The effect of economic status on height, insulin-like growth factor (IGF)-I and IGF binding protein-3 concentrations in healthy Turkish children

Abstract

Objectives: The effect of economic status (ES) on growth, insulin-like growth factor (IGF)-I and IGF-binding protein (IGFBP)-3 in healthy children is not well characterized. We aimed to study the interrelationship between height, weight, IGF-I, IGFBP-3, mid-parental height (MPH) and ES. Design/subjects: Eight hundred and fourteen healthy children (428 boys, 386 girls; age 3-18 years) were classified according to income of the families as low, middle and high. Standard deviation scores (SDSs) of height, weight, MPH, IGF-I and IGFBP-3 were compared between the groups. The combined effect of these parameters and ES on height SDS was investigated with complex statistical models. Results: There was a significant trend for height and weight SDSs to increase with higher income levels in boys, but not in girls. Body mass index (BMI) SDSs were similar in three groups. There was a general trend for MPH SDS to increase with income levels in both sexes. In boys, IGF-I SDS was significantly higher in high ES group than low ES. In girls, IGFBP-3 SDSs were significantly higher in high ES group than in middle ES group. For both genders, height SDS was highly correlated with weight SDS and moderately correlated with BMI SDS, MPH SDS and IGF-1 SDS. All correlations were significant and positive. Complex models showed that MPH (19%), IGF-I (13%) and ES (3%) in boys, and MPH (16%) and IGF-I (7%) in girls have significant contribution to height SDSs. Conclusions: ES per se, independent of overt malnutrition, affects height, weight, IGF-I and IGFBP-3 with some gender differences in healthy children. Influence of income on height and weight show sexual dimorphism, a slight but significant effect is observed only in boys. MPH is the most prominent variable effecting height in healthy children. Higher height and MPH SDSs observed in higher income groups suggest that secular trend in growth still exists, at least in boys, in a country of favorable economic development.

Puberty and Influencing Factors in Schoolgirls Living in Istanbul: End of the Secular Trend?

“…The effect of SES, a likely marker for better health and nutrition, is well illustrated in a study from India, where wealthy girls attained menarche ϳ3 years earlier than underprivileged girls. 15 It also is possible that the effect of SES on puberty may be related to BMI; a recent study 22 from Turkey reported that overweight and obesity were more common among children from higher SES families. Also in our study, the girls from low SES have BMI SD scores below the country average, whereas the girls from higher SES groups have BMI SD scores above the average.…”

The Insulin-Like Growth Factor System and Nutritional Assessment

“…In malnourished children, serum IGF-I correlates strongly with height SD score suggesting that it is a useful indicator of growth and nutritional status [57]. It has also been reported to correlate with economic status independently of overt malnutrition [70]. …”

Developmental stage‐dependent influence of environmental factors on growth of rural Sundanese children in West Java, Indonesia

“…The IGF-I level has been investigated in developed countries in relation to child growth, especially for clinical purposes (L€ ofqvist et al, 2001;Alberti et al, 2011;Isojima et al, 2012). To date, however, available data regarding IGF-I levels in developing countries among children whose growth is significantly retarded compared with children in developed countries (Jaruratanasirikul et al, 1999;Turan et al, 2007) are sparse. IGF-I concentrations are strongly age dependent, rising throughout childhood, peaking in adolescence and declining or plateauing thereafter (Juul et al, 1994;Xu et al, 2010).…”