Increased serum osteoprotegerin levels associated with decreased bone mineral density in familial Mediterranean fever.
Familial Mediterranean fever (FMF) has episodic or subclinical inflammation that may lead to a decrease in bone mineral density (BMD). The aim of this study was to evaluate the effect of FMF on bone metabolism and to investigate the factors that can influence bone metabolism, such as body mass index (BMI), mutations in Mediterranean fever (MEFV) gene, osteoprotegerin (OPG), leptin and inflammatory cytokines, including interleukin (IL)-1beta, IL-6 and tumor necrosis factor-alpha (TNF-alpha). OPG, a soluble protein produced by osteoblasts, favors increased bone mass. Leptin may influence bone metabolism by acting on differentiated osteoblasts, having anabolic effects on bone. Thirty-one FMF patients in attack-free period (12 females and 19 males; mean age 31.4 +/- 9.3 years) and 18 healthy controls (11 females and 7 males; mean age 34.6 +/- 9.5 years) were compared according to the above parameters. BMD (g/cm(2)) and standard deviation scores (Z-score) were measured at the lumbar spine L(1)-L(4) (BMD-L(1-4)) and proximal femur by dual X-ray absorptiometry. Osteopenia is defined as a Z-score between -1 and -2.5 and osteoporosis is equal or below -2.5. FMF patients showed statistically significant reduction in BMD-L(1-4) and Z-score-L(1-4). Moreover, serum OPG concentration was significantly elevated in FMF patients. In contrast, MEFV gene mutations, leptin and the inflammatory cytokines did not differ between the patient and control groups. In conclusion, BMD was decreased and OPG was increased in our FMF patients. The high OPG levels may reflect a preventive mechanism against bone loss; namely, OPG might protect the FMF patients from excessive osteoporosis.
Department of Internal Medicine, Afyon Kocatepe University School of Medicine, Afyonkarahisar, Turkey. serefyuksel@msn.com
Seref
S
Yuksel
Hale
H
Samli
Mehmet
M
Colbay
Umit
U
Dundar
Gursel
G
Acarturk
Serap
S
Demir
Tulay
T
Koken
Orhan Cem
OC
Aktepe
Vural
V
Kavuncu
Mustafa
M
Solak
D015502:Absorptiometry, Photon; D000328:Adult; D000704:Analysis of Variance; D015992:Body Mass Index; D015519:Bone Density / Q000502:physiology*; D001842:Bone and Bones / Q000378:metabolism; D016207:Cytokines / Q000097:blood; D003598:Cytoskeletal Proteins / Q000235:genetics; D004797:Enzyme-Linked Immunosorbent Assay; D010505:Familial Mediterranean Fever / Q000097:blood* / Q000235:genetics / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D009154:Mutation / Q000235:genetics; D053244:Osteoprotegerin / Q000097:blood* / Q000378:metabolism; D000071198:Pyrin; D018709:Statistics, Nonparametric
D016207:Cytokines; D003598:Cytoskeletal Proteins; C000604192:MEFV protein, human; D053244:Osteoprotegerin; D000071198:Pyrin