Assessment of linear growth of affluent urban Pakistani adolescents according to CDC 2000 references

The appropriateness of using international reference data for assessing growth of children and adolescents from developing countries has been debated. If the growth performance in at least those sections of the society that may be considered affluent has reached the levels represented by the international reference, the case for adoption of the NCHS reference would be strong. Findings from studies in younger children indicate appropriateness of these standards but data from older children are lacking.

The study aimed to compare the linear growth of affluent Pakistani adolescents living in Karachi with the NCHS reference so as to assess the appropriateness of using these standards for assessing the growth status of Pakistani adolescents.

Data were collected from 876 girls and 819 boys aged 10-15 years studying in well known and established affluent urban public schools in Karachi. A portable stadiometer (Minimeter by CMS, London) was used for measuring heights. Heights were compared using the United States Center for Disease Control (CDC 2000) reference values to assess growth status.

The mean ages of boys and girls were 12.82 and 12.63, respectively. Mean Height for Age Z score (HAZ) (-0.02) was very close to CDC 2000 reference values but the growth pattern was not similar. Younger children were relatively taller and the older children were shorter than CDC standards. Mean HAZ scores for 10, 11, 12, 13, 14 and 15-year-old boys and girls were 1.12 and 1.03, 0.54 and 0.55, 0.47 and 0.26, 0.29 and -0.21, -0.08 and -0.64, -0.19 and -0.53, respectively. The mean HAZ for boys (0.12) was slightly higher and that for girls slightly lower (HAZ = -0.14) than the reference population. Even among the relatively affluent group of children studied HAZ scores increased with relative socio-economic status.

Although in terms of averages for 10-15-year-old boys and girls the height status was not very different from CDC standards, the growth curves of Pakistani children was slightly different from CDC 2000 standards. Further studies are needed to assess the appropriateness of using international growth standards for assessing height status of Pakistani adolescents.