Low Birth Weight Does Not Predict the Ontogeny of Relative Leg Length of Infants and Children: An Allometric Analysis of the NHANES III Sample Barry Bogin 1 * and Jack Baker 2 1 School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, Leicestershire LE11 3TU, UK 2 Geospatial and Population Studies and Department of Anthropology, University of New Mexico, MSC063510, Albuquerque, New Mexico 87131 KEY WORDS perinatal health; developmental origins of health and disease; anthropometry; infancy; childhood ABSTRACT Previous research links both low birth weight (LBW) and relative leg length (RLL) to a similar set of adult pathologies, including type II diabetes, coro- nary vascular disease, and some cancers. Historically, LBW has been frequently used as a broad indicator of the quality of the intrauterine environment, while RLL has been considered a sensitive measure of childhood environmental quality. While these observations have been taken to suggest that these measures reflect inde- pendent exposures at different life-stages, their mutual association with a similar set of later pathologies makes this assumption less certain than it may have previ- ously seemed. Nationally representative data from the Third National Health and Nutrition Examination Sur- vey (NHANES III) are used to test the hypothesis that LBW predicts reductions in the development of leg length relative to stature. After controls for important socioeconomic exposures that might confound measure- ment of such a relationship, we find statistical and bio- logical evidence that variation in birth weight and vari- ation in the development of leg length relative to stat- ure (RLL) are independent. The results suggest that these two measures may represent independent infor- mation on prenatal and postnatal environmental qual- ity. Am J Phys Anthropol 000:000–000, 2012. V V C 2012 Wiley Periodicals, Inc. This article address the question, are low birth weight (LBW) and short leg length relative to total stature cau- sally related? This question is important because both LBW and short relative leg length (RLL) are linked with a variety of adult health problems. Both LBW and short RLL are considered to be due to early-life exposure to adverse environments. An accumulating body of evidence suggests stressors experienced during critical periods of early-life development, including the prenatal, infant, and childhood stages of growth, adversely alter physiol- ogy throughout the life-course (Barker, 1993; Cameron and Demerath, 2002; Gluckman and Hanson, 2005; Kuzawa and Quinn, 2009; Kuzawa and Sweet, 2009). Research in this area is commonly referred to as the De- velopmental Origins of Health and Disease. Over the last decade, a number of studies have sug- gested relationships between various measures of RLL and a number of pathological outcomes including type II diabetes and other insulin resistance-related diseases, obesity, hypertension, heart disease, stroke, and some cancers (Smith et al., 2001; Gunnell et al., 2003; Langen- berg et al., 2003; Ferrie et al., 2006; Bogin and Varela- Silva, 2010). Some studies link adult leg length of women to birth weight of their offspring (Lawlor et al., 2003; Martin et al., 2004). This body of evidence appears to war- rant the use of RLL as a retrospective measure of child- hood environments; however, previous research linking LBW to a nearly identical suite of adult physiological phenotypes and pathological risks may suggest a more complex picture (Barker, 1993; Rich-Edwards, 1997; Forsen et al., 2000; Frisancho et al., 2001; Bogin et al., 2002; Cameron and Demerath, 2002; Wadsworth et al., 2002; Malina et al., 2004; Yajnik, 2000, 2004; Asao et al., 2006; Frisancho, 2007; Baker et al., 2008; Kuzawa et al., 2007; Kuzawa and Quinn, 2009; Kuzawa and Sweet, 2009; Bogin and Varela-Silva, 2003, 2010). LBW is certainly one outcome of an adverse prenatal environment. It is highly likely that short RLL reflects exposure to adverse conditions during childhood. The pe- riod of life between birth and 7 years of age encom- passes the human life history stages of infancy and childhood: stages of rapid post-natal growth, motor de- velopment, and cognitive-emotional maturation (Bogin, 1999). During infancy and childhood, the legs grow abso- lutely faster than most other segments of the body (Scammon, 1930; Leitch, 1951). On average, under good conditions for growth, at ‘‘... birth, the lower limbs rep- resent 23% of their adult length; at 1 year of age they represent 35% and, at 10 years, 77%’’ (Tardieu, 2010 p. 174). Any insult experienced during the infancy and childhood stages, such as inadequate nutrition, serious illness, emotional trauma, or excessive physical labor, is likely to inhibit leg growth. This makes RLL a plausible indicator for the quality of life between birth and age 10 years. Indeed, a growing body of research makes use of *Correspondence to: Barry Bogin. E-mail: b.a.bogin@lboro.ac.uk Received 12 June 2011; accepted 1 March 2012 DOI 10.1002/ajpa.22064 Published online in Wiley Online Library (wileyonlinelibrary.com). V V C 2012 WILEY PERIODICALS, INC. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 000:000–000 (2012)