebound hyperglycemia (D). Analogue insulin is as effective as human insulin but is associated with less postprandial hyperglycemia and delayed hypoglycemia (B). The shortest needles (currently the 4-mm pen and 6-mm syringe needles) are safe, effective, and less painful and should be the first-line choice in all patient categories; intramuscular (IM) injections should be avoided, especially with long-acting insulins, because severe hypoglycemia may result; lipohypertrophy is a frequent complication of therapy that distorts insulin absorption, and therefore, injections and infusions should not be given into these lesions and correct site rotation will help prevent them (A). Many patients in East Africa reuse syringes for various reasons, including financial. This is not recommended by the manufacturer and there is an association between needle reuse and lipohypertrophy. However, patients who reuse needles should not be subjected to alarming claims of excessive morbidity from this practice (A). Health care authorities and planners should be alerted to the risks associated with syringe or pen needles 6 mm or longer in children (A).

Randomized Controlled Study of Metformin and Sitagliptin on Long-term Normoglycemia Remission in African American Patients With Hyperglycemic Crises

OBJECTIVE

After intensive insulin treatment, many obese African American patients with new-onset diabetic ketoacidosis (DKA) and severe hyperglycemia are able to achieve near-normoglycemia remission. The optimal treatment to prevent hyperglycemic relapses after remission is not known.

RESEARCH DESIGN AND METHODS

This prospective, 4-year, placebo-controlled study randomly assigned 48 African American subjects with DKA and severe hyperglycemia to metformin 1,000 mg daily (n = 17), sitagliptin 100 mg daily (n = 16), or placebo (n = 15) after normoglycemia remission. Hyperglycemic relapse was defined as fasting glucose >130 mg/dL (7.2 mmol/L) and HbA_1c >7.0% (53 mmol/mol). Oral glucose tolerance tests were conducted at randomization and at 3 months and then every 6 months for a median of 331 days. Oral minimal model and incremental area under the curve for insulin (AUCi) were used to calculate insulin sensitivity (Si) and β-cell function, respectively. Disposition index (DI) was calculated as a product of Si and incremental AUCi.

RESULTS

Relapse-free survival was higher in sitagliptin and metformin (P = 0.015) compared with placebo, and mean time to relapse was significantly prolonged in the metformin and sitagliptin groups compared with the placebo group (480 vs. 305 days, P = 0.004). The probability of relapse was significantly lower for metformin (hazard ratio 0.28 [95% CI 0.10-0.81]) and sitagliptin (0.31 [0.10-0.98]) than for placebo. Subjects who remained in remission had a higher DI (P = 0.02) and incremental AUCi (P < 0.001) than those with hyperglycemia relapse without significant changes in Si.

CONCLUSIONS

This study shows that near-normoglycemia remission was similarly prolonged by treatment with sitagliptin and metformin. The prolongation of remission was due to improvement in β-cell function.

Impact and characteristics of the non-Caucasian population in hospital admissions for diabetes onset during 2003-2010

AIMS

To assess the prevalence of non-Caucasian patients in hospital admissions for onset of symptomatic diabetes mellitus during the 2003-2010 period, and to analyze the characteristics differentiating them from the Caucasian population at diagnosis and 2 years later.

MATERIAL AND METHODS

A retrospective, observational study.

INCLUSION CRITERIA

Patients aged 18-40 years admitted for de novo symptomatic diabetes from January 2003 to October 2010. Prevalence of patients of non-Caucasian origin was analyzed, and clinical, biochemical, immunological, and beta-cell function of both populations were compared at diagnosis and 2 years later.

RESULTS

Nineteen percent of patients admitted to hospital for de novo symptomatic diabetes were non-Caucasian, with a progressive increase in recent years. Non-Caucasian patients had milder decompensation (3.0% had ketoacidosis, as compared to 15.2% in the Caucasian group, P<.05), lower presence of autoimmunity (27.2 vs. 73.1%, P<.01) and higher stimulated C-peptide levels (0.70±0.56 vs. 0.42±0.39 nmol/l, P<.05), mainly because of the subgroup with negative autoimmunity (0.82 vs. 0.25). Two years after diagnosis, less non-Caucasian patients were on intensified treatment (39.1 vs. 93.8%).

CONCLUSIONS

Non-Caucasian patients had a lower prevalence of autoimmunity, better beta-cell function at diagnosis, particularly due to the subgroup with negative autoimmunity, and less need for intensive treatment 2 years after diagnosis, features which are more characteristic of type 2 diabetes mellitus.

Hyperglycaemia per se does not affect erythrocyte glucose-6-phosphate dehydrogenase activity in ketosis-prone diabetes

AIM

Previously, we described patients with ketosis-prone type 2 diabetes (KPD) and glucose-6-phosphate dehydrogenase (G6PD) deficiency, but no mutation of the G6PD gene. Our present study used two complementary approaches to test whether hyperglycaemia might inhibit G6PD activity: (1) effect of acute hyperglycaemia induced by glucose ramping; and (2) effect of chronic hyperglycaemia using correlation between G6PD activity and HbA1c levels.

METHODS

In the first substudy, 16 KPD patients were compared with 11 healthy, non-diabetic control subjects of the same geographical background. Erythrocyte G6PD activity and plasma glucose were assessed at baseline and every 40 min during intravenous glucose ramping that allowed maintaining hyperglycaemia for more than 3h. In the second substudy, erythrocyte G6PD activity and HbA1c levels were evaluated in 108 consecutive African patients with either type 2 diabetes or KPD, and a potential correlation sought between the two variables.

RESULTS

The maximum plasma glucose level after 200 min of glucose perfusion was 20.9±3.7 mmol/L for patients and 10.7±2.3mmol/L for controls. There was no difference between baseline and repeated G6PD activity levels during acute hyperglycaemia in either KPD patients (P=0.94) or controls (P=0.57), nor was there any significant correlation between residual erythrocyte G6PD activity and HbA1c levels (r=-0.085, P=0.38).

CONCLUSION

Neither acute nor chronic hyperglycaemia affects erythrocyte G6PD activity. Thus, hyperglycaemia alone does not explain cases of G6PD deficiency in the absence of gene mutation as described earlier.

Changes in circulating adiponectin, leptin, glucose and C-peptide in patients with ketosis-prone diabetes

AIMS

To evaluate circulating adipokines in people with ketosis-prone diabetes, a heterogeneous disorder characterized by unprovoked ketoacidosis in people with previously unrecognized diabetes.

METHODS

Patients presenting with ketoacidosis with no previous diabetes diagnosis were compared with patients with previously established Type 1 diabetes. Baseline assessments of autoimmune status (A+/A-), and β-cell function (B+/B-), as well as leptin and adiponectin levels during a standardized mixed-meal tolerance test of 120 min, were performed. In all, 20 patients with heterogeneous ketosis-prone diabetes and 12 patients with Type 1 diabetes were evaluated at baseline, 12 and 24 months.

RESULTS

At baseline, during a mixed-meal tolerance test, glucose and adiponectin concentrations were lower in patients with ketosis-prone diabetes than in those with Type 1 diabetes (P = 0.0023 and P < 0.0001, respectively), whereas C-peptide concentrations were higher, with no significant difference in leptin concentrations. Within 12 months, 11 patients with ketosis-prone diabetes (all A-/B+) were discontinued from insulin treatment (ketosis-prone diabetes - insulin group), while nine patients (four A-B-, four A+B- and one A-B+) were maintained on insulin (ketosis-prone diabetes + insulin group). Fasting C-peptide levels increased significantly over 24 months in the ketosis-prone diabetes - insulin group (P = 0.01), while HbA1c levels decreased (P < 0.0001). Overall, the ketosis-prone diabetes - insulin group had a higher BMI (P = 0.018), yet a lower fasting glucose concentration (P = 0.003) compared with the ketosis-prone diabetes + insulin group. Over 24 months, the mixed-meal tolerance test area-under-the-curve of C-peptide increased in the ketosis-prone diabetes - insulin group, with no change in ketosis-prone diabetes + insulin (P < 0.0001). At 24 months, in spite of the higher BMI in the ketosis-prone diabetes - insulin group, mixed-meal tolerance test glucose and leptin concentrations were significantly lower (P < 0.0001 and P = 0.017, respectively), while adiponectin levels were higher (P = 0.023) compared with the ketosis-prone diabetes + insulin group.

CONCLUSIONS

In spite of the higher BMI in the ketosis-prone diabetes - insulin group, lower leptin and higher adiponectin levels may contribute to improved β-cell function and insulin sensitivity, as evidenced by lower glucose and higher C-peptide levels. This allows insulin therapy to be withdrawn.

Association of HLA class II markers with autoantibody-negative ketosis-prone atypical diabetes compared to type 2 diabetes in a population of sub-Saharan African patients

AIM

We investigated the association of HLA DRB1 and DQB1 alleles, haplotypes and genotypes with unprovoked antibody-negative ketosis-prone atypical diabetes (A(-) KPD) in comparison to type 2 diabetes (T2D).

METHODS

A(-) KPD and T2D sub-Saharan African patients aged 19-63 years were consecutively recruited. Patients positive for cytoplasmic islet cell, insulin, glutamic acid decarboxylase or islet antigen-2 autoantibodies were excluded. Odds ratios were obtained via logistic regression after considering alleles with a minimum frequency of 5% in the study population. Bonferroni correction was used in the case of multiple comparisons.

RESULTS

Among the 130 participants, 35 (27%) were women and 57 (44%) were A(-) KPD. DRB1 and DQB1 allele frequencies were similar for both A(-) KPD and T2D patients; they did not confer any substantial risk even after considering type 1 diabetes susceptibility and resistance alleles. We found no association between A(-) KPD and the derived DRB1*07-DQB1*02:02 (OR: 0.55 [95%CI: 0.17-1.85], P=0.336); DRB1*11-DQB1*03:01 (OR: 2.42 [95%CI: 0.79-7.42], P=0.123); DRB1*15-DQB1*06:02 (OR: 0.87 [95%CI: 0.39-1.95], P=0.731) and DRB1*03:01-DQB1*02:01 (OR: 1.48 [95%CI: 0.55-3.96], P=0.437) haplotypes. Overall, we did not find any evidence of susceptibility to ketosis associated with DRB1 and DQB1 genotypes (all P>0.05) in A(-) KPD compared to T2D. Similar results were obtained after adjusting the analysis for age and sex.

CONCLUSION

Factors other than DRB1 and DQB1 genotype could explain the propensity to ketosis in A(-) KPD. These results need to be confirmed in a larger population with the perspective of improving the classification and understanding of the pathophysiology of A(-) KPD.

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.

Atypical diabetes in children: ketosis-prone type 2 diabetes

Ketosis-prone type 2 diabetes mellitus also known as atypical or flatbush diabetes is being increasingly recognised worldwide. These patients are typically obese, middle-aged men with a strong family history of type 2 diabetes. The aetiology and pathophysiological mechanism is still unclear but some initial research suggests that patients with ketosis-prone type 2 diabetes have a unique predisposition to glucose desensitisation. These patients have negative autoantibodies typically associated with type 1 diabetes but have shown to have human leucocyte antigen (HLA) positivity. At initial presentation, there is an impairment of both insulin secretion and action. β Cell function and insulin sensitivity can be markedly improved by initiating aggressive diabetes management to allow for discontinuation of insulin therapy within a few months of treatment. These patients can be maintained on oral hypoglycaemic agents and insulin therapy can be safely discontinued after few months depending on their β cell function.

β- and α-cell dysfunctions in africans with ketosis-prone atypical diabetes during near-normoglycemic remission

OBJECTIVE

Ketosis-prone atypical diabetes (KPD) is a subtype of diabetes in which the pathophysiology is yet to be unraveled. The aim of this study was to characterize β- and α-cell functions in Africans with KPD during remission.

RESEARCH DESIGN AND METHODS

We characterized β- and α-cell functions in Africans with KPD during remission. The cohort comprised 15 sub-Saharan Africans who had been insulin-free for a median of 6 months. Patients in remission were in good glycemic control (near-normoglycemic) and compared with 15 nondiabetic control subjects matched for age, sex, ethnicity, and BMI. Plasma insulin, C-peptide, and glucagon concentrations were measured in response to oral and intravenous glucose and to combined intravenous arginine and glucose. Early insulin secretion was measured during a 75-g oral glucose tolerance test. Insulin secretion rate and glucagon were assessed in response to intravenous glucose ramping.

RESULTS

Early insulin secretion and maximal insulin secretion rate were lower in patients compared with control participants. In response to combined arginine and glucose stimulation, maximal insulin response was reduced. Glucagon suppression was also decreased in response to oral and intravenous glucose but not in response to arginine and insulin.

CONCLUSIONS

Patients with KPD in protracted near-normoglycemic remission have impaired insulin response to oral and intravenous glucose and to arginine, as well as impaired glucagon suppression. Our results suggest that β- and α-cell dysfunctions both contribute to the pathophysiology of KPD.

Characteristics of diabetic ketoacidosis in Chinese adults and adolescents -- a teaching hospital-based analysis

OBJECTIVE

To investigate the diabetic ketoacidosis (DKA) episodes occurred in diabetic adults and adolescents.

METHODS

We reviewed diabetic patients of admissions with DKA in West China Hospital in Chengdu from January 1, 2008 to December 31, 2008. Clinical and laboratory data including β-cell function and autoantibody status were collected respectively. Patients were classified as having type 1 or type 2 diabetes or atypical diabetes based on clinical diagnosis and treatment history. And groups were compared for differences in vital statistics and biochemical profiles at presentation.

RESULTS

Detailed and accurate information was obtained in relation to 263 of patients accounted for the 287 admissions admitted for DKA, of whom 41 patients had type 1 diabetes (15.59%) meanwhile 178 patients were diagnosis as T2DM (67.68%), and 37 patients could not be "typed" were classified as atypical DM (14.07%). In addition, there were two gestational diabetes mellitus (GDM) and five patients with other specific types. Sixty admissions (22.81%) were newly diagnosed diabetes, of which 28 admissions (46.67%) were atypical diabetes. The most common contributing factor for DKA was infection (39.16%), followed by noncompliance with anti-diabetes treatment including omission of insulin (25.5%), unknown causes (25.86%) and other medical conditions (11.73%). Of note, these middle-age obese male patients with atypical diabetes often lapse into diabetic ketoacidosis without identifiable precipitating factors.

CONCLUSIONS

DKA could occur not only in T1DM but also in patients with T2DM under infection or stress condition, furthermore without any identifiable precipitant. The prevalence of DKA and its clinical heterogeneity have significant implications for diagnosing and classification of diabetes. More attention and prevention strategies are needed in ketosis-prone atypical diabetes.

Challenges in diagnosing type 1 diabetes in different populations

Diabetes affects today an estimated 366 million people world-wide, including 20 million to 40 million of patients with type 1 diabetes (T1D). While T1D accounts for 5% to 20% of those with diabetes, it is associated with higher morbidity, mortality and health care cost than the more prevalent type 2 diabetes. Patients with T1D require exogenous insulin for survival and should be identified as soon as possible after diagnosis to avoid high morbidity due to a delay in insulin treatment. It is also important to present to the patient correct prognosis that differs by the type of diabetes. From the research point of view, correct classification should help to identify the etiologies and to develop specific prevention for T1D. This review summarizes evidence that may be helpful in diagnosing T1D in various ethnic groups. Challenges in interpretation of results commonly used to determine the type of diabetes are highlighted.

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.

Basal insulin resistance and secretion in Nigerians with type 2 diabetes mellitus

AIM

The objective of this study was to estimate basal insulin resistance (IR) and insulin secretion (IS) in Nigerians with type 2 diabetes mellitus (T2DM).

METHODS

The homeostasis model assessment (HOMA) method was used to estimate basal IR and IS in 146 Nigerians with T2DM and in 33 controls at the University of Nigeria Teaching Hospital (UNTH), Enugu, Nigeria. Correlations and multiple regression analysis between Box-Cox-transformed IR and log-transformed IS and anthropometric indices were carried out.

RESULTS

IR and reduced IS were present, respectively, in 139 (95.5%) and 109 (74.7%) of the diabetic subjects and in 25 (75.8%) and 4 (12.1%) of the controls. In the diabetic subjects, age at diagnosis, duration of diabetes, waist circumference (WC), and body mass index (BMI) correlated significantly with IR (r = -0.2399, P = 0.0035; r = 0.1993, P = 0.0166; r = 0.2267, P = 0.0059; r = 0.2082, P = 0.0120; respectively), whereas duration of diabetes, WC, and BMI correlated significantly with IS (r = -0.2166, P = 0.0091; r = 0.3062, P = 0.0002; r = 0.2746, P = 0.0008; respectively). Age at diagnosis, WC, and duration of diabetes were significant predictors of IR (beta = -0.0161, P < 0.001; beta = 0.0121, P = 0.002; beta = 0.0138, P = 0.042; respectively), whereas duration of diabetes and WC significantly predicted IS (beta = -0.0159, P = 0.025; beta = 0.0155, P < 0.001).

CONCLUSIONS

This study shows that both IR and reduced IS are major features of T2DM in Nigerians and that WC consistently correlated and predicted IR. WC measurement is simple and ideal in resource-poor settings for the detection of IR and abdominal obesity. The apparent rarity of coronary heart disease (CHD) in black Africans with T2DM despite a high prevalence of IR warrants further investigation.

Multitissue insulin resistance despite near-normoglycemic remission in Africans with ketosis-prone diabetes

OBJECTIVE

To characterize insulin action in Africans with ketosis-prone diabetes (KPD) during remission.

RESEARCH DESIGN AND METHODS

At Saint-Louis Hospital, Paris, France, 15 African patients with KPD with an average 10.5-month insulin-free near-normoglycemic remission period (mean A1C 6.2%) were compared with 17 control subjects matched for age, sex, BMI, and geographical origin. Insulin stimulation of glucose disposal, and insulin suppression of endogenous glucose production (EGP) and nonesterified fatty acids (NEFAs), was studied using a 200-min two-step (10 mU x m(-2) body surface x min(-1) and 80 mU x m(-2) x min (-1) insulin infusion rates) euglycemic clamp with [6,6-(2)H(2)]glucose as the tracer. Early-phase insulin secretion was determined during an oral glucose tolerance test.

RESULTS

The total glucose disposal was reduced in patients compared with control subjects (7.5 +/- 0.8 [mean +/- SE] vs. 10.5 +/- 0.9 mg x kg(-1) x min(-1); P = 0.018). EGP rate was higher in patients than control subjects at baseline (4.0 +/- 0.3 vs. 3.0 +/- 0.1 mg x kg(-1) x min(-1); P = 0.001) and after 200-min insulin infusion (10 mU x m(-2) x min(-1): 1.6 +/- 0.2 vs. 0.6 +/- 0.1, P = 0.004; 80 mU x m(-2) x min(-1): 0.3 +/- 0.1 vs. 0 mg x kg(-1) x min(-1), P = 0.007). Basal plasma NEFA concentrations were also higher in patients (1,936.7 +/- 161.4 vs. 1,230.0 +/- 174.1 micromol/l; P = 0.002) and remained higher after 100-min 10 mU x m(-2) x min(-1) insulin infusion (706.6 +/- 96.5 vs. 381.6 +/- 55.9 micromol/l; P = 0.015).

CONCLUSIONS

The triad hepatic, adipose tissue, and skeletal muscle insulin resistance is observed in patients with KPD during near-normoglycemic remission, suggesting that KPD is a form of type 2 diabetes.

Diabetes classification: grey zones, sound and smoke: Action LADA 1

Diseases gain identity from clinical phenotype as well as genetic and environmental aetiology. The definition of type 1 diabetes is clinically exclusive, comprising patients who are considered insulin dependent at diagnosis, whilst the definition of type 2 diabetes is inclusive, only excluding those who are initially insulin dependent. Ketosis-prone diabetes (KPD) and latent autoimmune diabetes in adults (LADA) are each exclusive forms of diabetes which are, at least initially, clinically distinct from type 2 diabetes and type 1 diabetes, and each have a different natural history from these major types of diabetes.KPD can be diagnosed unequivocally as diabetes presenting with the categorical clinical feature, ketoacidosis. In contrast, LADA can be diagnosed by the co-occurrence of three traits, not one of which is categorical or exclusive to the condition: adult-onset non-insulin-requiring diabetes, an islet autoantibody such as glutamic acid decarboxylase autoantibodies (GADA) or cytoplasmic islet cell autoantibodies (ICA), and no need for insulin treatment for several months post-diagnosis. But while some would split diabetes into distinct subtypes, there is a strong case that these subtypes form a continuum of varying severity of immune and metabolic dysfunction modified by genetic and non-genetic factors. This article discusses the nature of disease classification in general, and KPD and LADA in particular, emphasizing the potential value and pitfalls in classifying diabetes and suggesting a need for more research in this area.

Syndromes of ketosis-prone diabetes mellitus

Ketosis-prone diabetes (KPD) is a widespread, emerging, heterogeneous syndrome characterized by patients who present with diabetic ketoacidosis or unprovoked ketosis but do not necessarily have the typical phenotype of autoimmune type 1 diabetes. Multiple, severe forms of beta-cell dysfunction appear to underlie the pathophysiology of KPD. Until recently, the syndrome has lacked an accurate, clinically relevant and etiologically useful classification scheme. We have utilized a large, longitudinally followed, heterogeneous, multiethnic cohort of KPD patients to identify four clinically and pathophysiologically distinct subgroups that are separable by the presence or absence of beta-cell autoimmunity and the presence or absence of beta-cell functional reserve. The resulting "Abeta" classification system of KPD has proven to be highly accurate and predictive of such clinically important outcomes as glycemic control and insulin dependence, as well as an aid to biochemical and molecular investigations into novel causes of beta-cell dysfunction. In this review, we describe the current state of knowledge in regard to the natural history, pathophysiology, and treatment of the subgroups of KPD, with an emphasis on recent advances in understanding their immunological and genetic bases.

[Ketosis-prone atypical diabetes mellitus: report of two cases]

An atypical presentation of diabetes mellitus was described in black subjects, initially in adolescents by Winter et al. then, in adult populations. The principal characteristics of "African" diabetes are an acute onset with severe hyperglycemia and ketosis, and a clinical course of type 2 diabetes mellitus. In the subsequent clinical course after initiation of insulin therapy, prolonged remission is often possible with cessation of insulin therapy and maintenance of appropriate metabolic control. In the subsequent clinical course after initiation of insulin therapy, prolonged remission is often possible with cessation of insulin therapy and maintenance of appropriate metabolic control. The molecular mechanisms underlining the insulin secretory dysfunction are still to be understood and may involve glucolipotoxicity processes. The HLA alleles associated with susceptibility to type 1 diabetes were reported of high frequency in some populations with this form of diabetes, in the absence of makers of pancreatic beta cell autoimmunity. The aim of the present review is to discuss two cases of African diabetes and review the specific diagnostic, metabolic, pathogenic and management features of this atypical diabetes.

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.

Factors associated with insulin discontinuation in subjects with ketosis-prone diabetes but preserved beta-cell function

AIM

To evaluate factors predictive of insulin discontinuation in subjects with ketosis-prone Type 2 diabetes.

METHODS

One hundred and six subjects with ketosis-prone Type 2 diabetes were recruited during the index episode of diabetic ketoacidosis (DKA). All subjects were followed in a special clinic for at least 6 months. If the subject's glycaemic control reached specified glycaemic goals, exogenous insulin was gradually decreased until discontinuation. Baseline and follow-up characteristics were compared between the off-insulin and the on-insulin groups.

RESULTS

At the end of the follow-up period (915+/-375 days) insulin was discontinued in 47% subjects. Subjects in the off-insulin group were significantly older at the time of diagnosis of diabetes. In the off-insulin group the majority of subjects were newly diagnosed with diabetes. After 6 months of follow-up, subjects in the off-insulin group had significantly lower mean HbA(1c), higher mean C-peptide-to-glucose ratio and had more clinic visits per year. In the proportional hazard analysis, new-onset diabetes [hazard ratio (HR) 1.54; 95% confidence interval (CI) 1.02-2.45], and a higher C-peptide-to-glucose ratio at 6 months of follow-up (HR 1.77; 95% CI 1.22-2.63) were significant predictors of insulin discontinuation.

CONCLUSIONS

In subjects with ketosis-prone Type 2 diabetes, the best predictors of insulin discontinuation are having new-onset diabetes, and higher beta-cell functional reserve (as measured by the C-peptide-to-glucose ratio).

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.

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.

'Disappearing diabetes'--resolution of apparent Type 1 diabetes in a patient with AIDS and cytomegalovirus (CMV) infection

A 30-year-old African female with established acquired immunodeficiency syndrome (AIDS) and no history of diabetes, presented in severe diabetic ketoacidosis (DKA). Blood pH was 6.96, serum bicarbonate 5 mmol/l, plasma glucose (PG) 33.0 mmol/l, and urine heavily positive for ketones. She responded to standard treatment and was established on twice-daily subcutaneous insulin. Four months later her insulin was stopped because of hypoglycaemic attacks on small doses. A glucose tolerance test (GTT) at 6 months postdiagnosis was normal (fasting PG 4.4 mmol/l and 2 h PG 7.5 mmol/l), and at 12 months random PG was 4.1 mmol/l and HbA1c 4.3%. The onset of her apparent Type 1 diabetes coincided with an HIV-associated cytomegalovirus (CMV) infection, and a reversible 'CMV insulitis' may be an explanation. Alternatively, the patient may have had what has recently been described as 'atypical diabetes' in African or Afro-Caribbean diabetic patients. Here resolution of diabetes may occur after presentation, though complete return to normoglycaemia after true DKA is very unusual.

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.

Diabetes in African Americans: unique pathophysiologic features

Type 2 diabetes is an increasing public health problem among African Americans, especially children. Several features make type 2 diabetes among African Americans unique. First, African-American adults with type 2 diabetes, or Flatbush diabetes, present with diabetic ketoacidosis. Patients are insulin resistant with acute, severe defects in insulin secretion and no islet cell autoantibodies. Following treatment, some insulin secretory capacity is recovered and ketoacidosis generally does not recur. The second is remission in African Americans with type 2 diabetes. Recovery of glucose homeostasis, accompanied by recovery of beta-cell function, follows intensive glycemic regulation. Finally, among African Americans with diabetes who are not obese, normal insulin sensitivity is not uncommon. Such individuals do not have the increased cardiovascular risk of insulin-resistant individuals. Differences in visceral, not subcutaneous, adipose tissue volume appear to determine insulin sensitivity. Understanding the unique physiologic and clinical features of African Americans is critical in designing appropriate treatment strategies.

Adult-onset atypical (type 1) diabetes: additional insights and differences with type 1A diabetes in a European Mediterranean population

OBJECTIVE

In 1997, the American Diabetes Association proposed two subcategories for type 1 diabetes: type 1A or immunomediated diabetes and type 1B or idiopathic diabetes characterized by negative beta-cell autoimmunity markers, lack of association with HLA, and fluctuating insulinopenia. The aim of this study was to examine clinical characteristics, beta-cell function, HLA typing, and mutations in maturity-onset diabetes of the young (MODY) genes in patients with atypical type 1 diabetes (type 1 diabetes diagnosed at onset, without pancreatic autoantibodies and fluctuating insulinopenia).

RESEARCH DESIGN AND METHODS

Eight patients with atypical type 1 diabetes (all men, 30.7 +/- 7.6 years) and 16 newly diagnosed age- and sex-matched patients with type 1A diabetes were studied retrospectively. Islet cell, GAD, tyrosine phosphatase and insulin antibodies, and basal and stimulated plasma C-peptide were measured at onset and after 1 year. HLA-DRB1-DQA1-DQB1 typing and screening for mutations in the HNF-1alpha and HNF-4alpha genes were performed from genomic DNA.

RESULTS

Atypical patients displayed significantly higher BMI and better beta-cell function at onset and after 12 months. Three patients carried protective or neutral type 1 diabetes haplotypes, five patients displayed heterozygosity for susceptible and protective haplotypes, and seven patients showed Asp(beta57). We found a nondescribed variant Pro436Ser in exon 10 of the HNF-4alpha gene in one atypical patient without susceptible haplotypes.

CONCLUSIONS

In our population, there are atypical forms of young adult-onset ketosis-prone diabetes initially diagnosed as type 1 diabetes, differing from type 1 diabetes in the absence of beta-cell autoimmunity, persistent beta-cell function capacity, fluctuating insulin requirements and ketosis-prone episodes, as well as clinical features of type 2 diabetes. Only one subgroup could be strictly classified as having type 1B diabetes. Additional information is still needed to improve our understanding of the mechanisms that finally lead to the disease.

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.