Author(s): EVAN, B., MOULTON, C., Institution: UNILEVER, Country: UNITED STATES, Abstract-ID: 1861

INTRODUCTION:
There are well-understood ethnic differences among Americans in hemodynamics and metabolic health, while NHANES fluid intake data suggests certain ethnic groups are at greater risk for hypohydration. Recent evidence suggests that young African American (AA) adults may be more likely than young Caucasian adults to be hypohydrated, with reduced urine output, increased urine specific gravity, and elevated copeptin (1). It is generally accepted that dehydration is associated with diminished exercise performance, but less is known about the potential impact of hypohydration on non-exercise physical exertion. Therefore, we evaluated physical function capacity, hydration status and Quality of Life indicators in a multi-ethnic cohort of American women.
METHODS:
Healthy women (n=114) aged 19-70 yrs were enrolled from the San Francisco metropolitan area without preference for ethnicity. Health was defined as absence of chronic disease and no recent use of associated medications (e.g., insulin, diuretics, corticosteroids). Vitals were measured, and participants completed the PROMIS-29 QoL questionnaire. Fasted blood was collected and glucose, ADH, and copeptin were analyzed. Twenty-four-hour urine volume was collected, and urine was analyzed for osmolality, specific gravity, and creatinine. A two-way ANOVA was used to detect differences in means between ethnicities. All data are expressed as mean ± SEM.
RESULTS:
The cohort was comprised of Asian (n=51), African American (n = 24), Caucasian (n=21), and Hispanic (n=18) ethnicities. AA women had the highest BMI (33.25; p<0.0001) and highest systolic BP (124.54±3.18 mm Hg), while there were no differences in glucose or urine volume. There were group effects for ethnicity on PROMIS Physical Function (p=0.007), urine specific gravity (p=0.007), urine creatinine (p<0.0001), and ADH (p<0.001). AA women had the lowest aggregate score on the physical function domain (13.58±1.63), indicating more difficulty with activities of daily living . AA women had higher urine specific gravity (1.02±0.01) and markedly elevated urine creatinine (161.11±19.77 mg/dL). AA women had elevated ADH (27.31±2.53 pg/mL), and while not statistically significant, the highest mean level of copeptin.
CONCLUSION:
In this cross-sectional sample, AA women reported the lowest physical function capacity, while displaying multiple indicators of hypohydration and possible renal insufficiency. These findings could be in part related to differences in body composition. Hydration interventions targeted to specific ethnicities may have potential to improve free-living hydration status, kidney function, and capacity for physical activity.
1. Robinson AT, et al. Am J Clin Nutr. 2023 Oct;118(4):822-833.