Increased Serum Leptin Level Predicts Bone Mineral Density in Hemodialysis Patients

Background: Leptin acts through the adipose-bone axis to regulate bone mineral density (BMD). This study evaluated the relationship between BMD and serum leptin levels in patients on hemodialysis.

Methods: In this cross-sectional study including 98 hemodialysis patients, BMD was measured using dual energy X-ray absorptiometry of the lumbar vertebrae (L2-L4), and serum leptin levels were determined using an enzyme immunoassay.

Results: There were 25 (25.5%), 13 (13.3%), and 60 (61.2%) patients with osteopenia, osteoporosis, and normal BMD, respectively. Advanced age (=0.017); decreased body mass index (BMI, < 0.001); body height ( < 0.001); prehemodialysis body weight (BW, < 0.001); post-hemodialysis BW ( < 0.001); waist circumference ( < 0.001); and triglyceride (=0.015), albumin (=0.004), and leptin levels (=0.017) were associated with lower lumbar scores, whereas increased urea reduction rate (URR, =0.004) and fractional clearance index for urea (Kt/V, =0.004) were associated with lower lumbar scores. The multivariable forward stepwise linear regression analysis with adjustment for sex; age; body height; prehemodialysis BW; BMI; waist circumference; logarithmically transformed triglycerides (log-triglycerides), albumin, creatinine, and leptin (log-leptin) levels; URR; and Kt/V indicated that high serum level of log-leptin ( change = 0.184; < 0.001), increased prehemodialysis BW ( change = 0.325; =0.008), male sex ( change = 0.048; =0.001), young age ( change = 0.044; =0.012), and increased serum albumin level ( change = 0.017; =0.044) were significantly and independently associated with lumbar BMD.

Conclusions: Advanced age and female sex were associated with poor BMD, whereas increased BW, serum albumin, and leptin levels were positively associated with BMD in patients on hemodialysis.