Kenji Imai

Dr. Kenji Imai


Research Focus & Metrics

Academic Career Length

27Years (2000-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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29 June 2020 in Nutrients
Verified
Journal Article
Open access
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THtatsunori hanai
tatsunori hanai
MSMakoto Shiraki
Makoto Shiraki
KIKenji Imai
Kenji Imai
ASAtsushi Suetugu
Atsushi Suetugu
KTKoji Takai
Koji Takai
Masahito ShimizuMasahito Shimizu
Masahito Shimizu
Carnitine is a vitamin-like substance that regulates lipid metabolism and energy production. Carnitine homeostasis is mainly regulated by dietary intake and biosynthesis in the organs, including the skeletal muscle and the liver. Therefore, liver cirrhotic patients with reduced food intake, malnutrition, biosynthetic disorder, and poor storage capacity of carnitine in the skeletal muscle and liver are more likely to experience carnitine deficiency. In particular, liver cirrhotic patients with sarcopenia are at a high risk for developing carnitine deficiency. Carnitine deficiency impairs the important metabolic processes of the liver, such as gluconeogenesis, fatty acid metabolism, albumin biosynthesis, and ammonia detoxification by the urea cycle, and causes hypoalbuminemia and hyperammonemia. Carnitine deficiency should be suspected in liver cirrhotic patients with severe malaise, hepatic encephalopathy, sarcopenia, muscle cramps, and so on. Importantly, the blood carnitine level does not always decrease in patients with liver cirrhosis, and it sometimes exceeds the normal level. Therefore, patients with liver cirrhosis should be treated as if they are in a state of relative carnitine deficiency at the liver, skeletal muscle, and mitochondrial levels, even if the blood carnitine level is not decreased. Recent clinical trials have revealed the effectiveness of carnitine supplementation for the complications of liver cirrhosis, such as hepatic encephalopathy, sarcopenia, and muscle cramps. In conclusion, carnitine deficiency is not always rare in liver cirrhosis, and it requires constant attention in the daily medical care of this disease. Carnitine supplementation might be an important strategy for improving the quality of life of patients with liver cirrhosis.

Verified
Journal Article
Open access
PDF file
KIKenji Imai
Kenji Imai
KTKoji Takai
Koji Takai
THtatsunori hanai
tatsunori hanai
TITakayasu Ideta
Takayasu Ideta
TMTsuneyuki Miyazaki
Tsuneyuki Miyazaki
MSMasahito Shimizu
Masahito Shimizu
The aim of this study was to determine whether skeletal muscle depletion predicts the prognosis of patients with hepatocellular carcinoma (HCC) that is being treated with sorafenib. We evaluated 40 consecutive HCC patients who received sorafenib treatment. The skeletal muscle cross-sectional area was measured by computed tomography at the third lumbar vertebra (L3), from which the L3 skeletal muscle index (L3 SMI) was obtained. The factors contributing to overall survival, sorafenib dose reduction, and discontinuation of sorafenib were analyzed using the Cox proportional hazards model. L3 SMI (p = 0.020) and log (α-fetoprotein (AFP)) (p = 0.010) were identified as independent prognostic factors in HCC patients treated with sorafenib. The initial dose of sorafenib (p = 0.008) was an independent risk factor for sorafenib dose reduction, and log (AFP) (p = 0.008) was the only significant risk factor for the discontinuation of this drug. L3 SMI was not a risk factor for either dose reduction (p = 0.423) or the discontinuation (p = 0.132) of sorafenib. A multiple linear regression analysis determined the following relationship between skeletal muscle mass (assessed as L3 SMI) and the explanatory factors: L3 SMI = −0.1896 × (Age) − 10.3441 × (Child-Pugh score) − 9.3922 × (log (AFP)) + 1.6139 × (log (AFP)) × (Child-Pugh score) + 112.9166. Skeletal muscle depletion is inversely associated with age, Child-Pugh score, and log (AFP). Moreover, it is an independent prognostic factor for HCC patients treated with sorafenib.

22 September 2017 in Nutrients
Verified
Journal Article
Open access
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KIKenji Imai
Kenji Imai
KTKoji Takai
Koji Takai
SWSatoshi Watanabe
Satoshi Watanabe
THtatsunori hanai
tatsunori hanai
ASAtsushi Suetsugu
Atsushi Suetsugu
Masahito ShimizuMasahito Shimizu
Masahito Shimizu
Sarcopenia impairs survival in patients with hepatocellular carcinoma (HCC). This study aimed to clarify the factors that contribute to decreased skeletal muscle volume in patients with HCC. The third lumbar vertebra skeletal muscle index (L3 SMI) in 351 consecutive patients with HCC was calculated to identify sarcopenia. Sarcopenia was defined as an L3 SMI value ≤ 29.0 cm2/m2 for women and ≤ 36.0 cm2/m2 for men. The factors affecting L3 SMI were analyzed by multiple linear regression analysis and tree-based models. Of the 351 HCC patients, 33 were diagnosed as having sarcopenia and showed poor prognosis compared with non-sarcopenia patients (p = 0.007). However, this significant difference disappeared after the adjustments for age, sex, Child–Pugh score, maximum tumor size, tumor number, and the degree of portal vein invasion by propensity score matching analysis. Multiple linear regression analysis showed that age (p = 0.015) and sex (p < 0.0001) were significantly correlated with a decrease in L3 SMI. Tree-based models revealed that sex (female) is the most significant factor that affects L3 SMI. In male patients, L3 SMI was decreased by aging, increased Child–Pugh score (≥56 years), and enlarged tumor size (<56 years). Maintaining liver functional reserve and early diagnosis and therapy for HCC are vital to prevent skeletal muscle depletion and improve the prognosis of patients with HCC.

19 August 2019 in Cancers
Verified
Journal Article
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KIKenji Imai
Kenji Imai
KTKoji Takai
Koji Takai
TMTakao Miwa
Takao Miwa
DTDaisuke Taguchi
Daisuke Taguchi
THtatsunori hanai
tatsunori hanai
Masahito ShimizuMasahito Shimizu
Masahito Shimizu
The aim of this study was to investigate whether rapid depletions of fat mass and skeletal muscle mass predict mortality in hepatocellular carcinoma (HCC) patients treated with sorafenib. This retrospective study evaluated 61 HCC patients. The cross-sectional areas of visceral and subcutaneous fat mass and skeletal muscle mass were measured by computed tomography, from which the visceral fat mass index (VFMI), subcutaneous fat mass index (SFMI), and skeletal muscle index (L3SMI) were obtained. The relative changes in these indices per 120 days (ΔVFMI, ΔSFMI, and ΔL3SMI) before and after sorafenib treatment were calculated in each patient. Patients within the 20th percentile cutoffs for these indices were classified into the rapid depletion (RD) group. Kaplan–Meier analysis revealed that with respect to ΔL3SMI (p = 0.0101) and ΔSFMI (p = 0.0027), the RD group had a significantly poorer survival. Multivariate analysis using the Cox proportional-hazards model also demonstrated that ΔL3SMI (≤−5.73 vs. >−5.73; hazard ratio [HR]: 4.010, 95% confidence interval [CI]: 1.799–8.938, p = < 0.001) and ΔSFMI (≤−5.33 vs. >−5.33; HR: 4.109, 95% CI: 1.967–8.584, p = < 0.001) were independent predictors. Rapid depletions of subcutaneous fat mass and skeletal muscle mass after the introduction of sorafenib indicate a poor prognosis.

16 June 2020 in Molecular and Clinical Oncology
Verified
Journal Article
Open access
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HSHiroyasu Sakai
Hiroyasu Sakai
TMTakao Miwa
Takao Miwa
YIYoshikazu Ikoma
Yoshikazu Ikoma
THtatsunori hanai
tatsunori hanai
NNNobuhiko Nakamura
Nobuhiko Nakamura
Masahito ShimizuMasahito Shimizu
Masahito Shimizu
Recently, treatments for chronic hepatitis C virus (HCV) infection have significantly improved by the development of direct‑acting antiviral agents (DAAs) and almost all patients with HCV can complete antiviral treatment without apparent adverse events. Malignant lymphoma, particularly B‑cell non‑Hodgkin's lymphoma, is one of the extrahepatic manifestations associated with chronic HCV infection. The effectiveness of anti‑HCV therapy with DAAs for B‑cell non‑Hodgkin's lymphoma has been demonstrated in recent reports, whereas late‑onset B‑cell non‑Hodgkin's lymphoma after HCV eradication with DAAs has occasionally been reported. In the present study, a 77‑year‑old man with chronic hepatitis C and intermediate liver cancer risk received sofosbuvir‑ledipasvir treatment for 12 weeks. Two months following the end of antiviral therapy, he had achieved sustained virologic response for 8 weeks. However, the patient occasionally found swelling of the right cervical lymph nodes without any subjective symptoms. Lymph node biopsy revealed diffuse large B‑cell lymphoma and whole‑body 18F‑fluorodeoxyglucose (FDG) positron emission tomography with computed tomography showed increased FDG uptake in the right cervical, right submandibular, mediastinal and mesenteric lymph nodes. The patient received six courses of rituximab, cyclophosphamide, doxorubicin, vincristine and prednisolone chemotherapy and achieved complete response at 8 months after chemotherapy initiation. Thus, the development of lymphoid malignancies may arise, even after HCV eradication with DAAs. Therefore, clinicians should be aware of such risks during and after antiviral treatment with DAAs.

Verified
Journal Article
Open access
PDF file
THtatsunori hanai
tatsunori hanai
MSMakoto Shiraki
Makoto Shiraki
KIKenji Imai
Kenji Imai
ASAtsushi Suetsugu
Atsushi Suetsugu
KTKoji Takai
Koji Takai
Masahito ShimizuMasahito Shimizu
Masahito Shimizu
The clinical efficacy of a late evening snack (LES) is well documented in patients with cirrhosis, but its effect on survival remains unclear. This cohort study aimed to compare the overall survival between LES-treated patients and untreated patients. We conducted a retrospective cohort study to determine the effect of LES, which is defined as an oral intake of a branched-chain amino acids (BCAA)-enriched nutrient before bedtime, on survival in 523 patients with cirrhosis seen at a tertiary referral center in Japan from March 2004 to April 2019. The association between LES and all-cause mortality was evaluated using propensity score matching and inverse probability of treatment weighting analyses. The median age of the 523 participants was 66 years; 286 (55%) patients were men and 87 (17%) received LES therapy. Of the 231 propensity-matched patients, 20 (26%) LES-treated patients and 72 (47%) untreated patients died during a median follow-up of 2.0 years (interquartile range, 0.5–4.8). Propensity score matching analysis showed that the overall survival was significantly higher in LES-treated patients than in untreated patients (hazard ratio [HR], 0.57; 95% confidence interval [CI], 0.34–0.93). The survival benefit of LES therapy was most prominent in patients with Child–Pugh C cirrhosis (HR, 0.40; 95% CI, 0.20–0.81). Inverse probability of treatment weighting analysis also revealed that LES significantly improved the prognosis of patients with cirrhosis (HR, 0.57; 95% CI, 0.33–0.99). In this retrospective study of patients with cirrhosis, we found that nocturnal BCAA supplementation was associated with a significant reduction in the risk of death in patients with liver cirrhosis.