Body mass index and the risk of chronic renal failure: the Asian experience

There is a worldwide obesity epidemic, and the number of patients requiring dialysis because of obesity-related renal disease such as diabetes mellitus and hypertension is increasing. Obesity increases the risk of cardiovascular disease and premature death due to chronic kidney disease (CKD) and end-stage renal disease (ESRD). Although the effect of obesity might differ among races, obesity has a significant impact on CKD and ESRD.

We examined the relationship between obesity (i.e., body mass index [BMI]) and CKD or ESRD using a community based screening registry in Okinawa, Japan. For this purpose, we used a general screening registry (1983, 1993, and 2003), the ESRD patient registry (1971-2000), a hospital-based cardiovascular disease registry (1988-1990), and a hospital-based screening registry (2003).

The prevalence of obesity, based on a BMI>or=30 kg/m2, was 3.5% (1983), 4.7% (1993), and 6.2% (2003) in the general adult population. The incidence of ESRD increased when BMI increased, particularly in men. In the hospital-based screening study, the number of components of metabolic syndrome was significantly related with the prevalence of CKD. The relationship was linear when the modified National Cholesterol Education Program criteria were used to define abdominal obesity as a waist circumference of 85 cm or more in men and 90 cm or more in women.

Although prospective studies are needed, our findings indicate that obesity, including metabolic syndrome, is a potential treatable cause of CKD and ESRD. Rigorous efforts should be made to optimize weight to reduce the risk of CKD and ESRD by a judicious combination of diet, exercise, and psychologic therapies.