Significance of estimated glomerular filtration rate in predicting brain or heart attacks in obese and non-obese populations

Background: The Japanese Specific Health Checkup mainly focuses on metabolic syndrome for preventing cardiovascular events. Subjects are stratified by measuring waist circumference, body mass index, blood pressure, triglycerides, and fasting plasma glucose. However, estimated glomerular filtration rate (eGFR) is not considered essential. Methods: A longitudinal cohort study assessed the association of eGFR with new-onset brain or heart attacks in a large Japanese nationwide Specific Health Checkup database. A total of 109,349 Japanese subjects (mean age 63.2 years, 39.5 % men) were examined for the events 2 years later. The odds ratios were calculated for new events in the total and subgroup populations divided by BMI < or ≥25 kg/m², obese and non-obese, respectively. Results: Obese subjects were more often male and had proteinuria (dipstick test ≥1+), lower eGFR, and higher systolic and diastolic BP, fasting plasma glucose, hemoglobin A1c, and triglycerides (TG). Rates of new-onset brain or heart attacks were 3.1 and 4.0 % in the groups of non-obese and obese subjects, respectively. In the total population, eGFR as well as higher BMI (≥25 kg/m²), higher BP (high-normal hypertension or greater), higher TG (≥150 mg/dl), and proteinuria were significant risk factors for developing brain or heart attacks. The eGFR was significant in non-obese subjects, but not in the obese. Conclusion: As the ultimate aim of ‘Specific Health Checkup’ is to prevent cardiovascular events, our study suggests that eGFR should be evaluated in non-obese subjects.