Associations between urine specific gravity and race/ethnicity at the population level: Implications for hydration status categorization.

OBJECTIVE: We aimed to evaluate how urine specific gravity (USG) and rates of supposed hypohydration vary by race/ethnicity, and to examine how adjustment for several important factors impacts estimated USG. METHODS: Using the National Health and Nutrition Examination Survey, this cross-sectional study evaluated a total of 4195 (2098 female, 2097 male) Americans and categorized them as supposedly hypohydrated (USG≥1.020) or not using spot urine samples. USG and prevalence of supposed hypohydration were compared across racial/ethnic groups, separately by gender. The analyses considered the impact of urine creatinine, body composition, age, dietary nutrients, and physical activity. RESULTS: Differences in supposed hypohydration prevalence were observed by race/ethnicity in men (p = .030) and women (p < .001). In unadjusted models, Black women's USG (1.0189) was higher (p < .05) than all the other race/ethnicity groups' USG (1.0142-1.0171). In men, Blacks' USG (1.0197) was higher (p < .05) than the USG of Whites (1.0177) and other/multi-racial (1.0176) but not Mexican Americans (1.0196) or other Hispanics (1.0192). Adjustments for age, arm circumference, nutrients (protein, sodium, potassium, and moisture), and physical activity minimally influenced USG estimates. Further adjustment for urine creatinine lowered USG for Black women and men by 0.003 and 0.0023, respectively, with no notable lowering of USG in the other races/ethnicities. Supplemental analyses matching Whites and Blacks on age, moisture intake, and poverty-to-income ratio confirmed racial differences in urine creatinine and USG, though the effects were most pronounced in women. CONCLUSIONS: Using a USG≥1.020 to identify hypohydration in all races/ethnicities may be inappropriate due to, among other factors, differences in urinary creatinine.

Differences in urine creatinine and osmolality between black and white Americans after accounting for age, moisture intake, urine volume, and socioeconomic status.

Urine osmolality is used throughout research to determine hydration levels. Prior studies have found black individuals to have elevated urine creatinine and osmolality, but it remains unclear which factors explain these findings. This cross-sectional, observational study sought to understand the relationship of self-reported race to urine creatinine and urine osmolality after accounting for age, socioeconomic status, and fluid intake. Data from 1,386 participants of the 2009-2012 National Health and Nutrition Examination Survey were utilized. Age, poverty-to-income ratio (PIR), urine flow rate (UFR), fluid intake, estimated lean body mass (LBM), urine creatinine, and urine osmolality were measured. In a sex-specific manner, black and white participants were matched on age, dietary moisture, UFR, and PIR. Urine creatinine was greater in black men (171 mg/dL) than white men (150 mg/dL) and greater in black women (147 mg/dL) than white women (108 mg/dL) (p < .001). Similarly, urine osmolality was greater in black women than white women (723 vs. 656 mOsm/kg, p = .001), but no difference was observed between white and black men (737 vs. 731 mOsm/kg, p = .417). Estimated LBM was greater in black men (61.8 kg) and women (45.5 kg) than in white men (58.9 kg) and women (42.2 kg) (p≤.001). The strongest correlate of urine osmolality in all race-sex groups was urine creatinine (Spearman ρ = .68-.75). These results affirm that individuals identifying as black produce higher urine creatinine concentrations and, in women, higher urine osmolality after matching for age, fluid intake, and socioeconomic status. The findings suggest caution when comparing urine hydration markers between racial groups.

Interprofessional Education in Radiation Oncology.

PURPOSE: Interprofessional education (IPE) is demonstrated to improve patient outcomes in a variety of health care fields and clinical settings. However, the extent and effectiveness of IPE in radiation oncology is undefined. This systematic literature review identifies reports of radiation oncology IPE and summarizes the outcomes of those initiatives. METHODS: The literature was queried through PubMed using search terms focusing on IPE targeted toward radiation oncologists, radiation therapists, nurses, medical physicists, and medical dosimetrists in the undergraduate medical education, graduate medical education, and continuing medical education settings. IPE was defined as any educational initiative designed to improve understanding or teamwork efficiency between the learners of interest. Because of the lack of published material pertaining to IPE in radiation oncology, noninterventional, descriptive studies were included. RESULTS: Of 1,306 articles screened, 4 were included in the qualitative analysis. Radiation therapists were included in IPE most frequently (four articles), followed by radiation oncologists, nurses, physicists, and dosimetrists (one article each). IPE initiatives identified ranged from descriptive surveys and written source review to IPE workshops and longitudinal IPE curricula with quantified outcomes. Descriptive studies viewed IPE positively, and all studies collecting quantitative data demonstrated positive outcomes. Undergraduate health profession students were included most frequently (three articles), followed by practicing professionals (one article). No articles reported IPE in the graduate medical education setting. CONCLUSIONS: This systematic review demonstrates that despite the general association of IPE with improved outcomes, radiation oncology IPE initiatives are lacking. There is a significant opportunity to further develop radiation oncology IPE.