Background: Low bone mineral density (BMD) predisposes to os-teoporosis and elevated risk of fractures. Osteoprotegerin is a soluble molecule associated to metabolism of bone tissue with inhibition of osteoclast-differentiation. Several studies determined the relation among polymorphisms in osteoprotegerin gene and low BMD, but the results are contradictory, so an evaluation about these polymorphisms is necessary. This study carried out a meta-analysis to four polymor-phisms in osteoprotegerin gene (A163G, G1181C, T950C, T245G). Methods: A search in literature was made to identify studies with relevant information. The data was extracted by two investigators independently, following a standardized form. The statistical software Review Manager version 5.2 was used to calculation of heterogeneity (I²), Odds Ratio (OR) and Funnel plots with P<0.05. Results: Nineteen papers with twenty-one eligible studies with 5,120 patients and 4,386 controls were identified. G allele was associated to case group in A163G, G1181C and T245G polymorphisms (OR = 1.27, 95% CI 1.10, 1.46, P = 0.0010; OR = 1.25, 95% CI 1.14, 1.37, P < 0.00001; OR = 1.24, 95% CI 1.05, 1.48, P = 0.01, respectively). In T950C polymorphism, T allele neither C allele was associated to risk of bone low mineral density. No bias of publication was found in this analysis. Rerefences 1. Gnudi S, Sitta E, Fiumi N: Relationship between body composition and bone mineral density in women with and without osteoporosis: relative contribution of lean and fat mass. J Bone Miner Metab 2007, 25(5):326. 2. Jian WX, Long JR, Li MX, Liu XH, Deng HW: Genetic determination of variation and covariation of bone mineral density at the hip and spine in a Chinese population. J Bone Miner Metab 2005, 23(2):181-185. 3. Hussien YM, Shehata A, Karam RA, Alzahrani SS, Magdy H, El-Shafey AM: Polymorphism in vitamin D receptor and osteoprotegerin genes in Egyptian rheumatoid arthritis patients with and without osteoporosis. Mol Biol Rep 2013, 40:3675-3680. 4. Panach L, Mifsut D, Tarín JJ, Cano A, García-Pérez MÁ: Replication study of three functional polymorphisms associated with bone mineral density in a cohort of Spanish women. J Bone Miner Metab 2014, 32(6):691-698. 5. Horst-Sikorska W, Kalak R, Wawrzyniak A, Marcinkowska M, Celczynska-Bajew L, Slomski R: Association analysis of the polymorphisms of the VDR gene with bone mineral density and the occurrence of fractures. J Bone Miner Metab 2007, 25(5):310-319. 6. Yu F, Huang X, Miao J, Guo L, Tao D: Association between osteoprotegerin genetic variants and osteoporosis in Chinese postmenopausal women. Endocr J 2013, 60(12):1303-1307. 7. Nakashima T, Takayanagi H: Osteoclasts and the immune system. J Bone Miner Metab 2009, 27(5):519-529. 8. Wu ZZ, Liu M: The effect of low-body weight combined with T149C and A163G polymorphism of osteoprotegerin promoter region on osteoporosis. Chin J Geriatr 2006, 25:645-650. 9. Shui MM, Na SP, Xie RJ, Wang MG, Mu SH: Relationship between the polymorphisms of T149C and T950C in osteoprotegerin gene and the...