Facilitators of peer leader retention within a Type 2 diabetes intervention trial for US Latinos/Hispanics of Mexican origin

Peer support is effective in improving self-management behaviors and health outcomes among individuals with Type 2 diabetes. Volunteer peer support programs offer a cost-effective resource for diabetes self-management support; however, factors affecting the retention of volunteer peer leaders remain understudied. Herein, we examined factors associated with volunteer retention and satisfaction among 34 predominantly Mexican-origin peer leaders who assisted patients from a Federally Qualified Health Center located on the US/Mexico border with their diabetes management. Peer leaders completed surveys with open- and close-ended questions at baseline, 6 months and 12 months. Quantitative and qualitative data analyses were guided by the Volunteer Process Model. Using nonparametric Mann-Whitney U tests, self-efficacy as a peer leader at 6 months was most associated with interest to continue volunteering (P = 0.01), and satisfaction with support from the program at 12 months was most associated with interest to continue volunteering (P = 0.01). The qualitative data indicated that the relationship between the peer leaders and their patients was the primary factor for a satisfying volunteer experience. Future research should focus on increasing peer leaders' self-efficacy and satisfaction with program support and examine how organizations can support the development of the patient-peer relationship. Practitioners should consider appealing to volunteer peers' motivations to promote their retention.

Pharmacokinetics and Pharmacodynamics of Insulin Tregopil in Relation to Premeal Dosing Time, Between Meal Interval, and Meal Composition in Patients With Type 2 Diabetes Mellitus

We evaluated the pharmacokinetics and pharmacodynamics of oral insulin tregopil in relation to premeal dosing time, between‐meal interval, and meal composition type in type 2 diabetes mellitus patients in a randomized, placebo‐controlled, crossover study consisting of 3 sequential cohorts. In Cohort 1, insulin tregopil administered 10 to 20 minutes before a meal resulted in optimal postmeal exposure and demonstrated better postprandial glucose‐lowering effect (glucose area under concentration‐time curve [AUC]) compared to the 30‐minute group. In Cohort 2, insulin tregopil pharmacokinetic exposure (plasma AUC) showed a progressive increase through 4, 5, and 6 hours of between‐meal interval. The 6‐hour between‐meal interval resulted in better absorption of insulin tregopil in comparison to 4‐ and 5‐hour intervals. However, no significant differences were observed in pharmacodynamic parameters except for higher glucose AUC_0‐180min in the insulin tregopil 4‐hour group during the afternoon meal as compared to the morning meal. In Cohort 3, a high‐fiber meal had the least impact on insulin tregopil absorption and resulted in the highest reduction in plasma glucose levels in the afternoon. A high‐fat meal reduced insulin tregopil absorption in the afternoon meal; however, pharmacodynamic response was not diminished significantly. Insulin tregopil has a rapid onset of action of approximately 10 minutes and, when administered 10 to 20 minutes before a meal, demonstrated up to 13% to 18% reduction in blood glucose levels compared to baseline. A 5‐hour between‐meal interval minimizes the impact of a meal on absorption of subsequent (afternoon) insulin tregopil dose, and the pharmacodynamic response of insulin tregopil is not altered by meal composition. Insulin tregopil was well tolerated in patients with type 2 diabetes mellitus.

Impact of Insulin Tregopil and Its Permeation Enhancer on Pharmacokinetics of Metformin in Healthy Volunteers: Randomized, Open-Label, Placebo-Controlled, Crossover Study

Oral insulin tregopil (IN‐105; a new drug under development) may be coadministered with oral antidiabetic drugs, such as metformin in patients with type 2 diabetes mellitus for optimal glycemic control. IN‐105 has sodium caprate excipient, a permeation enhancer, for enhancing absorption in the stomach and increasing bioavailability via an oral route. Sodium caprate may increase bioavailability of metformin by a similar mechanism. Therefore, it was necessary to study the effect of IN‐105 on pharmacokinetics (PKs) of metformin. In this randomized, open‐label, cross‐over study, metformin was administered to healthy volunteers receiving IN‐105/placebo under fed/fasting conditions. The 90% confidence interval (CI) of the geometric mean ratio of the area under the curve from time zero to infinity (AUC_0‐inf; fasting and fed) and peak plasma concentration (C_max; fed) of metformin were within 0.80–1.25 acceptance range. Under fasting conditions, the upper bound margin of C_max was just beyond this range (i.e., 1.27) and was concluded as functionally not relevant. There was no clinically significant effect of sodium caprate/IN‐105 on PKs of metformin under fasting/fed conditions, and it was safe.

Odd Chain Fatty Acids; New Insights of the Relationship Between the Gut Microbiota, Dietary Intake, Biosynthesis and Glucose Intolerance

Recent findings have shown an inverse association between circulating C15:0/C17:0 fatty acids with disease risk, therefore, their origin needs to be determined to understanding their role in these pathologies. Through combinations of both animal and human intervention studies, we comprehensively investigated all possible contributions of these fatty acids from the gut-microbiota, the diet, and novel endogenous biosynthesis. Investigations included an intestinal germ-free study and a C15:0/C17:0 diet dose response study. Endogenous production was assessed through: a stearic acid infusion, phytol supplementation, and a Hacl1^−/− mouse model. Two human dietary intervention studies were used to translate the results. Finally, a study comparing baseline C15:0/C17:0 with the prognosis of glucose intolerance. We found that circulating C15:0/C17:0 levels were not influenced by the gut-microbiota. The dose response study showed C15:0 had a linear response, however C17:0 was not directly correlated. The phytol supplementation only decreased C17:0. Stearic acid infusion only increased C17:0. Hacl1^−/− only decreased C17:0. The glucose intolerance study showed only C17:0 correlated with prognosis. To summarise, circulating C15:0 and C17:0 are independently derived; C15:0 correlates directly with dietary intake, while C17:0 is substantially biosynthesized, therefore, they are not homologous in the aetiology of metabolic disease. Our findings emphasize the importance of the biosynthesis of C17:0 and recognizing its link with metabolic disease.

Biologic comparison of inhaled insulin formulations: Exubera™ and novel spray-dried engineered particles of dextran-10

Inhaled peptides and proteins have promise for respiratory and systemic disease treatment. Engineered spray-dried powder formulations have been shown to stabilize peptides and proteins and optimize aerosol properties for pulmonary delivery. The current study was undertaken to investigate the in vitro and in vivo inhalation performance of a model spray-dried powder of insulin and dextran 10 in comparison to Exubera™. Dextrans are a class of glucans that are generally recognized as safe with optimum glass transition temperatures well suited for spray drying. A 70% insulin particle loading was prepared by formulating with 30% (w/v) dextran 10. Physical characterization revealed a "raisin like" particle. Both formulations were generated to produce a similar bimodal particle size distribution of less than 3.5 μm MMAD. Four female Beagle dogs were exposed to each powder in a crossover design. Similar presented and inhaled doses were achieved with each powder. Euglycemia was achieved in each dog prior and subsequent to dosing and blood samples were drawn out to 245 min post-exposure. Pharmacokinetic analyses of post-dose insulin levels were similar for both powders. Respective dextran 10-insulin and Exubera exposures were similar producing near identical area under the curve (AUC), 7,728 ± 1,516 and 6,237 ± 2,621; concentration maximums (C max), 126 and 121 (μU/mL), and concentration-time maximums, 20 and 14 min, respectively. These results suggest that dextran-10 and other dextrans may provide a novel path for formulating peptides and proteins for pulmonary delivery.

Evolution of exenatide as a diabetes therapeutic

Type 2 diabetes (T2DM) is a disease of epidemic proportion associated with significant morbidity and excess mortality. Optimal glucose control reduces the risk of microvascular and possibly macrovascular complications due to diabetes. However, glycemic control is rarely optimal and several therapeutic interventions for the treatment of diabetes cause hypoglycemia and weight gain; some may exacerbate cardiovascular risk. Exenatide (synthetic exendin-4) is a glucagon- like peptide-1 receptor (GLP-1R) agonist developed as a first-in-class diabetes therapy. This review presents an overview of the evolution of exenatide as a T2DM treatment, beginning with the seminal preclinical discoveries and continuing through to clinical pharmacology investigations and phase 3 clinical trials. In patients with T2DM, exenatide enhanced glucose-dependent insulin secretion, suppressed inappropriately elevated glucagon secretion, slowed gastric emptying, and enhanced satiety. In controlled phase 3 clinical trials ranging from 12 to 52 weeks, 10-mcg exenatide twice daily (ExBID) reduced mean HbA1c by -0.8% to -1.7% as monotherapy or in combination with metformin (MET), sulfonylureas (SFU), and/or thiazolidinediones (TZD); with mean weight losses of -1.2 kg to -8.0 kg. In controlled phase 3 trials ranging from 24 to 30 weeks, a 2-mg once-weekly exenatide formulation (ExQW) reduced mean HbA1c by -1.3% to -1.9%, with mean weight reductions of -2.3 to -3.7 kg. Exenatide was generally well-tolerated. The most common side effects were gastrointestinal in nature, mild, and transient. Nausea was the most prevalent adverse event. The incidence of hypoglycemia was generally low. By building upon early observations exenatide was successfully developed into an effective diabetes therapy.

Splanchnic cortisol production in dogs occurs primarily in the liver: evidence for substantial hepatic specific 11beta hydroxysteroid dehydrogenase type 1 activity

Eight dogs underwent combined hepatic/portal vein catheterization and infusion of D4-cortisol in order to determine the relative contributions of the viscera and liver to splanchnic cortisol production. D4-cortisol concentrations progressively decreased from 2.6 +/- 0.1 to 2.4 +/- 0.1 to 1.7 +/- 0.1 microg/dl (P < 0.001 by ANOVA) from hepatic artery to portal vein to hepatic vein, respectively, indicating 8 +/- 3 and 28 +/- 3% extraction across the viscera and liver, respectively. On the other hand, hepatic artery, portal vein, and hepatic vein cortisol concentrations did not differ (0.31 +/- 0.12 vs. 0.28 +/- 0.11 vs. 0.27 +/- 0.10 microg/dl, respectively), indicating zero net cortisol balance. This meant that 1.0 +/- 0.1 microg/min of cortisol was produced within the splanchnic bed, all of which occurred within the liver (1.2 +/- 0.1 microg/min). On the other hand, visceral cortisol production did not differ from zero (-0.2 +/- 0.2 microg/min; P < 0.001 vs. liver). Flux through the 11beta hydroxysteroid dehydrogenase (HSD) type 1 pathway can be measured by determining the rate of conversion of D4-cortisol to D3-cortisol. D3-cortisol concentrations were lower in the portal vein than hepatic artery (0.45 +/- 0.03 vs. 0.48 +/- 0.02, respectively; P < 0.01) but did not differ in the portal vein and hepatic vein, indicating net uptake across the viscera but zero balance across the liver. D3-cortisol production with the viscera and liver averaged 0.2 +/- 0.1 microg/min (P = NS vs. zero production) and 0.6 +/- 0.1 microg/min (P < 0.001 vs. zero production; P < 0.001 vs. viscera production), respectively. We conclude that most, if not all, of splanchnic cortisol production occurs within the liver. Taken together, these data suggest that the high local cortisol concentrations generated via the 11beta HSD type 1 pathway within the liver likely contribute to the regulation of hepatic glucose, fat, and protein metabolism.

Investigation into different skin conditions in certain occupations

The aim of this study was to establish whether those working in certain occupations had skin with a Lower moisture content than would be considered normaL. Skin moisture levels were measured as well as visual assessment. Results indicated that all occupational groups studied had skin that was less well hydrated than would be considered normal, although there were significant inter-individual variations within any one group. These variations were at least as significant as occupation. Awareness of the need to use gloves as protection against chemicals and to use emollients to restore condition was low, as was compliance.

Hepatic glucocorticoid receptor antagonism is sufficient to reduce elevated hepatic glucose output and improve glucose control in animal models of type 2 diabetes

Glucocorticoids amplify endogenous glucose production in type 2 diabetes by increasing hepatic glucose output. Systemic glucocorticoid blockade lowers glucose levels in type 2 diabetes, but with several adverse consequences. It has been proposed, but never demonstrated, that a liver-selective glucocorticoid receptor antagonist (LSGRA) would be sufficient to reduce hepatic glucose output (HGO) and restore glucose control to type 2 diabetic patients with minimal systemic side effects. A-348441 [(3b,5b,7a,12a)-7,12-dihydroxy-3-{2-[{4-[(11b,17b)-17-hydroxy-3-oxo-17-prop-1-ynylestra-4,9-dien-11-yl] phenyl}(methyl)amino]ethoxy}cholan-24-oic acid] represents the first LSGRA with significant antidiabetic activity. A-348441 antagonizes glucocorticoid-up-regulated hepatic genes, normalizes postprandial glucose in diabetic mice, and demonstrates synergistic effects on blood glucose in these animals when coadministered with an insulin sensitizer. In insulin-resistant Zucker fa/fa rats and fasted conscious normal dogs, A-348441 reduces HGO with no acute effect on peripheral glucose uptake. A-348441 has no effect on the hypothalamic pituitary adrenal axis or on other measured glucocorticoid-induced extrahepatic responses. Overall, A-348441 demonstrates that an LSGRA is sufficient to reduce elevated HGO and normalize blood glucose and may provide a new therapeutic approach for the treatment of type 2 diabetes.

Splanchnic free fatty acid kinetics

These studies were conducted to assess the relationship between visceral adipose tissue free fatty acid (FFA) release and splanchnic FFA release. Steady-state splanchnic bed palmitate ([9,10-(3)H]palmitate) kinetics were determined from 14 sampling intervals from eight dogs with chronic indwelling arterial, portal vein, and hepatic vein catheters. We tested a model designed to predict the proportion of FFAs delivered to the liver from visceral fat by use of hepatic vein data. The model predicted that 15 +/- 2% of hepatic palmitate delivery originated from visceral lipolysis, which was greater (P = 0.004) than the 11 +/- 2% actually observed. There was a good relationship (r(2) = 0.63) between the predicted and observed hepatic palmitate delivery values, but the model overestimated visceral FFA release more at lower than at higher palmitate concentrations. The discrepancy could be due to differential uptake of FFAs arriving from the arterial vs. the portal vein or to release of FFAs in the hepatic circulatory bed. Splanchnic FFA release measured using hepatic vein samples was strongly related to visceral adipose tissue FFA release into the portal vein. This finding suggests that splanchnic FFA release is a good indicator of visceral adipose tissue lipolysis.

Independent pathways for de-repression of the mouse Ig heavy chain germ-line epsilon promoter: an IL-4 NAF/NF-IL-4 site as a context-dependent negative element

The activation of germ-line promoters in the Ig heavy chain loci is regulated by cytokines as part of the regulation of B cell commitment to production of new antibody isotypes. Activation of the germ-line promoter of the epsilon heavy chain locus (Gepsilon) and production of IgE are induced by IL-4 and each is virtually undetectable in the absence of IL-4 or the homologous cytokine IL-13. Basal expression of the Gepsilon promoter is repressed by the non-histone chromosomal protein HMG-I(Y), which also contributes to promoter inducibility, and IL-4 stimulates phosphorylation of the C-terminus of HMG-I(Y) through a rapamycin-sensitive pathway. IL-4 treatment of mouse B cells also induces a Gepsilon DNA binding activity with the properties of IL-4 NAF, which is rapidly induced and requires phosphotyrosine for DNA binding activity. This protein binds to a different site from HMG-I(Y), but the IL-4 NAF/NF-IL-4 binding site also is a negative element more active in repression of basal transcription of the Gepsilon promoter. This site acts as a negative element when transferred to the thymidine kinase promoter, but does not confer inducibility. In contrast to HMG-I(Y), IL-4 NAF/NF-IL-4 activation is refractory to rapamycin but sensitive to genistein. These findings indicate that two independent signal transduction pathways diverge from the IL-4 receptor and suggest that normal expression of Gepsilon RNA or IgE is low in part because the germ-line promoter is kept in a state of repression which requires de-repression through several cooperative pathways. These pathways target conserved nucleotide sequence motifs whose precise function depends on the promoter context in which they are situated.

Nutrition and physical activity program to attenuate obesity and promote physical and metabolic fitness in elementary school children

Obesity and low levels of physical and metabolic fitness are risk factors for cardiovascular disease and diabetes. The purpose of this investigation was to attenuate obesity and improve physical and metabolic fitness in elementary school children. Schools have the opportunity, mechanisms, and personnel in place to deliver nutrition education, fitness activities, and a school food service that is nutritious and healthy. Cohorts from grades 3 to 5 in two school districts in rural Nebraska (Intervention/Control) participated in a 2-year study of physical activity and modified school lunch program. Data collection for aerobic capacity, body composition, blood chemistry, nutrition knowledge, energy intake, and physical activity was at the beginning and end of each year. Int received enhanced physical activity, grade specific nutrition education, and a lower fat and sodium school lunch program. Con continued with a regular school lunch and team sports activity program. At year 2, Int lunches had significantly less energy (9%), fat (25%), sodium (21%), and more fiber (17%). However, measures of 24-hour energy intake for Int and Con showed significant differences for sodium only. Physical activity in the classroom was 6% greater for Int compared to Con (p < 0.05) but physical activity outside of school was approximately 16% less for Int compared to Con (p < 0.05). Body weight and body fat were not different between schools for normal weight or obese children. No differences were found for cholesterol, insulin, and glucose; however, HDL cholesterol was significantly greater and cholesterol/HDL was significantly less for Int compared to Con (p < 0.05). It appears that compensation in both energy intake and physical activity outside of school may be responsible for the lack of differences between Int and Con.

Insulin metabolism in depancreatized dogs during hemorrhagic shock

This study was done to determine why the plasma insulin remained elevated during shock. Mongrel Female dogs (12-15 kg) were depancreatized and maintained on a constant intraportal infusion of porcine insulin while they were bled to reduce and maintain the mean arterial blood pressure at 50 mm Hg for 165 min. Blood samples were taken for glucose and plasma insulin at 15 min intervals. The data show that there was a progressive rise of plasma insulin during the course of hemorrhagic shock. This occurred despite a constant infusion of insulin, the sole source of insulin available to these depancreatized dogs. Since removal of plasma insulin is largely due to insulin utilization, our findings imply that the rise of plasma insulin in hemorrhagic shock is caused by decreased utilization.

Effect of glucagon on glucose turnover and plasma free fatty acids in depancreatized dogs maintained on matched insulin infusions

It has been shown previously that glucagon can increase the turnover of glucose in normal dogs and can enhance the secretion of insulin. The aim of this study was to determine the metabolic effects of glucagon independent of the effects of the insulin it releases directly through an action on β cells, and indirectly through hyperglycemia. Eight conscious dogs which could not mobilize extra insulin were obtained by replacing the endogenous insulin secretion of each with an equivalent intraportal infusion of the hormone immediately following removal of a remnant pancreatic autograft. Such infusions (200 μU/kg-min) maintained normal plasma concentrations of glucose and free fatty acids (FFA), as well as normal tracer-determined rates of glucose appearance (Ra) and disappearance (Rd) prior to glucagon infusion.There was a highly significant regression of the increments in glucose production on the rate of glucagon infusion (1.00–3.00 μg/kg-h). Rd increased proportionally to glucose levels, and there was therefore no significant change in the metabolic clearance of glucose. Hence a direct inhibitory effect of glucagon on glucose utilization could not be demonstrated. Corrections for recycling of the infused label did not appreciably affect the observed changes in Ra or Rd. Glucagon infusions did not increase the FFA level in plasma; when hyperglycemia was prominent a small decrease occurred. The role of glucagon in the net release of FFA from adipocytes in dogs is therefore questioned.