1. Purpose: To confirm the changes in lifestyle due to differences in perceptions of infectious disease risk after the COVID-19 pandemic, decrease in exposure levels of environmentally hazardous chemicals and changes in indicators related to chronic kidney disease

2. Methods:

   • Survey on health risk awareness and lifestyle for COVID-19
   • Blood and urine tests for exposure to environmentally hazardous chemicals
   • Collection of hospital clinical data utilization for indicators related to chronic kidney disease

3. Clinical endpoints:

   • Verification of differences in health risk perception level and lifestyle changes
   • Verification of changes in lifestyle changes and exposure to environmentally hazardous chemicals
   • Verification of changes in indicators related to kidney disease according to changes in exposure to environmentally hazardous chemicals

4. Statistical methods: chi-square test, independent mean comparison t-test, ANOVA test, regression analysis

1. Background In daily life, people are exposed to various environmental hormones (Endocrine Disrupting Chemicals) such as phthalates, bisphenols, heavy metals, and perfluorinated compounds. Due to the recent pandemic of the COVID-19, behavior patterns such as wearing a mask and refraining from going out in daily life have changed. Such behavioral changes have the potential to change the level of exposure to environmental hazards, like intervention studies. In addition, studies have been reported that exposure to various environmental hormones can affect kidney function, but epidemiological studies are insufficient. Therefore, the research team is trying to determine whether exposure to environmental hormones changes due to changes in behavioral patterns according to the new corona epidemic, and to determine the effect on renal function indices in patients with chronic kidney disease.

2. Hypothesis and Purpose

   • Differences in risk perception for disease after the COVID-19 pandemic can explain the degree of change in lifestyle.
   • The changed lifestyle will lead to reduced exposure to environmentally hazardous substances.
   • Reduction of exposure to environmentally harmful substances will reduce the level of exposure to harmful substances related to kidney disease, which will lead to changes in the prevalence of kidney disease and indicators related to kidney disease.
   • After the COVID-19 pandemic, it is verified whether the exposure level of environmentally hazardous chemicals decreases due to changes in the way of life and differences in perception of the risk of infectious diseases, and confirms which indicators related to chronic kidney disease change accordingly. Identify the role.

3. Methods (1) During the COVID-19 pandemic

   • Acquisition of consent (using explanations and posters) by explaining the research purpose and method

   • Survey on changes in awareness of diseases and changes in hygiene activities since the COVID-19 pandemic compared to before

   • Measurement of the concentration of environmentally hazardous substances through the acquisition of blood (serum, residual samples after blood tests for treatment) and urine samples that are normally performed in the office (3 months cycle, 4 times)

   • Acquisition of clinical information related to kidney disease (2) Recovery period of the COVID-19 pandemic

   • Survey on changes in awareness of diseases and hygiene activities that have changed since the end of the COVID-19 outbreak

   • Measurement of the concentration of environmentally harmful substances by obtaining blood (serum, residual sample after blood test for medical treatment) and urine sample (once after 6 months of termination)

   • Acquisition of clinical information related to kidney disease (3) Investigation variable

     a) Survey

   • Demographic information

   • Anthropometric information

   • Risk perception for the COVID-19

   • Individual behavior associated with hygiene

   • Social distancing pattern b) Chemical material in human sample (blood, urine)

   • Phthalate metabolite

   • Paraben metabolite

   • Benzophenone

   • Triclosan and triclocarban

   • Bisphenols

   • Phosphate metabolites

   • Organochlorine pesticides

   • Polychlorinated biphenyls c) Clinical information including estimated glomerular filtration rate, urine protein/creatinine ratio

Inclusion Criteria:

• aged 19 years or older
• who have been treated twice or more with chronic kidney disease as their main diagnosis in an outpatient department of kidney medicine for more than 3 months

Exclusion Criteria:

• Patients who do not observe the rapid deterioration of renal function (AKI)
• Patients who are likely to significantly change their lifestyle and exposure levels of environmentally hazardous chemicals due to the rapid progression of the disease itself, accompanied by the following chronic diseases (malignant tumors, dementia, immunosuppressants Use, stroke within 1 year, cerebral hemorrhage, myocardial infarction)
• Other patients who have difficulty in general communication or who are unable to carry out their daily life on their own

• Target number: around 310
• The total number of participants in the study is around 300-350. In order to figure outcomes, data from the Basic Survey on National Environmental Health were used, and the preceding study (intervention study) was referred to.
• In multiple regression analysis, the correlation between eGFR and ethylparaben (EtP) was examined by adjusting age, BMI, smoking history, and drinking history. In the full model, where all variables were corrected, R2 was 0.478, and when the independent variable EtP was excluded, R2 decreased by 0.012. Based on these values, as a result of setting the power of 0.7, 0.8, and 0.9 in the multiple regression model, n = 283, 359, and 479, respectively. Based on this result, the number of study participants was set to around 300-350.