Associations between body mass index categories and geriatric assessment tests among older adults with chronic kidney disease: A prospective study

Background: The optimal body mass index (BMI) among older adults with chronic kidney disease (CKD) in geriatric assessment tests has not been studied. This study investigates the relationship between BMI and Comprehensive Geriatric Assessment (CGA) parameters among older adults with CKD. Methods: A total of 319 older adults with CKD were included. Demographic and laboratory data and geriatric assessment tests of patients within different BMI categories (18.5–24.9, 25.0–29.9, 30.0–34.9, and >35.0 kg/m²) were compared. Logistic regression analysis was used to determine associations between CGA and BMI categories. Results: The mean age was 84 ± 7 years, the mean glomerular filtration rate was 47 ± 8 ml/min/1.73 m², and 236 patients (74%) were women. BMI categories of <25.0, 25.0–29.9, 30.0–34.9, and >35.0 included 51 (16%), 119 (37.3%), 88 (27.6%), and 61 (19.1%) patients. A BMI range of 25–35 showed the most favorable results, according to CGA scores for basic and instrumental activities of daily living, the Tinetti scale, Mini Nutritional Assessment (MNA), and the Geriatric Depression Scale (GDS) among BMI groups. Patients with a BMI of 30.0–34.9 had better scores in Mini Mental State Examination, GDS, and MNA than those with a BMI of 25.0–29.9, whereas other measures were comparable between these two categories. Conclusion: The optimum range of BMI levels for nutrition and cognitive health and mood status in older adults with CKD is 30.0–34.9.