Decreased body mass index as an independent risk factor for developing chronic kidney disease.
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 (DeltaBMI) 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 m(2), according to the modification of diet in renal disease study equation. Obesity was defined as BMI > or = 25 kg/m(2).


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 DeltaBMI on CKD incidence was evaluated after considering other confounding factors such as age, sex, blood pressure, BMI, fasting plasma glucose, and proteinuria. Median DeltaBMI was 1.0%. The adjusted odds ratio (95% CI) for the effect of DeltaBMI 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 DeltaBMI > or = 1% was taken as a reference. DeltaBMI was an independent predictor of CKD incidence.


CONCLUSIONS
The present results suggest that there was an inverse relationship between DeltaBMI and CKD incidence among screened subjects. The reasons for this observation are not clear, but careful follow-up for DeltaBMI is necessary, particularly in obese men with proteinuria.
Department of Cardiovascular Medicine, Nephrology, and Neurology, Faculty of Medicine and Dialysis Unit, University Hospital of The Ryukyus and Okinawa General Health Maintenance Association, Okinawa, Japan.
Kaori
K
Tokashiki
Masahiko
M
Tozawa
Chiho
C
Iseki
Kentaro
K
Kohagura
Kozen
K
Kinjo
Shuichi
S
Takishita
Kunitoshi
K
Iseki
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D002908:Chronic Disease; D003404:Creatinine / Q000097:blood; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D015994:Incidence; D007674:Kidney Diseases / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology*; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D009765:Obesity / Q000150:complications* / Q000453:epidemiology; D016017:Odds Ratio; D015995:Prevalence; D018570:Risk Assessment; D012307:Risk Factors; D012737:Sex Factors; D013997:Time Factors
D003404:Creatinine