Publication

Study of Seven Kanto Prefectures Using the National Database

• Comorbidities and Concomitant Medications in Middle-Aged Japanese People According to the Charlson Comorbidity Index and Age: Results of the NDB-K7Ps-Study-3.  Airi Sekine, Kei Nakajima. Epidemiologia. 7(2), 34. 2 March 2026

2025

• Correlations Between Wald Chi-Squared Values and Standardized Beta-Coefficients in Regression Analysis and Feature Importance Calculated Using Machine Learning. Kei Nakajima, Airi Sekine. AI in Clinical Medicine. 1(e10) 2025-10-08  

2024

• Possible pitfalls in the prediction of weight gain in middle-aged normal-weight individuals: Results from the NDB-K7Ps-study-2. Kei Nakajima, Airi Sekine, Ryoko Higuchi, Mai Enokido, Sadako Matsui. Obes Res Clin Pract. 2024 Jul-Aug;18(4):255-262. doi: 10.1016/j.orcp.2024.07.004. Epub 2024 Jul 31.

•  Moderate-to-Heavy Alcohol Consumption May Cause a Significant Decrease in Serum High-Density Lipoprotein Cholesterol in Middle-Aged Women: A Cohort Study of the National Database Study in the Kanto 7 Prefectures-4.  Airi Sekine, Kei Nakajima. Cureus 16(3): e55467. doi:10.7759/cureus.55467 2024-3-4  

2023

• Agreement in All-in-One Dataset between Diagnosis and Prescribed Medication for Common Cardiometabolic Diseases in the NDB-K7Ps. Airi Sekine, Kei Nakajima. Epidemiologia 2023, 4(4), 370-381; https://doi.org/10.3390/epidemiologia4040034 2023-10-2
• Relationship between non-restorative sleep and body weight in a general population: Results of NDB-K7Ps-Study-1. Kei Nakajima,  Airi Sekine. Obesity research & clinical practice 2023-3-29  

Kanagawa Investigation of Total Checkup Data from the National Database (KITCHEN)

2022

• U-Shaped Relationship Between Proteinuria and High-Density Lipoprotein Cholesterol: Results of Cross-Sectional and Six Years Cohort Studies (KITCHEN-10). Manami Igata, Kei Nakajima.  Journal of clinical medicine 14(8) 2022年8月 

2021

• Association of Serum High-Density Lipoprotein Cholesterol with High Blood Pressures at Checkup: Results of Kanagawa Investigation of Total Checkup Data from the National Database-9 (KITCHEN-9).Kei Nakajima, Manami Igata, Ryoko Higuchi, Kotone Tanaka, Kaori Mizusawa, Teiji Nakamura. Journal of clinical medicine 10(21) 2021年10月30日  
• Fasting biochemical hypoglycemia and related-factors in non-diabetic population: Kanagawa Investigation of Total Check-up Data from National Database-8.Kotone Tanaka, Ryoko Higuchi, Kaori Mizusawa, Teiji Nakamura, Kei NakajimaWorld journal of diabetes 12(7) 1131-1140 2021年7月15日  
• Potential Role of Artificial Intelligence for the Previous Study Using Traditional Analysis.Kei Nakajima, Manami Igata, Ryoko HiguchiJournal of clinical medicine research 13(7) 409-411 2021年7月  
• Association between extremely high high-density lipoprotein-cholesterol and hypertensive retinopathy: results of a cross-sectional study from Kanagawa Investigation of Total Checkup Data from the National Database-6 (KITCHEN-6).Kei Nakajima, Ryoko Higuchi, Kaori Mizusawa, Teiji NakamuraBMJ open 11(5) e043677 2021年5月11日  

2020

• Unexpectedly High Prevalence of Breakfast Skipping in Low Body-Weight Middle-Aged Men: Results of the Kanagawa Investigation of Total Checkup Data from the National Data Base-7 (KITCHEN-7).Kei Nakajima, Ryoko Higuchi, Kaori Mizusawa Nutrients 13(1) 2020年12月30日 
• Trace Proteinuria and the Incidence of Overt Proteinuria After Five Years: Results of the Kanagawa Investigation of the Total Checkup Data From the National Database-5 (KITCHEN-5).Kei Nakajima, Ryoko Higuchi, Kaori Mizusawa. Journal of clinical medicine research 12(9) 618-623 2020年9月  

2019

• Impaired Glucose Metabolism in People with Extremely Elevated High-Density Lipoprotein Cholesterol and Low Alcohol Consumption: Results of the Kanagawa Investigation of Total Checkup Data from the National Database-3 (KITCHEN-3).Nakajima K J Clin Med. 8(11) 2019年11月1日 
• High Concentration of Serum Aspartate Aminotransferase in Older Underweight People: Results of the Kanagawa Investigation of the Total Check-Up Data from the National Database-2 (KITCHEN-2).Shibata M, Nakajima K, Higuchi R, Iwane T, Sugiyama M, Nakamura TJournal of clinical medicine 8(9) 2019年8月22日 

• High Incidence of Diabetes in People with Extremely High High-Density Lipoprotein Cholesterol: Results of the Kanagawa Investigation of Total Checkup Data from the National Database-1 (KITCHEN-1).Nakajima K, Higuchi R, Iwane T, Shibata M, Takada K, Sugiyama M, Matsuda M, Nakamura TJournal of clinical medicine 8(3) 2019年3月19日  
• Kanagawa Investigation of the Total Check-up Data from the National database (KITCHEN): protocol for data-driven population-based repeated cross-sectional and 6-year cohort studies.Nakajima K, Iwane T, Higuchi R, Shibata M, Takada K, Uda J, Anan M, Sugiyama M, Nakamura TBMJ open 9(2) e023323 2019年2月21日 

Presentation

2023

• 傷病名の年度間の一致率について
  関根 愛莉, 中島 啓 第6回NDBユーザー会 2023年9月15日

• AIを用いた中高年女性における飲酒量と血清HDL-C濃度に関する解析：関東1都6県NDBコホート研究
  関根 愛莉, 中島 啓　第77回日本栄養・食糧学会大会， 2023年5月14日
• 飲酒の頻度および量と⾎清HDL濃度との関係︓関東1都6県NDBを⽤いたコホート研究
  関根愛莉, 中島啓　第56回⽇本成⼈病（⽣活習慣病）学会学術集会 ，2023年1月14日

2022

• 飲酒の頻度および量と血清HDL濃度との関係：関東1都6県NDBを用いたコホート研究
  関根 愛莉, 中島 啓　日本臨床疫学会 第5回年次学術大会， 2022年11月12日