医薬品副作用データベースを用いた生活習慣病治療薬の併用に伴う副作用リスク分析

科学研究費助成事業 研究成果報告書：若手研究(B)2015-2017課題番号 : 15K1921

An Efficient Procedure for Calculating Sample Size Through Statistical Simulations

While planning clinical trials, when simple formulas are unavailable to calculate sample size, statistical simulations are used instead. However, one has to spend much computation time obtaining adequately precise and accurate simulated sample size estimates, especially when there are many scenarios for the planning and/or the specified statistical method is complicated. In this article, we summarize the theoretical aspect of statistical simulation-based sample size calculation. Then, we propose a new simulation procedure for sample size calculation by fitting the probit model to simulation result data. From the theoretical and simulation-based evaluations, it is suggested that the proposed simulation procedure provide more efficient and accurate sample size estimates than ordinary algorithm-based simulation procedure especially when estimated sample sizes are moderate to large, therefore it would help to dramatically reduce the computational time required to conduct clinical trial simulations

SignalDetDDI: An SAS macro for detecting adverse drug-drug interactions in spontaneous reporting systems

Statistical methods for detecting adverse drug reactions (ADRs) resulting from drug-drug interactions (DDIs) have been used in recent years to analyze the datasets in spontaneous reporting systems. We provide the SignalDetDDI macro in SAS to calculate the criteria for detecting ADRs resulting from the concomitant use of two drugs. We outline two criteria for detecting DDIs with the combination of two drugs and illustrate the implementation of the macro by way of an example. To implement the macro, a user specifies the target ADR and the two drugs to be evaluated. The SignalDetDDI macro outputs a table showing the number of reports on ADRs, the values of the two criteria for detecting ADRs, and the presence of DDIs. This macro enables users to easily and automatically assess the clinical DDIs that result from ADRs

Dose-Dependent Effect of Sitagliptin on Carotid Atherosclerosis in Patients with Type 2 Diabetes Mellitus Receiving Insulin Treatment: A Post Hoc Analysis

IntroductionDipeptidyl peptidase-4 (DPP-4) inhibitors reduce blood glucose in a dose-dependent manner, but the dose-dependent effect relationship between DPP-4 inhibitors and atherosclerosis has not been investigated.MethodsPatients with type 2 diabetes mellitus (T2DM) treated with insulin were randomized to the sitagliptin (n = 137) or conventional treatment group (n = 137). In the sitagliptin group, each investigator was allowed to adjust the sitagliptin dose to avoid hypoglycemia. In this post hoc analysis, subjects in the sitagliptin group were divided into two groups based on the average dose of sitagliptin during the study period: greater than or equal to median (higher sitagliptin dose group) or less than median (lower sitagliptin dose group).ResultsIn this study, subjects were divided into three groups: the conventional treatment group (n = 137), lower sitagliptin dose group (n = 42), and higher sitagliptin dose group (n = 95). The higher sitagliptin dose group had a significantly larger reduction in HbA1c (−0.62 ± 1.05%) than the conventional treatment group (−0.20 ± 0.91%, P = 0.007). Over 104 weeks, the higher sitagliptin dose significantly reduced the mean intima media thickness-common carotid artery (IMT-CCA) and left max-IMT-CCA relative to baseline. In addition, the higher sitagliptin dose significantly inhibited the progression in mean-IMT-CCA compared with conventional treatment. Multiple linear regression analysis showed that changes in mean-IMT-CCA and left max-IMT-CCA decreased with higher sitagliptin dose.ConclusionsAddition of sitagliptin to insulin therapy might attenuate the progression of atherosclerosis in patients with T2DM in a dose-dependent manner

Changes in carotid intima-media thickening in patients with type 2 diabetes mellitus: Subanalysis of the Sitagliptin Preventive Study of Intima-Media Thickness Evaluation

Type 2 diabetes mellitus is a risk factor for cardiovascular disease. Both the absolute value and progression of carotid artery intima‐media thickness (IMT) are considered a marker of progression of atherosclerosis. We reported recently that treatment with sitagliptin, a dipeptidyl peptidase‐4 inhibitor, attenuated the progression of carotid IMT in insulin‐treated patients with type 2 diabetes mellitus compared with conventional therapy1. Here, we compared the efficacy of treatment with sitagliptin with that of other modalities on the progression of carotid IMT in prespecified subgroups of the Sitagliptin Preventive Study of Intima‐Media Thickness Evaluation (SPIKE) registered on the University Hospital Medical Information Network Clinical Trials Registry (UMIN000007396)1, 2. The aim of the comparison was to identify the characteristics of patients who benefited most from the sitagliptin treatment in terms of decrease in IMT.The recruits in the original study included 282 insulin‐treated Japanese type 2 diabetes mellitus patients free of past history of apparent cardiovascular disease. They were randomly allocated to either the sitagliptin group (n = 142) or the conventional treatment group (using drugs other than sitagliptin; n = 140). After the exclusion of eight patients, data of 137 patients of the sitagliptin group and 137 of the conventional treatment group were subjected to analysis. The mean‐IMT of the common carotid arteries (mean‐IMT‐CCA) and right and left max‐IMT‐CCA were measured by expert sonographers at the start of the study, and the procedure was repeated after 52 and 104 weeks, as reported previously1, 2. Figure 1 shows differences in treatment‐induced delta change in carotid IMT, relative to baseline in 243 patients whose IMT data were available at baseline and 104 weeks, according to various predefined risk factors for atherosclerosis. The results showed consistent reductions in mean IMT‐CCA and left max IMT‐CCA, but not right max IMT‐CCA, in the sitagliptin group (Figure 1). In particular, a greater reduction in carotid IMT was noted after treatment with sitagliptin in patients with risk factors for cardiovascular disease, such as higher glycated hemoglobin, higher body mass index, longer duration of type 2 diabetes mellitus, use of angiotensin‐converting enzyme inhibitors/angiotensin II receptor blocker, use of statins, worse hypertension and/or hyperlipidemia at baseline, compared with conventional treatment. These data suggest that treatment with dipeptidyl peptidase‐4 inhibitors seems to prevent the progression of carotid atherosclerosis regardless of disease burden. Previous studies showed that treatment with statins and angiotensin‐converting enzyme inhibitors reduces the progression of carotid atherosclerosis in patients with type 2 diabetes mellitus3, 4. In this subgroup analysis, sitagliptin still attenuated the progression of carotid IMT, even in patients who were receiving those therapies. Thus, dipeptidyl peptidase‐4 inhibitors seem to have unique and/or additive anti‐atherosclerotic effects as add‐on therapy to statins and/or angiotensin‐converting enzyme inhibitors/angiotensin II receptor blockers

Effect of oral tranexamic acid on macular edema associated with retinal vein occlusion or diabetes

Purpose: Tranexamic acid (TXA) is a widely used antifibrinolytic agent that can also cause a decrease in vascular permeability. We hypothesized that TXA could improve macular edema (ME) that is caused by an increase in retinal vascular permeability. The aim of this study is to evaluate the efficacy of oral TXA for ME associated with retinal vein occlusion (RVO) or diabetic ME (DME).Patients and methods: Oral TXA (1,500 mg daily for 2 weeks) was administered to patients with persistent ME secondary to RVO (7 eyes) and DME (7 eyes). After 2 weeks (ie, the final day of administration) and 6 weeks (ie, 4 weeks after the final administration), best-corrected visual acuity and central macular thickness (CMT) were measured and compared with baseline. Analyses were performed for RVO and DME cases. No other treatment was performed during the study period.Results: In RVO cases, significant improvement in CMT was found between baseline (467.7±121.4 µm) and 2-week measurements after treatment (428.7±110.5 µm, p=0.024). No significant change was found in CMT between measurements taken at baseline and 6 weeks after treatment. In DME cases, no significant change was found in CMT between measurements taken at baseline and 2 or 6 weeks after treatment. In all analyses of best-corrected visual acuity, no significant change was observed.Conclusion: The results support the hypothesis that plasmin plays a role in the development of ME associated with RVO, and oral TXA administration may be useful as an adjuvant treatment when combined with other agents such as anti-vascular endothelial growth factor

The Effect of Sitagliptin on the Regression of Carotid Intima-Media Thickening in Patients with Type 2 Diabetes Mellitus: A Post Hoc Analysis of the Sitagliptin Preventive Study of Intima-Media Thickness Evaluation

Background. The effect of dipeptidyl peptidase-4 (DPP-4) inhibitors on the regression of carotid IMT remains largely unknown. The present study aimed to clarify whether sitagliptin, DPP-4 inhibitor, could regress carotid intima-media thickness (IMT) in insulin-treated patients with type 2 diabetes mellitus (T2DM). Methods. This is an exploratory analysis of a randomized trial in which we investigated the effect of sitagliptin on the progression of carotid IMT in insulin-treated patients with T2DM. Here, we compared the efficacy of sitagliptin treatment on the number of patients who showed regression of carotid IMT of ≥0.10 mm in a post hoc analysis. Results. The percentages of the number of the patients who showed regression of mean-IMT-CCA (28.9% in the sitagliptin group versus 16.4% in the conventional group, P = 0.022) and left max-IMT-CCA (43.0% in the sitagliptin group versus 26.2% in the conventional group, P = 0.007), but not right max-IMT-CCA, were higher in the sitagliptin treatment group compared with those in the non-DPP-4 inhibitor treatment group. In multiple logistic regression analysis, sitagliptin treatment significantly achieved higher target attainment of mean-IMT-CCA ≥0.10 mm and right and left max-IMT-CCA ≥0.10 mm compared to conventional treatment. Conclusions. Our data suggested that DPP-4 inhibitors were associated with the regression of carotid atherosclerosis in insulin-treated T2DM patients. This study has been registered with the University Hospital Medical Information Network Clinical Trials Registry (UMIN000007396)

Ocular parameters before and after steep Trendelenburg positioning for robotic-assisted laparoscopic radical prostatectomy

Purpose: Intraocular pressure (IOP) increases in patients in a steep Trendelenburg position during robotic-assisted laparoscopic radical prostatectomy (RALP). We hypothesized that a steep Trendelenburg position during RALP, an unusual systemic condition involving a transiently increased IOP, may induce ocular pathology that can be detected by detailed evaluations long after the surgery. This study aims to explore ocular structural and functional parameters in patients before and in the long term after the surgery.Patients and methods: A comparative observational study was performed. A total of 44 eyes of 22 male patients scheduled for RALP at Aichi Medical University from August 2012 to July 2013 were included. Clinical parameters before and after RALP were compared. Peri­operative IOP was measured immediately post-induction of anesthesia in the flat supine position (T1), immediately post-steep Trendelenburg position (T2), and prior to returning to a flat supine position while in a steep Trendelenburg position (T3). The thicknesses of the peripapillary retinal nerve fiber layer, ganglion cell complex (GCC), and central fovea were measured with spectral domain optical coherence tomography. Humphrey perimetry was performed before and at 3 and 6 months after surgery.Results: The average IOPs (mmHg) at each stage were T1=10.4, T2=21.7, and T3=29.6, and differed significantly. The mean visual acuity (logarithm of the minimal angle of resolution), IOP, mean deviation, and pattern standard deviation measured by the Humphrey field analyzer showed no statistically significant difference before and after surgery. The ganglion cell complex and retinal nerve fiber layer thicknesses measured at each location and the central fovea thicknesses measured before and after surgery did not differ significantly.Conclusion: No significant disorders in ocular structural and functional parameters were found until long after RALP

Radiation-induced bronchiolitis obliterans organizing pneumonia (BOOP) syndrome in breast cancer patients is associated with age

BackgroundRadiation-induced bronchiolitis obliterans organizing pneumonia (BOOP) syndrome is a rarely observed phenomenon characterized by infiltration of the lungs outside of the radiation field, differentiating it from radiation pneumonitis (RP).The risk factors for radiation-induced BOOP (RT-BOOP) remain unclear and controversial. We retrospectively analyzed the incidence and risk factors for RT-BOOP associated with radiation therapy (RT) after breast conserving surgery (BCS) and post-mastectomy radiation therapy (PMRT).Methods and materialsWe analyzed 1,176 breast cancer patients treated with RT after BCS or PMRT between March 2005 and September2008 at the cancer institute hospital of the Japanese foundation for cancer research. Chest radiographs were routinely obtained every three to six months for at least 12 months after surgery, as well as when the patients experienced respiratory symptoms or fever.ResultsRT-BOOP syndrome was diagnosed in 16patients (1.4%), including12BCS patients (1.3%) and four PMRT patients (1.8%). An older age (≥52 years old) was significantly associated with the incidence of RT-BOOP syndrome in a univariate analysis (p =0.023). The type of treatment (BCS or PMRT) and irradiated lung volume at 20 Gy (V20) were not significantly associated with the incidence of RT-BOOP syndrome in the entire patient cohort. In the multivariate analysis, age and smoking were the significant factor associated with RT-induced BOOP syndrome (p =0.044 and 0.049, respectively).ConclusionsRT-BOOP syndrome was a rarity, and the incidence for BCT cases was similar to that for PMRT cases. The irradiated lung volume was not significantly associated with RT-BOOP syndrome. An older age can predict the incidence of RT-BOOP syndrome.Keywords: Breast Cancer; Postoperative radiotherapy; Radiation-induced bronchiolitis obliterans organizing pneumonia syndrome; Breast-conserving therapy; Post-mastectomy radiation therap

The Effect of Sitagliptin on the Regression of Carotid Intima-Media Thickening in Patients with Type 2 Diabetes Mellitus: A Post Hoc Analysis of the Sitagliptin Preventive Study of Intima-Media Thickness Evaluation

Background. The effect of dipeptidyl peptidase-4 (DPP-4) inhibitors on the regression of carotid IMT remains largely unknown. The present study aimed to clarify whether sitagliptin, DPP-4 inhibitor, could regress carotid intima-media thickness (IMT) in insulin-treated patients with type 2 diabetes mellitus (T2DM). Methods. This is an exploratory analysis of a randomized trial in which we investigated the effect of sitagliptin on the progression of carotid IMT in insulin-treated patients with T2DM. Here, we compared the efficacy of sitagliptin treatment on the number of patients who showed regression of carotid IMT of ≥0.10 mm in a post hoc analysis. Results. The percentages of the number of the patients who showed regression of mean-IMT-CCA (28.9% in the sitagliptin group versus 16.4% in the conventional group, P = 0.022) and left max-IMT-CCA (43.0% in the sitagliptin group versus 26.2% in the conventional group, P = 0.007), but not right max-IMT-CCA, were higher in the sitagliptin treatment group compared with those in the non-DPP-4 inhibitor treatment group. In multiple logistic regression analysis, sitagliptin treatment significantly achieved higher target attainment of mean-IMT-CCA ≥0.10 mm and right and left max-IMT-CCA ≥0.10 mm compared to conventional treatment. Conclusions. Our data suggested that DPP-4 inhibitors were associated with the regression of carotid atherosclerosis in insulin-treated T2DM patients. This study has been registered with the University Hospital Medical Information Network Clinical Trials Registry (UMIN000007396)