FIGURE 3.

Seasonal variation among Malawian children in plasma IGF-I concentration and standardized monthly change in their WLZ and LAZ at age 18 mo (n = 605). The monthly change in WLZ and LAZ was calculated using linear models to obtain an estimate. The estimates were standardized for the relative monthly changes in z scores, and seasonal fluctuation during the year was illustrated by using locally weighted scatterplot smoothing. IGF-I, insulin-like growth factor I; LAZ, length-for-age z score; WLZ, weight-for-length z score.