A5089010090- Pancreatic function and diabetes
- Diabetes, Cardiovascular Risks, and Lipoproteins
- Diabetes Management and Research
- Metabolism, Diabetes, and Cancer
- Liver Disease Diagnosis and Treatment
- Diabetes Treatment and Management
- Diabetes and associated disorders
- Neural dynamics and brain function
- Diet and metabolism studies
- Cardiovascular Health and Risk Factors
- Neuroscience and Neural Engineering
- Hemoglobinopathies and Related Disorders
- Adipose Tissue and Metabolism
- Hyperglycemia and glycemic control in critically ill and hospitalized patients
- Neuroscience and Neuropharmacology Research
- Metabolomics and Mass Spectrometry Studies
- Health, Environment, Cognitive Aging
- stochastic dynamics and bifurcation
- Folate and B Vitamins Research
- Immunodeficiency and Autoimmune Disorders
- Cardiovascular Function and Risk Factors
- Regulation of Appetite and Obesity
- Banking stability, regulation, efficiency
- Data Mining Algorithms and Applications
- Machine Learning in Healthcare
Howard University
2022-2024
National Institutes of Health
2011-2023
National Institute of Diabetes and Digestive and Kidney Diseases
2015-2021
University of Geneva
2013
University of Indianapolis
2010-2011
Indiana University – Purdue University Indianapolis
2010-2011
Abstract Type 2 diabetes (T2D) is generally thought to result from the combination of metabolic defects, insulin resistance, which increases level required maintain glucose within normal range, and failure insulin-secreting pancreatic β-cells compensate for increased demand. We build on a mathematical model pioneered by Topp colleagues elucidate how compensation succeeds or fails. Their added layer slow negative feedback classic insulin-glucose loop in form slow, glucose-dependent birth...
Morphological characteristics of the glucose curve during an oral tolerance test (OGTT) (time to peak and shape) may reflect different phenotypes insulin secretion action, but their ability predict diabetes risk is uncertain.To compare time shape detect prediabetes β-cell function.In a cross-sectional evaluation using OGTT, 145 adults without (age 42±9 years (mean±SD), range 24-62 years, BMI 29.2±5.3 kg/m2 , 19.9-45.2 ) were characterized by (30 minutes vs >30 minutes) (biphasic...
Context: There is a substantial interindividual variation in the association between glycated hemoglobin (HbA1c) and plasma glucose concentrations.Its impact on cardiovascular disease (CVD) has not been comprehensively evaluated.Objective: We examined associations variations HbA1c, which was estimated as glycation index (HGI), CVD.Design, Setting, Participants: performed cross-sectional analysis with 1248 treatmentnaïve subjects prediabetes or diabetes.The HGI defined measured HbA1c minus...
Diabetes is a chronic, progressive disease that calls for longitudinal data and analysis. We introduce mathematical model capable of representing the metabolic state an individual at any point in time during their progression from normal glucose tolerance to type 2 diabetes (T2D) over period years. As application model, we account diversity pathways typically followed, focusing on two extreme alternatives, one goes through impaired fasting (IFG) first (IGT) first. These are widely recognized...
The timing of increase in 1-hour PG and its utility as an earlier predictor both prediabetes (PreDM) type 2 diabetes (T2D) compared to 2-hour (2 h-PG) are unknown. To evaluate the crossing 1 h-PG ≥ 155 mg/dl (8.6 mmol/L) for PreDM 209 (11.6 T2D respective current thresholds 140 (7.8 200 (11.1 mmol/L).
The regulation of glucagon secretion in the pancreatic α-cell is not well understood. It has been proposed that glucose suppresses either directly through an intrinsic mechanism within or indirectly extrinsic mechanism. Previously, we described a mathematical model for isolated α-cells and used it to investigate possible mechanisms regulating secretion. We demonstrated can suppress both ATP-dependent potassium channels (KATP) store-operated current (SOC). have now developed islet combines...
Youth with obesity and abnormal glucose tolerance have an increased risk for atherosclerosis but the relative contributions of insulin resistance hyperglycemia to dyslipidemia development subclinical are unknown.This work aims determine association between resistance, dyslipidemia, carotid intimal thickness (cIMT) in adolescents normal tolerance.An observational cohort study 155 youth: 44 obese sensitive (OIS; fasting ≤ 20 µM/mL, body mass index [BMI] ≥ 95th percentile), 35 resistant (OIR; >...
Mouse islets exhibit glucose-dependent oscillations in electrical activity, intracellular Ca(2+) and insulin secretion. We developed a mathematical model which left shift glucose threshold helps compensate for resistance. To test this experimentally, we exposed isolated mouse to varying concentrations overnight monitored their sensitivity the next day by measuring Ca(2+), Glucose of all oscillation modes was increased when greater than 2.8mM. determine whether shifts were direct effect or...
Pancreatic islets respond to elevated blood glucose by secreting pulses of insulin that parallel oscillations in β-cell metabolism, intracellular Ca2+ concentration, and bursting electrical activity. The mechanisms maintain an oscillatory response are not fully understood, yet several models have been proposed. Only some can account for experiments supporting metabolism is intrinsically β-cells. dual oscillator model (DOM) implicates glycolysis as the source metabolism. In companion article,...
Uncertainties exist on whether the main determinant of abnormal glucose tolerance (Abnl-GT) in Africans is β-cell failure or insulin resistance (IR). Therefore, we determined prevalence, phenotype and characteristics Abnl-GT due to versus IR 486 African-born blacks (male: 64%, age: 38±10 years (mean±SD)) living America.Oral test were performed. a term which includes both diabetes prediabetes was defined as fasting plasma (FPG) ≥5.6 mmol/L and/or 2-hour ≥7.8 mmol/L. by lowest quartile Matsuda...
Introduction: To improve detection of undiagnosed diabetes in Africa, there is movement to replace the OGTT with A1C. The performance A1C absence hemoglobin-related micronutrient deficiencies, anemia and heterozygous hemoglobinopathies unknown. Therefore, we determined 441 African-born blacks living America (male: 65% (281/441), age: 38±10y (mean±SD), BMI: 27.5±4.4 kg/m2): (1) nutritional hematologic profiles and; (2) glucose tolerance categorization by Methods: Hematologic status were...
Dopamine neurotransmission has been found to play a role in addictive behavior and is altered psychiatric disorders. Dopaminergic (DA) neurons display two functionally distinct modes of electrophysiological activity: low- high-frequency firing. A puzzling feature the DA neuron following combination its responses: N-methyl-D-aspartate receptor (NMDAR) activation evokes firing, whereas other tonic excitatory stimuli (α-amino-3-hydroxyl-5-methyl-4-isoxazolepropionate (AMPAR) or applied...
Abstract Objective Elevated rates of gluconeogenesis are an early pathogenic feature youth-onset type 2 diabetes (Y-T2D), but targeted first-line therapies suboptimal, especially in African American (AA) youth. We evaluated glucose-lowering mechanisms metformin and liraglutide by measuring β-cell function after therapy AA Y-T2D. Methods In this parallel randomized clinical trial, 22 youth with Y-T2D—age 15.3 ± 2.1 years (mean SD), 68% female, body mass index (BMI) 40.1 7.9 kg/m2, duration...
Efficient and accurate methods to estimate insulin sensitivity (
Introduction Risk of insulin resistance, dyslipidemia, diabetes and cardiac death is increased in Asians Europeans with normal glucose tolerance (NGT) 1-hour ≥8.6 mmol/L. As African descent populations often have resistance but a lipid profile, the implications for Africans NGT mmol/L (NGT-1-hour-high) are unknown. Objective We performed oral tests (OGTTs) 434 born-blacks living Washington, DC (male: 66%, age 38±10 years (mean±SD)) determined group if either glucometabolic or profiles varied...
OBJECTIVE In African-born Blacks living in America, we determined by BMI category 1) prevalence of abnormal glucose tolerance (Abnl-GT) and 2) diagnostic value reproducibility hemoglobin A1c (HbA1c), fructosamine, glycated albumin (GA). RESEARCH DESIGN AND METHODS Participants (n = 416; male, 66%; 27.7 ± 4.5 kg/m2 [mean SD]) had an oral test with HbA1c, GA, fructosamine assayed. These glycemic markers were repeated 11 7 days later. Abnl-GT diagnosis required 0 h ≥5.6 mmol/L (≥100 mg/dL)...
We address a problem with the Bergman-Cobelli Minimal Model, which has been used for 40 years to estimate S I during an intravenous glucose tolerance test (IVGTT). During IVGTT blood and insulin concentrations are measured in response acute load. Insulin secretion is often assessed by area under curve first few minutes (Acute Response, AIR). The issue addressed here that we have found simulated IVGTTs, representing certain contexts, Model estimates of inversely related AIR, resulting...
The gold standard clamp measurements for insulin sensitivity (cSI), β-cell function (cBCF) and disposition index (cDI = cSI*cBCF), are not practical in large-scale studies. We sought to: 1) validate a mathematical model-derived DI from oral glucose tolerance tests (OGTT) with (mDI) without (mDI-woI) against cDI (oDI) evaluate the ability of novel indices to detect prediabetes type 2 diabetes.