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Article: Mitsuyo Kinjo, Soko Setoguchi, and Daniel H Solomon Bone Mineral Density in Adults with the Metabolic Syndrome: Analysis in a Population-based United States Sample J Clin Endocrinol Metab 2007; 0: jc.2007-0757v1 [Abstract]

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Metabolic Syndrome and Bone

Denise von Muhlen, Setareh Safii, Simerjot Jassal, Johan Svartberg, and Elizabeth Barrett-Connor   (11 September 2007)

Metabolic Syndrome and Bone 11 September 2007
Denise von Muhlen, Assistant Professor University of California, San Diego, Setareh Safii, Simerjot Jassal, Johan Svartberg, and Elizabeth Barrett-Connor Send letter to journal: Re: Metabolic Syndrome and Bone dvonmuhlen{at}ucsd.edu Denise von Muhlen, et al.	We read with interest the recent article by Kinjo et al. (1) who concluded that the metabolic syndrome was not associated with reduced bone mineral density (BMD) at the femoral neck in a large NHANES sample with 22% prevalence of metabolic syndrome. Kinjo et al. reported a positive association between metabolic syndrome with higher BMD at the femoral neck in multivariate analyses that was no longer present after stratification by BMI quintiles. We recently (May 2007) published a paper reporting the cross-sectional and longitudinal association of metabolic syndrome and its components with BMD and incident fractures in 417 men and 671 women from the Rancho Bernardo cohort (2). In agreement with Kinjo et al., we found that metabolic syndrome was associated with higher BMD at the femoral neck in men, but not in women. We also found that metabolic syndrome was associated with higher BMD at the total hip and at the lumbar spine in both sexes (total hip and lumbar spine were not examined in the NHANES paper). Like Kinjo et al., we also found that an increased number of metabolic syndrome components was associated with higher BMD at femoral neck, with significant associations in men, but not women. However, in contrast to Kinjo et al., we found that adjustment for BMI reversed most of the associations, such that in both sexes metabolic syndrome was associated with lower and not higher BMD at the femoral neck, and the number of metabolic syndrome components was associated with lower and not higher femoral neck BMD (P < 0.05 in men, non-significant in women). Our study also included fracture data; after 1-4 years of follow up, 2.9% of men and 4.5% of women experienced at least one non-vertebral fracture. After adjustments for age, BMI and other possible confounders, incident clinical fractures were 2.6 times (95% CI 1.2-5.4) more likely to occur in participants with metabolic syndrome compared to those without it. Sex-specific logistic regression models adjusted for age, BMI, estrogen use, exercise, calcium supplements, and alcohol intake showed that metabolic syndrome significantly increased the odds of incident fractures in women (OR = 3.76, 95% CI 1.27-11.13); a smaller, non-significant association was seen in men (OR = 2.48, 0.49-12.60). Taken together, these results suggest that the apparent association of metabolic syndrome with higher BMD is explained by the higher BMI of individuals with metabolic syndrome. Further research will be needed to clarify any effect of metabolic syndrome on BMD. References 1. Kinjo M, Setoguchi S, Solomon DH 2007 Bone Mineral Density in Adults with the Metabolic Syndrome: Analysis in a Population-based United States Sample. J Clin Endocrinol Metab. [Epub ahead of print] 2. von Muhlen D, Safii S, Jassal SK, Svartberg J, Barrett-Connor E 2007 Associations between the metabolic syndrome and bone health in older men and women: the Rancho Bernardo Study. Osteoporos Int. [Epub ahead of print]