Cardiovascular outcomes trial data from EMPA-REG OUTCOME, CAROLINA and CARMELINA: Assessment of a novel staging system for type 2 diabetes.

AIMS: To apply the diabetes staging system (DSS), a novel disease staging system similar to what is used in oncology but designed to improve diabetes management, to three large type 2 diabetes (T2D) cardiovascular (CV) outcome trials to assess whether increasing DSS stage was associated with higher rates of all-cause mortality (ACM) and/or CV death. MATERIALS AND METHODS: The DSS uses discrete CV events (none to ≥3: Stage 1 to 4), end-stage kidney disease (Stage 5) and microvascular complications (none to 3: A to D) to determine disease stage in individuals with T2D. The DSS stage for patients from the CAROLINA, EMPA-REG OUTCOME and CARMELINA trials was determined. Incidence rates for ACM/CV death were calculated across DSS stages and Cox regression analyses were performed. RESULTS: The risk of ACM or CV death increased with increasing DSS (Stage 1 to 5; P for trend <0.0001) in all trials. In CAROLINA, the risk of ACM and CV death increased with increasing number of microvascular complications (A to D; both P for trend <0.0001), similar in CARMELINA (P for trend = 0.0020 and 0.0005, respectively). In EMPA-REG OUTCOME, having all three microvascular complications (Stage D), versus none, increased the risk of ACM and CV death (P = 0.0015 and 0.0010, respectively). CONCLUSIONS: Applying the DSS across T2D clinical trial populations with different CV risk revealed a significantly increased risk of ACM and CV death with higher DSS stage. The DSS may merit assessment in other T2D populations and evaluation of the impact of additional outcomes, such as heart failure, could also be worthwhile.

Safety outcomes of SGLT2i in the heart failure trials: A systematic review and Meta-analysis.

AIMS: Sodium-glucose co-transporter inhibitors (SGLT2i) are emerging as a new treatment for heart failure (HF) after demonstrating favorable clinical outcomes in several randomized controlled trials (RCTs). In this meta-analysis, we assessed the safety of SGLT2i in the trials that prespecified heart failure in their inclusion criteria. MATERIALS AND METHODS: We searched the databases for RCTs comparing SGLT2i to placebo in heart failure patients. The primary outcome was the incidence of serious adverse events (SAEs). A sensitivity analysis according to the class of HF was also performed. RESULTS: The incidence of SAEs was significantly lower in the SGLT2i group (OR, 0.85; 95% CI, 0.77-0.92; P, 0.0002) and SAEs remained significantly lower after performing the sensitivity analysis (OR, 0.82; 95% CI, 0.75-0.89; P, <0.00001). Genital infections, urinary tract infections (UTIs), and hypotension were significantly higher in the SGLT2i group. CONCLUSIONS: SGLT2i remain a safe option for patients with HF with a lower incidence of SAEs. However, since they increase the risk of genital infection, UTIs and hypotension, the risks vs benefits in each patient should be weighed when making a prescribing decision.

Effect of a Comprehensive Telehealth Intervention vs Telemonitoring and Care Coordination in Patients With Persistently Poor Type 2 Diabetes Control: A Randomized Clinical Trial.

Importance: Persistently poorly controlled type 2 diabetes (PPDM) is common and causes poor outcomes. Comprehensive telehealth interventions could help address PPDM, but effectiveness is uncertain, and barriers impede use in clinical practice. Objective: To address evidence gaps preventing use of comprehensive telehealth for PPDM by comparing a practical, comprehensive telehealth intervention to a simpler telehealth approach. Design, Setting, and Participants: This active-comparator, parallel-arm, randomized clinical trial was conducted in 2 Veterans Affairs health care systems. From December 2018 to January 2020, 1128 outpatients with PPDM were assessed for eligibility and 200 were randomized; PPDM was defined as maintenance of hemoglobin A1c (HbA1c) level of 8.5% or higher for 1 year or longer despite engagement with clinic-based primary care and/or diabetes specialty care. Data analyses were preformed between March 2021 and May 2022. Interventions: Each 12-month intervention was nurse-delivered and used only clinical staffing/resources. The comprehensive telehealth group (n = 101) received telemonitoring, self-management support, diet/activity support, medication management, and depression support. Patients assigned to the simpler intervention (n = 99) received telemonitoring and care coordination. Main Outcomes and Measures: Primary (HbA1c) and secondary outcomes (diabetes distress, diabetes self-care, self-efficacy, body mass index, depression symptoms) were analyzed over 12 months using intent-to-treat linear mixed longitudinal models. Sensitivity analyses with multiple imputation and inclusion of clinical data examined the impact of missing HbA1c measurements. Adverse events and intervention costs were examined. Results: The population (n = 200) had a mean (SD) age of 57.8 (8.2) years; 45 (22.5%) were women, 144 (72.0%) were of Black race, and 11 (5.5%) were of Hispanic/Latinx ethnicity. From baseline to 12 months, HbA1c change was -1.59% (10.17% to 8.58%) in the comprehensive telehealth group and -0.98% (10.17% to 9.19%) in the telemonitoring/care coordination group, for an estimated mean difference of -0.61% (95% CI, -1.12% to -0.11%; P = .02). Sensitivity analyses showed similar results. At 12 months, patients receiving comprehensive telehealth had significantly greater improvements in diabetes distress, diabetes self-care, and self-efficacy; no differences in body mass index or depression were seen. Adverse events were similar between groups. Comprehensive telehealth cost an additional $1519 per patient per year to deliver. Conclusions and Relevance: This randomized clinical trial found that compared with telemonitoring/care coordination, comprehensive telehealth improved multiple outcomes in patients with PPDM at a reasonable additional cost. This study supports consideration of comprehensive telehealth implementation for PPDM in systems with appropriate infrastructure and may enhance the value of telehealth during the COVID-19 pandemic and beyond. Trial Registration: ClinicalTrials.gov Identifier: NCT03520413.

Factors associated with non-adherence to insulin and non-insulin medications in patients with poorly controlled diabetes.

OBJECTIVES: To evaluate differences in factors associated with self-reported medication non-adherence to insulin and non-insulin medications in patients with uncontrolled type 2 diabetes. METHODS: In this secondary analysis of a randomized trial in patients with obesity and uncontrolled type 2 diabetes, multivariable logistic regression was used to evaluate associations between several clinical factors (measured with survey questionnaires at study baseline) and self-reported non-adherence to insulin and non-insulin medications. RESULTS: Among 263 patients, reported non-adherence was 62% (52% for insulin, 55% for non-insulin medications). Reported non-adherence to non-insulin medications was less likely in white versus non-white patients (odds ratio (OR) = 0.42; 95%CI: 0.22,0.80) and with each additional medication taken (OR = 0.75; 95%CI: 0.61,0.93). Non-adherence to non-insulin medications was more likely with each point increase in a measure of diabetes medication intensity (OR = 1.43; 95%CI: 1.01,2.03), the Problem Areas in Diabetes (PAID) score (OR = 1.06; 95%CI: 1.02,1.12), and in men versus women (OR = 3.03; 95%CI: 1.06,8.65). For insulin, reporting non-adherence was more likely (OR = 1.02; 95%CI: 1.00,1.04) with each point increase in the PAID. DISCUSSION: Despite similar overall rates of reported non-adherence to insulin and non-insulin medications, factors associated with reported non-adherence to each medication type differed. These findings may help tailor approaches to supporting adherence in patients using different types of diabetes medications.

Clinical associations of an updated medication effect score for measuring diabetes treatment intensity.

OBJECTIVES: The medication effect score reflects overall intensity of a diabetes regimen by consolidating dosage and potency of agents used. Little is understood regarding how medication intensity relates to clinical factors. We updated the medication effect score to account for newer agents and explored associations between medication effect score and patient-level clinical factors. METHODS: Cross-sectional analysis of baseline data from a randomized controlled trial involving 263 Veterans with type 2 diabetes and hemoglobin A1c levels ≥8.0% (≥7.5% if under age 50). Medication effect score was calculated for all patients at baseline, alongside additional measures including demographics, comorbid illnesses, hemoglobin A1c, and self-reported psychosocial factors. We used multivariable regression to explore associations between baseline medication effect score and patient-level clinical factors. RESULTS: Our sample had a mean age of 60.7 (SD = 8.2) years, was 89.4% male, and 57.4% non-White. Older age and younger onset of diabetes were associated with a higher medication effect score, as was higher body mass index. Higher medication effect score was significantly associated with medication nonadherence, although not with hemoglobin A1c, self-reported hypoglycemia, diabetes-related distress, or depression. DISCUSSION: We observed several expected associations between an updated medication effect score and patient-level clinical factors. These associations support the medication effect score as an appropriate measure of diabetes regimen intensity in clinical and research contexts.

Practical telehealth to improve control and engagement for patients with clinic-refractory diabetes mellitus (PRACTICE-DM): Protocol and baseline data for a randomized trial.

BACKGROUND: Persistent poorly-controlled type 2 diabetes mellitus (PPDM), or maintenance of a hemoglobin A1c (HbA1c) ≥8.5% despite receiving clinic-based diabetes care, contributes disproportionately to the national diabetes burden. Comprehensive telehealth interventions may help ameliorate PPDM, but existing approaches have rarely been designed with clinical implementation in mind, limiting use in routine practice. We describe a study testing a novel telehealth intervention that comprehensively targets clinic-refractory PPDM, and was explicitly developed for practical delivery using existing Veterans Health Administration (VHA) clinical infrastructure. METHODS: Practical Telehealth to Improve Control and Engagement for Patients with Clinic-Refractory Diabetes Mellitus (PRACTICE-DM) is an ongoing randomized controlled trial comparing two 12-month interventions: 1) standard VHA Home Telehealth (HT) telemonitoring/care coordination; or 2) the PRACTICE-DM intervention, a comprehensive HT-delivered intervention combining telemonitoring, self-management support, diet/activity support, medication management, and depression management. The primary outcome is HbA1c. Secondary outcomes include diabetes distress, self-care, self-efficacy, weight, depressive symptoms, implementation barriers/facilitators, and costs. We hypothesize that the PRACTICE-DM intervention will reduce HbA1c by >0.6% versus standard HT over 12 months. RESULTS: Enrollment for this ongoing trial concluded in January 2020; 200 patients were randomized (99 to standard HT and 101 to the PRACTICE-DM intervention). The cohort has a mean age of 58 and is 23% female and 72% African American. Mean baseline HbA1c and BMI were 10.2% and 34.8 kg/m2. CONCLUSIONS: Because it comprehensively targets factors underlying PPDM using existing clinical infrastructure, the PRACTICE-DM intervention may be well suited to lower the complications and costs of PPDM in routine practice.

Comparison of Group Medical Visits Combined With Intensive Weight Management vs Group Medical Visits Alone for Glycemia in Patients With Type 2 Diabetes: A Noninferiority Randomized Clinical Trial.

Importance: Traditionally, group medical visits (GMVs) for persons with diabetes improved glycemia by intensifying medications, which infrequently led to weight loss. Incorporating GMVs with intensive dietary change could enable weight loss and improve glycemia while decreasing medication intensity. Objective: To examine whether a program of GMVs combined with intensive weight management (WM) is noninferior to GMVs alone for change in glycated hemoglobin (HbA1c) level at 48 weeks (prespecified margin of 0.5%) and superior to GMVs alone for hypoglycemic events, diabetes medication intensity, and weight loss. Design, Setting, and Participants: This randomized clinical trial identified via the electronic medical record 2814 outpatients with type 2 diabetes, uncontrolled HbA1c, and body mass index (BMI; calculated as weight in kilograms divided by height in meters squared) of 27 or higher from Veterans Affairs Medical Center clinics in Durham and Greenville, North Carolina. Between January 12, 2015, and May 30, 2017, 263 outpatients started the intervention. Interventions: Participants randomized to the GMV group (n = 136) received counseling about diabetes-related topics with medication optimization every 4 weeks for 16 weeks, then every 8 weeks (9 visits). Participants randomized to the WM/GMV group (n = 127) received low-carbohydrate diet counseling with baseline medication reduction and subsequent medication optimization every 2 weeks for 16 weeks followed by an abbreviated GMV intervention every 8 weeks (13 visits). Main Outcomes and Measures: Outcomes included HbA1c level, hypoglycemic events, diabetes medication effect score, and weight at 48 weeks analyzed using hierarchical generalized mixed models to account for clustering within group sessions. Results: Among 263 participants (mean [SD] age, 60.7 [8.2] years; 235 [89.4%] men; 143 [54.4%] black), baseline HbA1c level was 9.1% (1.3%) and BMI was 35.3 (5.1). At 48 weeks, HbA1c level was improved in both study arms (8.2% in the WM/GMV arm and 8.3% in the GMV arm; mean difference, -0.1%; 95% CI, -0.5% to 0.2%; upper 95% CI, <0.5% threshold; P = .44). The WM/GMV arm had lower diabetes medication use (mean difference in medication effect score, -0.5; 95% CI, -0.6 to -0.3; P < .001) and greater weight loss (mean difference, -3.7 kg; 95% CI, -5.5 to -1.9 kg; P < .001) than did the GMV arm at 48 weeks and approximately 50% fewer hypoglycemic events (incidence rate ratio, 0.49; 95% CI, 0.27 to 0.71; P < .001) during the 48-week period. Conclusions and Relevance: In GMVs for diabetes, addition of WM using a low-carbohydrate diet was noninferior for lowering HbA1c levels compared with conventional medication management and showed advantages in other clinically important outcomes. Trial Registration: ClinicalTrials.gov identifier: NCT01973972.

Transcriptomic characterization of signaling pathways associated with osteoblastic differentiation of MC-3T3E1 cells.

Bone remodeling involves the coordinated actions of osteoclasts, which resorb the calcified bony matrix, and osteoblasts, which refill erosion pits created by osteoclasts to restore skeletal integrity and adapt to changes in mechanical load. Osteoblasts are derived from pluripotent mesenchymal stem cell precursors, which undergo differentiation under the influence of a host of local and environmental cues. To characterize the autocrine/paracrine signaling networks associated with osteoblast maturation and function, we performed gene network analysis using complementary "agnostic" DNA microarray and "targeted" NanoString nCounter datasets derived from murine MC3T3-E1 cells induced to undergo synchronized osteoblastic differentiation in vitro. Pairwise datasets representing changes in gene expression associated with growth arrest (day 2 to 5 in culture), differentiation (day 5 to 10 in culture), and osteoblast maturation (day 10 to 28 in culture) were analyzed using Ingenuity Systems Pathways Analysis to generate predictions about signaling pathway activity based on the temporal sequence of changes in target gene expression. Our data indicate that some pathways involved in osteoblast differentiation, e.g. Wnt/ß-catenin signaling, are most active early in the process, while others, e.g. TGFß/BMP, cytokine/JAK-STAT and TNFα/RANKL signaling, increase in activity as differentiation progresses. Collectively, these pathways contribute to the sequential expression of genes involved in the synthesis and mineralization of extracellular matrix. These results provide insight into the temporal coordination and complex interplay between signaling networks controlling gene expression during osteoblast differentiation. A more complete understanding of these processes may aid the discovery of novel methods to promote osteoblast development for the treatment of conditions characterized by low bone mineral density.

TNM cancer staging: can it help develop a novel staging system for type 2 diabetes?

Type 2 diabetes (DM2) constitutes 90%-95% of the diabetes cases and is increasing at an alarming rate in the world. The Centers for Disease Control and Prevention (CDC) estimates that more than 29 million people in the United States have diabetes, which often causes mortality from macrovascular complications and morbidity from microvascular complications. Despite these troubling facts, there is currently no widely accepted staging system for DM2 like there is for cancer. TNM oncologic staging has taken a complex condition like cancer and conveyed likelihood of survival in simple alpha-numeric terms that both patients and providers can understand. Oncology is now entering the era of precision medicine where cancer treatment is increasingly being tailored to each patient's cancer. In contrast, DM2 lacks a staging system and remains a largely invisible disease even though it kills more Americans and costs more to treat than cancer. Is a comparable staging system for DM2 possible? We propose the Diabetes Staging System for DM2 that utilizes macrovascular events, microvascular complications, estimated glomerular filtration rate (GFR), and hemoglobin A1C to stage DM2.

High Incomplete Skeletal Muscle Fatty Acid Oxidation Explains Low Muscle Insulin Sensitivity in Poorly Controlled T2D.

Context: Almost 50% of type 2 diabetic (T2D) patients are poorly controlled [glycated hemoglobin (HbA1c) ≥ 7%]; however, the mechanisms responsible for progressively worsening glycemic control are poorly understood. Lower skeletal muscle mitochondrial respiratory capacity is associated with low insulin sensitivity and the development of T2D. Objective: We investigated if skeletal muscle insulin sensitivity (SI) was different between well-controlled T2D (WCD) and poorly controlled T2D (PCD) and if the difference was associated with differences resulting from mitochondrial respiratory function. Design: Vastus lateralis muscle mitochondrial respiration, mitochondrial content, mitochondrial enzyme activity, and fatty acid oxidation (FAO) were measured. SI and the acute response to glucose (AIRg) were calculated by MINMOD analysis from glucose and insulin obtained during a modified, frequently sampled, intravenous glucose tolerance test. Results: SI and AIRg were lower in PCD than WCD. Muscle incomplete FAO was greater in PCD than WCD and greater incomplete FAO was associated with lower SI and higher HbA1c. Hydroxyacyl-coenzyme A dehydrogenase expression and activity were greater in PCD than WCD. There was no difference in maximal mitochondrial respiration or content between WCD and PCD. Conclusion: The current results suggest that greater skeletal muscle incomplete FAO in poorly controlled T2D is due to elevated ß oxidation and is associated with worsening muscle SI.

Efficacy and Safety of Metreleptin in Patients with Partial Lipodystrophy: Lessons from an Expanded Access Program.

OBJECTIVE: Patients with lipodystrophy have severe metabolic abnormalities (insulin resistance, diabetes, and hypertriglyceridemia) that may increase morbidity and mortality. Metreleptin is approved by the United States Food and Drug Administration for treatment of generalized forms of lipodystrophy. We aimed to determine the efficacy and safety of metreleptin among patients with partial lipodystrophy using an expanded-access model. METHODS: Study FHA101 (ClinicalTrials.gov identifier: NCT00677313) was an open-label, expanded-access, long-term clinical effectiveness and safety study in 23 patients with partial lipodystrophy and diabetes and/or hypertriglyceridemia with no prespecified leptin level. Metreleptin was administered subcutaneously at 0.02 mg/kg twice daily (BID) at Week 1, followed by 0.04 mg/kg BID at Week 2. Dose adjustments thereafter were based on patient response (maximum dose of 0.08 mg/kg BID). One-year changes in glycated hemoglobin (HbA1c), fasting plasma glucose, triglycerides, alanine and aspartate aminotransferases, and treatment-emergent adverse events (TEAEs) were evaluated. RESULTS: HbA1c, fasting plasma glucose, and triglycerides were numerically decreased throughout 1 year, with mean (standard error) changes from baseline of -0.88 (0.62)%, -42.0 (22.4) mg/dL, and -119.8 (84.1) mg/dL, respectively, which were greater among patients with higher baseline abnormalities. Liver enzymes did not worsen, and the most frequently observed TEAEs (≥ 10% incidence) were mild to moderate and included nausea (39.1%), hypoglycemia (26.1%), and urinary tract infections (26.1%)-all reported previously. There were no reports of clinically significant immune-related adverse events or new safety signals. CONCLUSIONS: Our clinical observations document the large heterogeneity and disease burden of partial lipodystrophy syndromes and suggest that metreleptin treatment benefits may extend to patients with partial lipodystrophy. Additional studies are needed to confirm these preliminary findings.

Insulin sensitivity is related to glycemic control in type 2 diabetes and diabetes remission after Roux-en Y gastric bypass.

BACKGROUND: After initial onset, adequate glycemic control in patients with type 2 diabetes (T2DM) presents a continuing challenge even with aggressive pharmacologic treatment, and longer disease duration is associated with poorer resolution in response to Roux-en Y gastric bypass (RYGB). Skeletal muscle insulin sensitivity is an important determinant of glycemic control. We investigated whether skeletal muscle insulin sensitivity is predictive of T2DM resolution with RYGB and is in general lower in patients with longer-duration T2DM. METHODS: Insulin sensitivity (SI) and the acute response to glucose (AIRg) were calculated by MINMOD analysis from glucose and insulin obtained during a modified frequently sampled intravenous glucose tolerance test. RESULTS: Pre-RYGB SI and duration but not AIRg were predictive of T2DM resolution by RYGB. In addition, HbA1c was greater and SI and AIRg lower in long- (8+ years) compared with short-duration (1- to 7-year) T2DM. Multiple linear regression analysis demonstrated that SI explained 32% and AIRg 21% of the variance in HbA1c, respectively. CONCLUSION: The current results suggest that pre-RYGB SI is predictive of T2DM resolution after RYGB, skeletal muscle insulin sensitivity and ß-cell function worsen after the onset of T2DM, and low skeletal muscle insulin sensitivity as well as low ß cell function contribute to poor glycemic control in T2DM.

Impairments in site-specific AS160 phosphorylation and effects of exercise training.

The purpose of this study was to determine if site-specific phosphorylation at the level of Akt substrate of 160 kDa (AS160) is altered in skeletal muscle from sedentary humans across a wide range of the adult life span (18-84 years of age) and if endurance- and/or strength-oriented exercise training could rescue decrements in insulin action and skeletal muscle AS160 phosphorylation. A euglycemic-hyperinsulinemic clamp and skeletal muscle biopsies were performed in 73 individuals encompassing a wide age range (18-84 years of age), and insulin-stimulated AS160 phosphorylation was determined. Decrements in whole-body insulin action were associated with impairments in insulin-induced phosphorylation of skeletal muscle AS160 on sites Ser-588, Thr-642, Ser-666, and phospho-Akt substrate, but not Ser-318 or Ser-751. Twelve weeks of endurance- or strength-oriented exercise training increased whole-body insulin action and reversed impairments in AS160 phosphorylation evident in insulin-resistant aged individuals. These findings suggest that a dampening of insulin-induced phosphorylation of AS160 on specific sites in skeletal muscle contributes to the insulin resistance evident in a sedentary aging population and that exercise training is an effective intervention for treating these impairments.

GLP-1 response to a mixed meal: what happens 10 years after Roux-en-Y gastric bypass (RYGB)?

BACKGROUND: Oral meal consumption increases glucagon-like peptide 1 (GLP-1) release which maintains euglycemia by increasing insulin secretion. This effect is exaggerated during short-term follow-up of Roux-en-y gastric bypass (RYGB). We examined the durability of this effect in patient with type 2 diabetes (T2DM) >10 years after RYGB. METHODS: GLP-1 response to a mixed meal in the 10-year post-RYGB group (n = 5) was compared to lean (n = 9), obese (n = 6), and type 2 diabetic (n = 10) controls using a cross-sectional study design. Analysis of variance (ANOVA) was used to evaluate GLP-1 response to mixed meal consumption from 0 to 300 min, 0-20 min, 20-60 min, and 60-300 min, respectively. Weight, insulin resistance, and T2DM were also assessed. RESULTS: GLP-1 response 0-300 min in the 10-year post-RYGB showed a statistically significant overall difference (p = 0.01) compared to controls. Furthermore, GLP-1 response 0-20 min in the 10-year post-RYGB group showed a very rapid statistically significant rise (p = 0.035) to a peak of 40 pM. GLP-1 response between 20 and 60 min showed a rapid statistically significant (p = 0.041) decline in GLP-1 response from ~40 pM to 10 pM. GLP-1 response in the 10-year post-RYGB group from 60 to 300 min showed no statistically significant difference from controls. BMI, HOMA, and fasting serum glucose before and >10 years after RYGB changed from 59.9 → 40.4, 8.7 → 0.88, and 155.2 → 87.6 mg/dl, respectively, and were statistically significant (p < 0.05). CONCLUSIONS: An exaggerated GLP-1 response was noted 10 years after RYGB, strongly suggesting a durability of this effect. This phenomenon may play a key role in maintaining type 2 diabetes remission and weight loss after RYGB.

Regulator of G protein signaling 5 is highly expressed in parathyroid tumors and inhibits signaling by the calcium-sensing receptor.

The molecular mechanisms responsible for aberrant calcium signaling in parathyroid disease are poorly understood. The loss of appropriate calcium-responsive modulation of PTH secretion observed in parathyroid disease is commonly attributed to decreased expression of the calcium-sensing receptor (CaSR), a G protein-coupled receptor. However, CaSR expression is highly variable in parathyroid adenomas, and the lack of correlation between CaSR abundance and calcium-responsive PTH kinetics indicates that mechanisms independent of CaSR expression may contribute to aberrant calcium sensing in parathyroid disease. To gain a better understanding of parathyroid tumors and the molecular determinants that drive parathyroid adenoma development, we performed gene expression profiling on a panel of 64 normal and neoplastic parathyroid tissues. The microarray data revealed high-level expression of genes known to be involved in parathyroid biology (PTH, VDR, CGA, CaSR, and GCM2). Moreover, our screen identified regulator of G protein signaling 5 (RGS5) as a candidate inhibitor of CaSR signaling. We confirmed RGS5 to be highly expressed in parathyroid adenomas relative to matched-pair normal glands. Transient expression of RGS5 in cells stably expressing CaSR resulted in dose-dependent abrogation of calcium-stimulated inositol trisphosphate production and ERK1/2 phosphorylation. Furthermore, we found that RGS5-nullizygous mice display reduced plasma PTH levels, an outcome consistent with attenuated opposition to CaSR activity. Collectively, these data suggest that RGS5 can act as a physiological regulator of calcium sensing by CaSR in the parathyroid gland. The abnormally elevated expression of RGS5 observed in parathyroid adenomas could thus represent a novel mechanism of CaSR desensitization in patients with primary hyperparathyroidism.

Amelioration of insulin requirement in patients undergoing duodenal bypass for reasons other than obesity implicates foregut factors in the pathophysiology of type II diabetes.

BACKGROUND: Foregut diversion and weight loss have been proposed as potential mechanisms for resolution of type II diabetes mellitus (T2DM) observed in patients undergoing gastric bypass for obesity. To support or refute the role of the foregut, we analyzed glycemic control in T2DM patients before and after foregut bypass for reasons other than morbid obesity. STUDY DESIGN: Using ICD9/CPT codes, we identified patients undergoing Roux-en-Y gastrojejunostomy (RY) or Billroth II (BII) reconstruction over 10 years. Fasting blood glucose, insulin or oral diabetic agent requirement, and body mass index (BMI) before and after surgery were tabulated and compared using the Student's t-test. Linear regression was applied to determine specific factors predictive of resolution or improvement in glycemic control including age, duration of diabetes, antidiabetic regimen, type of operation, and surgical indication. RESULTS: Between 1996 and 2006, we identified 24 patients with T2DM out of a cohort of 209 who underwent either RY (12 of 24) or BII reconstruction (12 of 24) for cancer or peptic ulcer disease and survived more than 30 days after operation. Of this group, 75% were overweight (18 of 24 with BMI < 30 kg/m(2)) and 25% were class I morbidly obese (6 of 24 with BMI 30 to 35 kg/m(2)). Seventeen patients (71%) had either complete resolution (7 of 24 or 29%) or significant reduction (10 of 24 or 42%) in medication requirements; 7 patients (29%) did not have any improvement. Logistic regression failed to identify specific factors predicting improved glycemic control. CONCLUSIONS: Complete resolution of T2DM in patients undergoing duodenal diverting surgery occurs in about one-third of nonobese patients. Improved glycemic control occurs in more than two-thirds and cannot be explained by surgically related weight loss alone. Surgical cure of T2DM may be possible in carefully selected nonobese patients.

Bariatric surgery: what is the effect on type 2 diabetes?

Type 2 diabetes mellitus (T2DM) is a costly chronic disease that is associated with increased morbidity and mortality. Despite the development of numerous pharmacological agents, diet and exercise programs, and behavior-modification protocols, bariatric surgery remains the most effective tool for the durable reversal of T2DM. This review discusses the known effects of bariatric surgery on T2DM, with a particular focus on Roux-en-Y gastric bypass.

Impact of 25-hydroxyvitamin D deficiency on perioperative parathyroid hormone kinetics and results in patients with primary hyperparathyroidism.

BACKGROUND: Successful parathyroidectomy for sporadic primary hyperparathyroidism (pHPT) is predicted by a 50% drop in PTH intra-operatively. Vitamin D is a known inhibitor of PTH secretion and is associated with secondary HPT following adenoma resection. This study examined the impact of 25-hydroxyvitamin D (25OHD) deficiency on perioperative PTH kinetics and outcomes following parathyroidectomy. METHODS: Patients undergoing adenoma resection for pHPT (n=93) had PTH levels recorded at six perioperative time points. Preoperative 25OHD levels were examined retrospectively. Patients were considered 25OHD deficient if the level was <25 ng/mL (n=47) and adequate if the level was >or=25 ng/mL (n=46). RESULTS: Patients with 25OHD-deficiency had significantly higher preoperative calcium, alkaline phosphatase, and PTH levels. PTH levels were significantly higher in 25OHD-deficient patients at incision, at 1 week postop and 1-3 months postop. Average drop in PTH level five minutes post resection was 79+/-14% in the deficient group and 72+/-22% in the non-deficient group (P=.03). 25OHD levels inversely correlated with adenoma weight (P=.03) and postoperative PTH measurements (P=.008). CONCLUSIONS: Sporadic pHPT patients with 25OHD deficiency have higher baseline and postoperative PTH levels compared to non-deficient patients but do not have altered intraoperative PTH kinetics. Vitamin D deficiency is associated with postoperative elevation of PTH.

Ruboxistaurin, a protein kinase C beta inhibitor, as an emerging treatment for diabetes microvascular complications.

OBJECTIVE: To review current clinical data regarding the pharmacologic actions of ruboxistaurin (LY333531) mesylate, an inhibitor of protein kinase C (PKC) beta, and its role to potentially reduce the development and/or the progression of diabetic microvascular complications. DATA SOURCES: Primary literature was obtained via a MEDLINE search (1966-August 2004) and through review of pertinent abstracts and presentations at major medical meetings. STUDY SELECTION AND DATA EXTRACTION: Literature relevant to PKC physiology, the pharmacokinetics of ruboxistaurin, and data evaluating the use of ruboxistaurin in treating diabetic microvascular complications in human and relevant animal models was reviewed. DATA SYNTHESIS: PKC is part of a group of intracellular signaling molecules activated in response to various specific hormonal, neuronal, and growth factor stimuli. Hyperglycemia leads to PKC beta 1 and 2 isoform activation, which experimentally has been shown to contribute to the development and progression of diabetic microvascular complications (retinopathy, nephropathy, neuropathy) through various biochemical mechanisms. Animal and/or human studies using ruboxistaurin mesylate, a novel, highly selective inhibitor of PKC beta, have shown delay in the progression and, in some cases, reversal of diabetic retinopathy, nephropathy, and neuropathy. CONCLUSIONS: Ruboxistaurin mesylate, by inhibiting excessive activation of certain PKC isoforms, has the potential to reduce the burden of microvascular complications for patients with diabetes.