Influence of immobilization upon calcium metabolism in the week following hemiplegic stroke
Authors: H Kuno
K Etoh
Y Sato
K Oizumi
M Kaji
Journal: Journal of the Neurological Sciences (2000)
Discipline: NEUROSCIENCE & BEHAVIOR
Keywords: Hip fractures; paretic side; post-stroke complication; disuse hemiosteopenia; hypovitaminosis D

Abstract:  Hip fractures on the paretic side are a serious post-stroke complication and may result from disuse hemiosteopenia, hypovitaminosis D, and an increasing risk of falls. To evaluate short-term immobilization effects, we assessed calcium metabolism in 89 patients 1 week after the hemiplegic stroke and in 36 controls. Patient activity was rated using the Barthel index (BI). Sera from stroke patients and control subjects were assayed for ionized calcium, parathyroid hormone (PTH), 25-hydroxyvitamin D (25-OHD), 1, 25-dihydroxyvitamin D (1,25-(OH)(2)D), bone Gla protein (BGP; a bone formation marker) and pyridinoline cross-linked carboxy-terminal telopeptide of type I collagen (ICTP; a bone resorption marker). Patients' serum concentrations of ionized calcium and ICTP were higher than in controls and correlated negatively with BI; their BGP concentrations were low, correlating positively with BI. Concentrations of serum 25-OHD, 1,25-(OH)(2)D, and PTH also were low; serum 25-OHD was at a deficient level (&lt;10 ng/ml) in nine patients (10%), an insufficient level (10-20 ng/ml) in 56 (63%), and a sufficient level (&gt;20 ng/ml) in only 24 (27%). PTH correlated negatively with calcium and 1,25-(OH)(2)D. Hypovitaminosis D is common in acute stroke patients. Immobilization from acute hemiplegia can increase bone resorption and serum calcium, and inhibit PTH secretion and 1,25-(OH)(2)D production to add to the effects of hypovitaminosis D. 

Retracted: No

PubPeer comments:
 This paper should be retracted. There is a context of multiple ( 90) retractions of work by this group of researchers for a wide range of reasons that include fabrication, authorship misconduct, duplicate data reporting, plagiarism, unethical research practices, unresolved concerns about data integrity and scientific misconduct (http: retractionwatch.com the-retraction-watch-leaderboard ). The journal and its publisher were notified about the concerns with this paper in October 2018 Concerns Ethics The study was reported to be conducted at Kurume University Medical Center and to have been approved by the u2018local human investigation committeeu2019. However, recent retractions of papers by Dr Sato and colleagues by Stroke and Bone indicate that Kurume University Medical Center did not have an ethics committee at the time the work reported in this paper was supposedly conducted. Thus, this work is unethical. Funding No funding support is reported for a moderately large cross-sectional study. Implausible participant recruitment 89 patients with stable hemiplegic stroke of 1 week duration, without several co-morbid conditions and treatments, and with full medical records retrospectively obtained from other institutions, were recruited within 11 months (December 1997-October 1998), at a rate of 8 month. This is an implausible recruitment rate for such a selective group of participants. The stated recruitment rate is rendered even more implausible when one considers that, overlapping with the same 11 month period, Dr Sato and colleagues allegedly recruited evaluated: 98 patients with stroke to participate in a randomized trial, recruitment at Futase Hospital 1 97-12 98 (J Bone Min Res 2000;15: 2487-2494) 71 patients with hemiplegic stroke, recruitment at Kurume University Medical Center 12 97-12 98 (Am J Phys Med Rehabil 2001;80:19-24) 191 consecutive patients with first-ever non-cardioembolic ischemic stroke 1y previously, recruitment at Kurume University Medical Center 4 97-8 00 (J Neurol Sci 2002;202:65-68) 171 patients 65y hospitalized for 1y with hemiplegic stroke, recruitment at Futase Hospital 11 97-1 98 (Bone 2004;34:710-715) Implausible biochemical testing Several biochemical tests reported to have been undertaken, eg 25 (OH)D, 1,25(OH)2D, ionized calcium, PTH, ICTP, and osteocalcin, are not standard and require specialised laboratory facilities. No analytic laboratory is identified in the paper, and no funding is reported that would support this costly exercise. Overlapping and duplicate implausible data with other publications Please refer to the table, which sets out data from the control groups of several publications by Dr Sato and colleagues. The current paper is in the top row. It is readily apparent that the mean and or SD values for several variables in the control group in this J Neurol Sci paper are identical to those in the control groups in other papers, despite the groups differing in size, age and gender composition. Mean and SD data for ionized calcium in the control group in this paper are identical to those in the control groups in 7 other papers. Mean and SD data for 1,25(OH)2D in this paper are identical to those in 5 other papers. Mean and SD data for 25(OH)D in the control group in this paper are identical to those in the control group in 8 other papers. Mean and SD data for PTH in the control group in this paper are identical to those in 2 other papers. Mean or SD values for 3 variables are identical to those in control groups in 3 other papers. These data are very very unlikely to be reliable. ![file] Impossible data The mean value for a variable in the whole group should = the sum of the mean value x n of each subgroup, divided by the total n. In table 1, the mean age of the stroke patients, 71.2y, does not equal that calculated from the male and female subgroups reported in table 4 u2013 70.6 x 50 + 69.5 x 39, divided by 89 = 70.1y. These data are mathematically impossible. , 
 On 14 June 2020 the publisher informed us that this paper was to be retracted. 9 months later, it has not been. In that time, it has been cited another 2 times (total of 42 citations on Scopus). Lengthy delays in publication of retraction notices are not in the best interests of readers. , 
 It is now 21 months since Elsevier communicated, via COPE, its undertaking to retract this paper. Recent requests for an update on the retraction to Elsevier, COPE, and the journal did not receive a response. The society associated with the journal, the World Federation of Neurology, responded but was unable to provide any information. ,