Bone health and dietary, lifestyle and anthropometric factors in urban dwelling South Asians ( n 2438): data from the UK Biobank cohort

Abstract

Background: There is an urgent need for large scale research to identify modifiable risk factors associated with low bone mineral density (BMD) in ethnic minority groups; research to date has been very limited. Objective: In this study we investigate the association between BMD, as estimated from heel bone ultrasound attenuation (BUA; Sahara Heel Ultrasound, Hologic, USA) and dietary, lifestyle and anthropometric factors in UK South Asians. Methods: The UK Biobank is a large, ongoing UK-wide cohort with data on >500,000 individuals, aged 40-69 years, recruited from 2006-2010. Our analysis uses data from n 2438 South Asians (n 1079 females, n 1359 males; n 114 Bangladeshi, n 1625 Indian and n 699 Pakistani) who had a baseline heel BUA measurement. Mean (+/-SD) for age was 53+/-8 years and for Body Mass Index (BMI) was 27(5) kg/m2. Results: Partial correlations, adjusted for age, or chi-square tests (as appropriate) were undertaken to assess the association between heel BMD and a range of anthropometric and demographic variables. A Bonferroni adjusted P value cut-off for statistical significance of P<0.002 was used (n=33 tests). For brevity, only statistically significant results are reported here. In females, there was a positive partial correlation between gross household income and heelBMD (r=0.17 P<0.001 n 752). Inmales, there was a positive partial correlation between BMI and heel BMD, (r=0.07 P<0.001 n 1349). Discussion and Conclusion: Our results suggest that having a lower income (females) or a lower BMI (males), are associated with lower heel BMD. Western dwelling South Asians with these particular characteristics may benefit from public health interventions to improve bone health. This is the first analysis to date assessing the association between heel BUA, dietary, lifestyle and anthropometric factors in a large UK South Asian cohort. We are now conducting further work using more clinically relevant measures of bone health (e.g. hip, wrist and spine BMD) in this cohort. This research has been conducted using the UK Biobank Resource under application number 15168.