Insulin resistance before type 2 diabetes onset is associated with increased risk of albuminuria after diabetes onset: A prospective cohort study

AIM

Reduced renal insulin signalling is implicated in the pathogenesis of albuminuria. We sought to investigate whether insulin action and secretion, measured before diabetes onset, are associated with the development of albuminuria after diabetes onset.

MATERIALS AND METHODS

Baseline body composition, insulin sensitivity by hyperinsulinaemic-euglycaemic clamp at submaximal and maximal insulin stimulation (240 and 2400 pmol/m2/min; M-low and M-high), and insulin secretion by intravenous glucose tolerance test [acute insulin response (AIR)] were measured in 170 Southwestern Indigenous American adults who subsequently developed diabetes. After diabetes onset and during the median follow-up of 13.6 years, 81 participants (48%) developed albuminuria (urine albumin-to-creatinine ratio ≥30 mg/g). Separate associations of M-low, M-high and AIR (per 1-SD change) with the risk of albuminuria were assessed by Cox regression models adjusted for age, sex and body fat (%).

RESULTS

Participants who developed albuminuria were of similar age (26.4 ± 5.4 vs. 27.5 ± 6.1 years), sex (46% vs. 48% male), body fat (36.4 ± 7.5 vs. 35.7 ± 7.9%) and AIR [2.3 ± 0.3 vs. 2.3 ± 0.3, pmol/L (log)] as those who did not develop albuminuria but had lower insulin sensitivity [M-low: 0.33 ± 0.08 vs. 0.36 ± 0.12, p = .03; M-high: 0.87 ± 0.11 vs. 0.91 ± 0.12, p = .02; mg/kg-metabolic body size/min (log)]. In separate adjusted models, lower M-low and M-high were both associated with an increased risk for albuminuria [hazard ratio (HR) 1.51, 95% confidence interval (CI) 1.14, 2.00, p = .004; HR 1.31, 95% CI 1.06, 1.63, p = .01), whereas AIR was not (HR 1.15, 95% CI 0.87, 1.56, p = .3).

CONCLUSIONS

Lower insulin sensitivity is associated with the development of albuminuria, suggesting a role for insulin signalling in the pathogenesis of proteinuria.

Adipocyte size, adipose tissue calories, and circulating adipokines, before and after diet-induced weight loss in humans

OBJECTIVE

Adipose tissue (AT) contains a bimodal population of large and small adipocytes. Changes in fat cell size (FCS) distribution and AT caloric density (kcal/g) with weight loss are unclear. We aimed to evaluate changes in FCS and AT calories in weight loss and determine associations with anthropometrics.

MATERIALS AND METHODS

Healthy adults (6 men/4 women; age 33 ± 11 years; BMI 35 ± 6 kg/m2) underwent DXA and subcutaneous abdominal/thigh fat biopsies, before and after 6 weeks of caloric restriction. AT calories (bomb calorimetry) and hormones (adiponectin, leptin, FGF21) were measured.

RESULTS

Abdominal large cell diameter (LCD; Δ = -13.2 μm, p = 0.01) and nadir (Δ = -7.3 μm, p = 0.03) decreased. In repeated measures correlations (rrm), abdominal and thigh LCD and nadir were associated with fat mass (FM) loss (rrm = 0.68; rrm = 0.63; rrm = 0.66; rrm = 0.62, p's < 0.05, respectively) and waist circumference decrease (rrm = 0.70; rrm = 0.60, p's ≤ 0.05). Small cell percentage did not change and was not associated with FM changes. Abdominal AT calories were unchanged with weight loss. Change in leptin was associated with change in abdominal LCD (rrm = 0.77, p = 0.01).

CONCLUSIONS

Caloric restriction reduces adipocyte LCD and nadir. These changes are associated with FM loss. Larger fat cells should be considered as phenotypic targets for weight loss.

CLINICAL TRIALS REGISTRATION

clinicaltrials.gov identifier: NCT00687115, May 29, 2008.

Impaired metabolic flexibility to fasting is associated with increased ad libitum energy intake in healthy adults

OBJECTIVE

We investigated how changes in 24-h respiratory exchange ratio (RER) and substrate oxidation during fasting versus an energy balance condition influence subsequent ad libitum food intake.

METHODS

Forty-four healthy, weight-stable volunteers (30 male and 14 female; mean [SD], age 39.3 [11.0] years; BMI 31.7 [8.3] kg/m2) underwent 24-h energy expenditure measurements in a respiratory chamber during energy balance (50% carbohydrate, 30% fat, and 20% protein) and 24-h fasting. Immediately after each chamber stay, participants were allowed 24-h ad libitum food intake from computerized vending machines.

RESULTS

Twenty-four-hour RER decreased by 9.4% (95% CI: -10.4% to -8.5%; p < 0.0001) during fasting compared to energy balance, reflecting a decrease in carbohydrate oxidation (mean [SD], -2.6 [0.8] MJ/day; p < 0.0001) and an increase in lipid oxidation (2.3 [0.9] MJ/day; p < 0.0001). Changes in 24-h RER and carbohydrate oxidation in response to fasting were correlated with the subsequent energy intake such that smaller decreases in fasting 24-h RER and carbohydrate oxidation, but not lipid oxidation, were associated with greater energy intake after fasting (r = 0.31, p = 0.04; r = 0.40, p = 0.007; and r = -0.27, p = 0.07, respectively).

CONCLUSIONS

Impaired metabolic flexibility to fasting, reflected by an inability to transition away from carbohydrate oxidation, is linked with increased energy intake.

Higher glucose and insulin responses to a mixed meal are associated with increased risk of diabetic retinopathy in Indigenous Americans

PURPOSE

Prior research has focused on glucose/insulin responses to meal challenges to create personalized diets to improve health, though it is unclear if these responses predict chronic diseases. We aimed to identify glucose and insulin responses to a mixed meal tolerance test (MMTT) that predict the development of diabetic retinopathy (DR) and compare the predictive abilities with the oral glucose tolerance test (OGTT).

METHODS

Indigenous American adults without diabetes (n = 168) underwent a 4-h MMTT, body composition assessment, and a 3-h OGTT at baseline. During follow-up (median 13.4 years), DR was diagnosed by direct ophthalmoscopy (n = 28) after onset of type 2 diabetes. Total and incremental area under the curve (AUC and iAUC) were calculated from glucose/insulin responses after the MMTT and OGTT.

RESULTS

In separate Cox proportional hazards models adjusted for age, sex, and body fat (%), MMTT glucose AUCs (180-min and 240-min) and iAUC (180-min) predicted DR (HR 1.50, 95% CI 1.06, 2.12; HR 1.50, 95% CI 1.05, 2.14; HR 1.58, 95% CI 1.01, 2.46). The predictive abilities were better than the fasting OGTT glucose (p < 0.01) but similar to the 120-min OGTT glucose (p = 0.53). MMTT insulin AUCs (180-min and 240-min) and iAUC (180-min) also predicted DR (HR 1.65, 95% CI 1.09, 2.51; HR 1.58, 95% CI 1.00, 2.35; HR 1.53 95% CI 1.06, 2.22) while insulin AUC and iAUC from the OGTT did not (p > 0.05).

CONCLUSIONS

Higher MMTT glucose and insulin responses predicted DR and were comparable to the OGTT, supporting the use of a meal challenge for precision nutrition.

TRIAL REGISTRATIONS

Clinical Trial Registry: ClinicalTrials.gov identifier: NCT00340132, NCT00339482.

Dietary Adherence Is Associated with Perceived Stress, Anhedonia, and Food Insecurity Independent of Adiposity

We examined whether perceived stress, anhedonia, and food insecurity were associated with dietary adherence during a 6-week intervention. Sixty participants (23 m; 53 ± 14 y) completed psychosocial measures and were provided with full meals. Individuals with obesity were randomized to a weight-maintaining energy needs (WMENs) (n = 18; BMI 33 ± 4) or a 35% calorie-reduced diet (n = 19; BMI 38 ± 9); normal-weight individuals (n = 23; BMI 23 ± 2) were assigned to a WMENs diet. Adherence scores were determined via weekly assessments and daily ecological momentary assessments (EMAs) of real-time behavior in a natural environment. Perceived stress and anhedonia were associated with % body fat (all r-values > 0.25, all p-values < 0.05), but food insecurity and adherence were not. Higher perceived stress (r = -0.31, p = 0.02), anhedonia (r = -0.34, p = 0.01), and food insecurity (r = -0.27, p = 0.04) were associated with lower adherence scores, even after adjusting for age, sex, and % body fat. In all adjusted models, % body fat was not associated with adherence. Higher measures of stress, anhedonia, and food insecurity predicted lower adherence independently of body fat, indicating that psychosocial factors are important targets for successful adherence to dietary interventions, regardless of body size.

Investigation of seasonality of human spontaneous physical activity and energy expenditure in respiratory chamber in Phoenix, Arizona

OBJECTIVE

The existence of seasonal changes in energy metabolism is uncertain. We investigated the relationship between the seasons and spontaneous physical activity (SPA), energy expenditure (EE), and other components measured in a respiratory chamber.

METHODS

Between 1985-2005, 671 healthy adults (aged 28.8 ± 7.1 years; 403 men) in Phoenix, Arizona had a 24-hour stay in the respiratory chamber equipped with radar sensors; SPA (expressed as a percentage over the time interval), the energy cost of SPA, EE, and respiratory exchange ratio (RER) were measured.

RESULTS

In models adjusted for known covariates, SPA (%) was lower during summer (7.2 ± 2.9, p = 0.0002), spring (7.5 ± 2.9, p = 0.025), and fall (7.6 ± 3, p = 0.038) compared to winter (8.3 ± 3.5, reference). Conversely, energy cost of SPA (kcal/h/%) was higher during summer (2.18 ± 0.83, p = 0.0008), spring (2.186 ± 0.83, p = 0.017), and fall (2.146 ± 0.75, p = 0.038) compared to winter (2.006 ± 0.76). Protein (292 ± 117 kcal/day, β = -21.2, p = 0.08) oxidation rates was lower in the summer compared to winter. Carbohydrate and lipid oxidation rates (kcal/day) did not differ across seasons. RER and 24-h EE did not differ by season.

CONCLUSION

SPA, representing fidgeting-like behavior in the chamber, demonstrated a winter peak and summer nadir in humans living in a desert climate. These findings indicate that the physiological propensity for movement may be affected by seasonal factors.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov identifiers: NCT00340132, NCT00342732.

Greater anhedonia scores in healthy individuals are associated with less decline in 24-hour energy expenditure with fasting: Evidence for a link between behavioral traits and spendthrift phenotype

Obesity rates are increasing and affecting mental health. It is important to understand how behavioral traits such as anhedonia are associated with physiologic traits that may predict weight-change in clinical and non-clinical populations. We studied whether 24-hour energy expenditure (24hEE) changes with fasting and overfeeding are associated with anhedonia in a healthy cohort. We performed behavioral assessments (physical anhedonia scale (PAS) and inventory for depressive symptoms (IDS)) followed by measures of 24hEE and urinary catecholamines in a whole-room indirect calorimeter (respiratory chamber) during energy balance, and then randomly during fasting and 2 different overfeeding diets. Participants (n=98) were medically healthy, between 18 and 55 years of age, with normal glucose regulation and weight-stable 6 months before admission. Women were premenopausal and not pregnant. Higher PAS was significantly associated with lesser decrease in 24hEE with fasting and higher urinary catecholamine excretion rates - consistent with spendthrift metabolism. As IDS increased, the association between anhedonia and the change in 24hEE from energy balance to fasting decreased (B-values were lower for change in EE). Here, higher PAS scores may reflect the ability to respond with appropriate homeostatic reactions which balance energy needs. IDS scores blunting this response may explain how anhedonia and depression can lead to weight gain.

Validation of Total Water Intake from the Automated Self-Administered 24-h Recall, 4-d Food Records, and a Food Frequency Questionnaire Using Doubly Labeled Water

BACKGROUND

Although prior evidence indicates that water intake is important for health, the ability to accurately measure community-dwelling intake is limited. Only a few studies have evaluated self-reported water intake against an objective recovery biomarker.

OBJECTIVES

The aim was to compare preformed water intakes (all sources including food) by multiple Automated Self-Administered 24-h recalls (ASA24s), food frequency questionnaires (FFQs), and 4-d food records (4DFRs) against a recovery biomarker, doubly labeled water (DLW), to assess measurement error.

METHODS

Over 1 y, 1082 women and men (50%), aged 50 to 74 y, were asked to complete 6 ASA24s, 2 FFQs, 2 unweighted 4DFRs, and an administration of DLW (n = 686). Geometric means of water intake by self-report tools were compared with DLW. Attenuation factors and correlation coefficients between self-reported and the recovery biomarker (DLW) were estimated.

RESULTS

Mean water intakes by DLW were 2777 mL/d (interquartile range, 2350 to 3331) in women and 3243 mL/d (interquartile range, 2720 to 3838) in men. Compared with DLW, water intake was underestimated by 18% to 31% on ASA24s and 43% to 44% on 4DFRs. Estimated geometric means from FFQs differed from DLW by -1% to +13%. For a single ASA24, FFQ, and 4DFR, attenuation factors were 0.28, 0.27, and 0.32 and correlation coefficients were 0.46, 0.48, and 0.49, respectively. Repeated use of 6 ASA24s, 2 FFQs, and 2 4DFRs improved attenuation factors to 0.43, 0.32, and 0.39 and correlation coefficients to 0.58, 0.53, and 0.54, respectively.

CONCLUSIONS

FFQs may better estimate population means for usual water intake compared with ASA24 and 4DFR. Similar attenuation factors and correlation coefficients across all self-report tools indicate that researchers have 3 feasible options if the goal is understanding intake-disease relationships. The findings are useful for planning future nutrition studies that set policy priorities for populations and to understand the health impact of water. This trial was registered at clinicaltrials.gov as NCT03268577.

Diagnostic criteria and etiopathogenesis of type 2 diabetes and its complications: Lessons from the Pima Indians

The Phoenix Epidemiology and Clinical Research Branch of the National Institute of Diabetes and Digestive and Kidney Diseases has conducted prospective studies of diabetes and its complications in the Pima Indians living in Arizona, USA for over 50 years. In this review we highlight areas in which these studies provided vital insights into the criteria used to diagnose type 2 diabetes, the pathophysiologic changes that accompany the development of type 2 diabetes, and the course and determinants of diabetes complications-focusing specifically on diabetic kidney disease. We include data from our longitudinal population-based study of diabetes and its complications, studies on the role of insulin resistance and insulin secretion in the pathophysiology of type 2 diabetes, and in-depth studies of diabetic kidney disease that include measures of glomerular function and research kidney biopsies. We also focus on the emerging health threat posed by youth-onset type 2 diabetes, which was first seen in the Pima Indians in the 1960s and is becoming an increasing issue worldwide.

Closed-loop control of air supply to whole-room indirect calorimeters to improve accuracy and standardize measurements during 24-hour dynamic metabolic studies

OBJECTIVE

The aim of this study was to test proportional-integral-derivative (PID) control of air inflow rate in a whole-room indirect calorimeter to improve accuracy in measuring oxygen (O₂ ) consumption ( V ̇ O 2 ) and carbon dioxide (CO₂ ) production ( V ̇ CO 2 ).

METHODS

A precision gas blender infused nitrogen (N₂ ) and CO₂ into the calorimeter over 24 hours based on static and dynamic infusion profiles mimicking V ̇ O 2 and V ̇ CO 2 patterns during resting and non-resting conditions. Constant (60 L/min) versus time-variant flow set by a PID controller based on the CO₂ concentration was compared based on errors between measured versus expected values for V ̇ O 2 , V ̇ CO 2 , respiratory exchange ratio, and metabolic rate.

RESULTS

Compared with constant inflow, the PID controller allowed both a faster rise time and long-term maintenance of a stable CO₂ concentration inside the calorimeter, resulting in more accurate V ̇ CO 2 estimates (mean hourly error, PID: -0.9%, 60 L/min = -2.3%, p < 0.05) during static infusions. During dynamic infusions mimicking exercise sessions, the PID controller achieved smaller errors for V ̇ CO 2 (mean: -0.6% vs. -2.7%, p = 0.02) and respiratory exchange ratio (mean: 0.5% vs. -3.1%, p = 0.02) compared with constant inflow conditions, with similar V ̇ O 2 (p = 0.97) and metabolic rate (p = 0.76) errors.

CONCLUSIONS

PID control in a whole-room indirect calorimeter system leads to more accurate measurements of substrate oxidation during dynamic metabolic studies.

Disinhibition augments thirst perception from two dehydrating stimuli in men

Physiological systems controlling water and energy ingestion are coordinated. Whether maladaptive eating behavior and appetite for water are linked is unknown. Thus, we sought to investigate the association between maladaptive eating and both thirst and water drinking behavior with two dehydrating conditions. Twenty-two lean men and 20 men with obesity (mean age 32.3 ± 8.4 years and 30.0 ± 11.1 years, respectively) completed the Three-Factor Eating Questionnaire (TFEQ) and Gormally Binge Eating Scale. On separate days, volunteers were dehydrated by a 2-h hypertonic saline infusion and a 24-h water deprivation, and thirst was measured on a 100-mm visual analogue scale (VAS) during each procedure. After each dehydrating condition, ad libitum water intake was measured. In the saline infusion, higher Disinhibition on the TFEQ was associated with thirst in the lean group (β = 4.2 mm VAS, p = 0.03) but not in the group with obesity (p = 0.51). In the water-deprivation condition, higher Disinhibition was also associated with thirst in the lean group (β = 5.6 mm VAS, p = 0.01) with the strength of relationship being 3.5-fold stronger than that observed in the group with obesity (β = 1.6 mm VAS, p = 0.0003). Hunger, Restraint, and binge-eating scores were not associated with thirst in either dehydrating condition (all p > 0.05). Maladaptive eating behaviors were not associated with ad libitum water intake (all p > 0.05). Disinhibition is associated with higher thirst perception in healthy weight individuals and may be attenuated in obesity. The characteristics of disinhibition which typically includes a heightened readiness to eat, may reflect a more general phenotype that also reflects a readiness to drink.

Energy expenditure measurements are reproducible in different whole-room indirect calorimeters in humans

OBJECTIVE

This study aimed to evaluate the agreement of commonly reported energy metabolism measurements obtained from two different whole-room indirect calorimeters (WRICs).

METHODS

Nine healthy adult volunteers were evaluated over four separate 24-hour periods in a crossover design, twice in two different WRICs of different sizes, each operated according to the Room Indirect Calorimetry Operating and Reporting Standards published in 2020. The reproducibility of repeated measurements was quantified by the coefficient of variation (CV) and intraclass correlation coefficient (ICC).

RESULTS

The CVs between and within each WRIC for average 24-hour carbon dioxide production rate (VCO₂ ) and oxygen consumption rate (VO₂ ), 24-hour energy expenditure (EE), and respiratory exchange ratio ranged from 1.5% to 3.6%, whereas sleep EE ranged from 3.1% to 5.5%. CVs for macronutrient oxidation rates and spontaneous physical activity were higher, ranging from 9.2% to 38.1%. ICCs of VCO₂ , VO₂ , 24-hour EE, and energy expenditure at zero activity were >0.95, indicating excellent reproducibility, whereas ICCs for lipid oxidation, awake and fed thermogenesis, and sleep EE ranged from 0.55 to 0.92, indicating moderate to high reproducibility. ICCs for respiratory exchange ratio and carbohydrate and protein oxidation rates were lower (<0.70). Spontaneous physical activity showed high reproducibility within chambers (ICC = 0.88) but differed substantially between chambers (ICC = 0.23).

CONCLUSIONS

Cross-chamber reproducibility is high for common outcome measures assessed in the respiratory chamber. The results support efforts to promote standardization across WRICs to allow multicenter studies.

Water intake, thirst, and copeptin responses to two dehydrating stimuli in lean men and men with obesity

OBJECTIVE

Physiological systems responsible for water homeostasis and energy metabolism are interconnected. This study hypothesized altered responses to dehydration including thirst, ad libitum water intake, and copeptin in men with obesity.

METHODS

Forty-two men (22 lean and 20 with obesity) were stimulated by a 2-hour hypertonic saline infusion and a 24-hour water deprivation. In each dehydrating condition, thirst, ad libitum water intake after dehydration, and urinary and hormonal responses including copeptin were assessed.

RESULTS

After each dehydration condition, ad libitum water intake was similar between both groups (p > 0.05); however, those with obesity reported feeling less thirsty (p < 0.05) and had decreased copeptin response and higher urinary sodium concentrations when stressed (p < 0.05). Angiotensin II, aldosterone, atrial and brain natriuretic peptides, and apelin concentrations did not differ by adiposity group and did not explain the different thirst or copeptin responses in men with obesity. However, leptin was associated with copeptin response in lean individuals during the hypertonic saline infusion (p < 0.05), but the relationship was diminished in those with obesity.

CONCLUSIONS

Diminished thirst and copeptin responses are part of the obesity phenotype and may be influenced by leptin. Adiposity may impact pathways regulating thirst and vasopressin release, warranting further investigation.

Food insecurity is associated with higher respiratory quotient and lower glucagon-like peptide 1

OBJECTIVE

Food insecurity is known to be associated with obesity, but its association with physiological measures is unclear. Therefore, it was hypothesized that, compared with food-secure individuals, those with food insecurity would have higher 24-hour energy expenditure (EE [kilocalories per day]) and 24-hour respiratory quotient (RQ [ratio]). Subsequently, hormones involved in appetite regulation, substrate oxidation, and EE were explored.

METHODS

A total of 113 healthy participants without diabetes (75 men; mean [SD], age 40 [12] years; BMI 30 [8] kg/m² ) were included in this analysis. Participants completed the Food Security Short Form, underwent a dual-energy x-ray absorptiometry scan, and spent 24 hours in a human respiratory chamber following a weight-maintaining diet.

RESULTS

Compared with individuals with food security, participants with food insecurity had no difference in 24-hour EE. However, they had higher carbohydrate oxidation rates (p = 0.03) and lower lipid oxidation rates (p = 0.02), resulting in higher 24-hour RQ (p < 0.01). They also had lower fasting glucagon-like peptide 1 (p = 0.03) concentrations.

CONCLUSIONS

Food insecurity is associated with higher 24-hour RQ and lower fasting glucagon-like peptide 1 concentrations, metabolic and hormonal differences previously shown to drive greater calorie intake in the setting of unrestricted food availability. These findings therefore provide new insight into the paradoxical link between restricted food access and increased adiposity.

Trends in spontaneous physical activity and energy expenditure among adults in a respiratory chamber, 1985 to 2005

OBJECTIVE

Fidgeting, a type of spontaneous physical activity (SPA), has substantial thermogenic potential. This research aims to examine secular trends in SPA and energy expenditure (EE) inside a respiratory chamber.

METHODS

From 1985 to 2005, healthy adults (n = 678; mean age: 28.8 years; men: 60%; 522 Indigenous American, 129 White, and 27 Black) had a 24-hour stay in the respiratory chamber equipped with radar sensors. Body composition, glucose tolerance, fasting insulin, insulin action (hyperinsulinemic-euglycemic clamp), and insulin secretion (intravenous glucose tolerance test) were measured as covariates.

RESULTS

SPA, adjusted for age, sex, race, and body composition, declined (r = -0.30, p < 0.0001), with a concomitant rise in the energy cost of SPA (r = 0.30, p < 0.0001). The 24-hour EE adjusted for covariates increased (r = 0.31, p < 0.0001), which was reflected in increases in EE during sleep (r = 0.18, p < 0.0001) and during the awake, fed condition (r = 0.28, p < 0.0001). The secular trends in SPA or 24-hour EE were unchanged with adjustment for measures related to glucose metabolism.

CONCLUSIONS

Secular trend analyses showed a decline in fidgeting. However, this decline in SPA was partially counterbalanced by an increase in energy cost of this activity and a rise in EE. Nevertheless, our results support public health efforts to promote small but sustained changes in these behaviors.

Lower insulin clearance is associated with increased risk of type 2 diabetes in Native Americans

AIMS/HYPOTHESIS

Impaired insulin clearance is implicated in the pathogenesis of type 2 diabetes, but prospective evidence remains limited. Therefore, we sought to identify factors associated with the metabolic clearance rate of insulin (MCRI) and to investigate whether lower MCRI is associated with increased risk of incident type 2 diabetes.

METHODS

From a longitudinal cohort, 570 adult Native Americans without diabetes living in the Southwestern United States were characterised at baseline and 448 participants were monitored over a median follow-up period of 7.9 years with 146 (32%) incident cases of diabetes identified (fasting plasma glucose ≥7.0 mmol/l, 2 h plasma glucose [2-h PG] ≥11.1 mmol/l, or clinical diagnosis). At baseline, participants underwent dual-energy x-ray absorptiometry or hydrodensitometry to assess body composition, a 75 g OGTT, an IVGTT to assess acute insulin response (AIR), and a hyperinsulinaemic-euglycaemic clamp to assess MCRI and insulin action (M).

RESULTS

In adjusted linear models, MCRI was inversely associated with body fat percentage (r = -0.35), fasting plasma insulin (r = -0.55) and AIR (r = -0.22), and positively associated with M (r = 0.17; all p < 0.0001). In multivariable Cox proportional hazard models, lower MCRI was associated with an increased risk of diabetes after adjustment for age, sex, heritage, body fat percentage, AIR, M, fasting plasma glucose, 2-h PG, and fasting plasma insulin (HR per one-SD difference in MCRI: 0.77; 95% CI 0.61, 0.98; p = 0.03).

CONCLUSIONS/INTERPRETATION

Lower MCRI is associated with an unfavourable metabolic phenotype and is associated with incident type 2 diabetes independent of established risk factors.

CLINICAL TRIAL REGISTRATION NUMBERS

ClinicalTrials.gov NCT00339482; NCT00340132.

Reduced Albumin Concentration Predicts Weight Gain and Higher Ad Libitum Energy Intake in Humans

OBJECTIVE

Circulating albumin is negatively associated with adiposity but whether it is associated with increased energy intake, lower energy expenditure or weight gain has not been examined.

METHODS

In study 1 (n=238; 146 men), we evaluated whether fasting albumin concentration was associated with 24-h energy expenditure and ad libitum energy intake. In study 2 (n=325;167 men), we evaluated the association between plasma albumin and change in weight and body composition.

RESULTS

After adjustment for known determinants of energy intake lower plasma albumin concentration was associated with greater total daily energy intake (β= 89.8 kcal/day per 0.1 g/dl difference in plasma albumin, p=0.0047). No associations were observed between plasma albumin concentrations and 24-h energy expenditure or 24-h respiratory quotient (p>0.2). Over 6 years, volunteers gained on average 7.5 ± 11.7 kg (p<0.0001). Lower albumin concentrations were associated with greater weight [β=3.53 kg, p=0.039 (adjusted for age, sex, follow up time), CI 0.16 to 6.21 per 1 g/dl difference albumin concentration] and fat mass (β=2.3 kg, p=0.022), respectively, but not with changes in fat free mass (p=0.06).

CONCLUSIONS

Lower albumin concentrations were associated with increased ad libitum food intake and weight gain, indicating albumin as a marker of energy intake regulation.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, identifiers NCT00340132, NCT00342732.

Barriers to Women Entering Surgical Careers: A Global Study into Medical Student Perceptions

BACKGROUND

Barriers to female surgeons entering the field are well documented in Australia, the USA and the UK, but how generalizable these problems are to other regions remains unknown.

METHODS

A cross-sectional survey was developed by the International Federation of Medical Students' Associations (IFMSA)'s Global Surgery Working Group assessing medical students' desire to pursue a surgical career at different stages of their medical degree. The questionnaire also included questions on students' perceptions of their education, resources and professional life. The survey was distributed via IFMSA mailing lists, conferences and social media. Univariate analysis was performed, and statistically significant exposures were added to a multivariate model. This model was then tested in male and female medical students, before a further subset analysis by country World Bank income strata.

RESULTS

639 medical students from 75 countries completed the survey. Mentorship [OR 3.42 (CI 2.29-5.12) p = 0.00], the acute element of the surgical specialties [OR 2.22 (CI 1.49-3.29) p = 0.00], academic competitiveness [OR 1.61 (CI 1.07-2.42) p = 0.02] and being from a high or upper-middle-income country (HIC and UMIC) [OR 1.56 (CI 1.021-2.369) p = 0.04] all increased likelihood to be considering a surgical career, whereas perceived access to postgraduate training [OR 0.63 (CI 0.417-0.943) p = 0.03], increased year of study [OR 0.68 (CI 0.57-0.81) p = 0.00] and perceived heavy workload [OR 0.47 (CI 0.31-0.73) p = 0.00] all decreased likelihood to consider a surgical career. Perceived quality of surgical teaching and quality of surgical services in country overall did not affect students' decision to pursue surgery. On subset analysis, perceived poor access to postgraduate training made women 60% less likely to consider a surgical career [OR 0.381 (CI 0.217-0.671) p = 0.00], whilst not showing an effect in the men [OR 1.13 (CI 0.61-2.12) p = 0.70. Concerns about high cost of training halve the likelihood of students from low and low-middle-income countries (LICs and LMICs) considering a surgical career [OR 0.45 (CI 0.25-0.82) p = 0.00] whilst not demonstrating a significant relationship in HIC or UMIC countries. Women from LICs and LMICs were 40% less likely to consider surgical careers than men, when controlling for other factors [OR 0.59 CI (0.342-1.01 p = 0.053].

CONCLUSION

Perceived poor access to postgraduate training and heavy workload dissuade students worldwide from considering surgical careers. Postgraduate training in particular appears to be most significant for women and cost of training an additional factor in both women and men from LMICs and LICs. Mentorship remains an important and modifiable factor in influencing student's decision to pursue surgery. Quality of surgical education showed no effect on student decision-making.

Metabolic Responses to 24-Hour Fasting and Mild Cold Exposure in Overweight Individuals Are Correlated and Accompanied by Changes in FGF21 Concentration

A greater decrease in 24-h energy expenditure (24 EE) during 24-h fasting defines a "thriftier" metabolic phenotype prone to weight gain during overfeeding and resistant to weight loss during caloric restriction. As the thermogenic response to mild cold exposure (COLD) may similarly characterize this human phenotype identified by acute fasting conditions, we analyzed changes in 24 EE and sleeping metabolic rate (SLEEP) in a whole-room indirect calorimeter during 24-h fasting at thermoneutrality (24°C) and during energy balance both at thermoneutrality (24°C) and mild cold (19°C) in 20 healthy volunteers (80% male; aged 36.6 ± 11.4 years; percentage body fat 34.8 ± 10.5%). Greater decrease in 24 EE during fasting (thriftier phenotype) was associated with less increase in 24 EE during COLD (i.e., less cold-induced thermogenesis). Greater decreases in plasma fibroblast growth factor 21 (FGF21) after 24-h fasting and after COLD were highly correlated and associated with greater decreases in SLEEP in both conditions. We conclude that the metabolic responses to short-term fasting and COLD are associated with and mediated by the liver-derived hormone FGF21. Thus, the 24 EE response to COLD further identifies the "thrifty" versus "spendthrift" phenotype, providing an additional setting to investigate the physiological mechanisms underlying the human metabolic phenotype and characterizing the individual susceptibility to weight change.

Thigh Adipocyte Size is Inversely Related to Energy Intake and Respiratory Quotient in Healthy Women

OBJECTIVE

The relationship between adipocyte size and ad libitum energy intake has not been previously examined. This study hypothesized an inverse relationship between adipocyte size and daily energy intake (DEI).

METHODS

Seventy healthy adults (39 men and 31 women; BMI 30.0  [SD 6.3]) underwent dual-energy x-ray absorptiometry and subcutaneous fat biopsies from the abdomen and thigh. Osmium-fixed adipocytes were sized with a Coulter counter. Volunteers self-selected food from a vending machine paradigm as the only source of energy intake over 3 days as inpatients. Volunteers also had 24-hour respiratory quotient (RQ) measured in a whole-room indirect calorimeter.

RESULTS

In women, the large cell peak diameter of the thigh depot was greater than that of the abdominal depot (Δ = +15.8 μm; P < 0.0001). In women, thigh peak diameter was inversely associated with DEI (β = -264.7 kcal/d per 10-μm difference; P = 0.03) after adjusting for demographics and body composition. The thigh peak diameter in women was associated with 24-hour RQ (r = -0.47, P = 0.04) after adjusting for demographics, body composition, and 24-hour energy balance. These associations did not extend to men or the abdominal depot.

CONCLUSIONS

In women, thigh adipocyte size was associated with reduced DEI and 24-hour RQ, indicating a special role for thigh fat in women. This depot-specific sexual dimorphism indicates common regulation of energy intake and adipocyte size in the thigh region of women.

Barriers to Women Entering Surgical Careers: A Global Study into Medical Student Perceptions

BACKGROUND

Barriers to female surgeons entering the field are well documented in Australia, the USA and the UK, but how generalizable these problems are to other regions remains unknown.

METHODS

A cross-sectional survey was developed by the International Federation of Medical Students' Associations (IFMSA)'s Global Surgery Working Group assessing medical students' desire to pursue a surgical career at different stages of their medical degree. The questionnaire also included questions on students' perceptions of their education, resources and professional life. The survey was distributed via IFMSA mailing lists, conferences and social media. Univariate analysis was performed, and statistically significant exposures were added to a multivariate model. This model was then tested in male and female medical students, before a further subset analysis by country World Bank income strata.

RESULTS

639 medical students from 75 countries completed the survey. Mentorship [OR 3.42 (CI 2.29-5.12) p = 0.00], the acute element of the surgical specialties [OR 2.22 (CI 1.49-3.29) p = 0.00], academic competitiveness [OR 1.61 (CI 1.07-2.42) p = 0.02] and being from a high or upper-middle-income country (HIC and UMIC) [OR 1.56 (CI 1.021-2.369) p = 0.04] all increased likelihood to be considering a surgical career, whereas perceived access to postgraduate training [OR 0.63 (CI 0.417-0.943) p = 0.03], increased year of study [OR 0.68 (CI 0.57-0.81) p = 0.00] and perceived heavy workload [OR 0.47 (CI 0.31-0.73) p = 0.00] all decreased likelihood to consider a surgical career. Perceived quality of surgical teaching and quality of surgical services in country overall did not affect students' decision to pursue surgery. On subset analysis, perceived poor access to postgraduate training made women 60% less likely to consider a surgical career [OR 0.381 (CI 0.217-0.671) p = 0.00], whilst not showing an effect in the men [OR 1.13 (CI 0.61-2.12) p = 0.70. Concerns about high cost of training halve the likelihood of students from low and low-middle-income countries (LICs and LMICs) considering a surgical career [OR 0.45 (CI 0.25-0.82) p = 0.00] whilst not demonstrating a significant relationship in HIC or UMIC countries. Women from LICs and LMICs were 40% less likely to consider surgical careers than men, when controlling for other factors [OR 0.59 CI (0.342-1.01 p = 0.053].

CONCLUSION

Perceived poor access to postgraduate training and heavy workload dissuade students worldwide from considering surgical careers. Postgraduate training in particular appears to be most significant for women and cost of training an additional factor in both women and men from LMICs and LICs. Mentorship remains an important and modifiable factor in influencing student's decision to pursue surgery. Quality of surgical education showed no effect on student decision-making.

Hydration biomarkers and copeptin: relationship with ad libitum energy intake, energy expenditure, and metabolic fuel selection

Background/Objective

Evidence from non-human species indicate that hydration and arginine vasopressin (AVP) influence fuel selection, energy expenditure (EE), and food intake, but these relationships are unclear in humans. We sought to assess whether hydration biomarkers [24-h urine volume (UVol) and urine urea nitrogen concentration (UUN)] and copeptin (a surrogate for AVP) are associated with 24-h EE, respiratory quotient (RQ), and daily energy intake (DEI).

Subjects/Methods

In a secondary analysis of collected data, we selected healthy adults (Group 1, n = 177) who had 24-h whole-room indirect calorimetry measurements in energy balance with 24-h urine collection and fasting copeptin measurements (n=117), followed by 3 days ad libitum food intake. A separate group (Group 2, n=284) with hydration markers and calorimetry measurements was also studied. The main outcome measures were 24-h RQ, 24-h EE, DEI, substrate oxidation.

Results

In Group 1, lower 24-h UVol and higher 24-h UUN, indicating lower hydration, were correlated with lower 24-h RQ (r = 0.35, p <0.0001, and r = −0.29, p = 0.0001, respectively; results similar in Group 2) and predicted subsequent reduced DEI (r = 0.20, p = 0.01, and r = −0.27, p = 0.0003, respectively), adjusted for confounders. Copeptin was independently associated with 24-h lipid oxidation (r = −0.23, p = 0.01). In Group 2, lower hydration was associated with reduced 24-h EE (24-h UVol: r = 0.29, p <0.0001; 24-h UUN: r = −0.25, p <0.0001).

Conclusions

Hydration biomarkers were associated with metabolic differences characterized by altered food intake, fuel selection, and possibly EE. Independently, copeptin was associated with higher lipid oxidation.

Reduced plasma albumin predicts type 2 diabetes and is associated with greater adipose tissue macrophage content and activation

BACKGROUND

Plasma albumin is reduced during inflammation. Obesity, a strong risk factor for type 2 diabetes (T2D), is associated with adipose tissue inflammation. However, whether albumin is associated with adipose tissue inflammation and whether it predicts T2D are unclear.

METHODS

Adults (predominantly American Indian) from a longitudinal study were included. Macrophage content and gene expression related to recruitment/activation were measured from subcutaneous adipose tissue (n = 51). The relationship between plasma albumin and adiposity (dual-energy X-ray absorptiometry or hydrodensitometry), glucose (oral glucose tolerance test), insulin action (hyperinsulinemic-euglycemic clamp), and insulin secretion (intravenous glucose tolerance test) were evaluated (n = 422). Progression to T2D was evaluated by Cox regression (median follow-up 8.8 years; 102 progressors).

RESULTS

Albumin was associated with macrophage markers including C1QB (r = - 0.30, p = 0.04), CSF1R (r = - 0.30, p = 0.03), and CD11b (r = - 0.36, p = 0.01). Albumin was inversely associated with body fat percentage (r = - 0.14, p = 0.003), fasting plasma glucose (r = - 0.17, p = 0.0003), and 2 h plasma glucose (r = - 0.11, p = 0.03), and was reduced in impaired glucose regulation compared with normal glucose regulation (mean ± SD: 39.4 ± 3.6 g/l and 40.1 ± 3.9 g/l, respectively; p = 0.049). Albumin predicted T2D, even after adjustment for confounders (HR, 0.75; 95% CI 0.58-0.96; p = 0.02; per one SD difference in albumin).

CONCLUSIONS

Reduced albumin is associated with an unfavorable metabolic profile, characterized by increased adipose tissue inflammation, adiposity, and glucose, and with an increased risk for T2D.

Predictive Accuracy of Surrogate Indices for Hepatic and Skeletal Muscle Insulin Sensitivity

Context

Surrogate indices of muscle and hepatic insulin sensitivity derived from an oral glucose tolerance test (OGTT) are frequently used in clinical studies. However, the predictive accuracy of these indices has not been validated.

Design

In this cross-sectional study, hyperinsulinemic-euglycemic glucose clamp with tritiated glucose infusion and a 75-g OGTT were performed in individuals (n = 659, aged 18 to 49 years, body mass index of 16 to 64 kg/m²) with varying degrees of glucose tolerance. A calibration model was used to assess the ability of OGTT-derived, tissue-specific surrogate indices [hepatic insulin resistance index (HIRI) and muscle insulin sensitivity index (MISI)] to predict insulin sensitivity/resistance indices derived from the reference glucose clamp [Hepatic-IR_basal, a product of fasting plasma insulin and hepatic glucose production (HGP), Hepatic-IR_clamp, reciprocal of the percent suppression of HGP during the insulin clamp corrected for plasma insulin concentration, and Muscle-IS_clamp, a measure of peripheral glucose disposal]. Predictive accuracy was assessed by root mean squared error of prediction and leave-one-out, cross-validation-type square root of the mean squared error of prediction.

Results

HIRI and MISI were correlated with their respective clamp-derived indices. HIRI was negatively related to Muscle-IS_clamp (r = -0.62, P < 0.0001) and MISI correlated with Hepatic-IR derived from the clamp (Hepatic-IR_basal: r = -0.48, P < 0.0001 and Hepatic-IR_clamp: r = -0.41, P < 0.0001). However, the accuracy of HIRI and MISI to predict Hepatic-IR (basal or during clamp) was not significantly different. Likewise, the ability of HIRI and MISI to predict Muscle-IS_clamp was also similar.

Conclusion

Our findings indicate that the surrogate indices derived from an OGTT are accurate in predicting insulin sensitivity but are not tissue specific.

One-Hour Plasma Glucose Compared With Two-Hour Plasma Glucose in Relation to Diabetic Retinopathy in American Indians

OBJECTIVE

We compared the ability of 1- and 2-h plasma glucose concentrations (1h-PG and 2h-PG, respectively), derived from a 75-g oral glucose tolerance test (OGTT), to predict retinopathy. 1h-PG and 2h-PG concentrations, measured in a longitudinal study of an American Indian community in the southwestern U.S., a population at high risk for type 2 diabetes, were analyzed to assess the usefulness of the 1h-PG to identify risk of diabetic retinopathy (DR).

RESEARCH DESIGN AND METHODS

Cross-sectional (n = 2,895) and longitudinal (n = 1,703) cohorts were assessed for the prevalence and incidence of DR, respectively, in relation to deciles of 1h-PG and 2h-PG concentrations. Areas under the receiver operating characteristic (ROC) curves for 1h-PG and 2h-PG were compared with regard to predicting DR, as assessed by direct ophthalmoscopy.

RESULTS

Prevalence and incidence of DR, based on direct ophthalmoscopy, changed in a similar manner across the distributions of 1h-PG and 2h-PG concentrations. ROC analysis showed that 1h-PG and 2h-PG were of similar value in identifying prevalent and incident DR using direct ophthalmoscopy. 1h-PG cut points of 230 and 173 mg/dL were comparable to 2h-PG cut points of 200 mg/dL (type 2 diabetes) and 140 mg/dL (impaired glucose tolerance), respectively.

CONCLUSIONS

1h-PG is a useful predictor of retinopathy risk, has a predictive value similar to that of 2h-PG, and may be considered as an alternative glucose time point during an OGTT.

Increased Gonorrhea Screening and Case Finding After Implementation of Expanded Screening Criteria-Urban Indian Health Service Facility in Phoenix, Arizona, 2011-2013

BACKGROUND

Gonorrhea screening is recommended for women at risk and men who have sex with men; expanded screening is encouraged based on local epidemiology. In response to a substantial increase in gonorrhea cases at an urban medical center serving American Indians, gonorrhea screening of all sexually active patients aged 14 to 45 years was initiated in March 2013. We describe gonorrhea screening coverage and case finding before and after implementation of expanded screening.

METHODS

In March 2013, provider training, electronic health record prompts, and bundled laboratory orders were implemented to facilitate gonorrhea screening of all sexually active patients aged 14 to 45 years. We assessed the proportions of patients screened and testing positive for gonorrhea in the 2 years before (March 2011-February 2012 [indicated as 2011], March 2012-February 2013 [2012]) and 1 year after (March 2013-February 2014 [2013]) expanded screening measures.

RESULTS

Gonorrhea screening coverage increased from 22% (2012) to 38% (2013); coverage increased 50% among females and 202% among males. Screening coverage increased in nearly all clinics. Gonorrhea case finding increased 68% among females in 2013 (n = 104) compared with 2012 (n = 62), primarily among women aged 25 to 29 years. No corresponding increase in gonorrhea case finding occurred among males. Most increased case finding occurred in the emergency department.

CONCLUSIONS

After introduction of expanded gonorrhea screening, there was a significant increase in gonorrhea screening coverage and a subsequent increase in gonorrhea case finding among females. Despite increased screening in all clinics, increased case finding only occurred in the emergency department.

Autoantibodies against PFDN2 are associated with an increased risk of type 2 diabetes: A case-control study

BACKGROUND

The adaptive immune system is involved in type 2 diabetes mellitus (T2DM), indicating the presence of unidentified autoantibodies that might be useful biomarkers for emerging immunomodulatory therapy. A prior microarray study with a small number of participants suggested the association of novel autoantibodies with T2DM in Southwest American Indians. We therefore sought to determine whether antibodies against 14 target proteins are associated with T2DM in a large case-control study.

METHODS

Participants were adults (age 20-59 y) of Southwest American Indian heritage. Plasma antibodies against 14 possible target proteins were measured in 476 cases with T2DM of less than 5 years duration and compared with 424 controls with normal glucose regulation.

RESULTS

Higher levels of antibodies against prefoldin subunit 2 (PFDN2) were associated with T2DM (P = .0001; Bonferroni-corrected threshold for multiple tests = 0.0036 [α = 0.05]). The association between anti-PFDN2 antibodies and T2DM remained in multivariable logistic regression (odds ratio 1.27; 95% confidence interval, 1.09-1.49; per one SD difference in anti-PFDN2 antibody). The odds of T2DM were increased in the highest anti-PFDN2 antibody quintile by 66% compared with the lowest quintile. Differences in anti-PFDN2 antibodies were most prominent among cases with earlier onset of disease (ie, age 20-39 y) compared with controls.

CONCLUSIONS

Anti-PFDN2 antibodies are associated with T2DM and might be a useful biomarker. These findings indicate that autoimmunity may play a role in T2DM in Southwest American Indians, especially among adults presenting with young onset of disease.

One-hour and two-hour postload plasma glucose concentrations are comparable predictors of type 2 diabetes mellitus in Southwestern Native Americans

AIMS/HYPOTHESIS

Elevated 2-h plasma glucose concentration (2 h-PG) during a 75 g OGTT predict the development of type 2 diabetes mellitus. However, 1-h plasma glucose concentration (1 h-PG) is associated with insulin secretion and may be a better predictor of type 2 diabetes. We aimed to investigate the association between 1 h-PG and 2 h-PG using gold standard methods for measuring insulin secretion and action. We also compared 1 h-PG and 2 h-PG as predictors of type 2 diabetes mellitus.

METHODS

This analysis included adult volunteers without diabetes, predominantly Native Americans of Southwestern heritage, who were involved in a longitudinal epidemiological study from 1965 to 2007, with a baseline OGTT that included measurement of 1 h-PG. Group 1 (n = 716) underwent an IVGTT and hyperinsulinaemic-euglycaemic clamp for measurement of acute insulin response (AIR) and insulin-stimulated glucose disposal (M), respectively. Some members of Group 1 (n = 490 of 716) and members of a second, larger, group (Group 2; n = 1946) were followed-up to assess the development of type 2 diabetes (median 9.0 and 12.8 years follow-up, respectively).

RESULTS

Compared with 2 h-PG (r = -0.281), 1 h-PG (r = -0.384) was more closely associated with AIR, whereas, compared with 1 h-PG (r = -0.340), 2 h-PG (r = -0.408) was more closely associated with M. Measures of 1 h-PG and 2 h-PG had similar abilities to predict type 2 diabetes, which did not change when both were included in the model. A 1 h-PG cut-off of 9.3 mmol/l provided similar levels of sensitivity and specificity as a 2 h-PG cut-off of 7.8 mmol/l; the latter is used to define impaired glucose tolerance, a recognised predictor of type 2 diabetes mellitus.

CONCLUSIONS/INTERPRETATION

The 1 h-PG was associated with important physiological predictors of type 2 diabetes and was as effective as 2 h-PG for predicting type 2 diabetes mellitus. The 1 h-PG is, therefore, an alternative method of identifying individuals with an elevated risk of type 2 diabetes mellitus.

A Novel Approach to Predict 24-Hour Energy Expenditure Based on Hematologic Volumes: Development and Validation of Models Comparable to Mifflin-St Jeor and Body Composition Models

BACKGROUND

Accurate prediction of 24-hour energy expenditure (24EE) relies on knowing body composition, in particular fat-free mass (FFM), the largest determinant of 24EE. FFM is closely correlated with hematologic volumes: blood volume (BV), red cell mass (RCM), and plasma volume (PV). However, it is unknown whether predicted hematologic volumes, based on easily collected variables, can improve 24EE prediction.

OBJECTIVE

The aim was to develop and validate equations to predict 24EE based on predicted BV, RCM, and PV and to compare the accuracy and agreement with models developed from FFM and with the Mifflin-St Jeor equation, which is recommended for clinical use by the Academy of Nutrition and Dietetics.

DESIGN

Participants had body composition measured by underwater weighing and 24EE by respiratory chamber. BV, RCM, and PV were calculated from five published equations.

PARTICIPANTS/SETTING

Native American and white men and women were studied (n=351). Participants were healthy adults aged 18 to 49 years from the Phoenix, AZ, metropolitan area.

MAIN OUTCOME MEASURE

Accuracy to within ±10% of measured 24EE and agreement by Bland-Altman analysis.

STATISTICAL ANALYSIS

Regression models to predict 24EE from hematologic and body composition variables were developed in half the dataset and validated in the other half.

RESULTS

Hematologic volumes were all strongly correlated with FFM in both men and women (r≥0.94). Whereas the accuracy of FFM alone was 69%, four hematologic volumes were individually more accurate (75% to 78%) in predicting 24EE. Equations based on hematologic volumes plus demographics had mean prediction errors comparable to those based on body composition plus demographics; although the Mifflin-St Jeor had modestly better mean prediction error, body composition, hematologic, and Mifflin-St Jeor models all had similar accuracy (approximately 80%).

CONCLUSIONS

Prediction equations based on hematologic volumes were developed, validated, and found to be comparable to Mifflin-St Jeor and body composition models in this population of healthy adults.

Simple preoperative risk scale accurately predicts perioperative mortality following esophagectomy for malignancy

Surgery remains one of the major treatment options available to patients with esophageal cancer, with high mortality in certain cohorts. The aim of this study was to develop a simple preoperative risk scale based on patient factors, hospital factors, and tumor pathology to predict the risk of perioperative mortality following esophagectomy for malignancy. The Nationwide Inpatient Sample database was used to create the risk scale. Patients who underwent open or laparoscopic transhiatal and transthoracic esophageal resection were identified using International Classification of Diseases, 9th edition codes. Patients <18 years and those with peritoneal disease were excluded. Multivariate logistic regressions were used to define a predictive model of perioperative mortality and to create a simple risk scale. From 1998 to 2011, a total of 23 751 patients underwent esophagectomy. The observed overall perioperative mortality rate for this cohort was 7.7%. Minimally invasive techniques, and operations performed in higher volume centers were protective, whereas increasing age, comorbidities and diagnosis of squamous cell carcinoma were independent predictors of mortality. Based on this population, a risk scale from 0-16 was created. The calibration revealed a good agreement between the observed and risk scale-predicted probabilities. A set of sensitivity/specificity analyses was then performed to define normal (score 0-7) and high risk (score 8-16) patients for clinical practice. Mortality in patients with a score of 0-7 ranged from 1.3-7.6%, compared with 10.5-34.5% in patients with a score of 8-16. This simple preoperative risk scale may accurately predict the risk of perioperative mortality following esophagectomy for malignancy and can be used as a clinical tool for preoperative counseling.

Higher insulin and higher body fat via leptin are associated with disadvantageous decisions in the Iowa gambling task

Elevated body mass index and post-prandial state are associated with disadvantageous choices on the Iowa Gambling Task (IGT). Whether physiological factors including percent body fat, and peripheral glucose, insulin, and leptin concentrations, are associated with IGT performance is unknown. In196 healthy adults without diabetes, we measured body fat by DXA scan, glucose, insulin and leptin (n=138) concentrations during an oral glucose tolerance test and IGT performance after a standardized meal. Glucose was not associated with IGT performance. Disadvantageous IGT performance was associated with higher percent body fat (r=-0.16, p=0.03), 30-min insulin concentrations (insulin₃₀, r=-0.27, p<0.001), and 30-min leptin concentrations (leptin₃₀, r=-0.23, p=0.008). Mediation analysis demonstrated that leptin₃₀ was almost completely responsible for the percent body fat effect on IGT performance. Even adjusted for age, sex, race, and education, insulin₃₀ (b=-46.5, p=0.03) and leptin₃₀ (b=-50.9, p=0.03) concentrations remained independently associated with IGT performance and interacted together such that higher leptin₃₀ blunted effects of higher insulin₃₀ (b=23.8, p=0.048). These findings may indicate an internal metabolic signature of energy availability (higher body fat, insulin, and leptin levels) associated with disadvantageous IGT performance.

Comparison of the Use of Administrative Data and an Active System for Surveillance of Invasive Aspergillosis

Background.

Administrative data, such as International Classification of Diseases, Ninth Revision (ICD-9) codes, are readily available and are an attractive option for surveillance and quality assessment within a single institution or for interinstitutional comparisons. To understand the usefulness of administrative data for the surveillance of invasive aspergillosis, we compared information obtained from a system based on ICD-9 codes with information obtained from an active, prospective surveillance system, which used more extensive case-finding methods (Transplant Associated Infection Surveillance Network).

Methods.

Patients with suspected inyasive aspergillosis were identified by aspergillosis-related ICD-9 codes assigned to hematopoietic stem cell transplant recipients and solid organ transplant recipients at a single hospital from April 1, 2001, through January 31, 2005. Suspected cases were classified as proven or probable invasive aspergillosis by medical record review using standard definitions. We calculated the sensitivity and positive predictive value (PPV) of identifying invasive aspergillosis by individual ICD-9 codes and by combinations of codes.

Results.

The sensitivity of code 117.3 was modest (63% [95% confidence interval {CI}, 38%-84%]), as was the PPV (71% [95% CI, 44%-90%]); the sensitivity of code 117.9 was poor (32% [95% CI, 13%-57%]), as was the PPV (15% [95% CI, 6%-31%]). The sensitivity of codes 117.3 and 117.9 combined was 84% (95% CI, 60%-97%); the PPV of the combined codes was 30% (95% CI, 18%-44%). Overall, ICD-9 codes triggered a review of medical records for 64 medical patients, only 16 (25%) of whom had proven or probable invasive aspergillosis.

Conclusions.

A surveillance system that involved multiple ICD-9 codes was sufficiently sensitive to identify most cases of invasive aspergillosis; however, the poor PPV of ICD-9 codes means that this approach is not adequate as the sole tool used to classify cases. Screening ICD-9 codes to trigger a medical record review might be a useful method of surveillance for invasive aspergillosis and quality assessment, although more investigation is needed.

Intracellular water in Artemia cysts (brine shrimp): Investigations by deuterium and oxygen-17 nuclear magnetic resonance

The dormant cysts of Artemia undergo cycles of hydration-dehydration without losing viability. Therefore, Artemia cysts serve as an excellent intact cellular system for studying the dynamics of water-protein interactions as a function of hydration. Deuterium spin-lattice (T(1)) and spin-spin (T(2)) relaxation times of water in cysts hydrated with D(2)O have been measured for hydrations between 1.5 and 0.1 g of D(2)O per gram of dry solids. When the relaxation rates (I/T(1), I/T(2)) of (2)H and (17)O are plotted as a function of the reciprocal of hydration (1/H), an abrupt change in slope is observed near 0.6 g of D(2)O (or H(2) (17)O)/gram of dry solids, the hydration at which conventional metabolism is activated in this system. The results have been discussed in terms of the two-site and multisite exchange models for the water-protein interaction as well as protein dynamics models. The (2)H and (17)O relaxation rates as a function of hydration show striking similarities to those observed for anisotropic motion of water molecules in protein crystals.It is suggested here that although the simple two-site exchange model or n-site exchange model could be used to explain our data at high hydration levels, such models are not adequate at low hydration levels (<0.6 g H(2)O/g) where several complex interactions between water and proteins play a predominant role in the relaxation of water nuclei. We further suggest that the abrupt change in the slope of I/T(1) as a function of hydration in the vicinity of 0.6 g H(2)O/g is due to a change in water-protein interactions resulting from a variation in the dynamics of protein motion.

Validating the Injury Severity Score (ISS) in different populations: ISS predicts mortality better among Hispanics and females

INTRODUCTION

The Injury Severity Score (ISS) is the most commonly used measure of injury severity. The score has been shown to have excellent predictive capability for trauma mortality and has been validated in multiple data sets. However, the score has never been tested to see if its discriminatory ability is affected by differences in race and gender.

OBJECTIVE

This study is aimed at validating the ISS in men and women and in three different race/ethnic groups using a nationwide database.

METHODS

Retrospective analysis of patients age 18-64 y in the National Trauma Data Bank 7.0 with blunt trauma was performed. ISS was categorized as mild (<9,) moderate (9-15), severe (16-25), and profound (>25). Logistic regression was done to measure the relative odds of mortality associated with a change in ISS categories. The discriminatory ability was compared using the receiver operating characteristics curves (ROC). A P value testing the equality of the ROC curves was calculated. Age stratified analyses were also conducted.

RESULTS

A total of 872,102 patients had complete data for the analysis on ethnicity, while 763,549 patients were included in the gender analysis. The overall mortality rate was 3.7%. ROC in Whites was 0.8617, in Blacks 0.8586, and in Hispanics 0.8869. Hispanics have a statistically significant higher ROC (P value < 0.001). Similar results were observed within each age category. ROC curves were also significantly higher in females than in males.

CONCLUSION

The ISS possesses excellent discriminatory ability in all populations as indicated by the high ROCs.

Hyperbaric oxygen ameliorates delayed neuropsychiatric syndrome of carbon monoxide poisoning

OBJECTIVES

Delayed neuropsychiatric syndrome (DNS) is characterized by mental impairment, motor dysfunction, dementia, or psychosis that develops between a few days and weeks after acute carbon monoxide (CO) poisoning. One possible mechanism responsible for CO-mediated encephalopathy involves oxidative stress, such as lipid peroxidation, caused by the cellular uptake of CO and which leads to an inflammatory cascade. There is no current effective treatment for DNS. We applied 8-40 sessions of hyperbaric oxygen therapy (HBO2) to patients with DNS and evaluated its effectiveness.

METHODS

After admission, all patients were administered piracetam or bromocriptine, or both, and received HBO2. Neuropsychiatric tests included EEG, mini-mental status examination (MMSE), brain MRI, event-related potential (ERP), and brain perfusion scan (brain SPECT). Results of these tests were compared before and after HBO2, and the clinical features were monitored during this period.

RESULTS

The symptoms of DNS for all patients improved significantly after HBOT. Although white matter changes remained evident in the brain MRI scans, other examinations such as EEG, MMSE, ERP, and 99mTc-ECD brain SPECT were nearly normal after HBOT.

CONCLUSION

Our results suggest that HBO2 decreases the severity of impairment in patients with DNS. Although a large randomized trial is required to address the efficacy of this therapy, therapeutic application of HBO2 may be recommended in patients with DNS after CO poisoning.

National outbreak of Acanthamoeba keratitis associated with use of a contact lens solution, United States

Premarket standardized testing for Acanthamoeba spp. is warranted.

An outbreak of Acanthamoeba keratitis, a rare, potentially blinding, corneal infection, was detected in the United States in 2007; cases had been increasing since 2004. A case–control study was conducted to investigate the outbreak. We interviewed 105 case-patients from 30 states and 184 controls matched geographically and by contact lens use. Available contact lenses, cases, solutions, and corneal specimens from case-patients were cultured and tested by molecular methods. In multivariate analyses, case-patients had significantly greater odds of having used Advanced Medical Optics Complete Moisture Plus (AMOCMP) solution (odds ratio 16.9, 95% confidence interval 4.8–59.5). AMOCMP manufacturing lot information was available for 22 case-patients, but none of the lots were identical. Three unopened bottles of AMOCMP tested negative for Acanthamoeba spp. Our findings suggest that the solution was not intrinsically contaminated and that its anti-Acanthamoeba efficacy was insufficient. Premarket standardized testing of contact lens solutions for activity against Acanthamoeba spp. is warranted.

Functional assessment of the arm following breast cancer treatment using the DASH survey

Abstract #4096

Treatment of the axilla with surgery and radiation therapy (RT) has a risk of lymphedema and diminished function of the arm. The purpose of this study is to evaluate the Disability of the Arm, Shoulder and Hand survey (DASH) as a potential functional assessment tool post breast cancer treatment by comparing it to the Lymphedema and Breast Cancer Questionnaire (LBCQ), a lymphedema-specific questionnaire, the SF12, and functional arm measurements.&#x2028; A series of patients presenting to the Johns Hopkins Hospital Avon Foundation Breast Center for follow-up of breast cancer were collected. Inclusion criteria are patients &gt; eighteen years receiving either a sentinel lymph node biopsy (SLNB) or axillary node dissection (ALND) at Johns Hopkins Hospital. Exclusion criteria were individuals who reported mental illness, prior deficits of the arm, or any bilateral procedure for treatment of breast cancer. Dependent variables are the DASH, LBCQ, and SF12 scores. Independent measures are arm circumferences and range-of-motion measurements of both arms.&#x2028; The study population included 41 female individuals presenting either prior to or following surgical procedures in the axilla. See Table 1 for demographics. Of those undergoing lumpectomy, 95.24% had RT, none received axillary RT, and 31.58% of the mastectomy patients had RT to the axillary basin. Subjects receiving RT (65.85%) either had whole breast RT (74.07%) or axillary RT (25.93%), others received chemotherapy (53.66%), and a small percentage received herceptin (7.32%).&#x2028; Internal validation of the quality of life surveys were highly correlated to each other. (Table 2). External validity was determined by comparing the quality of life surveys to the physiologic measures. The physical component of the SF-12 was significantly correlated to moderate lymphedema (p=0.019), which is defined as a difference in arm circumference of 2.0 to 3.0 cm. The patient sample included 11 patients with lymphedema, therefore the sample size was insufficient to assess the correlations between arm circumference and range of motion with the DASH and LBCQ.&#x2028; The DASH, LBCQ, and SF-12 are appropriate and valid measures of post-operative quality of life in the patient population post breast cancer treatment. Further patient recruitment is necessary to adequately determine the external validity of the DASH as a measure of the quality of life of patients with lymphedema.&#x2028; &#x2028; &#x2028; &#x2028;

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 4096.

Use of mastectomy in rural versus urban patients: the effects of medical community factors

Abstract #5089

Background: Disparity exists in surgical treatment of breast cancer patients living in rural versus urban counties. Past studies evaluating this used patient level data. We examine county-level medical community factors that potentially impact the geographic variation of mastectomy versus breast-conserving therapy.&#x2028; Methods: Data from 137,303 patients and 200 counties were analyzed combining the 2006 SEER and 2004 ARF (Area Resource File) databases. Inclusion criteria identified in SEER were: stage I, II, or III disease, female, diagnosis after 1992. Patients were linked to county level data from the ARF based on their county of residence. Medical community variables analyzed with ARF are seen in Table 1.&#x2028; Results: A total of 9.58% of the patients reside in a rural county, and 59.90% of these received a mastectomy, compared to 44.92% of the urban patients. Multivariate analysis of the medical community factors was calculated by both land area and population with calculation by population accounting for the disparity in mastectomy use (Table 1). Of the medical community factors in this analysis, the screening hospital density was highly significant, accounted for the difference in rural versus urban mastectomy rates, and resulted in an increased likelihood of receiving mastectomy (OR 1.009, 95% CI 1.004-1.014). Bivariate analysis also revealed a higher density of screening hospitals in rural counties (57.62) than in urban counties (18.22).&#x2028; Conclusions: Analysis using land area versus population to estimate availability of services suggests that disparity in the rural community is most affected by availability of providers and not to required travel distance. Density of screening hospitals was found to be the most important factor resulting in disparity between rural versus urban mastectomy rates. Rural counties have a higher density of screening facilities, yet they also have a higher mastectomy rate. This may represent a volume/quality issue that will require further investigation.&#x2028; &#x2028;

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5089.

Testing for coccidioidomycosis among patients with community-acquired pneumonia

Lack of testing may lead to underdiagnosis and underestimates of disease prevalence.

Coccidioidomycosis is a common cause of community-acquired pneumonia (CAP) in disease-endemic areas. Because testing rates influence interpretation of reportable-disease data and quality of CAP patient care, we determined the proportion of CAP patients who were tested for Coccidioides spp., identified testing predictors, and determined the proportion of tested patients who had positive coccidioidomycosis results. Cohort studies to determine the proportion of ambulatory CAP patients who were tested in 2 healthcare systems in metropolitan Phoenix found testing rates of 2% and 13%. A case-control study identified significant predictors of testing to be age >18 years, rash, chest pain, and symptoms for >14 days. Serologic testing confirmed coccidioidomycosis in 9 (15%) of 60 tested patients, suggesting that the proportion of CAP caused by coccidioidomycosis was substantial. However, because Coccidioides spp. testing among CAP patients was infrequent, reportable-disease data, which rely on positive diagnostic test results, greatly underestimate the true disease prevalence.

Phylogenetic diversity and microsphere array-based genotyping of human pathogenic Fusaria, including isolates from the multistate contact lens-associated U.S. keratitis outbreaks of 2005 and 2006

In 2005 and 2006, outbreaks of Fusarium keratitis associated with soft contact lens use occurred in multiple U.S. states and Puerto Rico. A case-control study conducted by the Centers for Disease Control and Prevention (CDC) showed a significant association between infections and the use of one particular brand of lens solution. To characterize the full spectrum of the causal agents involved and their potential sources, partial DNA sequences from three loci (RPB2, EF-1alpha, and nuclear ribosomal rRNA) totaling 3.48 kb were obtained from 91 corneal and 100 isolates from the patient's environment (e.g., contact lens and lens cases). We also sequenced a 1.8-kb region encoding the RNA polymerase II second largest subunit (RPB2) from 126 additional pathogenic isolates to better understand how the keratitis outbreak isolates fit within the full phylogenetic spectrum of clinically important fusaria. These analyses resulted in the most robust phylogenetic framework for Fusarium to date. In addition, RPB2 nucleotide variation within a 72-isolate panel was used to design 34 allele-specific probes to identify representatives of all medically important species complexes and 10 of the most important human pathogenic Fusarium in a single-well diagnostic assay, using flow cytometry and fluorescent microsphere technology. The multilocus data revealed that one haplotype from each of the three most common species comprised 55% of CDC's corneal and environmental isolates and that the corneal isolates comprised 29 haplotypes distributed among 16 species. The high degree of phylogenetic diversity represented among the corneal isolates is consistent with multiple sources of contamination.

A high throughput drug screen based on fluorescence resonance energy transfer (FRET) for anticancer activity of compounds from herbal medicine

BACKGROUND AND PURPOSE

We report the development of a very efficient cell-based high throughput screening (HTS) method, which utilizes a novel bio-sensor that selectively detects apoptosis based on the fluorescence resonance energy transfer (FRET) technique.

EXPERIMENTAL APPROACH

We generated a stable HeLa cell line expressing a FRET-based bio-sensor protein. When cells undergo apoptosis, they activate a protease called 'caspase-3'. Activation of this enzyme will cleave our sensor protein and cause its fluorescence emission to shift from a wavelength of 535 nm (green) to 486 nm (blue). A decrease in the green/blue emission ratio thus gives a direct indication of apoptosis. The sensor cells are grown in 96-well plates. After addition of different chemical compounds to each well, a fluorescence profile can be measured at various time-points using a fluorescent plate reader. Compounds that can trigger apoptosis are potential candidates as anti-cancer drugs.

KEY RESULTS

This novel cell-based HTS method is highly effective in identifying anti-cancer compounds. It was very sensitive in detecting apoptosis induced by various known anti-cancer drugs. Further, this system detects apoptosis, but not necrosis, and is thus more useful than the conventional cell viability assays, such as those using MTT. Finally, we used this system to screen compounds, isolated from two plants used in Chinese medicine, and identified several effective compounds for inducing apoptosis.

CONCLUSIONS AND IMPLICATIONS

This FRET-based HTS method is a powerful tool for identifying anti-cancer compounds and can serve as a highly efficient platform for drug discovery.

Principles and problems revolving around rhythm-related genetic variants

Much of what is known about the regulation of circadian rhythms has stemmed from the induction, recognition, or manufacture of genetic variants. Such investigations have been especially salient in chronobiological analyses of Drosophila. Many starting points for elucidation of rhythmic processes operating in this insect entailed the isolation of mutants or the design of engineered gene modifications. Various features of the principles and practices associated with the genetic approach toward understanding clock functions, and chronobiologically related ones, are discussed from perspectives that are largely genetic as such, although intertwined with certain neurogenetic and molecular-genetic concerns when appropriate. Key themes in this treatment connect with the power and problems associated with multiply mutant forms of rhythm-related genes, with the opportunistic or problematical aspects of multigenic variants that are in play (sometimes surprisingly), and with a question as to how forceful chronogenetic inferences have been in terms of elucidating the mechanisms of circadian pacemaking.

Gastroschisis in the United States 1988-2003: analysis and risk categorization of 4344 patients

OBJECTIVE

Gastroschisis is a rare congenital abdominal wall defect through which intraabdominal organs herniate and it requires surgical management soon after birth. The objectives of this study were to profile patient characteristics of this anomaly utilizing data from two large national databases and to validate previous risk stratification categories of infants born with this condition.

METHODS

An analysis was performed using 13 years of the National Inpatient Sample database (1988-1996, 1998, 1999, 2001, 2002) and 3 years of the Kids' Inpatient Database (1997, 2000, 2003). These combined databases contain information from nearly 93 million discharges in the United States. Infants with gastroschisis were identified by International Classification of Disease-9 procedure code 54.71 (repair of gastroschisis) and an age at admission of <8 days. Variables of gender, race, geographic region, co-existing diagnoses, length of stay, hospital charges adjusted to 2005 dollars, complications and inpatient mortality were collected from the databases. Infants were divided into simple and complex categories based on the absence or presence of intestinal atresia, stenosis, perforation, necrosis or volvulus. Comparisons between groups were performed using Pearson's chi (2) for categorical outcomes and the Kruskal-Wallis test for non-normally distributed continuous variables.

RESULTS

A total of 4344 infants with gastroschisis were identified. These were comprised of 44.0% female infants (n=1910), 46.4% male infants (n=2017) whereas 9.6% were not reported (n=415). Racial analysis showed the largest subset being white in 40.9% of infants (n=1775) with Hispanic infants being the next highest group reported at 17.2% (n=745). Co-existing intestinal anomalies were the most common, affecting 9.9% (n=429) infants, whereas certain cardiac (6.8%, n=294) and pulmonary (1.7%, n=72) conditions were also identified. Simple gastroschisis represented 89.1% (n=3870) of the group whereas 10.9% (n=474) were complex in nature. Simple and complex patients differed in median length of stay (28 vs 67 days, P<0.01), inpatient mortality (2.9 vs 8.7%, P<0.01) and median inflation-adjusted hospital charges (90,788 dollars vs 197,871 dollars, P<0.01).

CONCLUSIONS

These data represent a national analysis of the largest group of infants with gastroschisis to date which further aids the characterization and understanding of this serious congenital condition.

Multistate outbreak of Fusarium keratitis associated with use of a contact lens solution

CONTEXT

Fusarium keratitis is a serious corneal infection, most commonly associated with corneal injury. Beginning in March 2006, the Centers for Disease Control and Prevention received multiple reports of Fusarium keratitis among contact lens wearers.

OBJECTIVE

To define the specific activities, contact lens hygiene practices, or products associated with this outbreak.

DESIGN, SETTING, AND PARTICIPANTS

Epidemiological investigation of Fusarium keratitis occurring in the United States. A confirmed case was defined as keratitis with illness onset after June 1, 2005, with no history of recent ocular trauma and a corneal culture growing Fusarium species. Data were obtained by patient and ophthalmologist interviews for case patients and neighborhood-matched controls by trained personnel. Available Fusarium isolates from patients' clinical and environmental specimens were genotyped by multilocus sequence typing. Environmental sampling for Fusarium was conducted at a contact lens solution manufacturing plant.

MAIN OUTCOME MEASURES

Keratitis infection with Fusarium species.

RESULTS

As of June 30, 2006, we identified 164 confirmed case patients in 33 states and 1 US territory. Median age was 41 years (range, 12-83 years). Corneal transplantation was required or planned in 55 (34%). One hundred fifty-four (94%) of the confirmed case patients wore soft contact lenses. Forty-five case patients and 78 controls were included in the case-control study. Case patients were significantly more likely than controls to report using a specific contact lens solution, ReNu with MoistureLoc (69% vs 15%; odds ratio, 13.3; 95% confidence interval, 3.1-119.5). The prevalence of reported use of ReNu MultiPlus solution was similar between case patients and controls (18% vs 20%; odds ratio, 0.7; 95% confidence interval, 0.2-2.8). Fusarium was not recovered from the factory, warehouse, solution filtrate, or unopened solution bottles; production of implicated lots was not clustered in time. Among 39 isolates tested, at least 10 different Fusarium species were identified, comprising 19 unique multilocus genotypes.

CONCLUSIONS

The findings from this investigation indicate that this outbreak of Fusarium keratitis was associated with use of ReNu with MoistureLoc contact lens solution. Contact lens users should not use ReNu with MoistureLoc.

Thirty robotic adrenalectomies

BACKGROUND

Robotic adrenalectomy is a minimally invasive alternative to traditional laparoscopic adrenalectomy. To date, only case reports and small series of robotic adrenalectomies have been reported. This study presents a single institution's series of 30 robotic adrenalectomies, and evaluates the procedure's safety, efficacy, and cost.

METHODS

Thirty patients underwent robotic adrenalectomy at the Johns Hopkins Hospital between April 2001 and January 2004. Patient morbidity, hospital length of stay, operative time, and conversion rate to traditional laparoscopic or open surgery are presented. Improvement in operative time with surgeon experience is evaluated. Hospital charges are compared to charges for traditional laparoscopic and open adrenalectomies performed during the same time period.

RESULTS

Median operative time was 185 min. Patient morbidity was 7%. There were no conversions to traditional laparoscopic or open surgery. The median hospital stay was 2 days. Operative time improved significantly by 3 min with each operation. Hospital charges for robotic adrenalectomy (12,977 dollars) were not significantly different than charges for traditional laparoscopic (11,599 dollars) or open adrenalectomy (14,600 dollars).

CONCLUSIONS

Robotic adrenalectomy is a safe and effective alternative to traditional laparoscopic adrenalectomy.