Vegetarian Diet and Chronic Degenerative Diseases

Study Overview
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Brief Summary
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To investigate the prospective association between a vegetarian diet and chronic degenerative diseases in two cohorts of Taiwanese Buddhists

Detailed Description
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The Tzu Chi Vegetarian Study (TCVS) recruited 12062 community volunteers of the Buddhists Tzu Chi Foundation throughout Taiwan in the year 2005. All participants completed a self-administered questionnaire on basic information, medical history, lifestyle, and diet. The Tzu Chi Health Study (TCHS) recruited 6002 participants who came to the Buddhist Tzu Chi Dalin General Hospital for health examination. All participants were interviewed on basic information, medical history, lifestyle, and diet. Biochemical and anthropometric data was collected through a health examination: Biochemical variables: CBC, fasting glucose, lipid profile (TCH, LDL, HDL, TG), BUN, Cr, ALT, AST, and UA. In addition, homocysteine, serum vitamin B12, folate, and C-reactive protein (CRP) are available for 1500 subjects. Blood: Extra blood samples have been obtained and stored for 3500 subjects and will be available for future investigation. Anthropometric variables: body weight, height, waist circumference, % body fat (with BIA), blood pressure, pulse wave velocity, bone mineral density through DXA (at spine for female and hip for male), lung function test (spirometric), abdominal sonography, colonoscopy, esophageal-gastro-duodenal-scopy, chest X-ray, KUB. Follow-up: Individual baseline data were linked to the National Health Insurance Database and the National Death Registry to ascertain disease outcomes at the Health and Welfare Data Science Center.

Official Title
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Vegetarian Diet and Chronic Degenerative Diseases in the Tzu Chi Health Study (TCHS) and the Tzu Chi Vegetarian Study (TCVS)

Conditions
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Dementia, Depression, Cardiovascular Diseases, Stroke, Gout, Cataract, Gallstone, Urinary Tract Infections

Intervention / Treatment
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* Other: Diet Exposure


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Participants who consent to be followed. Exclusion Criteria: Participants with inaccurate ID which make linkage to NHIRD impossible. Participants already with study outcome (disease) prior to enrollment in the study. Participants with missing covariates

Ages Eligible for Study
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Minimum Age: 18 Years


Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Tzu Chi Vegetarian Study<br>12062 Tzu Chi volunteers of the Buddhist Tzu Chi Foundation recruited throughout communities in Taiwan in the year 2005. All participants filled out a self-administered questionnaire on basic information, medical history, lifestyle, and diet. Diet exposure: 1/3 vegetarians, 2/3 nonvegetarians. | Other: Diet Exposure<br>* Vegetarian diet vs nonvegetarian diet<br>|
| Tzu Chi Health Study<br>6002 participants who came for health examination at the Dalin Tzu Chi Hospital between the years 2007 to 2009. 77% were Tzu Chi volunteers. All participants were interviewed on a structured questionnaire including basic information, medical history, lifestyle, and diet, and received a comprehensive health examination. Diet exposure: 1/3 vegetarians, 2/3 nonvegetarians. | Other: Diet Exposure<br>* Vegetarian diet vs nonvegetarian diet<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Gout | Incidence of gout are ascertained by linking individual participants' baseline data to the the National Health Insurance Database. Cases of gout are identified using ICD-9 code: 274. | From enrollment to time of disease occurrence, death of any cause, or end of study period (December 31st 2014). | 
| Stroke | Incidence of stroke are ascertained by linking individual participants' baseline data to the the National Health Insurance Database. Cases of stroke are identified using ICD-9 code: 430-438, where hemorrhagic stroke is defined by ICD9 430-432 and ischemic stroke is defined by ICD9 433-434. | From enrollment to time of disease occurrence, death of any cause, or end of study period (December 31st 2014). | 
| Cataract | Incidence of cataract are ascertained by linking individual participants' baseline data to the the National Health Insurance Database. Cases of cataract are identified using ICD-9 code: 366. | From enrollment to time of disease occurrence, death of any cause, or end of study period (December 31st 2014). | 
| Gallstone disease | Incidence of gallstone disease are ascertained by linking individual participants' baseline data to the the National Health Insurance Database. Cases of gallstone diseases are identified using ICD-9 code: 574. | From enrollment to time of disease occurrence, death of any cause, or end of study period (December 31st 2014). | 
| Dementia and mild cognitive impairment | Incidence of dementia are ascertained by linking individual participants' baseline data to the the National Health Insurance Database. Cases of dementia and mild cognitive impairment are identified using ICD-9 code: 290.0, 290.1,290.4, 331.0, 331.1, 331.82, 331.83. | From enrollment to time of disease occurrence, death of any cause, or end of study period (December 31st 2014). | 
| Depression | Incidence of depression are ascertained by linking individual participants' baseline data to the the National Health Insurance Database. Cases of depression and are identified using ICD-9 code: 296.2, 296.3, 300.4 and 311. | From enrollment to time of disease occurrence, death of any cause, or end of study period (December 31st 2014). | 
| Urinary tract infections (UTI) | Incidence of UTI are ascertained by linking individual participants' baseline data to the the National Health Insurance Database. Cases of UTI are identified using ICD-9 code: 599.0, 595, 590. | From enrollment to time of disease occurrence, death of any cause, or end of study period (December 31st 2014). | 
| Medical expenditures | Actual medical expenditure associated with different dietary patterns are analyzed. Medical expenditures are obtained and computed from the National Health Insurance Database claim data for outpatient treatment, inpatient treatment, and dental treatment. This also includes costs associated with laboratory work and medication prescription. | From enrollment to December 31st 2014. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Diet, vegetarian, Dementia, Depression, Cardiovascular Diseases, Stroke, Gout, Cataract, Gallstone, Urinary Tract Infections