Urinalysis May Be Effective Screening Tool for Kidney Disease in Prader-Willi Syndrome

In a study using urinalysis screening to detect microvascular disease, 1 in 5 adults with Prader-Willi syndrome (PWS) showed early signs of kidney disease, with elevated levels of urinary albumin and microalbuminuria.

“Our findings suggest that pre-symptomatic kidney injury may be missed when only blood measurements are performed,” wrote the researchers of the study. “Therefore, in this patient group, urinalysis is essential for timely screening of microvascular (kidney) disease. We propose an algorithm for the detection and management of microvascular disease in adults with PWS.”

The literature review study is published in Frontiers in Endocrinology.

PWS is a rare genetic disorder characterized by hyperphagia, hypotonia, delayed psychomotor development, low muscle mass, and hypothalamic dysfunction. Furthermore, individuals with PWS often have obesity, hypertension, and type 2 diabetes (T2D), known risk factors for cardiovascular disease (CVD) and chronic kidney disease (CKD). Moreover, kidney diseases are often asymptomatic, and early symptoms of CVD and CKD may be overlooked due to patient intellectual disability and inability to express physical concerns.

In the study, the researchers aimed to understand the prevalence of kidney disease in patients with PWS.

They retrospectively collected information from electronic patient files, including anthropometric measurements, blood pressure, medical history, medication use, urine dipstick, and biochemical measurements. Eligible studies included in the review required reports of 1 or both: the prevalence of kidney disease, urological abnormalities, treatment for kidney disease, or markers for kidney function and PWS, Prader-Willi-like syndrome (PWLS) with an abnormality in chromosone 15q11.2-13, or one of the genes on the PWS critical region.

A total of 162 adults with genetically confirmed PWS were included in the review, in which 56% were male and had a median (IQR) age of 28 (22-38) years. Additionally, 44 (27%) of these individuals had T2D, none had known CVD, and all had normal estimated glomerular filtration rate (eGFR) according to non-PWS reference intervals.

The researchers identified elevated urinary albumin or microalbuminuria in 28 (18%) individuals. Additionally, 19 of 75 (25%) had an increased urinary albumin-to-creatinine ratio. Furthermore, elevated urinary albumin was present at a young age, with a median age of 26 (24-32) years and was associated with a significantly higher BMI (P = .027), and low-density lipoprotein (P = .019), as well as higher prevalence of type 2 diabetes (P < .001), hypertension (P < .001), and dyslipidemia (P = .011) compared with individuals with normal urinary albumin-to-creatinine ratio (UACR), respectively.

The researchers acknowledged some limitations in the study, including that blood and urine samples were not always collected on the same day and some blood results were excluded in the statistical analysis due to a prolonged time of more than 12 months between blood and urine sample collection. Furthermore, the researchers suggest that low muscle mass in patients with PWS may have led to a low serum creatinine, resulting in an overestimation of microalbuminuria by the UACR and urinary protein-to-creatinine ratio tests.

Despite these limitations, the researchers believe the study suggests how urinalysis in this patient group may be a useful screening tool for detecting microvascular disease.

“Health care providers should be aware of the increased risk for CKD and CVD in adults with PWS and should optimize treatment to reduce these risk factors,” wrote the researchers. “To prevent long-term complications and impaired quality of life, we provide an algorithm for the screening and management of micro-albuminuria and proteinuria in adults with PWS.”

Reference

van Abswoude DH, Pellikaan K, Nguyen N, et al. Kidney disease in adults with Prader-Willi syndrome: international cohort study and systematic literature review. Front Endocrinol (Lausanne). Published online July 21, 2023. doi:10.3389/fendo.2023.1168648