Does metabolic syndrome increase the risk of fracture? A systematic review and meta-analysis

Summary Metabolic syndrome is of increasing concern globally. The aspects of this disease and its interaction with other morbidities should be discussed in detail. By investigating the effects of metabolic syndrome on the bone fracture rate, we have shown a protective role for metabolic syndrome in the male population. Purpose There is controversy on the effects of metabolic syndrome on bone health and fracture risk. This systematic review and meta-analysis reappraises the literature on the subject and quantitatively evaluates the fracture risk in individuals with metabolic syndrome. Methods PubMed, Embase, Web of Science, and Scopus were searched for all relevant articles. Studies were selected if they included the rate of any type of fracture in individuals with metabolic syndrome. Non-English studies, review articles, case reports, and editorials were excluded. The titles and abstracts were screened to identify relevant studies and the data was extracted from these. The data were analyzed to determine the estimated effect at a 95% confidence interval. Publication bias was assessed using the Egger’s test, and funnel plots were drawn. The heterogeneity of the results was determined according to I 2 statistics. Results Of the 3141 articles from the initial search, 20 studies were selected for review and included 13 cross-sectional and seven cohort studies. A meta-analysis of all studies showed no association between metabolic syndrome and fractures across the entire population (HR = 0.954; p = 0.410). However, separate analysis of the cohort studies showed a decreased risk over the entire population (HR = 0.793; p = 0.000) and in males (HR = 0.671; p = 0.000), but not in females (HR = 1.029; p = 0.743). Conclusion This systematic review and meta-analysis showed that the current literature suggests that metabolic syndrome is a protective factor for bone fractures in males but has no net effect on fractures among females.