Bone Abstracts

Objective: The aim of this study was to assess the relationship between renal function (estimated glomerular filtration rate (eGFR) using Cockcroft–Gault (CG) equation and modification of diet in renal disease (MDRD), respectively), bone mineral density (BMD) and both arterial stiffness in Korean postmenopausal women.

Materials and methods: From January 2008 until December 2010, among the person who got medical examinations including bone densitometry in one university hospital health promotion center, 252 postmenopausal women were included after excluding thyroid disease, history of malignant tumor, or taking medicines for osteoporosis over 6 months. The renal functions according to CG equation and MDRD equation were calculated. Renal function was categorized by the criteria of the Kidney Disease Outcomes Quality Initiative Committee. BMD was measured in spine, femur and total hip by dual-energy X-ray absorptiometry. We measured the pulse wave velocity (PWV) to assess arterial stiffness. Standard statistical analyses were performed among the three subjects.

Results: Of the 252 women, ranging in age from 45 to 75 years old with mean age of 55.4±5.8 years, who had eGFR ≥ 90, 69–89, and 30–59 ml/min were 10 (4.0%), 18 (71.8%), and 61 (24.2%), respectively. The mean eGFR (CG) was 68.3±12.1 ml/min and mean arterial stiffness was 1349.3±165.8 cm/s. The BMD for the spine, femur and total hip were 0.90±0.12, 0.67±0.09, 0.77±0.96 g/cm², respectively. By using simple linear regression analysis, age, height, body weight, eGFR and arterial stiffness were significantly associated with BMD for the three aforementioned anatomic sites (P<0.05, each). When multiple regression analyses were applied, age and body weight still had significant associations with BMD at three different anatomic sites (P<0.0001). The renal function according to CG had significant associations with BMD in the spine (P=0.0021), femur (P<0.0001) and total hip (P< 0.0001). While a significant association of eGFR (MDRD) with BMD remained in the femur (P=0.0413) but not in the spine (P=0.7768) and total hip (P=0.3076). Increased arterial stiffness as assessed with PWV is associated with reduced BMD in the spine (r=−0.129, P=0.041), femur (r=−0.259, P<0.0001) and total hip (r=−0.240, P=0.0001).

Conclusions: This study indicates that a decline in renal function may be associated with BMD and increased arterial stiffness in Korean postmenopausal women.

Keywords: Renal function, Bone mineral density, Arterial stiffness, Association, Postmenopause.