Aging is associated with a combination of several lower urinary tract (LUT) signs and symptoms, including residual urine, overactive bladder and nocturia. One of the mechanisms of this LUT dysfunction that has not been discussed in dept so far is the role of dopamine (DA).
In this narrative review, we explore the dopaminergic hypothesis in the development of this combination of LUT signs and symptoms in older adults.
DA is one of the neurotransmitters whose regulation and production is disrupted in aging. In synucleinopathies, altered DAergic activity is associated with the occurrence of LUTS and sleep disorders. Projections of DAergic neurons are involved in the regulation of sleep, diuresis, and bladder activity. The low dopamine hypothesis could explain the genesis of a set of LUT signs and symptoms commonly seen in this population, including elevated residual urine, Overactive bladder syndrome and Nocturia (discussed as the RON syndrome). This presentation is however also common in older patients without synucleinopathies or neurological disorders and therefore we hypothesise that altered DAergic activity because of pathological aging, and selective destruction of DAergic neurons, could underpin the presentation of this triad of LUT dysfunction in the older population.
The concept of RON syndrome helps to better understand this common phenotypic presentation in clinical practice, and therefore serves as a useful platform to diagnose and treat LUTS in older adults. Besides recognizing the synucleinopathy "red flag" symptoms, this set of multi-causal LUT signs and symptoms highlights the inevitable need for combination therapy, a challenge in older people with their comorbidities and concomitant medications.
Progres en urologie : journal de l'Association francaise d'urologie et de la Societe francaise d'urologie. 2023 Jan 27 [Epub ahead of print]
R Haddad, J N Panicker, I Verbakel, K Dhondt, L Ghijselings, F Hervé, M Petrovic, M Whishaw, D L Bliwise, K Everaert
Department of Urology, NOPIA Research Group, Ghent University Hospital, Ghent, Belgium; GRC 001 GREEN Neuro-Urology Research Group, Sorbonne Université, Rothschild Academic Hospital, AP-HP, 75012 Paris, France. Electronic address: ., Department of Uro-Neurology, The National Hospital for Neurology and Neurosurgery and Department of Brain Repair and Rehabilitation, UCL Queen Square Institute of Neurology, Faculty of Brain Sciences, University College London, London, United Kingdom., Department of Urology, NOPIA Research Group, Ghent University Hospital, Ghent, Belgium., Department of Psychiatry, Pediatric sleep center, Ghent University Hospital, Ghent, Belgium., Department of Urology, NOPIA Research Group, Ghent University Hospital, Ghent, Belgium; Department of Urology, Cliniques Universitaires Saint Luc, Brussels, Belgium., Department of Geriatrics, Ghent University Hospital, Ghent, Belgium., Department of Aged Care, Royal Melbourne Hospital, Melbourne, Australia., Department of Neurology, Emory University School of Medicine, Atlanta, Georgia, USA.