[Dual-photon bone densitometry in dialyzed patients]

Area of Science:

• Nephrology
• Endocrinology
• Bone Metabolism

Background:

• Renal osteodystrophy diagnosis requires evaluating bone mineral content and turnover.
• Double-energy bone densitometry is accurate for bone mineral assessment.
• Standardization of skeletal sites for densitometry in renal osteodystrophy is lacking.

Purpose of the Study:

• To identify representative skeletal areas for bone densitometry in dialyzed patients.
• To assess the prevalence, severity, and regional distribution of bone demineralization.
• To correlate bone density with bone turnover markers.

Main Methods:

• Cross-sectional study of 45 dialyzed patients (24 male, 21 female) with 20-24 months of treatment.
• Whole-body bone densitometry with regional analysis (trunk, upper/lower extremities).
• Assessment of bone turnover using serum intact parathormone levels (low <50 pg/ml, normal 50-200 pg/ml, high >200 pg/ml).

Main Results:

• 58% of patients showed significant bone density reduction (Z-score <-1).
• Extremities were most affected (92%), particularly lower extremities (69%) and upper extremities (23%).
• Trunk involvement was less common (8%); these patterns were independent of bone turnover, sex, or age in women.

Conclusions:

• The diaphysis of long bones is a representative skeletal site for densitometry in patients undergoing regular dialysis.
• Bone demineralization is prevalent and predominantly affects peripheral sites in dialyzed patients.
• Bone turnover markers did not influence the regional pattern of bone density reduction.