Genetic admixture and body composition in Puerto Rican adults from the Boston Puerto Rican osteoporosis study

Authors: NOEL, SABRINA - University Of Massachusetts; AREVALO, SANDRA - University Of Massachusetts; SMITH, CAREN - Jean Mayer Human Nutrition Research Center On Aging At Tufts University; Lai, Chao Qiang; DAWSON-HUGHES, BESS - Jean Mayer Human Nutrition Research Center On Aging At Tufts University; ORDOVAS, JOSE - Jean Mayer Human Nutrition Research Center On Aging At Tufts University; TUCKER, KATHERINE - University Of Massachusetts

Submitted to: Journal of Bone and Mineral Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/30/2016
Publication Date: 9/14/2016
Citation: Noel, S.E., Arevalo, S., Smith, C.E., Lai, C., Dawson-Hughes, B., Ordovas, J.M., Tucker, K.T. 2016. Genetic admixture and body composition in Puerto Rican adults from the Boston Puerto Rican Osteoporosis Study. Journal of Bone and Mineral Research. doi: 10.1007/s00774-016-0775-6.

Interpretive Summary: Low bone density reflects a loss and weakening of bone. This condition is called osteoporosis, and it greatly increases the risk of fractures. Like many physical traits, bone density is determined by a combination of environmental and genetic factors. Understanding the determinants of bone density can help to identify individuals at greater risk of osteoporosis to better prevent disease. For example, osteoporosis risk has been reported to differ across racial and ethnic groups. Puerto Ricans, who are characterized by three ancestries (European, African, and American Indian,) are an under-studied group that experiences health disparities for several chronic diseases. We aimed to investigate how ancestry was related to bone density in a population of older Puerto Ricans living in the Boston, MA area. In this group, we observed that European ancestry was associated with lower bone density at two locations at the hip, which are important fracture sites. American Indian ancestry was also associated with lower density at one of the same hip locations after other factors (age, sex, and body weight) were taken into account. In contrast, African ancestry was associated with a higher bone density at both hip locations. Our findings are consistent with existing research demonstrating greater risk for low bone density in individuals of European and Native American ancestries and greater protection for individuals of African ancestry. This work contributes to our understanding of the high prevalence of chronic disease experienced by the Puerto Rican population and has public health implications for other ethnic minority groups. Future research is needed to consider interactions between genetic ancestry and environmental factors, as these may provide more individualized approaches for disease prevention.

Technical Abstract: Population admixture plays a role in the risk of chronic conditions that are related to body composition; however, our understanding of these associations in Puerto Ricans, a population characterized by multiple ancestries, is limited. This study investigated the relationship between genetic admixture and body composition in 652 Puerto Ricans from the Boston Puerto Rican Osteoporosis Study. Genetic ancestry was estimated from 100 ancestry-informative markers. Body composition measures were obtained from dual-energy X-ray absorptiometry. Multivariable linear regression analyses examined associations between bone mineral density (BMD) of the hip and lumbar spine and percent fat mass and lean mass with genetic admixture. In Puerto Ricans living on the US mainland, European ancestry was associated with lower BMD at the trochanter (P = 0.039) and femoral neck (P = 0.01), and Native American ancestry was associated with lower BMD of the trochanter (P = 0.04). African ancestry was associated with a higher BMD at the trochanter (P = 0.004) and femoral neck (P = 0.001). Ancestry was not associated with percent fat mass or lean mass or waist circumference. Our findings are consistent with existing research demonstrating inverse associations between European and Native American ancestries and BMD and positive relationships between African ancestry and BMD. This work contributes to our understanding of the high prevalence of chronic disease experienced by this population and has implications for other ethnic minority groups, particularly those with multiple ancestries. Future research should consider interactions between ancestry and environmental factors, as this may provide individualized approaches for disease prevention.