Thyroid Hormone Levels Correlate With the Maturation of Implanted Pancreatic Endoderm Cells in Patients With Type 1 Diabetes.

BACKGROUND: Macroencapsulated pancreatic endoderm cells (PECs) can reverse diabetes in rodents and preclinical studies revealed that thyroid hormones in vitro and in vivo bias PECs to differentiate into insulin-producing cells. In an ongoing clinical trial, PECs implanted in macroencapsulation devices into patients with type 1 diabetes were safe but yielded heterogeneous outcomes. Though most patients developed meal responsive C-peptide, levels were heterogeneous and explanted grafts had variable numbers of surviving cells with variable distribution of endocrine cells. METHODS: We measured circulating triiodothyronine and thyroxine levels in all patients treated at 1 of the 7 sites of the ongoing clinical trial and determined if thyroid hormone levels were associated with the C-peptide or glucagon levels and cell fate of implanted PECs. RESULTS: Both triiodothyronine and thyroxine levels were significantly associated with the proportion of cells that adopted an insulin-producing fate with a mature phenotype. Thyroid hormone levels were inversely correlated to circulating glucagon levels after implantation, suggesting that thyroid hormones lead PECs to favor an insulin-producing fate over a glucagon-producing fate. In mice, hyperthyroidism led to more rapid maturation of PECs into insulin-producing cells similar in phenotype to PECs in euthyroid mice. CONCLUSION: These data highlight the relevance of thyroid hormones in the context of PEC therapy in patients with type 1 diabetes and suggest that a thyroid hormone adjuvant therapy may optimize cell outcomes in some PEC recipients.

Encapsulated stem cell-derived ß cells exert glucose control in patients with type 1 diabetes.

Clinical studies on the treatment of type 1 diabetes with device-encapsulated pancreatic precursor cells derived from human embryonic stem cells found that insulin output was insufficient for clinical benefit. We are conducting a phase 1/2, open-label, multicenter trial aimed at optimizing cell engraftment (ClinicalTrials.gov identifier: NCT03163511 ). Here we report interim, 1-year outcomes in one study group that received 2-3-fold higher cell doses in devices with an optimized membrane perforation pattern. ß cell function was measured by meal-stimulated plasma C-peptide levels at 3-month intervals, and the effect on glucose control was assessed by continuous glucose monitoring (CGM) and insulin dosing. Of 10 patients with undetectable baseline C-peptide, three achieved levels ≥0.1 nmol l-1 from month 6 onwards that correlated with improved CGM measures and reduced insulin dosing, indicating a glucose-controlling effect. The patient with the highest C-peptide (0.23 nmol l-1) increased CGM time-in-range from 55% to 85% at month 12; ß cell mass in sentinel devices in this patient at month 6 was 4% of the initial cell mass, indicating directions for improving efficacy.

Routine postoperative computed tomography (CT) scans following acetabulum open reduction internal fixation (ORIF): A survey of orthopaedic traumatologists.

OBJECTIVE: The purpose of this study was to assess the practices related to obtaining postoperative pelvic CT scans following acetabular ORIF and revision surgery rates. DESIGN: A 20-question survey published on the Orthopaedic Trauma Association (OTA) website assessed each surgeon's preference and rationale for or against the routine use of postoperative CT scans for acetabular fractures. PARTICIPANTS: Fellowship-trained orthopaedic traumatologists. MAIN OUTCOME MEASUREMENTS: We examined the percentage of surgeons ordering routine postoperative CT scans, surgeon demographics, and revision surgery rates based on these routine CT scan results. RESULTS: Responses were received from 57 surgeons. Practices varied regarding postoperative CT scans, with 16 surgeons (28%, Group A) routinely ordering them and 41 surgeons (72%, Group B) not ordering them on all patients. No significant difference in surgeon demographics were found between the groups. Majority of Group A report a revision surgery rate of <1% based on the results of the postoperative CT. Group A report routine postoperative scans were obtained to assess reduction, hardware placement, identify intra-articular fragments, and for educational purposes. Group B did not obtain routine postoperative CTs due to the following: unlikely to change postoperative treatment, adequate reduction and instrumentation placement assessed intraoperatively and by postoperative radiographs, and increased radiation exposure and cost to patients. Group B did report obtaining postop CT scans on select patients, with inadequate intraoperative imaging and postoperative neurological changes being the most common indications. CONCLUSION: The routine use of postoperative CTs following open reduction internal fixation of acetabular fractures is a controversial topic. While we recognize the role for postoperative CT scans in select patients, our study questions the clinical utility of these scans in all patients and in conclusion do not recommend this protocol.

Functional Localization of Adult-Onset Idiopathic Nesidioblastosis.

Nesidioblastosis is a rare pancreatic disorder involving enlarged beta cells throughout the pancreas, causing elevated insulin production. We present the case of a 53-year-old woman with the initial symptom of fasting hypoglycemia. No pancreatic lesions were indicated on computed tomography and magnetic resonance imaging scans, and an octreotide scan was negative for insulinoma. Selective arterial calcium stimulation (SACST) showed increased insulin production from the stimulation of 3 out of 5 arteries. The SACST results suggested a diagnosis of nesidioblastosis, which was confirmed by histopathology after a subtotal distal pancreatectomy. The patient has normal glucose tolerance after surgery with no further problems of hypoglycemia, indicating that this is a rare case of nesidioblastosis extending only partially through the pancreas.

Routine Postoperative Computed Tomography Scans Following Posterior Pelvic Fixation of Pelvic Ring Fractures: A Survey of (OTA) Orthopaedic Traumatologists.

OBJECTIVE: To assess practices related to ordering computed tomography (CT) scans routinely after posterior pelvic ring fixation and revision surgery rates. DESIGN: A 20-question cross-sectional survey. PARTICIPANTS: Fellowship-trained orthopaedic traumatologists. MAIN OUTCOME MEASUREMENTS: (1) Percentage of surgeons ordering a routing postoperative CT after posterior pelvic ring fixation, (2) Revision surgery rates based on routine CT scan results. RESULTS: Responses were received from 57 surgeons. Practices varied regarding postoperative CT scans, with 20 surgeons (35%, group A) routinely ordering them and 37 surgeons (65%, group B) not ordering them on all patients. Group A were younger and with less years of experience than those in Group B. Most group A surgeons report a revision surgery rate of <1% based on results of the postoperative CT. Group A report routine postoperative scans were obtained to assess reduction, instrumentation placement, and for educational purposes. Group B did not obtain routine postoperative CTs because of the following: unlikely to change postoperative treatment course, adequate reduction and instrumentation placement assessed intraoperatively and by postoperative radiographs, and increased radiation exposure and cost to patients. Group B did report obtaining postop CT scans on select patients, with postoperative neurological deficit being the most common indication. CONCLUSIONS: The routine use of postoperative CTs following posterior fixation of pelvic ring fractures is a controversial topic. Although we recognize the role for postoperative CT scans in select patients, our study questions the clinical utility of these scans in all patients and in conclusion do not recommend this protocol.

Implanted pluripotent stem-cell-derived pancreatic endoderm cells secrete glucose-responsive C-peptide in patients with type 1 diabetes.

An open-label, first-in-human phase 1/2 study is being conducted to evaluate the safety and efficacy of pancreatic endoderm cells (PECs) implanted in non-immunoprotective macroencapsulation devices for the treatment of type 1 diabetes. We report an analysis on 1 year of data from the first cohort of 15 patients from a single trial site that received subcutaneous implantation of cell products combined with an immunosuppressive regimen. Implants were well tolerated with no teratoma formation or severe graft-related adverse events. After implantation, patients had increased fasting C-peptide levels and increased glucose-responsive C-peptide levels and developed mixed meal-stimulated C-peptide secretion. There were immunosuppression-related transient increases in circulating regulatory T cells, PD1high T cells, and IL17A+CD4+ T cells. Explanted grafts contained cells with a mature ß cell phenotype that were immunoreactive for insulin, islet amyloid polypeptide, and MAFA. These data, and associated findings (Shapiro et al., 2021), are the first reported evidence of meal-regulated insulin secretion by differentiated stem cells in patients.

Side Effect Patterns in a Crossover Trial of Statin, Placebo, and No Treatment.

BACKGROUND: Most people who begin statins abandon them, most commonly because of side effects. OBJECTIVES: The purpose of this study was to assess daily symptom scores on statin, placebo, and no treatment in participants who had abandoned statins. METHODS: Participants received 12 1-month medication bottles, 4 containing atorvastatin 20 mg, 4 placebo, and 4 empty. We measured daily symptom intensity for each using an app (scale 1-100). We also measured the "nocebo" ratio: the ratio of symptoms induced by taking statin that was also induced by taking placebo. RESULTS: A total of 60 participants were randomized and 49 completed the 12-month protocol. Mean symptom score was 8.0 (95% CI: 4.7-11.3) in no-tablet months. It was higher in statin months (16.3; 95% CI: 13.0-19.6; P < 0.001), but also in placebo months (15.4; 95% CI: 12.1-18.7; P < 0.001), with no difference between the 2 (P = 0.388). The corresponding nocebo ratio was 0.90. In the individual-patient daily data, neither symptom intensity on starting (OR: 1.02; 95% CI: 0.98-1.06; P = 0.28) nor extent of symptom relief on stopping (OR: 1.01; 95% CI: 0.98-1.05; P = 0.48) distinguished between statin and placebo. Stopping was no more frequent for statin than placebo (P = 0.173), and subsequent symptom relief was similar between statin and placebo. At 6 months after the trial, 30 of 60 (50%) participants were back taking statins. CONCLUSIONS: The majority of symptoms caused by statin tablets were nocebo. Clinicians should not interpret symptom intensity or timing of symptom onset or offset (on starting or stopping statin tablets) as indicating pharmacological causation, because the pattern is identical for placebo. (Self-Assessment Method for Statin Side-effects Or Nocebo [SAMSON]; NCT02668016).

The impact of provider recommendation on human papillomavirus vaccine and other adolescent vaccines.

This study explored the association between provider recommendation and adolescent vaccine coverage. We analyzed data from the 2008 to 2018 National Immunization Survey-Teen including coverage with one dose of quadrivalent meningococcal conjugate vaccine (MenACWY), Tetanus-diphtheria-acellular pertussis vaccine (Tdap), and one and three doses of Human papillomavirus (HPV) vaccine. We compared vaccine coverage between those who recalled a provider recommendation and those who did not. Among those who received a provider recommendation for MenACWY, coverage trended from 67.8% (2008) to 88.1% (2013), contrasted to those who did not, trending from 30.9% to 73.1%. Among those with a provider recommendation for Tdap, coverage trended from 47.6% to 89.7%, contrasted to those who did not, trending from 35.6% to 82.2%. Among females with a provider recommendation for HPV vaccine, receipt of initial dose of HPV vaccine trended from 57.5% (2008) to 74.3% (2018), contrasted to those who did not, trending from 18.1% to 49.8%, and among males, trended from 17.2% (2010) to 75.1% (2018) for those with a provider recommendation, compared to 0.5% to 44.7% for those without. In 2013, coverage difference by provider recommendation was 26.0% among females for one dose of HPV vaccine and 21.9% for three doses, and among males was 44.8% and 20.8%, respectively, while it was lower at 15% for MenACWY and 7.6% for Tdap. For each vaccine, coverage was higher with a provider recommendation; the largest difference was noted for HPV vaccine. This finding verifies for providers the importance of their recommendation, especially for the HPV vaccine.

Predictive Factors for Recurrence in Infantile Blount Disease Treated With Tibial Osteotomy.

BACKGROUND: This study aimed to determine the recurrence rate in infantile Blount disease (IBD) in a cohort of patients treated with a tibial osteotomy; and also to identify which factors were associated with recurrence. METHODS: We reviewed the records of 20 patients, under the age of 7 years, with IBD (35 involved extremities) treated by proximal tibial realignment osteotomy to physiological valgus at a single institution over 4 years. We then analyzed the data to determine the rate of recurrence and identify the risk factors for recurrence. RESULTS: The mean age of the included patients was 4.2 years (range, 2 to 6 y). We observed a recurrence rate of 40% (n=14) at a mean follow-up of 42 months (range, 21 to 72 mo). Knee instability [odds ratios OR, 6.6; 95% confidence interval (CI), 2.0-22.2], Langenskiöld stage (OR, 6.3; 95% CI, 2.0-19.4), and severity of the deformity, as measured by medial physeal slope (MPS) (OR, 1.2; 95% CI, 1.1-1.4), were associated with recurrence. On multiple logistic regression analysis, MPS remained the most relevant predictor of recurrence. Receiver operating curve analysis showed that an MPS ≥60 degrees predicted recurrence with a sensitivity of 79% and specificity of 95% (area under the curve=0.925). Postoperatively, increased varus alignment on weight-bearing as measured by the tibio-femoral angle was indicative of knee instability and associated with increased odds of recurrence (OR, 1.5; 95% CI, 1.1-1.9; P=0.004). CONCLUSIONS: We observed a recurrence rate of 40% in children with IBD under 7 years treated with acute correction to a tibio-femoral angle of 5 to 10 degrees valgus through a dome proximal tibial osteotomy. Knee instability, Langenskiöld stage, and MPS were associated with recurrence. Cases with an MPS ≥60 degrees seem to be particularly at risk for recurrence. Further research is needed to validate these findings. LEVEL OF EVIDENCE: Level IV.

Correction: Using financial incentives to promote physical activity in American Indian adolescents: A randomized controlled trial.

[This corrects the article DOI: 10.1371/journal.pone.0198390.].

Loss of alveolar bone density in postmenopausal, osteopenic women is associated with circulating levels of gelatinases.

OBJECTIVE: To determine whether circulating levels of two matrix metalloproteinases, MMP-2 and MMP-9, are associated with loss of alveolar bone density (ABD) or height (ABH), or with progression of periodontitis (relative clinical attachment level [RCAL]), among postmenopausal women with local and systemic bone loss. BACKGROUND: This study was planned as part of a 2-year randomized, double-blind, placebo-controlled, clinical trial examining efficacy/safety of subantimicrobial dose doxycycline (20 mg bid) in postmenopausal osteopenic women. This study examines whether serum levels of gelatinases are associated with local changes in the periodontium. METHODS: A sample of 113 women received periodontal maintenance for moderate to advanced chronic periodontitis and consented to analysis of stored serum biomarkers. Posterior vertical bitewings were taken, and serum collected, at baseline, one, and 2 years. ABD was determined by computer-assisted densitometric image analysis (CADIA), ABH by the Hausmann et al (1992, J Periodontol 63, 657) method, and RCAL by Florida Probe (every 6 months). MMPs were measured densitometrically on gelatin zymograms using denatured type I collagen as substrate and purified MMP-2 (72 kDa) and MMP-9 (92 kDa) as standards. Evidence of worsening in the periodontium at a tooth site was defined as a change from baseline of, for ABD, at least 14 densitometric units (for subcrestal locations) or 17 units (for crestal locations); of at least 0.4 mm for ABH; and of at least 1.5 mm for RCAL. Logistic regression models, while accounting for clustering, compared the odds of worsening in ABD, ABH, or RCAL, after 2 years of observation, between groups defined by baseline and concurrent levels of serum gelatinases. RESULTS: Changes in ABH and RCAL were not associated with circulating levels of MMP-2 or MMP-9. However, elevated odds of ABD loss over 24 months were associated, among smokers, with both baseline and concurrent levels of MMP-9 in the middle and highest tertile, and with concurrent levels of MMP-2 in the middle (but not the highest) tertile. Elevated odds of ABD loss were also associated, among women within 5 years of menopause, with baseline levels of MMP-2 in the highest tertile. CONCLUSION: Among postmenopausal osteopenic women, loss of ABD was associated, in smokers, with elevated circulating levels of MMP-9 and MMP-2. In those within 5 years of menopause, ABD loss was associated with elevated circulating levels of MMP-2.

Secondary Data Analysis of the 2012 Peru Demographic and Health Survey Examining Immunization Campaign Participation Among Children Aged 18 to 59 Months.

Objective. To evaluate the association between characteristics known to be associated with under-immunization and participation in immunization campaigns among Peruvian children. Methods. This is an analysis of data collected as part of the Peru 2012 Demographic and Health Survey. Analyses were conducted among children in 2 groups: children aged 18 to 29 months among whom core vaccine coverage is typically determined by the Peruvian authorities and children aged 30 to 59 months who may have received the core vaccines at older ages. The associations between relative wealth, location, maternal education, primary maternal language and the outcome, participation in an immunization campaign within the past 2 years were estimated using logistic regression models adjusted for survey design in each age group. Results. For children aged 18 to 29 months, campaign participation was higher if the mother had completed secondary school compared with those not having completed secondary school (27.4% vs 20.1% [prevalence odds ratio (POR) = 1.51 (1.08, 2.13)]). For children aged 30 to 59 months, campaign participation was higher if the mother had completed secondary school (40.4% vs 35.1% [POR = 1.23 (1.02, 1.49)], adjusted for residence) and if the child resided in Lima versus in other urban areas (46% vs 35.4% [POR = 1.52 (1.16, 2.01)], adjusted for maternal education). Relative wealth and mothers' primary language were not associated with campaign participation. Conclusions. This study suggests that children of mothers with higher education and those residing in Lima had higher prevalence odds of reporting that their children had participated in a vaccination campaign. This contrasts with the populations vaccination campaigns typically target (poor, rural, or indigenous) to improve vaccination coverage.

Flexural properties of rectangular nickel-titanium orthodontic wires when used as ribbon archwires.

OBJECTIVE: To compare the flexural properties of rectangular nickel-titanium (Ni-Ti) orthodontic wires in occlusoapical and faciolingual orientations using a standardized test method. MATERIALS AND METHODS: Twenty-two rectangular Ni-Ti wire groups were tested in occlusoapical (ribbon) orientation: eight conventional Ni-Ti products, five superelastic Ni-Ti products, and nine thermal Ni-Ti products (n = 10 per group). Six products of thermal Ni-Ti wire were tested in faciolingual (edgewise) orientation. A three-point bending test was performed to measure deactivation force at 3.0-, 2.0-, 1.0-, and 0.5-mm deflections of each rectangular wire at 37.0 ± 0.5°C. Analysis of variance and post hoc Student-Newman-Keuls tests were used to compare the mean values of the different groups (α = .05). RESULTS: The ranges of deactivation forces varied greatly with different kinds, sizes, products, and deflections of Ni-Ti wires. One product of conventional and superelastic Ni-Ti wires had steeper force-deflection curves. Four products had similarly shaped flat force-deflection curves, whereas the sixth product had a moderately steep force-deflection curve. Thermal Ni-Ti wires had smaller deactivation forces ranging from 0.773 N (78.8 g) to 2.475 N (252.4 g) between deflections of 1.0 and 0.5 mm, whereas wider ranges of force from 3.371 N (343.7 g) to 9.343 N (952.7 g) were predominantly found among conventional Ni-Ti wires between deflections of 3.0 and 2.0 mm. CONCLUSIONS: Clinicians should critically select archwires for use in the occlusoapical orientation not only based on Ni-Ti wire type, size (0.022 × 0.016-in or 0.025 × 0.017-in), and product but also with deactivation deflections from 0.5 and 1.0 mm to obtain light forces in the occlusoapical orientation.

The relationship between nicotine metabolism and nicotine and carcinogen exposure among American Indian commercial cigarette smokers and electronic nicotine delivery system users.

BACKGROUND: In American Indian (AI) tobacco users from the southern plains region of the US, we examined the relationship between nicotine and carcinogen exposure and nicotine metabolism. METHODS: Smokers (n = 27), electronic nicotine delivery system (ENDS) users (n = 21), and dual users (n = 25) of AI descent were recruited from a southern plains state. Urinary biomarkers of nicotine metabolism (nicotine metabolite ratio [NMR]), nicotine dose (total nicotine equivalents [TNE]), and a tobacco-specific lung carcinogen (4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol and its glucuronides [total NNAL] were measured. RESULTS: The geometric mean of NMR was 3.35 (95% Confidence Interval(CI): 2.42, 4.65), 4.67 (95% CI: 3.39, 6.43), and 3.26 (95% CI: 2.44, 4.37) among smokers, ENDS users, and dual users. Each of the three user groups had relatively low levels of TNE, indicative of light tobacco use. Among smokers, there were inverse relationships between NMR and TNE (r = -0.45) and between NMR and NNAL (r = -0.50). Among dual users, NMR and TNE, and NMR and NNAL were not associated. Among ENDS users, NMR and TNE were not associated. CONCLUSIONS: AI tobacco users with higher NMR did not have higher TNE or NNAL exposure than those with lower NMR. This supports prior work among light tobacco users who do not alter their tobacco consumption to account for nicotine metabolism. IMPACT: The high prevalences of smoking and ENDS among AI in the southern plains may not be related to nicotine metabolism. Environmental and social cues may play a more important role in light tobacco users and this may be particularly true among AI light tobacco users who have strong cultural ties.

Tobacco Use Patterns among GED Recipients.

U.S. General Educational Development diploma (GED) recipients have the highest smoking prevalence of any education level. This paper describes demographic characteristics and tobacco use patterns and examines effect modification and confounding as potential explanations for higher crude prevalence of smoking. METHODS: The study population included adults aged 25 and older in the 2013 National Health Interview Survey. We estimated adjusted prevalence ratios and 95% CIs for smoking and quitting behaviors using weighted multivariable logistic regression. RESULTS: Among women with a GED, adjusted prevalence of ever use (58.7%) and smoking (32.4%) was 1.50 and 1.52 times the prevalence among high school dropouts (39.1%, 21.3%). Female GED recipients had a significantly higher prevalence of ever smoking compared with dropouts. We found no significant educational differences in smoking prevalence among men or quit behaviors for either sex. CONCLUSIONS: More research is needed to identify targeted interventions to prevent smoking in this disparate population.

Sustained Virologic Response and Costs Associated with Direct-Acting Antivirals for Chronic Hepatitis C Infection in Oklahoma Medicaid.

BACKGROUND: Outcomes involving newer direct-acting antiviral (DAA) hepatitis C virus (HCV) regimens have not been studied extensively among the Medicaid population. OBJECTIVE: To assess clinical (treatment failure) and economic outcomes for chronic HCV-infected Oklahoma Medicaid members following treatment with DAAs and to measure associations with patient, treatment, and clinical characteristics. METHODS: This cross-sectional study used Oklahoma Medicaid pharmacy and medical claims data for adult members who used a newer DAA agent and had reported a successful or failed sustained virological response rate 12 weeks after therapy completion (SVR12) from January 1, 2014, to June 30, 2016. Multivariable logistic and gamma regressions assessed predictors of SVR12 failure and costs controlling for member demographics (i.e., age, sex, race, rural residence); type of DAA and adherence; clinical characteristics (e.g., comorbid conditions, advanced liver disease); and the implementation of changes to a prior authorization program. RESULTS: Of 934 Medicaid members eligible for treatment with DAAs between January 1, 2014, and June 30, 2016, 906 received DAA treatment, 40.6% (368/906) had reported SVR12 outcomes, and 59.4% (n = 538) did not have a reported SVR recorded. Of those with reported SVR12 outcomes, patients were 53.1 ± 9.7 years of age, 51.1% were male, 8.4% had SVR12 failure, and each member had mean costs of $140,283 ± $52,779. Multivariable analyses indicated higher odds of SVR12 failure was independently associated with cirrhosis (OR [decompensated] = 6.69 and OR [compensated] = 3.52, P < 0.001), while males had higher odds of failure than females (OR = 3.34, P < 0.010). No significant difference in SVR12 failure was noted, according to DAA type or a medication adherence threshold of > 95%. Ledipasvir/sofosbuvir was independently associated with lower costs (exp[b] = 0.81; P < 0.001) compared with sofosbuvir, while higher costs were associated with decompensated cirrhosis (exp[b] = 1.22; P < 0.001) and treatment failure (exp[b] = 1.18, P < 0.010). In an analysis including members without reported SVR12 outcomes, decompensated and compensated cirrhosis had lower odds (P < 0.001) of no reported SVR12 from ambulatory clinic settings. CONCLUSIONS: Almost 60% of Medicaid members receiving DAA treatment did not have a final reported SVR12 outcome. Among those with viral load measurements, treatment success was high and both decompensated and compensated cirrhosis were independently associated with significantly higher odds of treatment failure. Addressing a loss to follow-up among HCV patients and curtailing the development of cirrhosis to improve treatment success may warrant interventions that improve access to care and remove barriers that impede treatment initiation and completion. DISCLOSURES: No outside funding supported this study. Pham, Keast, Holderread, Nesser, and Skrepnek disclose either employment by the Oklahoma Health Care Authority or contractual work for this employer. Pham discloses fellowship funding from Purdue Pharma unrelated to this study. Keast and Skrepnek disclose research grant funding from Gilead Sciences and Abbvie. Holderread also reports grant funding from Gilead Sciences and fees from PRIME Education. Thompson, Farmer, and Rathbun have nothing to disclose.

Using financial incentives to promote physical activity in American Indian adolescents: A randomized controlled trial.

American Indians (AI) have high prevalence of diabetes in youth and may benefit from increasing physical activity as a strategy to improve metabolic health. We tested whether financial incentives would elicit greater frequency and/or duration of exercise in AI youth at high risk for developing diabetes. Overweight/obese AI boys and girls, 11-20 years old, were instructed to exercise on 3 days/week for 48 weeks at a tribal wellness center. The program was divided into three, 16-week-long phases to test different financial incentive strategies. Within each phase participants were randomly assigned to one of two groups that received different payments for exercise. Phase 1 was designed to test whether the size of the incentive would affect exercise frequency. In Phase 1, the number of exercise sessions did not differ between the group receiving a modest fixed-value payment per exercise session and the group receiving enhanced incentives to exercise more frequently (26 ± 3 versus 28 ± 2 sessions, respectively, p = 0.568). In Phase 2, the provision of an enhanced financial incentive to increase exercise duration resulted longer sessions, as the incentivized and standard payment groups exercised 38 ± 2 versus 29 ± 1 minutes per session (p = 0.002), respectively. In Phase 3, the effect of reducing the incentives on maintenance of exercise behaviors was inconclusive due to high participant withdrawal. Aerobic fitness increased 10% during Phase 1 but was unchanged thereafter. Insulin sensitivity and body composition were unchanged during the study. In conclusion, enhanced financial incentives increased the duration of exercise sessions, but had minimal effects on exercise participation. These results indicate that financial incentives hold promise in motivating previously sedentary, overweight/obese adolescents to exercise longer, but motivating them to sustain an exercise program remains the major challenge. TRIAL REGISTRATION: ClinicalTrials.gov NCT01848353.

A structural equation modeling approach to understanding pathways that connect socioeconomic status and smoking.

The inverse association between socioeconomic status and smoking is well established, yet the mechanisms that drive this relationship are unclear. We developed and tested four theoretical models of the pathways that link socioeconomic status to current smoking prevalence using a structural equation modeling (SEM) approach. Using data from the 2013 National Health Interview Survey, we selected four indicator variables (poverty ratio, personal earnings, educational attainment, and employment status) that we hypothesize underlie a latent variable, socioeconomic status. We measured direct, indirect, and total effects of socioeconomic status on smoking on four pathways through four latent variables representing social cohesion, financial strain, sleep disturbance, and psychological distress. Results of the model indicated that the probability of being a smoker decreased by 26% of a standard deviation for every one standard deviation increase in socioeconomic status. The direct effects of socioeconomic status on smoking accounted for the majority of the total effects, but the overall model also included significant indirect effects. Of the four mediators, sleep disturbance and psychological distress had the largest total effects on current smoking. We explored the use of structural equation modeling in epidemiology to quantify effects of socioeconomic status on smoking through four social and psychological factors to identify potential targets for interventions. A better understanding of the complex relationship between socioeconomic status and smoking is critical as we continue to reduce the burden of tobacco and eliminate health disparities related to smoking.