Effects of rosuvastatin on serum glucose and insulin in hyperuricemic rats

Background

Hyperuricemia is a state in which the serum levels of uric acid (UA) are elevated. This study was to determine the roles of rosuvastatin in fasting blood glucose (FGB) and insulin levels in hyperuricemic rats.

Methods

Thirty-six Sprague-Dawley (SD) rats were randomized divided into the control, model and rosuvastatin groups: the control was given no intervention, the model group was established by administrating yeast extract powder and oxonic acid potassium salt, and the rosuvastatin group was given intravenous administration of rosuvastatin for 28 days in hyperuricemic rats. Serum uric acid (SUA), fasting blood glucose (FBG), fasting blood insulin (FBI), glutamic acid decarboxylase antibody (GADA), oral glucose tolerance test (OGTT) levels, and the ultrastructure of pancreatic β-cells were measured. Also, homeostasis model assessment of insulin resistance (HOMA-IR) scores was computed in three groups.

Results

Compared to the model group, SUA were decreased, while the FBG, GADA, OGTT and HOMA-IR at week 4 were significantly increased in rosuvastatin group. However, FBI was not significantly changed between three groups. It was also showed that the structure of pancreatic β-cells was damaged and the number of β-cells was changed in hyperuricemic rats while they were aggravated in rosuvastatin group.

Conclusion

Rosuvastatin has roles in inducing FGB, GADA, OGTT and pancreatic β-cells damage in hyperuricemic rats.

Adult-onset autoimmune diabetes identified by glutamic acid decarboxylase autoantibodies: a retrospective cohort study

AIMS/HYPOTHESIS

Patients with GAD antibodies (GADAb) showing clinical features of type 2 diabetes typically exhibit progression to an insulin-dependent state in several months or years. This condition is diagnosed as slowly progressive insulin-dependent (type 1) diabetes mellitus (SPIDDM) or latent autoimmune diabetes in adults, a subtype of adult-onset autoimmune diabetes. However, some patients diagnosed with adult-onset autoimmune diabetes do not progress to an insulin-dependent state. We conducted a retrospective cohort study to identify patients with non-insulin-dependent diabetes among those diagnosed with adult-onset autoimmune diabetes using measurable indicators in routine clinical practice.

METHODS

We surveyed data from the electronic medical records of all patients with GADAb from eight medical centres in Japan for selecting and analysing patients who matched the diagnostic criteria of SPIDDM.

RESULTS

Overall, 345 patients were analysed; of these, 162 initiated insulin therapy (insulin therapy group), whereas 183 did not (non-insulin therapy group) during the follow-up period (median 3.0 years). Patients in the non-insulin therapy group were more likely to be male and presented a later diabetes onset, shorter duration of diabetes, higher BMI, higher blood pressure levels, lower HbA_1c levels, lower GADAb levels and lesser antidiabetic agent use than those in the insulin therapy group when GADAb was first identified as positive. A Cox proportional hazards model showed that BMI, HbA_1c levels and GADAb levels were independent factors for progression to insulin therapy. Kaplan-Meier analyses revealed that 86.0% of the patients with diabetes having GADAb who presented all three factors (BMI ≥ 22 kg/m², HbA_1c < 75 mmol/mol [9.0%] and GADAb <10.0 U/ml) did not require insulin therapy for 4 years.

CONCLUSIONS/INTERPRETATION

Higher BMI (≥22 kg/m²), lower HbA_1c (<75 mmol/mol [9.0%]) and lower GADAb levels (<10.0 U/ml) can predict a non-insulin-dependent state for at least several years in Japanese patients with diabetes having GADAb.

A convenient diagnostic tool for discriminating adult-onset glutamic acid decarboxylase antibody-positive autoimmune diabetes from type 2 diabetes: a retrospective study

Background

The glutamic acid decarboxylase antibody (GADA) test, commonly used to diagnose autoimmune diabetes, is not cost-effective in areas of low prevalence. The aim of this study was to develop a convenient tool to discriminate adult-onset GADA-positive autoimmune diabetes from type 2 diabetes (T2DM) in patients with newly diagnosed diabetes.

Methods

This retrospective cross-sectional study, conducted at Changhua Christian Hospital in Taiwan, collected electronic medical record data from January 2009 to December 2018. Patients were divided into a case group (GADA+, n = 152) and a reference group (T2DM, n = 358). Variables that differed significantly between the groups were subjected to receiver operator characteristic analysis to establish cutoff values. Discriminant function analysis was then employed to discriminate the two groups.

Results

At the onset of diabetes, the GADA+ group was younger, with lower body mass index (BMI), higher hemoglobin A1c (HbA1c), higher high-density lipoprotein cholesterol (HDL-C), and lower total cholesterol and triglycerides (TG). Five major factors were identified to form the linear discriminant functions: BMI, age at onset, TG, HDL-C, and HbA1c. BMI < 23 kg/m² was the most important factor, followed by TG < 98 mg/dL, HDL-C ≥ 46 mg/dL, age at onset < 30 years, and HbA1c ≥ 8.6%. The overall accuracy of the linear discriminant functions was 87.1%, with 84.2% sensitivity and 88.3% specificity.

Conclusions

Routine tests in diabetes care were used to establish a convenient, low-cost tool that may assist in the early identification of adult-onset GAD+ autoimmune diabetes in clinical practice.

Maturity-onset diabetes of the young type 5 uncovered during pregnancy with a long-term diagnosis of type 1 diabetes

We report a case of missed diagnosis of maturity-onset diabetes of the young type 5 uncovered during pregnancy with a previous diagnosis of type 1 diabetes. Maturity-onset diabetes of the young type 5 cannot be excluded in early-onset diabetes with positive islet-related autoantibodies and type 1 diabetes-prone human leukocyte antigen subtypes. Abdominal ultrasound should be used in all patients with pre-gestational diabetes, and maturity-onset diabetes of the young type 5 should be considered when renal abnormality is presented.

Association of stiff-person syndrome with autoimmune endocrine diseases

BACKGROUND

Stiff-person syndrome (SPS) and its subtype, stiff limb syndrome (SLS), are rare neurological disorders characterized by progressive muscular rigidity and spasms. Glutamic acid decarboxylase (GAD) is the enzyme that catalyzes the production of γ-aminobutyric acid (GABA), a major inhibitory neurotransmitter of the central nervous system. SPS is an autoimmune disease triggered by anti-glutamic acid decarboxylase antibody (anti-GAD Ab). Clinically, anti-GAD Ab is associated with SPS, type 1 diabetes mellitus (T1DM), and other autoimmune diseases.

AIM

To investigate the link of autoimmune endocrine disorders with anti-GAD Ab in SPS subjects.

METHODS

This retrospective study was approved by the Institutional Review Board of Chang Gung Memorial Hospital, Taiwan. We collected the patients with SPS from January 2001 to June 2018. By reviewing 14 patients from medical records, we analyzed the clinical findings with coexisting autoimmune diseases, particularly diabetes mellitus and thyroid disease, which are associated with anti-GAD antibody titers or other immunological test results (anti-thyroid peroxidase and anti-nuclear antibodies). We also evaluated malignancies, major complications, and reported treatment to improve symptoms. Anti-GAD antibodies were measured using radioimmunoassay and enzyme-linked immunosorbent assay (ELISA). The cut-off values of these tests are < 1 U/mL and < 5 U/mL, respectively.

RESULTS

The median age of all patients was 39.3 (range, 28.0-54.0) years with a median follow-up period of 6.0 (2.7-13.3) years. Five (35.7%) patients were female; twelve (85.7%) were diagnosed with classic SPS and two (14.3%) with SLS. The median age of onset of symptoms was 35.0 (26.0-56.0) years with a median follow-up duration of 9.0 (2.1-14.9) years in the classic SPS group; the SLS group had a median age of onset of 46.7 years and a shorter follow-up duration of 4.3 years. Among nine classic SPS patients who underwent the anti-GAD Ab test, three were anti-GAD Ab seropositive and each of these three patients also had T1DM, latent autoimmune diabetes in adults, and autoimmune thyroid disease, respectively. In contrast, other rare autoimmune diseases co-existed in six anti-GAD Ab seronegative SPS patients. None of the SLS patients had additional autoimmune diseases.

CONCLUSION

While typical clinical symptoms are crucial for the diagnosis of SPS, the presence of anti-GAD autoantibody may consolidate the diagnosis and predict the association with other autoimmune diseases.

Downregulation of T-Cell Transcription Factors in Adult Latent Autoimmune Diabetes with High-Titer Glutamic Acid Decaroxylase Antibody

INTRODUCTION

Latent autoimmune diabetes in adults (LADA) shows a heterogeneous clinical profile that is dependent on the glutamic acid decaroxylase antibody (GADA) titer. We speculated that LADA patients with a high or low GADA titer may have distinct T-lymphocyte subset profiles and distinct expression patterns of transcription factors involved in T-cell immunomodulation.

METHODS

Patients with LADA (n = 40) and type 2 diabetes (T2DM; n = 14) were recruited to the study, and peripheral blood mononuclear cells were isolated. The proportions of T-lymphocyte subsets (Th1 [T helper type 1], Th2 [T helper type 2], Treg [regulatory T], and Th17 [T helper type 17] cells) were determined by flow cytometry. Real-time polymerase chain reaction (PCR) was performed to estimate mRNA expression levels of the T-cell subtype-enriched transcription factors T-bet (Th1), GATA3 (Th2), transcription factor forkhead box protein 3 (FOXP3) (Treg), and RORC (Th17).

RESULTS

The frequency of Th1 (as a percentage of total CD4⁺T cells) was greater in the LADA patients with high-titer GADA than in the LADA patients with low-titer GADA (11.06 ± 1.62 vs. 7.05 ± 0.86, P = 0.030). Compared to the T2DM group, in the low-titer GADA group the frequency of Th1 was significantly reduced (7.05 ± 0.86 vs. 16.75 ± 3.73, P = 0.017) and the frequency of Th17 frequency was signficantly increased (1.11 ± 0.09 vs. 0.74 ± 0.16, P = 0.017). Compared to T2DM patients, in the high-titer GADA group there was a significantly reduced expression of FOXP3 (0.35 ± 0.13 vs. 1.75 ± 0.54, P = 0.002), RORC (0.53 ± 0.19 vs. 2.00 ± 0.77, P = 0.046), and GATA3 (0.74 ± 0.17 vs. 2.31 ± 0.91, P = 0.046). Similarly, the high-titer GADA group expressed reduced levels of FOXP3 and RORC compared to the low-titer GADA group (0.35 ± 0.13 vs. 1.50 ± 0.41, P = 0.027; 0.53 ± 0.19 vs. 1.35 ± 0.21, P  = 0.027, respectively). There was a negative correlation between FOXP3 expression level and GADA titer for the entire cohort (r = - 0.0433, P = 0.015) and a stronger negative correlation in LADA patients (r = - 0.606, P = 0.008).

CONCLUSION

LADA patients with high-titer GADA express lower levels of T-cell transcription factors, including the Treg transcription factor FOXP3, which may contribute to differences in the clinical profile compared to LADA patients with low-titer GADA.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT01159847.

Autoimmune encephalitis associated with glutamic acid decarboxylase antibodies: a case series

Antibodies against glutamic acid decarboxylase (GAD) are associated with various neurologic conditions described in patients including stiff person syndrome, cerebellar ataxia, refractory epilepsy, limbic and extralimbic encephalitis. GAD antibodies-related limbic encephalitis cases are well described; reports of extralimbic involvement are limited. We describe four cases of GAD antibody-related autoimmune encephalitis. Three of them had extralimbic involvement and only one had limbic encephalitis.

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

AIMS

The aim was to investigate the frequency and characteristics of persons with latent autoimmune diabetes in adults (LADA) amongst patients who had been clinically diagnosed as type 2 diabetes mellitus (CT2DM) in a tertiary care centre.

METHODOLOGY

One hundred and sixty patients with CT2DM participated in this cross-sectional study following selection by systematic random sampling. Demographic data, relevant clinical history and anthropometric measurements (weight, height, waist circumference and hip circumference) were taken and blood samples were obtained for analysis of fasting blood glucose, glycated haemoglobin (HbA1c) and glutamic acid decarboxylase antibodies (GADA). The results were analysed using SPSS version 16.

RESULTS

Nineteen (11.9%) out of 160 persons with CT2DM were positive for GADA. 95(59.4%) of the total study population were females. The mean (SD) age, BMI, waist circumference, were 60.49 (10.37) years, 26.47 (4.80) kg/m2, 92.16 (11.50)cm respectively. Subjects with CT2DM who were GADA positive had trend towards lower mean BMI (25.64 kg/m2 vs. 26.59 kg/m2) and waist circumference (89.80 kg/m2 vs. 92.47 kg/m2) than GADA negative subjects. GADA positive subjects also had a trend showing higher mean fasting blood glucose (144 mg/dl vs. 125 mg/dl, t=2.20, p=0.14), higher mean HbA1c (7% vs. 6.1%, t=3.19, p=0.077) and a higher proportion on insulin (31.6% vs. 22%, χ2=0.07, p=0.25) when compared with GADA negative patients.

CONCLUSION

The prevalence of LADA amongst a subset of Nigerians with CT2DM was 11.9%. There were no distinguishing clinical features to help characterize persons with LADA. The above finding emphasizes the importance of GADA testing for appropriate classification of persons with CT2DM. Early diagnosis of LADA would help direct appropriate therapy to optimize glycaemic control.

Stiff-person syndrome: case series

Stiff-person syndrome (SPS) is a rare disorder, characterized by progressive fluctuating muscular rigidity and spasms. Glutamic acid decarboxylase (GAD) antibody is primarily involved in the pathogenesis of SPS and SPS is strongly associated with other autoimmune disease. Here we report three cases of patients with classical SPS finally confirmed by high serum level of GAD antibodies. All of our patients respond favorably to gamma amino butyric acid-enhancing drugs and immunotherapies.

Six-year follow-up of pancreatic β cell function in adults with latent autoimmune diabetes

AIM: To investigate the characteristics of the progression of islet β cell function in Chinese latent autoimmune diabetes in adult (LADA) patients with glutamic acid decarboxylase antibody (GAD-Ab) positivity, and to explore the prognostic factors for β cell function.

METHODS: Forty-five LADA patients with GAD-Ab positivity screened from phenotypic type 2 diabetic (T2DM) patients and 45 T2DM patients without GAD-Ab matched as controls were followed-up every 6 mo. Sixteen patients in LADA1 and T2DM1 groups respectively have been followed-up for 6 years, while 29 patients in LADA2 and T2DM2 groups respectively for only 1.5 years. GAD-Ab was determined by radioligand assay, and C-peptides (CP) by radioimmune assay.

RESULTS: The percentage of patients whose fasting CP (FCP) decreased more than 50% compared with the baseline reached to 25.0% at 1.5^th year in LADA1 group, and FCP level decreased (395.8±71.5 vs 572.8±72.3 pmol/L, P<0.05) at 2.5^th year and continuously went down to the end of follow-up. No significant changes of the above parameters were found in T2DM1 group. The average decreased percentages of FCP per year in LADA and T2DM patients were 15.8% (4.0-91.0%) and 5.2% (-3.5 to 35.5%, P = 0.000) respectively. The index of GAD-Ab was negatively correlated with the FCP in LADA patients (r_s = -0.483, P = 0.000). The decreased percentage of FCP per year in LADA patients were correlated with GAD-Ab index, body mass index (BMI) and age at onset (r_s = 0.408, -0.301 and -0.523 respectively, P<0.05). Moreover, GAD-Ab was the only risk factor for predicting β cell failure in LADA patients (B = 1.455, EXP (B) = 4.283, P = 0.023).

CONCLUSION: The decreasing rate of islet β cell function in LADA, being highly heterogeneous, is three times that of T2DM patients. The titer of GAD-Ab is an important predictor for the progression of islet β cell function, and age at onset and BMI could also act as the predictors.