Hikaru Morooka

Dr. Hikaru Morooka

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Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

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

Representative Publications

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11 November 2020 in Diagnostics
Verified
Journal Article
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HMHikaru Morooka
Hikaru Morooka
DKDaisuke Kasugai
Daisuke Kasugai
ATAkihito Tanaka
Akihito Tanaka
MOMasayuki Ozaki
Masayuki Ozaki
ANAtsushi Numaguchi
Atsushi Numaguchi
SMShoichi Maruyama
Shoichi Maruyama
Acute kidney injury (AKI) is a major complication of sepsis that induces acid-base imbalances. While creatinine levels are the only indicator for assessing the prognosis of AKI, prognostic importance of metabolic acidosis is unknown. We conducted a retrospective observational study by analyzing a large China-based pediatric critical care database from 2010 to 2018. Participants were critically ill children with AKI admitted to intensive care units (ICUs). The study included 1505 children admitted to ICUs with AKI, including 827 males and 678 females. The median age at ICU admission was 22 months (interquartile range 7–65). After a median follow-up of 10.87 days, 4.3% (65 patients) died. After adjusting for confounding factors, hyperlactatemia, low pH, and low bicarbonate levels were independently associated with 28-day mortality (respective odds ratio: 3.06, 2.77, 2.09; p values: <0.01, <0.01, <0.01). The infection had no interaction with the three parameters. The AKI stage negatively interacted with bicarbonate and pH but not lactate. The current study shows that among children with AKI, hyperlactatemia, low pH, and hypobicarbonatemia are associated with 28-day mortality.

31 December 2020 in BMJ Open
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Journal Article
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HMHikaru Morooka
Hikaru Morooka
ATAkihito Tanaka
Akihito Tanaka
DIDaijo Inaguma
Daijo Inaguma
SMShoichi Maruyama
Shoichi Maruyama
Objectives Patients with peripheral artery disease (PAD) are reported to have a poorer prognosis than those without PAD. PAD is sometimes found at dialysis initiation, but its influence on the prognosis in these patients has not been investigated. We aimed to compare the mortality rate between patients with PAD at the time of dialysis initiation and those without PAD. Design We undertook an observational prospective multicenter study of patients starting dialysis treatment. Data were collected on patients’ sex, age, presence of PAD, medication, medical history and clinical and laboratory data. Setting Seventeen centers participated in the Aichi Cohort Study of Prognosis in Patients Newly Initiated into Dialysis. Participants A total of 1524 patients with chronic kidney disease started dialysis from October 2011 to September 2013. The patients were followed-up until March 2015. During this time, there were two patients who lost the follow-up. Primary and secondary outcome measures The primary outcome was defined as all-cause mortality. The secondary outcomes were defined as each cause of mortality. Results This study included 1030 men and 492 women with a mean age of 67.50±13.10 years. Of these, 71 had PAD and 1451 did not have PAD. After a median follow-up of 814.5 days, 33.80% of the former group and 17.00% of the latter group had died in March 2015 (p=0.001). After adjusting for confounding factors, PAD at dialysis initiation remained an independent risk factor for mortality (p<0.01). Conclusions Patients with PAD at the time of dialysis initiation had a poorer prognosis than patients without PAD. Therefore, the presence of PAD in patients starting dialysis should be considered for their monitoring and follow-up.

14 October 2021 in Clinical Kidney Journal
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Journal Article
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HMHikaru Morooka
Hikaru Morooka
ATAkihito Tanaka
Akihito Tanaka
DIDaijo Inaguma
Daijo Inaguma
SMShoichi Maruyama
Shoichi Maruyama
Background: Hyperphosphatemia in patients undergoing dialysis is common and is associated with mortality. Recently, the link between phosphate metabolism and iron dynamics has received increasing attention. However, the association between this relationship and prognosis remains largely unexplored. Methods: We conducted an observational study of patients who initiated dialysis in the 17 centers participating in the Aichi Cohort Study of the Prognosis in Patients Newly Initiated into Dialysis. Data were available on sex, age, use of phosphate binder, drug history, medical history and laboratory data. After excluding patients with missing values of phosphate, hemoglobin, ferritin and transferrin saturation, we used the Gaussian mixture model to divide the cohort into clusters based on phosphate, hemoglobin, logarithmic ferritin and transferrin saturation. We investigated the prognosis of patients in these clusters. The primary outcome was all-cause death. In each cluster, the prognostic impact of phosphate binder was also studied. Results: The study included 1175 patients with chronic kidney disease who initiated dialysis between October 2011 and September 2013. Among them, 785 were men and 390 were women, with a mean ± SD age of 67.9 ± 13.0 years. The patients were divided into three clusters, and mortality was higher in cluster c than in cluster a (P = 0.005). Moreover, the use of phosphate binders was associated with a lower risk of all-cause death in two clusters (a and c) that were characterized by older age and higher prevalence of diabetes mellitus, among other things. Conclusions: We used an unsupervised machine learning method to cluster patients, using phosphate, hemoglobin and iron-related markers. In two of the clusters, the oral use of a phosphate binder might improve prognosis.

26 March 2024 in Maturitas
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Journal Article
Open access
HMHikaru Morooka
Hikaru Morooka
EHEirin B. Haug
Eirin B. Haug
VMVegard Malmo
Vegard Malmo
JLJan Pål Loennechen
Jan Pål Loennechen
KMKenneth J. Mukamal
Kenneth J. Mukamal
JHJulie Horn
Julie Horn
Age at menarche, reproductive lifespan, and age at menopause are associated with several cardiovascular diseases, but their relationship with atrial fibrillation (AF) is uncertain. We linked information on all women who participated in the third survey of the population-based, longitudinal HUNT study in Norway with medical records from all local hospitals. A total of 14,632 women aged 60 or more were followed for validated incident AF. We retrieved age at menarche and age at menopause from the HUNT questionnaires. Reproductive lifespan was defined as the difference between age at menarche and age at menopause. We used Cox proportional hazards regression models to assess associations between AF and age at menarche, reproductive lifespan, and age at menopause. During a median follow-up of 8.17 years (136,494 person-years), 1217 (8.3 %) participants developed AF. In multivariable-adjusted analyses, we observed no associations between early or late age at menarche and AF (hazard ratios (HRs): <12 years: 0.85 [95 % confidence interval (CI), 0.65-1.12]; ≥16 years: 0.99 [95 % CI, 0.80-1.24] compared to those who attained menarche at 13-14 years). The HR for a reproductive lifespan shorter than 30 years was 0.91 [95 % CI, 0.72-1.15] compared to 34-37 years. Likewise, there was no clear association between premature or early age at menopause and AF (HRs: <40 years: 1.21 [95 % CI, 0.83-1.75]; 40-44 years: 0.97 [95 % CI, 0.77-1.22] compared to 50-54 years). In this population of women aged 60 years and over, the risk of AF was not associated with age at menarche, reproductive lifespan, or age at menopause.

1 July 2024 in European Journal of Preventive Cardiology
Verified
Journal Article
Open access
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HMHikaru Morooka
Hikaru Morooka
EHEirin B Haug
Eirin B Haug
VMVegard Malmo
Vegard Malmo
JLJan Pål Loennechen
Jan Pål Loennechen
KMKENNETH MUKAMAL
KENNETH MUKAMAL
JHJulie Horn
Julie Horn
Aims: Although parity, infertility, and age at first birth are important for later development of cardiovascular disease, research on their association with atrial fibrillation (AF) is limited. Methods and results: We linked data from the population-based HUNT study and the Medical Birth Registry of Norway (MBRN) and validated medical records from local hospitals. A total of 24 015 women aged 45 years or older were followed for verified incident AF. Parity and age at first birth were retrieved from the MBRN or from self-reported questionnaires in the HUNT study. A history of infertility was self-reported on the HUNT questionnaire. Cox proportional hazards models were used to calculate hazard ratios (HRs) for the multivariable-adjusted associations of parity, infertility, and age at first birth with risk of AF. During a median follow-up of 12.8 years, 1448 (6.0%) participants developed AF. Women with higher parity (four or more births vs. two births) were at 21% higher risk of AF [HR 1.21, 95% confidence interval (CI) 1.05–1.39]. A history of infertility was also associated with the risk of AF (HR 1.20, 95% CI 1.02–1.42). Among parous women, younger age at first birth (<20 vs. 20–29 years) was associated with a 20% higher risk of AF (HR 1.20, 95% CI 1.03–1.40). Conclusion: Women with four or more births, or a history of infertility, or younger age at first birth have approximately a 20% higher risk of AF among women over 45 years old.

15 April 2025 in European Journal of Preventive Cardiology
Verified
Journal Article
Open access
HMHikaru Morooka
Hikaru Morooka
EHEirin B Haug
Eirin B Haug
VMVegard Malmo
Vegard Malmo
JLJan Pål Loennechen
Jan Pål Loennechen
HEHanne Ellekjær
Hanne Ellekjær
JHJulie Horn
Julie Horn
Aims: Despite well-studied associations between hypertensive disorders of pregnancy (HDP) and atrial fibrillation (AF), the mechanisms of the excess risk of AF in women with history of HDP are not fully understood. Furthermore, little is known about associations between other adverse pregnancy outcomes (APOs) and AF, including preterm birth, small/large-for-gestational-age (SGA/LGA) offspring. Methods and results: By linking the population-based HUNT study with the Medical Birth Registry of Norway (MBRN) and electronic patient administrative systems, 15 104 women ≥45 years with 34 674 births were followed and assessed for validated AF for a median of 12.9 years. Information on APOs was retrieved from the MBRN. We used Cox proportional hazards models to calculate hazard ratios (HRs) for associations of APOs with the risk of AF. By inverse odds ratio weighting, we assessed modifiable AF risk factors that could explain the associations. Among women aged 45–65, those with HDP had a higher risk of AF [HR 2.03, 95% confidence interval (CI) 1.27–3.24] as women without HDP, but not among women >65 years (HR 0.95, 95% CI 0.57–1.60). A history of LGA was associated with increased risk of AF (HR 1.38, 95% CI 1.03–1.84), but histories of preterm birth or SGA were not (HR 0.94, 95% CI 0.63–1.41, HR 0.90, 95% CI 0.66–1.23). Post-pregnancy body mass index might possibly explain ∼45% of the associations between HDP or LGA and AF. Conclusion: Women with history of HDP or LGA offspring are at higher risk of AF.