Determinants of bone mineral density in young Australian women; results from the Safe-D study.

The study aimed to explore determinants of bone parameters in young women. Most bone parameters were associated with height and lean mass. Bone parameters were not associated with vitamin D status. Future research should address whether interventions aimed at improving lean mass are beneficial to bone health in young women. INTRODUCTION: The implementation of prevention strategies during young adulthood may be crucial for osteoporosis prevention in later life, yet literature examining the determinants of bone health in premenopausal women is limited. We aimed to assess determinants of bone health, including serum 25-hydroxyvitamin D (25OHD), in females aged 16-25 years, living in Victoria, Australia, recruited through Facebook advertising. METHODS: Serum 25OHD was measured by liquid chromatography-tandem mass spectrometry and bone health was measured using dual-energy X-ray absorptiometry (DXA) and peripheral quantitative computed tomography (pQCT) in 326 participants. RESULTS: Mean (± standard deviation) serum 25OHD was 69 ± 28 nmol/L and the prevalence of vitamin D deficiency (serum 25OHD <50 nmol/L) was 26%. Seven percent of participants (n = 23) reported taking a vitamin D supplement. Two percent of participants had low lumbar spine bone mineral density (Z-score <-2.0), 5% at the hip and 7% at the femoral neck. Serum 25OHD levels were not associated with DXA bone parameters, nor with pQCT bone parameters. Most bone parameters were positively associated with height and lean mass. CONCLUSION: Vitamin D status was not associated with bone health in young women in the current study. Our findings suggest that targeting other modifiable factors, such as lean body mass, is likely to be beneficial to bone health in young women. Longitudinal studies examining the association between vitamin D status and bone health in young women are necessary to confirm our findings. In addition, whether raising 25OHD levels is advantageous for young women's bone health is yet to be determined.

The association between inflammation, obesity and elevated blood pressure in 16-25-year-old females.

There is evidence to show an association between inflammation, obesity and elevated blood pressure. However, there is limited data for this relationship in adolescent females. We aimed to investigate the association between high sensitivity C-reactive protein (hs-CRP) and elevated blood pressure in young Australian females. Women aged 16-25 years living in Victoria were randomly recruited via targeted Facebook advertising. Socio-demographic information was collected via a web-based questionnaire. Anthropometric and blood pressure measurements were conducted by trained staff. Hs-CRP was assessed using the Abbott Architect assay. The demographic data were collected from 639 females (mean ±s.d. age: 22±3). The blood pressure data were available for 502 participants. Approximately 28% had elevated blood pressure (defined by a blood pressure reading ⩾120-139/80-89 mm Hg for adults and >90th and <95th percentiles for age, sex and height for adolescents). Approximately 24% had hs-CRP >3.0 mg l-1 and 30% were overweight or obese. In multivariable logistic regression analyses, obese females (OR: 5.5, 95% CI: 2.4-12.5, P<0.001) were more likely to have elevated blood pressure compared with those with a body mass index (BMI) in the normal range. Elevated hs-CRP levels were associated with an increased odds of elevated blood pressure (OR: 3.4, 95% CI: 1.8-6.3, P<0.001). However, this association was no longer significant after adjustment for BMI. Findings from this study demonstrate that hs-CRP and obesity are associated with elevated blood pressure in young females. Thus, our findings may promote further research into the underlying mechanisms of these associations and related long-term health risks.