Published in:
01-02-2009 | Original Article
Decreased body mass index as an independent risk factor for developing chronic kidney disease
Published in: Clinical and Experimental Nephrology | Issue 1/2009
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Background
Obesity and metabolic syndrome are risk factors for the development of chronic kidney disease (CKD). Few studies have examined the effect of change in body mass index (ΔBMI) on CKD incidence in a general screening setting.
Methods
Subjects of this study were screenees that participated in the screening program of the Okinawa General Health Maintenance Association in 1993 and 2003 in Okinawa, Japan. Using identification number, birth date, sex, and other recorded identifiers, we identified 33,389 subjects among the 1993 screening participants (N = 143,948) who also participated in the 2003 screening. CKD was defined as estimated glomerular filtration rate <60 ml/min/1.73 m2, according to the modification of diet in renal disease study equation. Obesity was defined as BMI ≥ 25 kg/m2.
Results
CKD prevalence was 13.8% in 1993 and 22.4% in 2003. The incidence of developing CKD in 10 years was 15.5%. The effect of ΔBMI on CKD incidence was evaluated after considering other confounding factors such as age, sex, blood pressure, BMI, fasting plasma glucose, and proteinuria. Median ΔBMI was 1.0%. The adjusted odds ratio (95% CI) for the effect of ΔBMI on CKD incidence was 1.111 (1.026–1.204, P < 0.01; entire study population), 1.271 (1.116–1.448, P = 0.0030; men), and 1.030 (0.931–1.139, NS; women), when ΔBMI ≥ 1% was taken as a reference. ΔBMI was an independent predictor of CKD incidence.
Conclusions
The present results suggest that there was an inverse relationship between ΔBMI and CKD incidence among screened subjects. The reasons for this observation are not clear, but careful follow-up for ΔBMI is necessary, particularly in obese men with proteinuria.