Arginine Metabolism Is Altered in Adults with A-ß + Ketosis-Prone Diabetes.

Background: A-ß + ketosis-prone diabetes (KPD) is a subset of type 2 diabetes in which patients have severe but reversible ß cell dysfunction of unknown etiology. Plasma metabolomic analysis indicates that abnormal arginine metabolism may be involved. Objective: The objective of this study was to determine the relation between gut microbiome and arginine metabolism and the relation between arginine availability and ß cell function in KPD patients compared with control participants. Methods: Kinetics of arginine and related metabolites were measured with stable isotope tracers, and insulin secretory responses to arginine and glucose were determined under euglycemic and hyperglycemic conditions in 6 KPD patients and 6 age-, gender-, and body mass index-matched control participants. Glucose potentiation of arginine-induced insulin secretion was performed in a different set of 6 KPD and 3 control participants. Results: Arginine availability was higher in KPD patients during euglycemia [53.5 ± 4.3 (mean ± SEM) compared with 40.3 ± 2.4 µmol · kg lean body mass (LBM)-1 · h-1, P = 0.03] but declined more in response to hyperglycemia (Δ 10.15 ± 2.6 compared with Δ 3.20 ± 1.3 µmol · kg LBM-1 · h-1, P = 0.041). During hyperglycemia, ornithine flux was not different between groups but after an arginine bolus, plasma ornithine AUC trended higher in KPD patients (3360 ± 294 compared with 2584 ± 259 min · µmol · L-1, P = 0.08). In both euglycemia and hyperglycemia, the first-phase insulin responses to glucose stimulation were lower in KPD patients (euglycemic insulin AUC 282 ± 108 compared with 926 ± 257 min · µU · mL-1, P = 0.02; hyperglycemic insulin AUC 358 ± 79 compared with 866 ± 292 min · µU · mL-1, P = 0.05), but exogenous arginine restored first-phase insulin secretion in KPD patients to the level of control participants. Conclusion: Compared with control participants, KPD patients have increased arginine availability in the euglycemic state, indicating a higher requirement. This is compromised during hyperglycemia, with an inadequate supply of arginine to sustain metabolic functions such as insulin secretion. Exogenous arginine administration restores a normal insulin secretory response.

A Case of Diffuse Thyroid Lipomatosis With Amyloid Deposits Presenting With Thyrotoxicosis.

Diffuse thyroid lipomatosis (DTL) is a rare entity of unknown etiology that can be associated with amyloidosis and rarely, thyrotoxicosis. Here, we present a case of DTL with amyloid deposits and concurrent thyrotoxicosis. A 64-year-old South-Asian woman with a several-year history of an enlarging goiter, unintentional weight loss, and work-up 10 months prior suggestive of thyroiditis presented with a viral syndrome in setting of several weeks of progressive fatigue. Her examination was notable for resting sinus tachycardia and massive painless goiter. Initial work-up revealed nephrotic range proteinuria with hypoalbuminemia, which progressed to end-stage-renal disease, elevated inflammatory markers, and elevated free thyroxine (FT4) with a suppressed thyrotropin. Hemodialysis was initiated. Further testing revealed a negative antithyroid antibody panel, an enlarged fatty thyroid per thyroid ultrasound and neck computed tomography, and normal 24-hour uptake on radioactive iodine uptake scan. Both renal and thyroid core biopsies showed amyloid deposits, with the latter confirming benign adipose tissue with entrapped thyroid follicles. Given her rising FT4 levels and persistent tachycardia, methimazole and atenolol were initiated. FT4 levels nearly normalized after uptitration of methimazole and dosing after dialysis. Although the etiopathogenesis and natural history of DTL remain unclear, we discuss the possible mechanisms of thyrotoxicosis in our patient.

Type 1 Diabetes Genetic Risk Score Differentiates Subgroups of Ketosis-Prone Diabetes.

OBJECTIVE: To determine whether genetic risk for type 1 diabetes (T1D) differentiates the four Aß subgroups of ketosis-prone diabetes (KPD), where A+ and A- define the presence or absence of islet autoantibodies and ß+ and ß- define the presence or absence of ß-cell function. RESEARCH DESIGN AND METHODS: We compared T1D genetic risk scores (GRS) of patients with KPD across subgroups, race/ethnicity, ß-cell function, and glycemia. RESULTS: Among 426 patients with KPD (54% Hispanic, 31% African American, 11% White), rank order of GRS was A+ß- > A+ß+ = A-ß- > A-ß+. GRS of A+ß- KPD was lower than that of a T1D cohort, and GRS of A-ß+ KPD was higher than that of a type 2 diabetes cohort. GRS was lowest among African American patients, with a similar distribution across KPD subgroups. CONCLUSIONS: T1D genetic risk delineates etiologic differences among KPD subgroups. Patients with A+ß- KPD have the highest and those with A-ß+ KPD the lowest GRS.

Perceptions of weight status and energy balance behaviors among patients with non-alcoholic fatty liver disease.

Weight loss through behavioral modification is central to treating non-alcoholic fatty liver disease (NAFLD). To achieve this, patients need to accurately self-perceive their health behaviors. We aimed to identify predictors of concordance between self-perception and objective measures of body weight, physical activity (PA) and dietary behaviors. We used data from the Harris County NAFLD Cohort, an ongoing prospective study in a regional safety-net healthcare system. Patients completed self-administered baseline questionnaires on demographics, diet, PA, and self-perceptions. We assessed concordance between actual and self-perceived body weight and energy-balance behaviors. Multivariable logistic regression identified predictors of concordance. Patients (n = 458; average age 46.5 years) were 90% Hispanic and 76% female. PA and fruit/vegetable intake guidelines were met among 37% and 9%, respectively. Most (89%) overweight/obese patients accurately perceived themselves as such. However, 41% of insufficiently-active and 34% of patients not meeting fruit/vegetable intake guidelines inaccurately self-perceived their behaviors as "just right". Women were 3 times more likely to accurately self-perceive weight status (adjusted odds ratio [AOR] 3.24; 95% CI 1.68-6.25) but 51% less likely to accurately self-perceive PA levels than men (AOR 0.49; 95% CI 0.29-0.81). Lower acculturation was associated with higher odds of accurate PA self-perception. Patients with prediabetes or diabetes vs normoglycemia were more likely to accurately self-perceive their fruit/vegetable intake. Most NAFLD patients accurately self-perceived their body weight. A third or more of those not meeting fruit/vegetable intake or PA guidelines had inaccurate perceptions about their behaviors. Our findings highlight key areas to target in NAFLD-specific behavioral modification programs.

Thyroid Storm in a Patient With COVID-19.

OBJECTIVE: A thyroid storm is a severe exacerbation of thyrotoxicosis that can cause significant morbidity and mortality. The emergence of the novel coronavirus (SARS-CoV-2) that originated in Wuhan, China, has become a worldwide pandemic. We present the first documented case of thyroid storm (as defined by the Burch-Wartofsky criteria) in a patient with COVID-19. METHODS: Laboratory and diagnostic studies, including thyroid function tests, thyroid antibody testing, SARS-CoV-2 nasopharyngeal polymerase chain reaction testing, and thyroid ultrasound were performed. RESULTS: A 25-year-old woman presented to the hospital with dry cough, dyspnea, palpitations, weight loss, diarrhea, and anxiety. Physical examination revealed exophthalmos with proptosis and chemosis, tachycardia, diffusely enlarged goiter with bruit, and fine tremor. Laboratory results demonstrated a thyroid-stimulating hormone level of <0.01 mIU/L (normal range [NR], 0.44-5.3 mIU/L), free thyroxine level of 5.34 ng/dL (NR, 0.64-1.42 ng/dL), total triiodothyronine level of 654 ng/dL (NR, 87-178 ng/dL), and thyroid-stimulating immunoglobulin level of 7.18 IU/L (NR, 0.00-0.55 IU/L). Thyroid ultrasound revealed heterogeneous echotexture with increased vascularity. Nasopharyngeal COVID-19 testing was positive. She was treated promptly with propranolol, propylthiouracil, and hydrocortisone with improvement in symptoms, and later switched to methimazole. Her COVID-19 course was uncomplicated, and she left the hospital with minimal respiratory symptoms. CONCLUSION: Thyroid storms are one of the more prevalent endocrine emergencies and are often precipitated by acute events including infections. Patients with thyroid storms may have concomitant SARS-CoV-2 infection that could influence the clinical course and severity of the disease. In patients with symptoms of thyrotoxicosis and respiratory symptoms, clinicians should consider performing a COVID-19 test.

Metabolomics Profiling of Patients With A-ß+ Ketosis-Prone Diabetes During Diabetic Ketoacidosis.

When stable and near-normoglycemic, patients with "A-ß+" ketosis-prone diabetes (KPD) manifest accelerated leucine catabolism and blunted ketone oxidation, which may underlie their proclivity to develop diabetic ketoacidosis (DKA). To understand metabolic derangements in A-ß+ KPD patients during DKA, we compared serum metabolomics profiles of adults during acute hyperglycemic crises, without (n = 21) or with (n = 74) DKA, and healthy control subjects (n = 17). Based on 65 kDa GAD islet autoantibody status, C-peptide, and clinical features, 53 DKA patients were categorized as having KPD and 21 type 1 diabetes (T1D); 21 nonketotic patients were categorized as having type 2 diabetes (T2D). Patients with KPD and patients with T1D had higher counterregulatory hormones and lower insulin-to-glucagon ratio than patients with T2D and control subjects. Compared with patients withT2D and control subjects, patients with KPD and patients with T1D had lower free carnitine and higher long-chain acylcarnitines and acetylcarnitine (C2) but lower palmitoylcarnitine (C16)-to-C2 ratio; a positive relationship between C16 and C2 but negative relationship between carnitine and ß-hydroxybutyrate (BOHB); higher branched-chain amino acids (BCAAs) and their ketoacids but lower ketoisocaproate (KIC)-to-Leu, ketomethylvalerate (KMV)-to-Ile, ketoisovalerate (KIV)-to-Val, isovalerylcarnitine-to-KIC+KMV, propionylcarnitine-to-KIV+KMV, KIC+KMV-to-C2, and KIC-to-BOHB ratios; and lower glutamate and 3-methylhistidine. These data suggest that during DKA, patients with KPD resemble patients with T1D in having impaired BCAA catabolism and accelerated fatty acid flux to ketones-a reversal of their distinctive BCAA metabolic defect when stable. The natural history of A-ß+ KPD is marked by chronic but varying dysregulation of BCAA metabolism.

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).

Factors associated with early relapse to insulin dependence in unprovoked A-ß+ ketosis-prone diabetes.

OBJECTIVE: Unprovoked "A-ß+" Ketosis-Prone Diabetes (KPD), a unique diabetic syndrome of adult-onset, obesity and proneness to ketoacidosis, is associated with rapid recovery of ß cell function and insulin-independence. Whereas most patients experience prolonged remission, a subset relapses early to insulin dependence. We sought to define factors associated with early relapse. METHODS: We utilized a prospective, longitudinal database to analyze 50 unprovoked A-ß+ KPD patients with >2 measurements of ß cell function and glycemia following baseline assessment. RESULTS: 19 patients (38%) relapsed to insulin dependence <1 year after the index DKA episode, while 31 (62%) remained insulin-independent for >1 year (median 4.2 years). Younger age at baseline (OR=0.947, P=0.033), and lower HOMA2-%ß (OR=0.982, P=0.001), lower HOMA2-IR (OR=0.582, P=0.046) and higher HbA1c at 1 year (OR=1.71, P=0.002) were associated with early relapse. A multivariate model with these variables and the interaction of HOMA2-%ß and HbA1c at 1 year provided a good fit (P<0.05). CONCLUSIONS: Relapse to insulin dependence in unprovoked A-ß+ KPD patients is associated with younger age and, after 1 year, lack of robust increase in ß cell functional reserve, and suboptimal glycemic control. Measurements of these parameters 1 year after the index DKA episode can be used to assess the need for insulin therapy.

Masked and overt autoantibodies specific to the DPD epitope of 65-kDa glutamate decarboxylase (GAD65-DPD) are associated with preserved ß-cell functional reserve in ketosis-prone diabetes.

CONTEXT: Ketosis-prone diabetes (KPD), defined by presentation with diabetic ketoacidosis (DKA), comprises 4 subgroups based on the presence or absence of islet cell autoantibodies (A(-) or A(+)) and ß-cell functional reserve (ß(-) or ß(+)). Among A(+) KPD, autoantibody epitope reactivity to 65-kDa glutamate decarboxylase (GAD65), defined by monoclonal GAD65Ab(DPD), was associated with greater ß-cell functional reserve. In a majority of healthy individuals, GAD65Ab are present in the sera but are masked by anti-idiotypic antibodies; in contrast, overtly GAD65Ab-positive patients with autoimmune type 1 diabetes patients lack these anti-idiotypic antibodies. OBJECTIVE: Our objective was to determine the presence of masked and overt GAD65Ab(DPD) in relation to ß-cell function and genetic risk factors in KPD patients. DESIGN: We investigated the associations of masked and overt GAD65Ab(DPD) with ß-cell functional reserve, and their relationship with human leukocyte antigen (HLA) class II haplotypes linked to autoimmune diabetes susceptibility or resistance, in a large KPD cohort. PATIENTS: Adult KPD patients (n = 384) were followed longitudinally in a research clinic. MAIN OUTCOME MEASURES: ß-Cell function, autoantibody status, GAD65Ab epitopes, and HLA class II haplotypes were evaluated. RESULTS: Overall, KPD patients with ß-cell functional reserve (ß(+) subgroups) showed significantly higher frequency of masked GAD65Ab(DPD) than patients without ß-cell functional reserve (ß(-) subgroups): 112 of 144 (79%) compared with 59 of 100 (59%), respectively (P = .002). Masked or overt GAD65Ab(DPD) were also more frequent among autoantibody-positive patients with preserved ß-cell functional reserve (A(+)ß(+) KPD) than those lacking ß-cell function (A(+)ß(-) KPD): 77% compared with 55% (P = .01). The susceptibility HLA haplotypes DQA1*0301/DQB1*0302 and DQA1*0301/DQB1*0201 were associated with absence of overt or masked GAD65Ab(DPD) (odds Ratios 2.3 and 2.2, respectively). CONCLUSIONS: Masked GAD65Ab(DPD) are strongly associated with preserved ß-cell functional reserve among patients with KPD. Absence of GAD65Ab(DPD) reactivity is associated with 2 HLA class II susceptibility haplotypes for autoimmune type 1 diabetes.