PLoS ONE
Volume 10, Issue 10, 2015

Urban-rural differences in bone mineral density: A cross sectional analysis based on the Hyderabad indian migration study (Article) (Open Access)

Viljakainen H.T. , Ben-Shlomo Y. , Kinra S. , Ebrahim S. , Kuper H. , Radhakrishna K.V. , Kulkarni B. , Tobias J.H.*
  • a Musculoskeletal Research Unit, School of Clinical Sciences, University of Bristol, Bristol, United Kingdom, Children's Hospital, Helsinki University Central Hospital, University of Helsinki, Helsinki, Finland
  • b School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom
  • c Department of Non Communicable Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, United Kingdom
  • d Department of Non Communicable Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, United Kingdom, South Asia Network for Chronic Disease, Public Health Foundation of India, New Delhi, India
  • e Department of Clinical Research, London School of Hygiene and Tropical Medicine, London, United Kingdom
  • f National Institute of Nutrition, Hyderabad, India
  • g National Institute of Nutrition, Hyderabad, India
  • h Musculoskeletal Research Unit, School of Clinical Sciences, University of Bristol, Bristol, United Kingdom

Abstract

Background Fracture risk is rising in countries undergoing rapid rural to urban migration, but whether this reflects an adverse effect of urbanization on intrinsic bone strength, as reflected by bone mineral density (BMD), is currently unknown. Methods Lumbar spine (LS) and total hip (TH) BMD, and total body fat and lean mass, were obtained from DXA scans performed in the Hyderabad arm of the Indian Migration Study (54% male, mean age 49 years). Sib-pair comparisons were performed between rural-urban migrants (RUM) and rural non-migrated (RNM) siblings (N = 185 sib-pairs). Results In analyses adjusted for height, gender, age and occupation, rural to urban migration was associated with higher lumbar and hip BMD and greater predicted hip strength; ΔLS BMD 0.030 (0.005, 0.055) g/cm2, ΔTH BMD 0.044 (0.024; 0.064) g/cm2, Δcross-sectional moment of inertia 0.162 (0.036, 0.289) cm4. These differences were largely attenuated after adjusting for body composition, insulin levels and current lifestyle factors ie. years of smoking, alcohol consumption and moderate to vigorous physical activity. Further analyses suggested that differences in lean mass, and to a lesser extent fat mass, largely explained the BMD differences which we observed. Conclusions Rural to urban migration as an adult is associated with higher BMD and greater predicted hip strength, reflecting associated alterations in body composition. It remains to be seen how differences in BMD between migration groups will translate into fracture risk in becoming years. © 2015 Viljakainen et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Author Keywords

[No Keywords available]

Index Keywords

urban population body composition photon absorptiometry Absorptiometry, Photon lifestyle Life Style India physiology human risk assessment middle aged rural population controlled study Cross-Sectional Studies diagnostic imaging cross-sectional study Humans male urban rural difference female Fractures, Bone Article adult fat mass migration lean body weight Femur Neck Bone Density body fat bone strength femoral neck lumbar spine Lumbar Vertebrae lumbar vertebra
Link
https://www.scopus.com/inward/record.uri?eid=2-s2.0-84949207847&doi=10.1371%2fjournal.pone.0140787&partnerID=40&md5=d3ade0b589156dbc0f20bf0d2fbfba6a
DOI: 10.1371/journal.pone.0140787
ISSN: 19326203
Original Language: English