Determinants of changes in bone density: a 5-year follow-up study of adult male monozygotic twins

Association of alcohol and bone mineral density dependent on type of alcohol consumed

INTRODUCTION

Osteoporosis prevalence will increase in coming decades, with significant financial and economic implications. Whilst alcohol excess has significant detrimental impacts on bone mineral density (BMD), knowledge of low-volume consumption is inconsistent. Type of alcohol may mediate impact on BMD and warrants further investigation.

MATERIALS AND METHODS

Participants were drawn from the Florey Adelaide Male Aging Study, a cohort of community dwelling men from Adelaide, Australia (n = 1195). The final cohort (n = 693) provided information regarding alcohol consumption and undertook BMD scan at wave one (2002-2005) and wave two (2007-2010). Cross-sectional and longitudinal multivariable regression was performed for whole-body and spine BMD. To assess change in exposure over time, change in BMD was compared to change in covariates between waves.

RESULTS

Cross-sectionally, whole-body BMD was positively associated with obesity (p < 0.001), exercise (p = 0.009), prior smoking (p = 0.001), oestrogen concentration (p = 0.001), rheumatoid arthritis (p = 0.013) and grip strength (p < 0.001). No association was identified with volume of differing types of alcohol consumed. Spinal BMD was inversely associated with low-strength beer consumption (p = 0.003). The volume of alcohol consumed at Wave 1 did not predict change in whole-body or spinal BMD; however, increases in full-strength beer consumption between waves were associated with reduced spinal BMD (p = 0.031).

CONCLUSION

When consumed at quantities in the usual social range, alcohol was not associated with whole-body BMD. However, low-strength beer consumption was inversely related to spinal BMD.

Coffee consumption and risk of fractures: a systematic review and dose-response meta-analysis

PURPOSE

The data on the association between coffee consumption and the risk of fractures are inconclusive. We performed a comprehensive literature review and meta-analysis to better quantify this association.

METHODS

We identified all potentially relevant articles by searching MEDLINE, EMBASE, Cochrane Library, Web of Science, SCOPUS, and CINAHL (until February 2013). The keywords "coffee," "caffeine," "drink," and "beverage" were used as the exposure factors, and the keyword "fracture" was used as the outcome factor. We determined the overall relative risk (RR) and confidence interval (CI) for the highest and lowest levels of coffee consumption. A dose-response analysis was performed to assess the risk of fractures based on the level of coffee consumption.

RESULTS

We included 253,514 participants with 12,939 fracture cases from 9 cohort and 6 case-control studies. The estimated RR of fractures at the highest level of coffee consumption was 1.14 (95% CI: 1.05-1.24; I(2)=0.0%) in women and 0.76 (95% CI: 0.62-0.94; I(2)=7.3%) in men. In the dose-response analysis, the pooled RRs of fractures in women who consumed 2 and 8 cups of coffee per day were 1.02 (95% CI: 1.01-1.04) and 1.54 (95% CI: 1.19-1.99), respectively.

CONCLUSIONS

Our meta-analysis suggests that daily consumption of coffee is associated with an increased risk of fractures in women and a contrasting decreased risk in men. However, future well-designed studies should be performed to confirm these findings.