TABLE 1.

Epidemiological studies of cardio‐renal‐metabolic disease in Japan

Authors (year of publication)	Type of study	Number of subjects	Findings
T2D and CVD
Shiba et al. (2011) 8	Prospective, multicentre, cohort study	10 219	22.5% of HF patients had diabetes
Cui et al. (2011) 26	Prospective, multicentre, cohort study	35 657	Diabetes associated with increased risk of stroke: Men: HR 1.64 (95% CI: 1.21‐2.23) Women: HR 2.19 (95% CI: 1.53‐3.12)
Akao et al. (2013) 27	Cross‐sectional, multicentre, cohort study	3183	23.2% of patients with atrial fibrillation had diabetes
Sato et al. (2013) 28	Prospective, multicentre, cohort study	4842	33.8% of hospitalized HF patients had diabetes
Kato et al. (2015) 29	Prospective, multicentre, cohort study	99 584	Diabetes associated with increased risk of death from IHD: Men: HR 2.32 (95% CI: 1.78‐3.03) Women: HR 4.56 (95% CI: 3.17‐6.57)
Takabayashi et al. (2016) 30	Prospective, multicentre, cohort study	647	31.8% of hospitalized HF patients had diabetes
Hirakawa et al. (2017) 25	Pooled analysis of 8 cohort studies	38 854	Diabetes associated with an increased risk of death from: CV death: HR 1.62 (95% CI: 1.35‐1.94) CHD: HR 2.13 (95% CI: 1.47‐3.09) Stroke: HR 1.40 (95% CI: 1.05‐1.85)
Yaku et al. (2018) 31	Prospective, multicentre, cohort study	4056	37% of hospitalized HF patients had diabetes (HFrEF 40%; HFpEF 33%)
Kaku et al. (2020) 32	Retrospective, multicentre, cohort study	198 861	26.2% of hospitalized HF patients had diabetes
Sato et al. (2020) 33	Prospective, multicentre, cohort study	4876	39.5% of elderly HF patients had diabetes
Ide et al. (2021) 34	Retrospective, multicentre, cohort study	13 238	34.2% of hospitalized HF patients had diabetes
Kaneko et al. (2021) 35	Cross‐sectional database study	1 180 062	In individuals aged 20 to 49 years, diabetes was associated with an increased risk for: Myocardial infarction: HR 2.09 (95% CI: 1.61‐2.71) Angina: HR 1.59 (95% CI: 1.42‐1.78) Stroke: HR 1.31 (95% CI: 1.07‐1.59) HF: HR 1.58 (95% CI: 1.41‐1.78) Atrial fibrillation: HR 1.69 (95% CI: 1.35‐2.13)
Seo et al. (2021) 36	Prospective, single‐centre, cohort study	349	43% of hospitalized HF patients had diabetes (HFrEF 42%; HFpEF 41%)
Ohsugi et al. (2021) 37	Cross‐sectional database study	10 151	2.8% of T2D patients had myocardial infarction, while 7.6% had ischaemic stroke
T2D and CKD
Ohta et al. (2010) 38	Retrospective, single‐centre, cohort study	3575	46.0% of T2D patients had CKD
Iwai et al. (2018) 39	Prospective, multicentre, cohort study	2484	28.1% of CKD patients had diabetes
Yokoyama et al. (2018) 40	Cross‐sectional, multicentre, cohort study	7251	Prevalence of CKD in T2D patients declined from 32.6% to 22.3% from 2004 to 2014
Nitta et al. (2019) 41	Cross‐sectional, multicentre, cohort study	1088	41.7% of CKD patients had diabetes
Yoshida et al. (2020) 42	Cross‐sectional, multicentre, cohort study	2385	54.0% of T2D patients had CKD
CKD and CVD
Tanaka et al. (2017) 43	Prospective, multicentre, cohort study	2966	8.6 HF events per 1000 person‐years in CKD patients
Kon et al. (2018) 44	Cross‐sectional, multicentre, cohort study	132 160	HR 2.28 (95% CI: 1.28‐4.03) for CV death in elderly patients with eGFR < 45 ml/min/1.73m2 compared with those with eGFR > 90 ml/min/1.73m2
Yaku et al. (2018) 31	Prospective, multicentre, cohort study	4056	45% of HF patients had CKD
Nitta et al. (2019) 41	Cross‐sectional, multicentre, cohort study	1088	23.4% of CKD patients had left ventricular hypertrophy
Sato et al. (2020) 33	Prospective, multicentre, cohort study	4876	47.7% of elderly HF patients had CKD
Ide et al. (2021) 34	Retrospective, multicentre, cohort study	13 238	38.9% of HF patients had CKD

Abbreviations: CHD, coronary heart disease; CI, confidence interval; CKD, chronic kidney disease; CV, cardiovascular; CVD, cardiovascular disease; eGFR, estimated glomerular filtration rate; HF, heart failure; HFpEF, heart failure with preserved ejection fraction; HFrEF, heart failure with reduced ejection fraction; HR, hazard ratio; IHD, ischaemic heart disease; T2D, type 2 diabetes.