Bone health of Bangladeshi mother–daughter pairs resident in the UK

2019-01-24T12:09:26Z (GMT) by Diane Harper
Osteoporosis, characterised by low bone mineral density (BMD) and increased risk of bone fracture, constitutes a high socio-economic cost worldwide and is predicted to rise further in the future due to the ageing population. Asians are generally reported as having shorter stature, lower BMD and lower fracture risk (despite lower BMD) than people of European origin. There is evidence that lower BMD in South Asians (SA) is associated with smaller skeletal size, whilst possible explanations for their lower fracture risk include smaller body size and stronger hip structure. Migration Theory predicts that migrants from poor income countries to higher income countries increase in height over subsequent generations, as a consequence of a healthier environment in the host country. If this is the case for UK SA, then it would suggest that their BMD and some hip geometry dimensions (markers for fracture risk) would increase in parallel with increased height i.e. skeletal size. My study thus aimed to evaluate intergenerational differences in SA mother-daughter dyads, and differences related to place of birth, as well as confirming previous studies that ethnic differences between SA and Europeans could be explained by skeletal size. My study focussed on a specific UK SA group, the Bangladeshi (BD) community. The study predictions were: 1) differences in bone mass and hip geometry dimensions between BD and indigenous British (IB) women would be associated with skeletal size, 2) BD daughters (born in UK or migrated at a younger age) would be taller, with greater bone mass and hip geometry dimensions, than their mothers (migrated at older age), and 3) BD daughters born in the UK would be taller, with greater bone mass and hip geometry dimensions, than BD daughters born in Bangladesh. Data on these measurements, along with sociodemographic, early life environment and reproductive variables, were collected from Bangladeshi (BD) and indigenous British (IB) mother-daughter pairs. Study results confirmed previous evidence that lower BMD in Asians compared to Europeans is associated with skeletal size, but the other two predictions could not be adequately tested, due to limitations of the data set including small sample size. UK-born BD daughters appeared to have greater height, but lower BMD, than BD-born daughters, contrary to the usual association of skeletal size with BMD, and might suggest that UK-born BD daughters have a more gracile skeletal frame than BD-born daughters. This agrees with previous reports that populations in higher income countries are becoming more gracile with increasing sedentism and lower physical activity, meriting further study. My study provides data on an under-researched area (bone status in the UK BD community) and hopefully will provide a useful platform for future research.