Sexual dimorphism in schoolchildren and its relation to nutritional status.

OYHENART EE; CESANI MF; QUINTERO F; ORDEN AB; TORRES MF; LUIS MA.

Anthropologie

Moravian Museum-Anthropo Institute

Año: 2006 vol. XLIV p. 229 - 234

0323-1119

To analyze if sexual dimorphism is modified by nutritional status (undernutrition or overweight-obesity) of individuals from the same population. If so, to determine which components or tissues are implied. Height, weight, arm circumference, and triceps and subscapular skinfolds were measured on 816 schoolchildren of Brandsen (Buenos Aires, Argentina) aged from 3 to 16, who were grouped in two categories: prepubertal and pubertal. Data were transformed to z-scores using NHANES I and II references. Prevalences of stunting and wasting were calculated by z-scores below ?2. Overweight were defined by BMI > 85th percentile. The sample was divided into four subsamples: normal, underweight, stunting and overweight. Data were processed by one way analysis of variance and Kruskall Wallis test. In normal prepubertal and pubertal children 78% of the variables showed sexual dimorphism. Sexual differences were inhibited both by chronic and acute undernutrition (45% in prepubertal and 34% in pubertal). In overweight prepubertal children sexual dimorphism was inhibited only in 11% of the variables. The remainder were even more dimorphic than normal children. At change, during pubertal period, sexual dimorphism was inhibited by about 56%. Both deficiencies and excess of nutrients interfere with the full expression of normal dimorphism based on gender, being male growth more affected than female growth. Although almost all tissues are implied in such modification of sexual dimorphism, the adipose tissue appears to be more sensitive to environmental stress. This study suggests that populations under nutrition transition -in which undernutrition coexists with obesity- may display a marked variation of sexual dimorphism.