title: Clinical features of CKD-MBD in Japan: cohort studies and registry.
abstract: Randomized controlled trials (RCTs) are essential for evidence-based medicine; however, cohort studies and registries provide an important information about risk factors and, hence, shed light on the target of laboratory parameters. The uniqueness of the current Japanese CKD-MBD guidelines lies in the lower target range of intact parathyroid hormone levels than those used in other countries, which is based on analyses of the nationwide Japan Renal Data Registry. Cohort studies were also useful in exploring risk factors of renal outcome in predialysis patients. It was revealed that low vitamin D status (very prevalent in Japan) and high fibroblast growth factor 23 (FGF23) levels predict poor renal outcome. The reported association of FGF23 levels with left ventricular hypertrophy (LVH) and heart failure observed in cohort studies may support the idea of adding the 4th component of CKD-MBD, namely, "LVH" to the three original components. When it is not feasible to conduct RCTs regarding intervention, we have no choice but to rely on observational studies with sophisticated analysis methods, such as facility-level analysis and marginal structural model minimizing indication bias. Observational studies conducted in Japan revealed that the side effects of medications for CKD-MBD, resultant compliance, and effective doses in terms of hard outcome in Japanese patients were found to be different from those in other countries. For example, the MBD-5D study confirmed the benefit of cinacalcet in terms of mortality despite its median dose of only 25 mg/day. These data are very helpful for future guidelines specific to Japanese patients with CKD.
authors.affiliation: Department of Comprehensive Kidney Disease Research (CKDR), Osaka University Graduate School of Medicine, D11, 2-2 Yamadaoka, Suita, Osaka, Japan. hamatea@kid.med.osaka-u.ac.jp.
authors.forename: Takayuki
authors.identifier: http://orcid.org/0000-0002-2100-9106
authors.initials: T
authors.lastname: Hamano
authors.affiliation: Department of Comprehensive Kidney Disease Research (CKDR), Osaka University Graduate School of Medicine, D11, 2-2 Yamadaoka, Suita, Osaka, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Sakaguchi
authors.affiliation: Department of Internal Medicine (Nephrology Unit), Hyogo Prefectural Nishinomiya Hospital, Hyogo, Japan.
authors.forename: Naohiko
authors.initials: N
authors.lastname: Fujii
authors.affiliation: Department of Nephrology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Isaka
mesh_terms: D012080:Chronic Kidney Disease-Mineral and Bone Disorder / Q000188:drug therapy / Q000209:etiology* / Q000503:physiopathology* / Q000601:surgery; D015331:Cohort Studies; D000089703:Fibroblast Growth Factor-23; D005346:Fibroblast Growth Factors; D006801:Humans; D007564:Japan; D016105:Parathyroidectomy; D016032:Randomized Controlled Trials as Topic; D012042:Registries; D051436:Renal Insufficiency, Chronic / Q000150:complications* / Q000188:drug therapy / Q000503:physiopathology* / Q000601:surgery; D014807:Vitamin D / Q000378:metabolism / Q000627:therapeutic use; D014815:Vitamins / Q000378:metabolism / Q000627:therapeutic use
chemical_list: C000717427:FGF23 protein, human; D014815:Vitamins; D014807:Vitamin D; D005346:Fibroblast Growth Factors; D000089703:Fibroblast Growth Factor-23
keywords: 25-Hydroxyvitamin D; Active vitamin D; Cinacalcet; Fibroblast growth factor 23; Lanthanum carbonate; Magnesium; Sevelamer