Heritability of obesity-related traits among Nigerians, Jamaicans and US black people.
OBJECTIVE
The mean values for anthropometric traits vary across population groups and this variation is clearly determined for the most part by the environment. The familiarity of anthropometric traits also varies in reports from different populations, although this variation has not been shown to follow a consistent pattern. To examine whether heritability is influenced by socio-cultural factors, we conducted a cross-cultural study of populations of the African diaspora.


METHODS
Data were collected on 1868 family members from Nigeria, 623 from Jamaica and 2132 from metropolitan Chicago, IL, USA.


METHODS
Height and weight were measured and body mass index (kg/m(2)) calculated. Fat-free mass, fat mass and percentage body fat were estimated using bioelectrical impedance analysis. Plasma leptin concentrations were also measured. The proportion of variance attributable to additive genetic and non-shared environmental components was estimated with the maximum likelihood variance decomposition method.


RESULTS
Mean values for all anthropometric traits increased along the socio-cultural gradient, and obesity increased from 5% in Nigeria to 23% in Jamaica and 39% in the USA. Within populations the relationships among traits both within individuals and within families were highly consistent. Heritability estimates for weight, body mass index, fat mass and percentage body fat were approximately 50% for all groups. Heritability for height was lower in Nigeria (62%) than in Jamaica (74%) or the US (87%).


CONCLUSIONS
The familial patterns of body size and energy storage appear to be consistent in these genetically related populations across a wide range of environmental conditions.
Luke
A
A
Department of Preventive Medicine and Epidemiology, Loyola University School of Medicine, Maywood, Illinois 60153, USA. aluke@luc.edu
Guo
X
X
Adeyemo
A A
AA
Wilks
R
R
Forrester
T
T
Lowe
W
W
Comuzzie
A G
AG
Martin
L J
LJ
Zhu
X
X
Rotimi
C N
CN
Cooper
R S
RS
D000328:Adult; D000886:Anthropometry; D044383:Black People; D001824:Body Constitution / Q000208:ethnology* / Q000235:genetics; D015992:Body Mass Index; D003431:Cross-Cultural Comparison; D017097:Electric Impedance; D004777:Environment; D005260:Female; D006801:Humans; D007563:Jamaica / Q000208:ethnology; D020738:Leptin / Q000097:blood*; D008297:Male; D009549:Nigeria / Q000208:ethnology; D009765:Obesity / Q000208:ethnology / Q000235:genetics; D014481:United States / Q000208:ethnology; D001741:Black or African American
D020738:Leptin