Bone remodeling markers as lithogenic risk factors in patients with osteopenia-osteoporosis.

Abstract

To analyze the presence of phosphocalcic metabolism disorders in patients with osteopenia-osteoporosis without nephrolithiasis with respect to a control group. A cross-sectional study was conducted in patients with osteopenia-osteoporosis without nephrolithiasis (n=67) in lumbar spine or femur and in a control group (n=61) with no lithiasis or bone disorders. Blood bone markers, phosphocalcic metabolism, fasting urine, 24-h urine lithogenic risk factors, and densitometry were recorded in both groups. SPSS 20.0 was used for statistical analysis. In comparison with the controls, significantly higher blood calcium (9.27±0.36 vs. 9.57±0.38, p=0.0001), intact parathormone (45.6±14.9 vs. 53.8±18.9, p=0.008), and alkaline phosphatase (61.9±20.9 vs. 70.74±18.9, p=0.014) levels were found in patients with osteopenia-osteoporosis. In the 24-h urine test, citrate (1010.7±647.8 vs. 617.6±315.8, p=0.0001) and oxalate (28.21±17.65 vs. 22.11±16.49, p=0.045) levels were significantly lower in osteopenia-osteoporosis patients than in controls, with no significant difference in calcium (187.3±106.9 vs. 207.06±98.12, p=0.27) or uric acid (540.7±186.2 vs. 511.9±167.06, p=0.35) levels. Patients with osteopenia-osteoporosis had significantly higher levels of lithogenic risk factors associated with bone remodeling, including significantly increased β-crosslaps and osteocalcin values and higher β-crosslaps/osteocalcin ratios. Patients with osteopenia-osteoporosis without nephrolithiasis showed phosphocalcic metabolism disorders as well as lower urinary citrate and higher β-crosslaps/osteocalcin and fasting calcium/creatinine ratios, which would increase the risk of nephrolithiasis. Hence, prospective studies are warranted to evaluate the long-term risks.