Causally interpretable meta-analysis combining aggregate and individual participant data.

Recent work in causally-interpretable meta-analysis (CIMA) has bridged the gap between traditional meta-analysis and causal inference. While traditional meta-analysis results generally do not apply to any well-defined population, CIMA approaches specify a target population to which meta-analytic treatment effect estimates are transported. While theoretically attractive, these approaches currently have some practical limitations. Most assume that all studies in the meta-analysis have individual participant data (IPD), which is rare in practice because most trials share only aggregate data. We propose a method to perform CIMA using a combination of aggregate data and IPD. This method borrows information from studies with IPD to augment the aggregate data and create aggregate-matched synthetic IPD (AMSIPD), which can be used readily in the existing CIMA framework. By allowing use of both aggregate data and IPD, the method opens CIMA to more applications and can avoid biases arising from using only studies with IPD. We present a case study and simulations showing the AMSIPD approach is promising and merits further investigation as an advancement of CIMA.

Increased kidney stone risk following total pancreatectomy with islet autotransplantation.

BACKGROUND/OBJECTIVES: Chronic pancreatitis (CP) is associated with increased risk of calcium-oxalate kidney stones, likely due to enteric hyperoxaluria. However, the risk of kidney stones for patients with CP after total pancreatectomy with islet autotransplantation (TPIAT) is unknown. We aimed to evaluate kidney stone risk in patients with CP after TPIAT. METHODS: A retrospective analysis of 629 patients who underwent TPIAT was conducted to identify patients who developed kidney stones post-TPIAT. Kaplan-Meier analysis estimated time to first event. An Anderson-Gill proportional-hazards analysis of all kidney stone events described key clinical associations. RESULTS: Mean age at TPIAT was 33 years (SD 15.3, range 3-69); 69.8 % (n = 439) were female. The estimated chance of any kidney stone episodes by 5 years post-TPIAT was 12.8 % (95 % CI: 8.8-16.6 %); by 10 years, 23.2 % (CI: 17.5-28.6 %); by 15 years, 29.4 % (CI: 21.8-36.2 %). Significant associations with kidney stones post-TPIAT included older age (HR 1.25 per 10 years), smoking history (HR 1.72), mild chronic kidney disease (HR 1.96), renal cysts (HR 3.67), pre-TPIAT kidney stones (HR 4.06), family history of kidney stones (HR 4.10), and Roux-en-Y reconstruction (HR 2.68). Of the 77 patients who developed kidney stones, 34 (44.1 %) had recurrent episodes. Of 143 total kidney stone events, 35 (24.5 %) required stone removal, 79 (55.2 %) resolved spontaneously, and 29 (20.3 %) were missing this data. CONCLUSIONS: Patients with CP post-TPIAT commonly have kidney stones: nearly 3 in 10 have ≥1 kidney stone episodes within 15 years. Clinicians should be aware of this risk and counsel patients on prevention.

Peri-Transplant Inflammation and Long-Term Diabetes Outcomes Were Not Impacted by Either Etanercept or Alpha-1-Antitrypsin Treatment in Islet Autotransplant Recipients.

The instant blood-mediated inflammatory response (IBMIR) causes islet loss and compromises diabetes outcomes after total pancreatectomy with islet autotransplant (TPIAT). We previously reported a possible benefit of etanercept in maintaining insulin secretion 3 months post-TPIAT. Here, we report 2-year diabetes outcomes and peri-operative inflammatory profiles from a randomized trial of etanercept and alpha-1 antitrypsin (A1AT) in TPIAT. We randomized 43 TPIAT recipients to A1AT (90 mg/kg IV x6 doses, n = 13), etanercept (50 mg then 25 mg SQ x 5 doses, n = 14), or standard care (n = 16). Inflammatory cytokines, serum A1AT and unmethylated insulin DNA were drawn multiple times in the perioperative period. Islet function was assessed 2 years after TPIAT with mixed meal tolerance test, intravenous glucose tolerance test and glucose-potentiated arginine induced insulin secretion. Cytokines, especially IL-6, IL-8, IL-10, and MCP-1, were elevated during and after TPIAT. However, only TNFα differed significantly between groups, with highest levels in the etanercept group (p = 0.027). A1AT increased after IAT in all groups (p < 0.001), suggesting endogenous upregulation. Unmethylated insulin DNA ratios (a marker of islet loss) and 2 years islet function testing were similar in the three groups. To conclude, we found no sustained benefit from administering etanercept or A1AT in the perioperative period.

Occurrence and Predictors of Postoperative Preauricular and Masticatory Muscle Pain Symptoms After Surgical Removal of Third Molars: A Single-Blind Randomized Controlled Trial Comparing Dental Assistants Supporting the Mandible and the Restful Jaw Device.

BACKGROUND: During third molar removal, the mandible is supported by a dental assistant (DA) to counter downward forces during surgery, and with sedation, to maintain airway patency. The Restful Jaw device (PEP Design; Saint Paul) provides this support instead of the DA. PURPOSE: This study compared the occurrence of postoperative preauricular and masticatory muscle pain symptoms (PMMPS) between the device and DAs providing mandibular support, using two outcome measures. Secondary aims identify predictors of outcome and providers' opinions of the device. STUDY DESIGN, SETTING, SAMPLE: In this multisite, single-blind, two-arm parallel randomized trial, participants without preoperative PMMPS had surgical removal of third molars, with sedation and bite blocks were randomly assigned to manual support or the device. EXPOSURE VARIABLE: The exposed group was randomly assigned to the device and the nonexposed group to manual support. MAIN OUTCOME VARIABLE(S): The primary outcome was patient-reported PMMPS. Two secondary outcomes were pain assessed with the temporomandibular disorder Pain Screener and providers' views on the device. Outcomes were assessed at 1-, 3-, and 6-month postsurgery. COVARIATES: The covariates are baseline demographics (eg, sex), clinical characteristics (eg, eruption status), and third molar surgeries. ANALYSES: For occurrence of pain, generalized estimating equations assessed differences between groups. Logistic regression analysis assessed predictors of pain at 1 month, per the Screener. The level for statistical significance was 5%. RESULTS: Enrollment was 86 and 83 participants in the device and DA groups, respectively. The average age was 20.8 years; the majority were female (65%) and Caucasian (66%). The retention rate was ≥95.9%. The groups did not differ significantly for occurrence of pain using the primary and secondary outcome measures at any follow-up (P ≥ .46). Fully impacted molars were associated with occurrence of pain (odds ratio = 3.44; 95% confidence interval 1.49-7.92; P = .004). CONCLUSION AND RELEVANCE: Occurrence of pain using the primary and secondary outcome measures did not differ significantly between groups at any follow-up and was associated with removal of fully impacted third molars. Four out of five surgeons reported wanting to use the device on a regular basis when performing this procedure in sedated patients.

How well do participants in clinical trials represent the U.S. population with chronic neck or back pain?

BACKGROUND: Randomized clinical trials (RCTs) are the gold standard for assessing treatment effectiveness; however, they have been criticized for generalizability issues such as how well trial participants represent those who receive the treatments in clinical practice. We assessed the representativeness of participants from eight RCTs for chronic spine pain in the U.S., which were used for an individual participant data meta-analysis on the cost-effectiveness of spinal manipulation for spine pain. In these clinical trials, spinal manipulation was performed by chiropractors. METHODS: We conducted a retrospective secondary analysis of RCT data to compare trial participants' socio-demographic characteristics, clinical features, and health outcomes to a representative sample of (a) U.S. adults with chronic spine pain and (b) U.S. adults with chronic spine pain receiving chiropractic care, using secondary data from the National Health Interview Survey (NHIS) and Medical Expenditure Panel Survey (MEPS). We assessed differences between trial and U.S. spine populations using independent t-tests for means and z-tests for proportions, accounting for the complex multi-stage survey design of the NHIS and MEPS. RESULTS: We found the clinical trials had an under-representation of individuals from health disparity populations with lower percentages of racial and ethnic minority groups (Black/African American 7% lower, Hispanic 8% lower), less educated (No high school degree 19% lower, high school degree 11% lower), and unemployed adults (25% lower) with worse health outcomes (physical health scores 2.5 lower and mental health scores 5.3 lower using the SF-12/36) relative to the U.S. population with spine pain. While the odds of chiropractic use in the U.S. are lower for individuals from health disparity populations, the trials also under-represented these populations relative to U.S. adults with chronic spine pain who visit a chiropractor. CONCLUSIONS: Health disparity populations are not well represented in spine pain clinical trials. Embracing key community-based approaches, which have shown promise for increasing participation of underserved communities, is needed.

Blood Levels of Environmental Heavy Metals are Associated with Poorer Iron Status in Ugandan Children: A Cross-Sectional Study.

BACKGROUND: Iron deficiency (ID) and environmental exposure to metals frequently co-occur among Ugandan children, but little is known about their associations, although iron and other divalent metals share the same intestinal absorption transporter, divalent metal transporter 1 (DMT1). OBJECTIVES: We examined associations between iron status and blood concentrations of lead, manganese (Mn), cobalt (Co), and cadmium, both singly and as a mixture. METHODS: We used data on sociodemographic status, iron biomarkers, and blood concentrations of heavy metals collected from a cross-sectional survey of 100 children aged 6-59 mo in Kampala, Uganda. We compared blood concentrations of metals in ID with iron-sufficient children. We examined associations between a metal mixture and iron biomarkers using multiple linear regression and weighted quintile sum regression. RESULTS: The median (interquartile range) blood Mn (µg/L) was higher in ID children defined by soluble transferrin receptor (sTfR) and ferritin (ID compared with iron-sufficient children): (sTfR [21.3 {15.1, 28.8}, 11.2 {8.6, 18.5}], ferritin [19.5 {15.0, 27.2}, 11.2 {8.8, 19.6}]; P < 0.001 for both). Similarly, the median (interquartile range) blood Co (µg/L) was higher in ID children by ferritin ([0.5 {0.4, 0.9}, 0.4 {0.3, 0.5}], P = 0.05). Based on the multiple linear regression results, higher blood Co and Mn were associated with poorer iron status (defined by all 4 iron indicators for Co and by sTfR for Mn). The weighted quintile sum regression result showed that higher blood concentrations of a metal mixture were associated with poorer iron status represented by sTfR, ferritin, and hepcidin, mainly driven by Co and Mn. CONCLUSIONS: Our study findings suggest that poorer iron status is associated with overall heavy metal burden, predominantly Co and Mn, among Ugandan children. Further prospective studies should confirm our primary findings and investigate the combined effects of coexposures to neurotoxicants on the neurodevelopment of young children.

A randomized controlled pilot trial of etanercept and alpha-1 antitrypsin to improve autologous islet engraftment.

BACKGROUND: In total pancreatectomy with islet auto-transplantation, successful diabetes outcomes are limited by islet loss from the instant blood mediated inflammatory response. We hypothesized that blockade of the inflammatory response with either etanercept or alpha-1-antitrypsin would improve islet function and insulin independence. METHODS: We randomized 43 participants to receive A1AT (90 mg/kg x 6 doses, n = 13), or etanercept (50 mg then 25 mg x 5 doses, n = 14), or standard care (n = 16), aiming to reduce detrimental effects of innate inflammation on early islet survival. Islet graft function was assessed using mixed meal tolerance testing, intravenous glucose tolerance testing, glucose-potentiated arginine-induced insulin secretion studies, HbA1c, and insulin dose 3 months and 1 year post-TPIAT. RESULTS: We observed the most robust acute insulin response (AIRglu) and acute C-peptide response to glucose (ACRglu) at 3 months after TPIAT in the etanercept-treated group (p ≤ 0.02), but no differences in other efficacy measures. The groups did not differ overall at 1 year but when adjusted by sex, there was a trend towards a sex-specific treatment effect in females (AIRglu p = 0.05, ACRglu p = 0.06), with insulin secretion measures highest in A1AT-treated females. CONCLUSION: Our randomized trial supports a potential role for etanercept in optimizing early islet engraftment but it is unclear whether this benefit is sustained. Further studies are needed to evaluate possible sex-specific responses to either treatment. CLINICAL TRIAL NOTATION: This study was performed under an Investigational New Drug Application (IND #119828) from the Food and Drug Administration and was registered on clinicaltrials.gov (NCT#02713997).

Accounting for post-randomization variables in meta-analysis: A joint meta-regression approach.

Meta-regression is widely used in systematic reviews to investigate sources of heterogeneity and the association of study-level covariates with treatment effectiveness. Existing meta-regression approaches are successful in adjusting for baseline covariates, which include real study-level covariates (e.g., publication year) that are invariant within a study and aggregated baseline covariates (e.g., mean age) that differ for each participant but are measured before randomization within a study. However, these methods have several limitations in adjusting for post-randomization variables. Although post-randomization variables share a handful of similarities with baseline covariates, they differ in several aspects. First, baseline covariates can be aggregated at the study level presumably because they are assumed to be balanced by the randomization, while post-randomization variables are not balanced across arms within a study and are commonly aggregated at the arm level. Second, post-randomization variables may interact dynamically with the primary outcome. Third, unlike baseline covariates, post-randomization variables are themselves often important outcomes under investigation. In light of these differences, we propose a Bayesian joint meta-regression approach adjusting for post-randomization variables. The proposed method simultaneously estimates the treatment effect on the primary outcome and on the post-randomization variables. It takes into consideration both between- and within-study variability in post-randomization variables. Studies with missing data in either the primary outcome or the post-randomization variables are included in the joint model to improve estimation. Our method is evaluated by simulations and a real meta-analysis of major depression disorder treatments.

Islet graft function by mixed meal tolerance testing is sustained over 4 years in young children undergoing total pancreatectomy with islet autotransplantation.

Children with intractable chronic pancreatitis may require total pancreatectomy with islet autotransplantation (TPIAT) for pain relief. The IAT reduces the severity of post- pancreatectomy diabetes. We analyzed 635 mixed meal tolerance tests (MMTT) in 134 children undergoing TPIAT to determine whether superior survival of islet grafts explains higher rates of insulin independence previously reported in young children (n = 52, age 3-11 years) versus adolescents (n = 82, age 12-18 years). For MMTT, children consumed Boost HP and we sampled C-peptide and glucose repeatedly over 2 h. The trajectory of outcomes before and after TPIAT was compared between children and adolescents using data from pre-TPIAT and 3, 6 months, 1, 2, 3, and 4 years post-TPIAT and mixed linear models with a random effect for child. Cox regression was used to analyze time outcomes (e.g., time to first off insulin). Islet mass transplanted, measured as islet equivalents (IEQ), was higher in adolescents (p = .003) but IEQ/kg was higher in young children (p < .001) because of their lower weight. AUC C-peptide in young children increased somewhat over 4 years, but was stable in adolescents (p = .0013). AUC glucose increased more in adolescents over time post-TPIAT (p = .0024). Islet function by AUC C-peptide:AUC glucose ratio was better preserved in young children (p < .001). Adolescents were less likely to wean off insulin (hazard ratio .44 [95% CI .28, .69]). These data support an advantage of young age in islet graft survival after TPIAT. The greater likelihood of insulin independence in young children may be driven by better islet survival after transplant.

Estimating the Complier Average Causal Effect in a Meta-Analysis of Randomized Clinical Trials With Binary Outcomes Accounting for Noncompliance: A Generalized Linear Latent and Mixed Model Approach.

Noncompliance, a common problem in randomized clinical trials (RCTs), can bias estimation of the effect of treatment receipt using a standard intention-to-treat analysis. The complier average causal effect (CACE) measures the effect of an intervention in the latent subpopulation that would comply with their assigned treatment. Although several methods have been developed to estimate the CACE in analyzing a single RCT, methods for estimating the CACE in a meta-analysis of RCTs with noncompliance await further development. This article reviews the assumptions needed to estimate the CACE in a single RCT and proposes a frequentist alternative for estimating the CACE in a meta-analysis, using a generalized linear latent and mixed model with SAS software (SAS Institute, Inc.). The method accounts for between-study heterogeneity using random effects. We implement the methods and describe an illustrative example of a meta-analysis of 10 RCTs evaluating the effect of receiving epidural analgesia in labor on cesarean delivery, where noncompliance varies dramatically between studies. Simulation studies are used to evaluate the performance of the proposed method.

Exposed bone in patients with head and neck cancer treated with radiation therapy: An analysis of the Observational Study of Dental Outcomes in Head and Neck Cancer Patients (OraRad).

BACKGROUND: Patients with head and neck cancer (HNC) treated with radiation therapy (RT) are at risk for jaw osteoradionecrosis (ORN), which is largely characterized by the presence of exposed necrotic bone. This report describes the incidence and clinical course of and risk factors for exposed intraoral bone in the multicenter Observational Study of Dental Outcomes in Head and Neck Cancer Patients (OraRad) cohort. METHODS: Participants were evaluated before RT and at 6, 12, 18, and 24 months after RT. Exposed bone was characterized by location, sequestrum formation, and other associated features. The radiation dose to the affected area was determined, and the history of treatment for exposed bone was recorded. RESULTS: The study enrolled 572 participants; 35 (6.1%) were diagnosed with incident exposed bone at 6 (47% of reports), 12 (24%), 18 (20%), and 24 months (8%), with 60% being sequestrum and with 7 cases (20%) persisting for >6 months. The average maximum RT dose to the affected area of exposed bone was 5456 cGy (SD, 1768 cGy); the most frequent associated primary RT sites were the oropharynx (42.9%) and oral cavity (31.4%), and 76% of episodes occurred in the mandible. The diagnosis of ORN was confirmed in 18 participants for an incidence rate of 3.1% (18 of 572). Risk factors included pre-RT extractions (P = .008), a higher RT dose (P = .039), and tobacco use (P = .048). CONCLUSIONS: The 2-year incidence of exposed bone in the OraRad cohort was 6.1%; the incidence of confirmed ORN was 3.1%. Exposed bone after RT for HNC is relatively uncommon and, in most cases, is a short-term complication, not a recurring or persistent one.

Surgical approach and short-term outcomes in adults and children undergoing total pancreatectomy with islet autotransplantation: A report from the Prospective Observational Study of TPIAT.

BACKGROUND: Total pancreatectomy with islet autotransplantation (TPIAT) is a viable option for treating debilitating recurrent acute pancreatitis (RAP) and chronic pancreatitis (CP) in adults and children. No data is currently available regarding variation in approach to operation. METHODS: We evaluated surgical techniques, islet isolation and infusion approaches, and outcomes and complications, comparing children (n = 84) with adults (n = 195) enrolled between January 2017 and April 2020 by 11 centers in the United States in the Prospective Observational Study of TPIAT (POST), which was launched in 2017 to collect standard history and outcomes data from patients undergoing TPIAT for RAP or CP. RESULTS: Children more commonly underwent splenectomy (100% versus 91%, p = 0.002), pylorus preservation (93% versus 67%; p < 0.0001), Roux-en-Y duodenojejunostomy reconstruction (92% versus 35%; p < 0.0001), and enteral feeding tube placement (93% versus 63%; p < 0.0001). Median islet equivalents/kg transplanted was higher in children (4577; IQR 2816-6517) than adults (2909; IQR 1555-4479; p < 0.0001), with COBE purification less common in children (4% versus 15%; p = 0.0068). Median length of hospital stay was higher in children (15 days; IQR 14-22 versus 11 days; IQR 8-14; p < 0.0001), but 30-day readmissions were lower in children (13% versus 26%, p = 0.018). Rate of portal vein thrombosis was significantly lower in children than in adults (2% versus 10%, p = 0.028). There were no mortalities in the first 90 days post-TPIAT. CONCLUSIONS: Pancreatectomy techniques differ between children and adults, with islet yields higher in children. The rates of portal vein thrombosis and early readmission are lower in children.

The role of FSH in body composition in hematopoietic cell transplant recipients.

BACKGROUND: Childhood cancer survivors who received a hematopoietic cell transplantation (HCT) are at increased risk for follicle-stimulating hormone (FSH) abnormalities, which may have a significant negative impact on bone health and body composition. This study's purpose was to examine FSH and body composition in HCT recipients, non-HCT recipients and healthy controls. METHODS: The study included HCT recipients (n = 24), non-HCT recipients (n = 309), and a control group of healthy siblings (n = 211) all aged 9-18 years. A fasting blood sample was collected to measure FSH. All participants underwent a dual X-ray absorptiometry scan to assess total and regional percent fat, lean mass (LM), fat mass (FM), bone mineral content (BMC), bone mineral density (BMD), and visceral adipose tissue (VAT) mass. RESULTS: FSH was significantly higher in HCT recipients compared to non-HCT recipients and healthy controls. HCT recipients had significantly lower total body weight, total LM, arm and leg LM, BMC and BMD compared to non-HCT recipients and healthy controls (p < .05). Non-HCT recipients had significantly higher total, trunk, android, gynoid, arm and leg FM compared to healthy controls. Also, healthy controls had significantly lower VAT mass compared to non-HCT recipients. CONCLUSIONS: This study's results show that HCT recipients have significant reductions in BMD, worse body composition, and abnormal FSH levels compared to non-HCT recipients and healthy controls.

The Role of Follicle-stimulating Hormone in Vascular Dysfunction Observed in Hematopoietic Cell Transplant Recipients.

Childhood cancer survivors who receive a hematopoietic cell transplantation (HCT) are at increased risk for follicle-stimulating hormone (FSH) abnormalities, which may have a substantial negative impact on vascular function. The purpose of this study was to examine the association of vascular function with FSH in HCT recipients, non-HCT recipients and healthy controls. The study included childhood cancer survivors who were HCT recipients (n=24) and non-HCT recipients (n=308), and a control group of healthy siblings (n=211) all between 9 and 18 years old. Vascular measures of carotid artery structure and function (compliance and distensibility), brachial artery flow-mediated dilation and endothelial-independent dilation were measured using ultrasound imaging. A fasting blood sample was collected to measure hormone levels. FSH was significantly higher in HCT recipients compared with non-HCT recipients and healthy controls (P<0.01). Carotid compliance and distensibility were significantly lower in HCT and non-HCT recipients compared with healthy controls (P<0.05). Higher FSH was associated with decreased carotid compliance (P<0.05). This study's results suggest that higher levels of FSH in HCT recipients may result in significant reductions in vascular function compared with non-HCT recipients and healthy controls. Therefore, gonadotropin endocrine dysfunction, particularly abnormal FSH levels, may be an underlying mechanism of vascular dysfunction.

The Age-Period-Cohort-Interaction Model for Describing and Investigating Inter-cohort Deviations and Intra-cohort Life-course Dynamics.

Social scientists have frequently sought to understand the distinct effects of age, period, and cohort, but disaggregation of the three dimensions is difficult because cohort = period - age. We argue that this technical difficulty reflects a disconnection between how cohort effect is conceptualized and how it is modeled in the traditional age-period-cohort framework. We propose a new method, called the age-period-cohort-interaction (APC-I) model, that is qualitatively different from previous methods in that it represents Ryder's (1965) theoretical account about the conditions under which cohort differentiation may arise. This APC-I model does not require problematic statistical assumptions and the interpretation is straightforward. It quantifies inter-cohort deviations from the age and period main effects and also permits hypothesis testing about intra-cohort life-course dynamics. We demonstrate how this new model can be used to examine age, period, and cohort patterns in women's labor force participation.

Progress in individualizing autologous islet isolation techniques for pediatric islet autotransplantation after total pancreatectomy in children for chronic pancreatitis.

Total pancreatectomy with islet autotransplantation is performed to treat chronic pancreatitis in children. Successful islet isolation must address the challenges of severe pancreatic fibrosis and young donor age. We have progressively introduced modifications to optimize enzymatic and mechanical dissociation of the pancreas during islet isolation. We evaluated 2 islet isolation metrics in 138 children-digest islet equivalents per gram pancreas tissue (IEQ/g) and digest IEQ per kilogram body weight (IEQ/kg), using multiple regression to adjust for key disease and patient features. Islet yield at digest had an average 4569 (standard deviation 2949) islet equivalent (IEQ)/g and 4946 (4009) IEQ/kg, with 59.1% embedded in exocrine tissue. Cases with very low yield (<2000 IEQ/g or IEQ/kg) have decreased substantially over time, 6.8% and 9.1%, respectively, in the most recent tertile of time compared to 19.2% and 23.4% in the middle and 34.1% and 36.4% in the oldest tertile. IEQ/g and IEQ/kg adjusted for patient and disease factors improved in consistency and yield in the modern era. Minimal mechanical disruption during digestion, warm enzymatic digestion using enzyme collagenase:NP activity ratio < 10:1, coupled with extended distension and trimming time during islet isolation of younger and fibrotic pediatric pancreases, gave increased islet yield with improved patient outcomes.

Reduced bone mineral density in the first year after total pancreatectomy with islet autotransplantation (TPIAT).

BACKGROUND/OBJECTIVES: The effect of total pancreatectomy with islet autotransplantation (TPIAT) on bone mineral density (BMD) in patients with CP is unknown. We aimed to assess bone health in patients with CP after TPIAT. METHODS: We measured BMD, BMD Z-score, and bone mineral content (BMC) for total body, lumbar spine, right and left hip in 78 patients before and after TPIAT using dual-energy X-ray absorptiometry (DXA, n = 78 pre-TPIAT, n = 65 paired pre- and 12 months post-TPIAT, n = 33 paired 12 and 18 months post-TPIAT), and tested for association with clinical history including age, smoking status, and medications using paired and two-sample t-tests, linear regression, and Fisher's exact test. Laboratory measures related to bone health were also assessed. RESULTS: In the patients with pre-TPIAT DXA, 12% had low BMD (Z-score ≤ -2). BMD, BMD Z-score, and BMC all decreased from pre-to 12 months post-TPIAT. BMD declined by 1.7%-4.1% with the greatest change at the hips. Adjusted for change in lean and fat body mass, DXA changes remained significant for total body and hip. Serum carboxy-terminal collagen crosslinks telopeptide and alkaline phosphatase increased at 12 months post-TPIAT, suggesting possible increased bone remodeling. BMD, BMD Z-score, and BMC did not change between 12 months and 18 months in any of the four regions (p > 0.6). CONCLUSIONS: TPIAT is associated with decreases in BMD in the body, lumbar, and hip regions of patients with CP in the first year after TPIAT but these appear to stabilize between 12 and 18 months after TPIAT.

Preoperative ERCP has no impact on islet yield following total pancreatectomy and islet autotransplantation (TPIAT): Results from the Prospective Observational Study of TPIAT (POST) cohort.

BACKGROUND AND AIMS: Many patients undergoing total pancreatectomy with islet autotransplant (TPIAT) for severe, refractory chronic pancreatitis or recurrent acute pancreatitis have a history of endoscopic retrograde cholangiopancreatography (ERCP). Using data from the multicenter POST (Prospective Observational Study of TPIAT) cohort, we aimed to determine clinical characteristics associated with ERCP and the effect of ERCP on islet yield. METHODS: Using data from 230 participants (11 centers), demographics, pancreatitis history, and imaging features were tested for association with ERCP procedures. Logistic and linear regression were used to assess association of islet yield measures with having any pre-operative ERCPs and with the number of ERCPs, adjusting for confounders. RESULTS: 175 (76%) underwent ERCPs [median number of ERCPs (IQR) 2 (1-4). ERCP was more common in those with obstructed pancreatic duct (p = 0.0009), pancreas divisum (p = 0.0009), prior pancreatic surgery (p = 0.005), and longer disease duration (p = 0.004). A greater number of ERCPs was associated with disease duration (p < 0.0001), obstructed pancreatic duct (p = 0.006), and prior pancreatic surgery (p = 0.006) and increased risk for positive islet culture (p < 0.0001). Mean total IEQ/kg with vs. without prior ERCP were 4145 (95% CI 3621-4669) vs. 3476 (95% CI 2521-4431) respectively (p = 0.23). Adjusting for confounders, islet yield was not significantly associated with prior ERCP, number of ERCPs, biliary or pancreatic sphincterotomy or stent placement. CONCLUSIONS: ERCP did not appear to adversely impact islet yield. When indicated, ERCP need not be withheld to optimize islet yield but the risk-benefit ratio of ERCP should be considered given its potential harms, including risk for excessive delay in TPIAT.

Voluntary and magnetically evoked muscle contraction protocol in males with Duchenne muscular dystrophy: Safety, feasibility, reliability, and validity.

INTRODUCTION/AIMS: Clinical trials addressing treatments for Duchenne muscular dystrophy (DMD) require reliable and valid measurement of muscle contractile function across all disease severity levels. In this work we aimed to evaluate a protocol combining voluntary and evoked contractions to measure strength and excitability of wrist extensor muscles for safety, feasibility, reliability, and discriminant validity between males with DMD and controls. METHODS: Wrist extensor muscle strength and excitability were assessed in males with DMD (N = 10; mean ± standard deviation: 15.4 ± 5.9 years of age), using the Brooke Upper Extremity Rating Scale (scored 1-6), and age-matched healthy male controls (N = 15; 15.5 ± 5.0 years of age). Torque and electromyographic (EMG) measurements were analyzed under maximum voluntary and stimulated conditions at two visits. RESULTS: A protocol of multiple maximal voluntary contractions (MVCs) and evoked twitch contractions was feasible and safe, with 96% of the participants completing the protocol and having a less than 7% strength decrement on either measure for both DMD patients and controls (P ≥ .074). Reliability was excellent for voluntary and evoked measurements of torque and EMG (intraclass correlation coefficient [ICC] over 0.90 and over 0.85 within and between visits, respectively). Torque, EMG, and timing of twitch-onset measurements discriminated between DMD and controls (P < .001). Twitch contraction time did not differ significantly between groups (P = .10). DISCUSSION: Findings from this study show that the protocol is a safe, feasible, reliable, and a valid method to measure strength and excitability of wrist extensors in males with DMD.

Performance of modified Igls criteria to evaluate islet autograft function after total pancreatectomy with islet autotransplantation - a retrospective study.

The Igls criteria assess islet function after islet allotransplant, based on C-peptide, insulin use, hemoglobin A1c, and severe hypoglycemia. However, these criteria as currently defined cannot be applied to total pancreatectomy islet autotransplant (TPIAT) patients. We tested modified criteria for assessing islet function in a large cohort of TPIAT patients (n = 379). Metabolic outcomes were assessed. We assigned Auto-Igls class to each patient as able and evaluated the utility, validity, and perioperative risk factors of Auto-Igls at 1-year post-IAT. We tested the association of Auto-Igls with independent measures of islet graft function, specifically continuous glucose monitoring (CGM) data or acute C-peptide response to glucose (ACRglu) from intravenous glucose tolerance tests. An Auto-Igls class was assigned to 264 patients (69%). Among patients who could not be classified, most were missing exact insulin dose. Seventy-three percent of TPIAT recipients were classified as optimal or good at 1 year. The only significant predictor of Auto-Igls class was islet mass transplanted (P < 0.0001). Auto-Igls class was associated with percent time in range (70-140 mg/dl) on CGM (P = 0.02) and ACRglu (P < 0.0001). Modified Igls classification for IAT permits simple, comprehensive assessment of metabolic outcomes after TPIAT and is associated with other islet functional measures.