Evaluation of Arm Span and Sitting Height as Proxy for Height in Children with Sickle Cell Anemia in Lagos, Nigeria

Abstract

Background: Sickle cell anemia may affect linear growth, and complications like avascular necrosis of femoral head may make direct measurement of height difficult.

Objective: To determine the relationship between height and arm span as well as between height and sitting height among children with sickle cell anemia in Lagos, Nigeria.

Methodology: A random sample of 200 children aged 8 months to 15 years were studied—100 with hemoglobin genotype SS and 100 with hemoglobin genotype AA, matched for age and sex. Height/length, sitting height, and arm span were measured. Correlations and regression analysis were performed to test the relationship between height as a dependent variable and the sitting height and arm span as independent variables.

Results: Height, arm span, and sitting height were slightly but not significantly lower in subjects with sickle cell anemia. Strong correlations (R ≥ 0.95) were observed between height and other measurements in both subgroups. Regression analysis with height as the independent variable showed that arm span had a higher coefficient of determination than sitting height in both subjects (R² = 0.94 vs 0.899) and controls (R² = 0.942 vs 0.940). On the other hand, sitting height had a lower mean difference between observed and predicted height (0.04 and −0.11, respectively).

Conclusion: Sitting height may be the preferred proxy for height in children with sickle cell anemia.

Key words:

• genetic disorders
• sickle cell anemia
• arm span
• sitting height
• regression