Lower urinary tract symptoms are associated with inadequate hydration in progressive multiple sclerosis, according to a recent prospective study.
Lower urinary tract symptoms (LUTS) are very common in people with multiple sclerosis (MS). The prevalence of self-reported LUTS is approximately 68% in MS patients. LUTS can be disabling and affect the quality of life in MS patients; therefore, restricting oral fluid intake to control symptoms is a common practice among persons with MS.
A study in the European Journal of Neurology objectively assessed the evidence of inadequate hydration in persons with progressive MS (pwPMS) and its association with LUTS.
Patient Characteristics
LUTS questionnaires and first-morning urine samples from 55 participants were analyzed. The mean age was 55 years, and 54.5% were females. The mean disease duration was 13 years, with 56.4% being primary progressive MS cases and 43.6% being secondary progressive MS.
High Prevalence of LUTS, With Varied Impact on Functional Scores
At baseline, 87% of LUTS patients reported urgency, 89% reported voiding symptoms, and 47% reported discomfort. No correlation was found between LUTS severity and the Expanded Disability Status Scale (EDSS) score at baseline. The severity of voiding symptoms correlated with a lower Multiple Sclerosis Functional Composite (MSFC) score at baseline (p=0.029), but urgency and discomfort did not.
No Evidence of Severe Hypohydration Found in Participants
Activation of the renin–angiotensin–aldosterone system occurs in severe dehydration, with a resultant decrease in urinary sodium/potassium ratio and an increase in urine osmolality (UOsm). There was no anti-correlation evident between urinary sodium and potassium (p<0.001 for both within-subject and between-subject). Moreover, the urinary sodium/potassium ratio was not anti-correlated with UOsm (within-subject p=0.541 and between-subject p=0.260). Hence, there was no evidence of severe hypohydration in the participants.
High Prevalence of Inadequate Hydration Noted
Hydration status was assessed by studying the distribution of the mean UOsm of each participant against the European Food Safety Authority’s thresholds for hydration levels. Half of the participants (n=26, 47%) showed inadequate hydration (UOsm: ≥500 mOsmol/kg). Three participants showed significant dehydration (UOsm: >800 mOsmol/kg).
Voiding Symptoms Found to Be Associated With Inadequate Hydration
Participants with a mean UOsm ≥500 mOsmol/kg experienced more severe voiding symptoms than those with a mean UOsm <500 mOsmol/kg (p<0.001); however, the severity of urgency and discomfort was not significantly different. With UOsm as a hydration marker after correcting for age, a between-subject correlation was established between inadequate hydration and increasing severity of voiding symptoms (p<0.001), but not urgency or discomfort symptoms.
With multiple samplings, a within-subject correlation was established between a higher UOsm and more severe voiding symptoms (p=0.012) but not urgency or discomfort symptoms. With urinary sodium as a hydration marker after correcting for age, a between-subject correlation was established between inadequate hydration (higher mean urinary sodium) and more severe voiding (p<0.001) and discomfort symptoms (p=0.039) but not urgency symptoms. Within subjects, higher urinary sodium was associated with more severe voiding symptoms (p=0.026), lower urinary sodium was associated with more severe discomfort symptoms (p=0.024), and no association was found with urgency symptoms.
Source:
Kaninia, S., Stuart, C. M., & Galea, I. (2023). Dehydration associates with lower urinary tract symptoms in progressive multiple sclerosis. European Journal of Neurology. https://doi.org/10.1111/ene.16175
