Corrigendum: Kidney disease in adults with Prader-Willi syndrome: international cohort study and systematic literature review

[This corrects the article DOI: 10.3389/fendo.2023.1168648.].

Kidney disease in adults with Prader-Willi syndrome: international cohort study and systematic literature review

Background

Prader-Willi syndrome (PWS) is a rare, complex, genetic disorder characterized by hyperphagia, hypotonia, delayed psychomotor development, low muscle mass and hypothalamic dysfunction. Adults with PWS often have obesity, hypertension and type 2 diabetes mellitus (DM2), known risk factors for cardiovascular disease (CVD) and chronic kidney disease (CKD). Early symptoms of CVD and CKD may be masked by intellectual disability and inability to express physical complaints. Furthermore, kidney diseases are often asymptomatic. Therefore, renal and cardiovascular disease might be missed in patients with PWS. Microalbuminuria is an early sign of microvascular damage in the kidneys and other vascular beds. Therefore, we screened our adult PWS cohort for the presence of elevated urinary albumin and (micro)albuminuria.

Methods

We retrospectively collected anthropometric measurements, blood pressure, medical history, medication use, urine dipstick and biochemical measurements form electronic patient files. In addition, we performed a systematic literature review on kidney disease in PWS.

Results

We included 162 adults with genetically confirmed PWS (56% male, median age 28 years), of whom 44 (27%) had DM2. None had known CVD. All subjects had normal estimated glomerular filtration rate (eGFR) according to non-PWS reference intervals. Elevated urinary albumin or (micro)albuminuria was present in 28 (18%); 19 out of 75 (25%) had an increased urinary albumin-to-creatinine ratio (UACR) and 10 out of 57 (18%) had an increased urinary protein-to-creatinine ratio. Elevated urinary albumin was present at a young age (median age 26 (IQR 24-32) years) and was associated with an significantly higher BMI and LDL-cholesterol levels and higher prevalence of DM2, hypertension and dyslipidemia than those with normal UACR (p=0.027, p=0.019, p<0.001, p<0.001, p=0.011 and respectively).

Conclusion

Upon screening, one in every five adults with PWS had increased urinary albumin or (micro)albuminuria, early signs of microvascular disease. All had normal eGFR, according to non-PWS reference intervals, and none had a formal diagnosis of CVD. As muscle mass is low in PWS, creatinine levels and eGFR may be spuriously normal. Urinalysis in this patient group can be used as a screening tool for microvascular (kidney) disease. We propose an algorithm for the detection and management of microvascular disease in adults with PWS.

Current practice on the management of pre-operative urine dipstick results in women undergoing gynaecological surgery in Wales

A survey was circulated to consultant gynaecologists across Wales, to evaluate the management of pre-operative urine dipstick results. Questions were based on NICE guideline 171, regarding the management of urinary incontinence in women. Six respondents never checked their patient's urine dipstick results. Of the remaining 37 respondents, 70% always check and 30% sometimes check. Overall, 37.1% cancelled surgery when a urine dipstick was positive for either nitrite or leukocyte-esterase (LE). A significantly larger proportion cancelled surgery when symptomatic for urinary tract infection (p< 0.001), and when nitrite and LE positive compared to only LE positive (p< 0.05). This survey provides evidence that gynaecological operations are potentially being cancelled unnecessarily based on a screening test with limited sensitivity and specificity. Further research is needed into the outcomes of gynaecological surgery in women symptomatic of urinary tract infection to provide guidance on the use of pre-operative urinalysis and the management of test results. Impact statement What is already known on this subject? The strongest risk factor for postoperative urinary tract infections (UTIs) is a pre-operative recurrent UTI (Nygaard et al. 2011 ). This is the reason behind the urine dipstick being part of the pre-operative checklist for gynaecological surgery. Traditionally, a suspected UTI would mean postphoning surgery whilst treating the UTI. It is known that the sensitivity of the nitrite test and leukocyte-esterase test when used alone is low and cannot rule out UTI in most patients (Mambatta et al. 2015 ). Urine culture is therefore suggested for all patients with a suspected UTI (John et al. 2006 ). To our knowledge, there are no data available on whether we should be postphoning gynaecological surgery based on a urine dipstick result. What the results of this study add? Overall, 37.1% of respondents cancelled surgery when a pre-operative urine dipstick was positive for either nitrite or leukocyte-esterase. This provides evidence of variation in the practice of using the urine dipstick in women undergoing gynaecological surgery in Wales. These cancellations are potentially unnecessarily. Furthermore, 14% of respondents did not use a urine dipstick and the majority did not act on an abnormal results, implying clinicians have a low confidence in the test as a screening tool. What the implications are of these findings for clinical practice and/or further research? We propose removing the urine dipstick as a pre-operative screening test. Asymptomatic bacteriuria is common in women and routine screening for UTI pre-operatively will therefore inevitably lead to unnecessary intervention (i.e. cancellation). Further research is needed into the outcomes of gynaecological surgery in women symptomatic of UTI to be able to provide guidance on the use of pre-operative urinalysis and management of the test results.