Which anthropometric parameter is best related with urinary albumin excretion and creatinine clearance in type 2 diabetes: body mass index, waist circumference, waist-to-hip ratio, or conicity index?

Objective: We analyzed the relationships between body mass index (BMI), waist circumference (WC), waist-to-hip ratio, and conicity index and 24-hour urinary albumin excretion rate (UAER) and creatinine clearance.

Design: Cross-sectional study.

Setting: Patients presenting to a state hospital.

Patients: Study involved patients with type 2 diabetes.

Methods: Study participants underwent medical history examination, measurement of office blood pressure (BP), measurement of anthropometric factors and calculations (including BMI, WC, waist-to-hip ratio, and conicity index), physical examination, biochemical analysis, and 24-hour urine specimen collection to determine creatinine clearance and UAER.

Results: In all, 202 patients with type 2 diabetes (male/female: 91/111, aged: 58.4 ± 10.1 years) were included. It was found that 24-hour UAER correlated with WC (rho: +0.176, P = .012), serum albumin (rho: -0.324, P < .0001), and systolic BP (rho: +0.153, P = .029), whereas creatinine clearance correlated with age (rho: -0.152, P = .031), BMI (rho: +0.191, P = .007), albumin level (rho: +0.365, P < .0001), and uric acid level (rho: -0.369, P < .0001). The stepwise linear regression analysis revealed that WC (P = .012), glycosylated hemoglobin (P = .018), and systolic BP (P = .043) were found to be independently related to logarithmically converted 24-hour UAER, whereas creatinine clearance was found to be related to duration of diabetes (P = .001), BMI (P = .008), presence of peripheral arterial disease (P = .021), fasting serum glucose level (P = .003), and uric acid level (P < .0001). However, after correction for body surface area, BMI was no longer associated with creatinine clearance.

Conclusion: Among the anthropometric parameters, only an increase in WC was found to be independently related to 24-hour UAER. Although BMI was associated with creatinine clearance, this association was lost after creatinine clearance was corrected for body surface area.