RESUMO
Chronic kidney disease (CKD) patients experience a wide range of symptoms that deteriorate their health-related quality of life (HRQoL). We aimed to estimate the prevalence and severity of lower gastrointestinal (GI) symptoms in non-dialysis CKD adult outpatients, and to summarize the relationships between these symptoms and HRQoL, laboratory test results, and clinical data. The protocol of the study was preregistered (PROSPERO CRD42021255122). We searched MEDLINE, Scopus, Web of Science, and grey literature sources from the databases' inception up until 27 November 2021. Wide citation chasing was conducted. Single proportions (prevalence of functional constipation, self-reported constipation, diarrhea, abdominal bloating, fecal incontinence, and abdominal/rectal pain) were pooled using generalized linear mixed models. A total of 37 studies with 12,074 patients were included. We found that lower GI symptoms, especially self-reported abdominal bloating [CKD G1-2: 48.45% (95% CI: 43.5-53.4%; 2 studies); G3: 46.95% (95% CI: 45.0-48.9%; 2 studies), G4-5: 36.1% (95% CI: 25.4-48.5%; 8 studies)] and constipation [CKD G1-2: 31.8% (95% CI: 13.9-54.9%); G3: 29.8% (95% CI: 21.2-40.1%; 4 studies); G4-5: 38.8% (95% CI: 30.9-47.4%); 22 studies)], were common in non-dialysis CKD patients. The severity of the symptoms was limited. Self-reported constipation was most consistently associated with worse HRQoL, whereas hard stool consistency was associated with higher uremic toxins levels. To conclude, since lower GI symptoms are common in CKD, using symptom questionnaires that do not take them into account cannot provide full insight into the patient's experience. Further studies are needed to cover identified knowledge gaps, including the exploration of the pathophysiology of GI symptoms in CKD with multi-omics data.
RESUMO
Systematic reviews with meta-analyses (SR/MA) are frequently conducted to investigate clinical efficacy of probiotics. However, only rigorously prepared analyses can serve as the highest level of evidence for a specified research question. We have aimed to determine (1) what is the methodological quality of recent SR/MA conducted to assess the efficacy of probiotics; (2) whether the results of SR/MA have a clinical application; and (3) what are factors associated with better quality and applicability of the SR/MA. We systematically searched 4 databases for SR/MA on the probiotics efficacy published in 2020 (PROSPERO CRD42020222716). The AMSTAR 2 tool and pre-defined authors' criteria were used to evaluate methodological quality and clinical applicability, respectively. A total of 114 SR/MA were appraised. In the case of 88 papers (77%), the overall confidence in the results was rated as "critically low". The most prevalent flaws were lack of list of excluded studies with justification (79.8%), lack of study protocol (60.5%), and problems with appropriate results combination(54.4%). A declaration of conduction a probiotic efficacy SR/MA could have been misleading in case of 18 studies that included also synbiotics, paraprobiotics, and prebiotics trials in analyses. Only 14 SR/MA provided results that can be apply in clinical practice. Higher journal impact factor and European affiliation of the 1st and corresponding authors were most consistently associated with higher odds of AMSTAR 2 items fulfillments. Based on our findings, SR/MA of probiotics trials cannot be treated as the highest level of evidence without a careful evaluation of their methodological validity.
