Early risk factors for increased adiposity: a cohort study of African American subjects followed from birth to young adulthood

Abstract

Background:Obesity is an increasing concern in the United States. Effective prevention of obesity requires the risk factors to be well defined. African Americans have a high risk of obesity. Objective: The objective of this study was to identify risk factors, present at birth, for increased adiposity in adulthood in an African American population. Design: In this retrospective analysis of a prospective cohort study, anthropometric and socioeconomic variables were collected at birth. A representative sample of 447 African American subjects was followed up until young adulthood, when skinfold thickness was measured. Associations between the independent variables and increased adiposity (skinfold thickness above the 85th percentile) were explored by using unadjusted and adjusted analyses. Results: Three variables measured at birth were independently associated with adiposity in young adulthood, explaining 12% of the variance. The odds ratios (with 95% CIs) of these variables for increased adiposity were 2.7 (1.2, 6.2) for female sex, 4.0 (1.4, 11.2) for first-born status, and 1.15 (1.06, 1.25) for each unit increment in maternal prepregnancy body mass index (BMI; in kg/m 2 ). After adjustment for these variables, birth weight for gestational age and socioeconomic variables were not associated with adiposity. Conclusions: This cohort study of African American subjects was the first to identify first-born status as an independent risk factor for increased adiposity in adulthood in a US population. The results of the study strengthen previous reports of the effect of female sex and maternal BMI on adulthood obesity. Identification of risk factors early in life may help target prevention toward high-risk children and allow healthy lifestyles to be established before the onset of obesity.

Epidemiology of overweight and obesity among school children and adolescents in three provinces of central Italy, 1993–2001: study of potential influencing variables

“…According to our study, being a firstborn was the aspect that proved to affect overweight or obese status, as there was no difference in comparison to being a single child. Association of firstborn status and risk of obesity has been reported by other studies (Stettler et al, 2000), and has been attributed to potential factorsFnot yet identified wellFconnected to gestational period, postnatal period or both.…”

Parental influence on children's early eating environments and obesity risk: implications for prevention

“…Experimental studies in humans are rare, but observational studies in humans have shown that gestational diabetes or excessive gestational weight gain is associated with fetal overnutrition and elevated birth weight, which predict later offspring obesity; elevated maternal pre-pregnancy weight status is also positively associated with higher birth weight and later obesity risk. [33][34][35][36][37] Cole and colleagues 38 describe two ways to end up with an overweight phenotype: by starting out large or by growing fast. Links between fetal overnutrition and obesity risk take on particular significance in countries where obesity is prevalent among adult women of childbearing age, as in the United States, where two-thirds of adults are overweight or obese, 39 and gestational weight gain guidelines are frequently exceeded.…”

Developmental and epigenetic pathways to obesity: an evolutionary-developmental perspective

“…For example, fetal growth is impaired in those who are born to smaller mothers, to primigravida, or to very young mothers; this is sometimes termed 'maternal constraint'. Thus, first-born children may be at particular risk 40 and demographic changes that have led to a decrease in family size mean that the proportion of first-born children in the population has increased. Similarly, there is evidence that variation in maternal nutrition within the usual range of intakes of Western women can affect fetal physiology, size at birth and subsequent endothelial function in childhood.…”

“…The model can explain a number of apparently puzzling features of the demography of obesity, such as the rapid appearance in populations undergoing the nutrition transition 72 and the higher incidence in first-born children. 40 A particular concern arises from observations that for cultural and socioeconomic reasons women even in developed countries may not receive optimal nutrition during pregnancy. In Japan, birth weight is falling in parallel with a reduction in maternal weight gain, in part because of an unsubstantiated belief that dietary restriction of weight gain improves pregnancy outcome.…”