Body Mass Index, waist circumference, and health-related quality of life in adults with chronic kidney disease

Purpose: Obesity is linked to poor health-related quality of life (HRQOL) in the general population, but its role in chronic kidney disease (CKD) is uncertain. Methods: We conducted a cross-sectional study that investigated 1880 participants from the KoreaN cohort study for Outcome in patients With CKD (KNOW-CKD) who underwent complete baseline laboratory tests, health questionnaires, and HRQOL. HRQOL was assessed by physical component summary (PCS) and mental component summary (MCS) of the SF-36 questionnaire. We used multivariable linear regression models to examine the relationship between Body Mass Index (BMI) and sex-specific waist circumference (WC) with HRQOL. Results: Adults with higher BMI and greater WC showed lower PCS. After adjusting for age, sex, socioeconomic state, comorbidities, and laboratory findings, we found that WC, but not BMI, was associated with PCS. Greater WC quintiles were associated with lower PCS [WC-4th quintile (β, − 2.63, 95% CI − 5.19 to − 0.06) and WC-5th quintile (β, − 3.71, 95% CI − 6.28 to − 1.15)]. The association between WC and PCS was more pronounced in older adults, woman, patients with diabetes, cardiovascular disease, or lower eGFR. The relationship between BMI and WC with MCS was not significant. Conclusions: In adults with CKD, WC is a better indicator of poor physical HRQOL than BMI. The association between WC and physical HRQOL is modified by age, sex, eGFR, and comorbidities such as diabetes and cardiovascular disease.