Latent autoimmune diabetes amongst adults with type 2 diabetes in a Nigerian tertiary hospital

Precision subclassification of type 2 diabetes: a systematic review

BACKGROUND

Heterogeneity in type 2 diabetes presentation and progression suggests that precision medicine interventions could improve clinical outcomes. We undertook a systematic review to determine whether strategies to subclassify type 2 diabetes were associated with high quality evidence, reproducible results and improved outcomes for patients.

METHODS

We searched PubMed and Embase for publications that used 'simple subclassification' approaches using simple categorisation of clinical characteristics, or 'complex subclassification' approaches which used machine learning or 'omics approaches in people with established type 2 diabetes. We excluded other diabetes subtypes and those predicting incident type 2 diabetes. We assessed quality, reproducibility and clinical relevance of extracted full-text articles and qualitatively synthesised a summary of subclassification approaches.

RESULTS

Here we show data from 51 studies that demonstrate many simple stratification approaches, but none have been replicated and many are not associated with meaningful clinical outcomes. Complex stratification was reviewed in 62 studies and produced reproducible subtypes of type 2 diabetes that are associated with outcomes. Both approaches require a higher grade of evidence but support the premise that type 2 diabetes can be subclassified into clinically meaningful subtypes.

CONCLUSION

Critical next steps toward clinical implementation are to test whether subtypes exist in more diverse ancestries and whether tailoring interventions to subtypes will improve outcomes.

The worldwide prevalence of latent autoimmune diabetes of adults among adult-onset diabetic individuals: a systematic review and meta-analysis

PURPOSE

The actual global burden of Latent Autoimmune Diabetes of Adults (LADA) remains unknown even though its prevalence is almost equal to the type 1 form of diabetes. Hence the present systematic review and meta-analysis were performed to estimate the prevalence of LADA among diabetic individuals using the studies published at global levels.

METHODS

A comprehensive literature revival was performed to identify articles on the prevalence of LADA published till 2023. The prevalence estimates were calculated using DerSimonian and Laird random-effects models with a heterogeneity measure by Cochrane Q and I2 statistics. Publication bias was assessed by the Doi plot and Luis Furuya-Kanamori asymmetry index (LFKindex). P < 0.05 was considered statistically significant.

RESULTS

The overall pooled prevalence of LADA obtained from a total of 51,725 diabetic individuals was found to be 8.9% (95%CI 7.5-10.4, P < 0.001) with a prevalence range of 2.3% in to 18.9% in United Arab Emirates and Bahrain respectively. Subgroup analysis of LADA in the context of the IDF geographic regions showed a higher prevalence in North America (13.5%), 9.5% in Middle East and North Africa, 9.4% in Africa, 9.2% in South East Asia, 8.3% in Western Pacific and the lowest prevalence of 7.0% in Europe.

CONCLUSION

The Meta-analysis revealed a worldwide prevalence of LADA as 8.9%, with the highest prevalence in Bahrain and the lowest in United Arab Emirates. Further, the higher prevalence in some IDF regions and the inconsistent association between socioeconomic status and LADA recommend more research in the future.

Systematic review of precision subclassification of type 2 diabetes

Heterogeneity in type 2 diabetes presentation, progression and treatment has the potential for precision medicine interventions that can enhance care and outcomes for affected individuals. We undertook a systematic review to ascertain whether strategies to subclassify type 2 diabetes are associated with improved clinical outcomes, show reproducibility and have high quality evidence. We reviewed publications that deployed 'simple subclassification' using clinical features, biomarkers, imaging or other routinely available parameters or 'complex subclassification' approaches that used machine learning and/or genomic data. We found that simple stratification approaches, for example, stratification based on age, body mass index or lipid profiles, had been widely used, but no strategy had been replicated and many lacked association with meaningful outcomes. Complex stratification using clustering of simple clinical data with and without genetic data did show reproducible subtypes of diabetes that had been associated with outcomes such as cardiovascular disease and/or mortality. Both approaches require a higher grade of evidence but support the premise that type 2 diabetes can be subclassified into meaningful groups. More studies are needed to test these subclassifications in more diverse ancestries and prove that they are amenable to interventions.

Islet autoantibody positivity in an adult population with recently diagnosed diabetes in Uganda

Aims

This study aimed to investigate the frequency of islet autoantibody positivity in adult patients with recently diagnosed diabetes in Uganda and its associated characteristics.

Methods

Autoantibodies to glutamic acid decarboxylase-65 (GADA), zinc transporter 8 (ZnT8-A), and tyrosine phosphatase (IA-2A) were measured in 534 adult patients with recently diagnosed diabetes. Islet autoantibody positivity was defined based on diagnostic thresholds derived from a local adult population without diabetes. The socio-demographic, clinical, and metabolic characteristics of islet autoantibody-positive and negative participants were then compared. The differences in these characteristics were analysed using the x² test for categorical data and the Kruskal Wallis test for continuous data. Multivariate analysis was performed to identify predictors of islet autoantibody positivity.

Results

Thirty four (6.4%) participants were positive for ≥1 islet autoantibody. GADA, IA-2A and ZnT8-A positivity was detected in 17 (3.2%), 10 (1.9%), and 7 (1.3%) participants, respectively. Compared with those negative for islet autoantibodies, participants positive for islet autoantibodies were more likely to live in a rural area (n = 18, 52.9% Vs n = 127, 25.5%, p = 0.005), to be initiated on insulin therapy (n = 19, 55.9% Vs n = 134, 26.8%, p<0.001), to have a lower median waist circumference (90 [80–99] cm Vs 96 [87–104.8], p = 0.04), waist circumference: height ratio (0.55 [0.50–0.63] vs 0.59 [0.53–0.65], p = 0.03), and fasting C-peptide concentration (0.9 [0.6–1.8] Vs 1.4 [0.8–2.1] ng/ml, p = 0.01). On multivariate analysis, living in a rural area (odds ratio or OR 3.62, 95%CI 1.68–7.80, p = 0.001) and being initiated on insulin therapy (OR 3.61, 95% CI 1.67–7.83, p = 0.001) were associated with islet autoantibody positivity.

Conclusion

The prevalence of islet autoantibody positivity was relatively low, suggesting that pancreatic autoimmunity is a rare cause of new-onset diabetes in this adult Ugandan population. Living in a rural area and being initiated on insulin therapy were independently associated with islet autoantibody positivity in this study population.

Prevalence of diabetes-associated autoantibodies among patients presenting with type 2 diabetes and related metabolic differences

BACKGROUND

To explores the prevalence of autoantibodies (zinc transporter 8 autoantibodies (ZnT8A), antibodies to insulin (IAAs), glutamic acid decarboxylase autoantibody (GAD65)), the relation of the type of positive autoantibody and the number of positive autoantibodies with the glycemic and lipid profile of the patients with LADA (Latent Autoimmune Diabetes in Adults) and compares it to the metabolic profile of patients presenting with type 2 diabetes (T2DM).

METHODS

263 patients with T2DM were recruited for this cross-sectional study in Tehran, Iran. Data from patients included complete medical history, GAD65, ZnT8A, IAA and routine metabolic laboratory workup. Assay for autoantibodies were conducted using ELISA kits. The association between autoantibodies and glycemic and lipid profile of patients with diabetes was assessed using univariate and multivariate regression analysis.

RESULTS

Our study revealed that among 263 patients with T2DM, 29 (11%) cases were positive for IAAs, 9 (3.4%) for ZnT8A, and 12 (4.6%) for GAD65. Six (2.3%) of the patients had triple positive antibodies. Patients with positive results were younger, had lower body mass index (BMI), c-peptide, triglyceride, low-density lipoprotein (LDL), and higher high-density lipoprotein (HDL), HbA1c and fasting blood glucose (FBG) levels. Triple antibody positivity was significantly associated with lower levels of C-Peptide, Triglycerides, FBG, and HbA1c compared to triple negative antibodies.

CONCLUSION

Patients with LADA positive for either of the autoantibodies (GAD65, ZnT8 and IAA) presented with worse glycemic control. Measurement of these autoantibodies can assist in discrimination of these patients and help with earlier control of glycemic profile.

Latent Autoimmune Diabetes in Adults (LADA) and its Metabolic Characteristics among Yemeni Type 2 Diabetes Mellitus Patients

PURPOSE

Although there is ample data about the prevalence of diabetes in the Middle East, little is known about the prevalence and features of autoimmune diabetes in this region. The aim of this study was to investigate the prevalence and metabolic characteristics of latent autoimmune diabetes in adults (LADA) amongst Yemeni Type 2 DM patients.

PATIENTS AND METHODS

In this cross-section study, 270 Type 2 DM patients aged 30-70 years were recruited from the National Diabetes Center, Al-Thowra Hospital, Sana'a city, during the period November 2015 to August 2016. All Type 2 DM patients were diagnosed within 5 years and who did not require insulin for a minimum of 6 months following diagnosis. Levels of glutamic acid decarboxylase autoantibodies (GADA) were measured in all patients, and LADA was diagnosed in patients testing positive for anti-GAD antibodies. Further, biochemical analysis was carried out including fasting blood glucose (FBG), glycated haemoglobin (HbA1c), insulin, and lipid profile. Insulin resistance (HOMA-IR) and β-cell function (HOMA-β) were calculated.

RESULTS

The prevalence of LADA, as defined by GADA-positive, amongst patient with Type 2 DM was 4.4%; with no significant difference in the prevalence between male (5.8%) and female (3.4%). LADA patients were younger than GADA-negative Type 2 DM. Body mass index, waist circumference, insulin and HOMA-β were significantly lower in LADA patients, whereas triglyceride, cholesterol, HDL-c and HOMA-IR were non-significantly lower with respect to Type 2 DM. In contrast, FBG and HbA1c were significantly higher in LADA patients. Moreover, the prevalence of metabolic syndrome was significantly lower in LADA as compared with Type 2 DM. Only 2 out of the 12 GADA-positive (16.7%) were on insulin treatment at the time of the study.

CONCLUSION

The prevalence of LADA in Yemeni Type 2 DM is lower than many of those reported in the literature, with no gender preference. Metabolic syndrome was significantly lower in LADA patients. Patients with LADA share insulin resistance with Type 2 DM but display a more severe defect in β-cell function, thus highlighting the importance of an early diagnosis of LADA, to correctly treat LADA patients, allowing safe and effective therapies.

A Global Perspective of Latent Autoimmune Diabetes in Adults

Latent autoimmune diabetes in adults (LADA) is characterized by the presence of islet autoantibodies and initial insulin independence, which can lead to misdiagnosis of type 2 diabetes (T2D). As such, understanding the genetic etiology of LADA could aid in more accurate diagnosis. However, there is ongoing debate regarding the exact definition of LADA, so understanding its impact in different populations when contrasted with type 1 diabetes (T1D) and T2D is one potential strategy to gain insight into its etiology. Unfortunately, the lack of consistent and thorough autoantibody screening around the world has hampered well-powered genetic studies of LADA. This review highlights recent genetic and epidemiological studies of LADA in diverse populations as well as the importance of autoantibody screening in facilitating future research.

The prevalence and characteristics of latent autoimmune diabetes in adults subset among type two diabetes mellitus patients in Northern Nigeria

INTRODUCTION

Latent autoimmune diabetes in adult (LADA) is a form of Type 1 diabetes mellitus (T1DM) that occurs in adult or with advancing age. It commonly occurs in people aged ≥30 years and is characterized by initial response to oral hypoglycemic agents, lean body mass, and presence of glutamic acid decarboxylase autoantibody (GAD-Ab). It exhibits rapid deterioration of the pancreatic β-cells secretory function due to the destructive action of the autoantibodies. The prevalence of LADA among T2DM patients varies among population due to different diagnostic criteria, patients' characteristics, the assay used, and genetic predisposition. In this study, we intend to document prevalence and clinical characteristics of LADA subset patients in Northern Nigeria.

METHODS

Two-hundred noninsulin-requiring T2DM patients were recruited from the diabetes clinic based on the selection criteria. Their clinical characteristics were documented, and we measured their serum GAD-Ab, glycated hemoglobin (HbA1c), fasting C-peptide, fasting plasma glucose, and fasting serum lipids. The mean (standard deviation) of these clinical and biochemical parameters was compared between GAD-Ab+ and GAD-Ab- groups. The data were analyzed using SPSS version 20 with P< 0.05 as statistically significant.

RESULTS

The prevalence of LADA among the T2DM patients studied was found to be 10.5% (21/200); there were more males than females (15 [71%]:6 [29%], χ2 = 4.2, P< 0.05). The mean age of the GAD-Ab+ was 52.0 (11.0), and there was no statistical difference with GAD-Ab- group. GAD-Ab+ was found more common in the age group of 40-49 years 10/21 (48%). The body mass index, waist circumference, and serum C-peptide were found to be significantly lower in GAD-Ab+ than in GAD-Ab- group (22.1 [51], 80.1 [12.4], 0.84 [0.05] vs. 27.3 [4.9], 93.2 [10.9], 1.72 [0.43]), P< 0.05. The HbA1c was found to be significantly higher in GAD-Ab+ than in GAD-Ab- (8.3 [1.4] vs. 7.0 [2.1]). Other clinical and metabolic parameters were found not to be significantly different between the two groups.

CONCLUSION

We conclude that the prevalence of LADA among T2DM patients in Northern Nigeria is 10.5%. It is more common among males aged 40-49 years and lean subjects. The male sex and decreasing central adiposity are predictors of GAD-Ab+ among T2DM subjects.