Body mass index has no effect on rate of progression of chronic kidney disease in non-diabetic subjects.

Background: Chronic kidney disease (CKD) is increasingly prevalent worldwide. Furthermore, obesity is now a global problem with major health implications. There is a clear association between obesity and the development of CKD but it is not known whether obesity is a risk factor for the progression of pre-existing kidney disease. We examined the relationship between the body mass index (BMI) and the rate of progression of CKD in non-diabetic adults.

Methods: The Chronic Renal Insufficiency Standards Implementation Study (CRISIS) is a prospective observational study in a predominantly white population in Greater Manchester. From the CRISIS database, we assessed rate of progression of CKD in 499 adults attending the hospital. Baseline measurements including BMI were obtained and estimated glomerular filtration rate (eGFR) was monitored. The rate of deterioration of eGFR was derived over time, defined as ΔeGFR (mL/min/1.73 m2/year) and assessed using univariate analysis of variance.

Results: In the groups as a whole, no relationship between BMI and ΔeGFR was shown. Dividing the subjects into obese (BMI≥30) and non-obese (BMI<30) groups and further breakdown into CKD stages 3, 4 and 5, also showed no relationship between BMI and ΔeGFR. Univariate analysis of variance was used.

Conclusions: Neither BMI as a continuous variable nor obesity (BMI≥30) as a categorical variable was associated with an increased rate of progression of existing CKD in this predominantly white population.