Circulating leptin and bone mineral density in rheumatoid arthritis.
OBJECTIVE
To evaluate the association between circulating leptin and bone mineral density (BMD) in patients with rheumatoid arthritis (RA).


METHODS
One-hundred thirty postmenopausal women with RA were assessed for body mass index (BMI), disease characteristics, history of drug use, rheumatoid factor, and erythrocyte sedimentation rate (ESR). BMD (g/cm(2)) was determined in the hip and spine by DEXA. Serum leptin concentrations were measured by ELISA. Spearman's correlation coefficients (rho) were determined between BMD and leptin and other variables. A multiple regression analysis was used to adjust for confounders.


RESULTS
Patients' serum leptin levels varied widely (range 2-128 ng/ml). Thirty-three patients (25%) had osteoporosis. Higher levels of leptin correlated significantly with BMD in the lumbar spine (rho = 0.17, p = 0.04) and total hip (rho = 0.21, p = 0.01). The variables that were negatively correlated with BMD were age, duration of menopause, and ESR. After adjustment for confounders, leptin was no longer associated with BMD. In the multivariate model, factors that remained associated with BMD in the total hip were age (p = 0.021) and BMI (p = 0.003); and the factors that remained associated with BMD in the lumbar spine were BMI (p = 0.03) and ESR (p = 0.01).


CONCLUSIONS
No relevant association was found between circulating leptin levels and BMD in patients with RA in this cross-sectional study. Followup studies are needed to evaluate whether abnormal leptin levels confer a risk for fractures due to osteoporosis.
Aguilar-Chavez
Erika A
EA
Department of Internal Medicine, Hospital General Regional, Guadalajara, Mexico.
Gamez-Nava
Jorge I
JI
Lopez-Olivo
Maria A
MA
Galvan-Melendres
Silvia
S
Corona-Sanchez
Esther G
EG
Loaiza-Cardenas
Carlos A
CA
Celis
Alfredo
A
Cardona-Muñoz
Ernesto G
EG
Gonzalez-Lopez
Laura
L
D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000097:blood*; D015519:Bone Density; D003430:Cross-Sectional Studies; D006801:Humans; D020738:Leptin / Q000097:blood*; D008875:Middle Aged; D010024:Osteoporosis / Q000097:blood; D018709:Statistics, Nonparametric
D020738:Leptin