ASSOCIATION BETWEEN 25-HYDROXYVITAMIN D AND INTACT PARATHYROID HORMONE LEVELS ACROSS LATITUDE AMONG ADULTS WITH AFRICAN ANCESTRY.

OBJECTIVE: To compare levels of 25-hydroxyvitamin D (25[OH]D) associated with a plateauing of intact parathyroid (iPTH) across latitudes among adults with African ancestry. METHODS: This study included approximately 500 adults of African ancestry ages 25 to 45 years living in 4 sites: Chicago, Illinois (41°N), Jamaica (17°N), Ghana (6°N), and South Africa (34°S). Multivariate linear regression models, a nonlinear logistic growth curve model, and piecewise linear models with a single knot were fitted to estimate the 25[OH]D level associated with a plateauing of iPTH with adjustment for covariates. Goodness of fit was compared using computer intensive permutation tests. RESULTS: Mean age was 34.7 (SD 6.2) years, and 46.5% were male. Within each site, the percentage of participants with an iPTH level ≥65 pg/mL was higher among females versus males and was most frequent among South African females (17.1%) and lowest among Jamaican males (0.6%). Goodness of fit tests supported linear regression as the preferred model for the association between iPTH and 25[OH]D in the 4 sites with no 25[OH]D level associated with iPTH plateauing in any site. The slope of the association between 25[OH]D and iPTH differed by latitude; it was strongest in the U.S. (ß = -0.81; 95% confidence interval [CI] = -1.03, -0.59), and weakest in Jamaica (ß = -0.45; 95% CI -0.71, -0.18) with covariate adjustment, but differences in slopes were small. CONCLUSION: The association between 25[OH]D and iPTH appears linear among adults with African ancestry regardless of latitude within a range of 25[OH]D levels between 10 and 60 ng/mL. ABBREVIATIONS: BMI = body mass index CI = confidence interval eGFR = estimated glomerular filtration rate iPTH = intact parathryoid hormone 25[OH]D = 25-hydroxyvitamin D.

Fibroblast Growth Factor-23 (FGF-23) Levels Differ Across Populations by Degree of Industrialization.

CONTEXT: Compensatory increases in fibroblast growth factor 23 (FGF23) with increasing phosphate intake may adversely impact health. However, population and clinical studies examining the link between phosphate intake and FGF23 levels have focused mainly on populations living in highly industrialized societies in which phosphate exposure may be homogenous. OBJECTIVE: The objective of the study was to contrast dietary phosphate intake, urinary measures of phosphate excretion, and FGF23 levels across populations that differ by the level of industrialization. DESIGN: This was a cross-sectional analysis of three populations. SETTING: The study was conducted in Maywood, Illinois; Mahé Island, Seychelles; and Kumasi, Ghana. PARTICIPANTS: Adults with African ancestry aged 25-45 years participated in the study. MAIN OUTCOME: FGF23 levels were measured. RESULTS: The mean age was 35.1 (6.3) years and 47.9% were male. Mean phosphate intake and fractional excretion of phosphate were significantly higher in the United States vs Ghana, whereas no significant difference in phosphate intake or fractional excretion of phosphate was noted between the United States and Seychelles for men or women. Overall, median FGF23 values were 57.41 RU/mL (interquartile range [IQR] 43.42, 75.09) in the United States, 42.49 RU/mL (IQR 33.06, 55.39) in Seychelles, and 33.32 RU/mL (IQR 24.83, 47.36) in Ghana. In the pooled sample, FGF23 levels were significantly and positively correlated with dietary phosphate intake (r = 0.11; P < .001) and the fractional excretion of phosphate (r = 0.13; P < .001) but not with plasma phosphate levels (r = -0.001; P = .8). Dietary phosphate intake was significantly and positively associated with the fractional excretion of phosphate (r = 0.23; P < .001). CONCLUSION: The distribution of FGF23 levels in a given population may be influenced by the level of industrialization, likely due to differences in access to foods preserved with phosphate additives.

Robotic objective structured assessment of technical skills: a randomized multicenter dry laboratory training pilot study.

STUDY OBJECTIVE: The goal of this study was to determine if a robotic dry laboratory curriculum for gynecology and urology residents improved their basic robotic skills. METHODS: After the institution-specific institutional review board approval or exemption, 165 residents from 8 gynecology and/or urology programs were enrolled. Residents underwent standardized robotic orientation followed by dry laboratory testing on 4 unique robotic tasks. Residents were block randomized by program to unstructured or structured training programs. Regardless of group, residents were expected to practice for 15 minutes twice monthly over 7 months. Errors, time to completion, and objective structured assessment of technical skills global rating scores were recorded for each task before and after the training period. Statistics were calculated using the Student t tests, Pearson correlation, and analysis of variance with STATA systems (version 11.2). RESULTS: A total of 99 residents completed both the pretraining and posttraining testing. A mean of 4 (range, 0-15) 15-minute training sessions per resident was self-reported. The structured group had faster posttraining times on the transection task, although the unstructured group had higher posttraining scores on the knot-tying task. CONCLUSIONS: Overall, the residents' robotic skills improved after participating in a dry laboratory curriculum; however, robotic availability, duty hour restrictions, and clinical responsibilities limit the curriculum implementation.

Energy expenditure in adults living in developing compared with industrialized countries: a meta-analysis of doubly labeled water studies.

BACKGROUND: There is an assumption that people in developing countries have a higher total energy expenditure (TEE) and physical activity level (PAL) than do people in developed nations, but few objective data for this assertion exist. OBJECTIVE: We conducted a meta-analysis of TEE and PAL by using data from countries that have a low or middle human development index (HDI) compared with those with a high HDI to better understand how energy-expenditure variables are associated with development status and population differences in body size. DESIGN: We performed a literature search for studies in which energy expenditure was measured by using doubly labeled water. Mean data on age, weight, body mass index (BMI; in kg/m(2)), TEE, and PAL were extracted, and HDI status was assessed. Pooled estimates of the mean effect by sex were obtained, and the extent to which age, weight, HDI status, and year of publication explained heterogeneity was assessed. RESULTS: A total of 98 studies (14 studies from low- or middle-HDI countries) that represented 183 cohorts and 4972 individuals were included. Mean (±SE) BMI was lower in countries with a low or middle HDI than in those with a high HDI for both men and women (22.7 ± 1.0 compared with 26.0 ± 0.7, respectively, in men and 24.3 ± 0.7 compared with 26.6 ± 0.4, respectively, in women). In meta-regression models, there was an inverse association of age (P < 0.001) and a positive association of weight (P < 0.001) with TEE for both sexes; there was an association of age only in men with PAL (P < 0.001). There was no association of HDI status with either TEE or PAL. CONCLUSION: TEE adjusted for weight and age or PAL did not differ significantly between developing and industrialized countries, which calls into question the role of energy expenditure in the cause of obesity at the population level.