Hyperosmolality, High Blood Pressure, and Decreased Estimated Glomerular Filtration Rate in US Adolescents, National Health and Nutrition Examination Survey 1999-2012.

BACKGROUND

Experimental evidence suggests that hyperosmolality may be a causative factor in the development of both salt-sensitive hypertension and chronic kidney disease (CKD). There are no population-wide studies in young persons to assess the relationships among these factors.

OBJECTIVE

To determine the association of serum osmolality and serum sodium with high systolic blood pressure (SBP) and decreased estimated glomerular filtration rate (eGFR) among a nationally representative population of adolescents.

METHOD: Relevant data among participants ages 12-14 were obtained from the National Health and Nutrition Examination Survey cycles 1999-2012. Serum osmolality was calculated using the Worthley equation. eGFR was calculated using the Counahan-Barratt equation, and values < 90 mL/min/1.73 m2 were considered decreased. High SBP was defined as SBP ≥95th percentile for age, height, and sex.

RESULTS

A total of 4,168 adolescents were analyzed (representative population: 10,464,592). Adolescents with serum osmolality ≥290 mOsm/kg and/or serum sodium ≥143 mmol/L had increased odds for both high SBP (serum osmolality ≥290 mOsm/kg: OR 2.04; 95% CI 1.03-4.02; sodium ≥143 mmol/L: OR 4.36; 95% CI 1.58-12.04) and decreased eGFR (serum osmolality ≥290 mOsm/kg: OR 1.61; 95% CI 1.18-2.21; sodium ≥143 mmol/L: OR 3.27; 95% CI 1.77-6.03) when compared to participants with values below these thresholds. These thresholds remained significant even after multivariable adjustment.

CONCLUSION

Among adolescents in a nationally representative survey, hypernatremia and hyperosmolality were associated with high SBP and decreased eGFR. These findings may support the hypothesis that an imbalance of salt and water contribute to hypertension and CKD.