Endocrinologists at work: management of hyponatremia in clinical practice

Hyponatremia, hypernatremia and impairment of functional, psychological and sexual domains

OBJECTIVE

To determine the influence of serum sodium on physical, psychologic and sexual function.

METHODS

This is a cross-sectional survey on 3340 community-dwelling men aged 40-79 years from a prospective cohort study in eight European countries, the European Male Ageing Study (EMAS). Participants filled-out the Short Form-36 (SF-36), the Physical Activity Scale for the Elderly (PASE), and the EMAS sexual function questionnaire. For all the analyses, serum sodium corrected for glycaemia ([Na+]G) was used.

RESULTS

The relationship between [Na+]G and SF-36 physical function score (F = 3.99; p = 0.01), SF-36 mental health score (F = 7.69; p < 0.001), and PASE score (F = 14.95; p < 0.001) were best described by a quadratic equation, with worse scores for [Na+]G in either the lowest or the highest ends of the range. After dividing the sample into [Na+]G < 136 mmol/L (n = 81), 136-147 mmol/L (n = 3223) and > 147 mmol/L (n = 36), linear regression analyses with linear spline functions adjusted for confounders did not confirm these relationships. Similarly, erectile dysfunction and [Na+]G, were in a quadratic relationship (F = 9.00; p < 0.001). After adjusting for confounders, the linear regression with spline functions denoted a significantly worsened erectile function for increases in serum [Na+]G > 147 mmol/L (B = 0.15 [0.04;0.26], p < 0.01) but no relationship with [Na+]G < 136 mmol/L. Likewise, the relationship of [Na+]G with concerns about sexual dysfunction was confirmed only for men with serum [Na+]G > 147 mmol/L.

CONCLUSIONS

This is the first study supporting an association between [Na+]G and sexual function. A worsening of erection and concerns about sexual function were observed for the highest values of [Na+]G, independently of other relevant factors.

Palatability of two different formulations of urea for the treatment of hyponatremia: A double-blind, randomized, cross-over study

BACKGROUND AND AIMS

Hyponatremia (HN) is the most common disorder of electrolytes encountered in clinical practice. Considering that HN is associated with high morbidity and mortality, it is important to identify treatments for these patients. The therapeutic approaches for HN depend on the severity and the character of the pathology (acute vs. chronic). Among intervention strategies, oral urea represents an effective, safe, and well-tolerated therapeutic approach in the management of chronic hyponatremia. Oral ureal is commonly prepared as a galenic formulation that is usually associated with distaste problems. A double-blind, randomized, cross-over clinical trial was conducted to evaluate and compare the palatability of two different urea formulations: a commercial urea formulation and a galenic one (trial registered on www.isrctn.com, number: ISRCTN18369035).

MATERIALS AND METHODS

Thirty-six healthy subjects (18 female and 18 male, median age 55 years) were enrolled in the study and randomized to consume 7 g of formulation A (commercial formulation) or formulation B (galenic formulation) twice a day away from meals, solubilizing the products in 125 mL of water (T0). After three days of a wash-out, the formulations were crossed-over and consumed twice a day away from meals (T4). After the consumption of products, both in the morning and the evening, participants completed a specific questionnaire to evaluate the products' palatability.

RESULTS

The commercial formulation was globally more appreciated than the galenic one, in terms of smell, taste, and aftertaste. The commercial formulation was better accepted as a potential treatment in 44 % of subjects compared to 14 % of subjects for galenic formulation.

CONCLUSIONS

The clinical trial confirmed the better palatability of the commercial oral urea formulation, containing citrus flavor, which therefore represents a therapeutic strategy that could improve adherence to the therapy in chronic patients with hyponatremia.