Letters to the Editor

Waist circumference gain compared with waist circumference as predictors of type 2 diabetes risk Dear Sir: The findings of a recent study published in the Journal, “Com-parison of abdominal adiposity and overall obesity in predicting risk of type 2 diabetes among men ” (1), indicate that the relative age-adjusted risk of diabetes is best targeted by waist circumference (WC) and that those persons in the highest quintile of WC are at a much greater relative risk than are those in the lower quintiles. Nevertheless, of the 884 diagnosed cases of diabetes, 379 (45%) were found in the first 4 WC quintiles, that is, at a level below the current WC cutoff of 102 cm. We believe that if abdominal adiposity in this cohort of 27 270 health professionals were assessed in terms of quintiles of WC gain since age 21 y, diabetes cases could be predicted even more effec-tively than by WC quintiles. According to another report on the same cohort (2), the questionnaires submitted by participants in the study included weight and height at age 21 y. On the basis of our research on physically active, largely normal-weight young men (average age: 31 y) (3), it is possible to estimate WC from weight, height, and age with reasonable accuracy. It can be assumed that most of the members of the Health Professionals Follow-Up Study cohort, who reached age 21 y close to the time of World War II, were lean as young adults. The WC prediction equation from our database (R2 0.82, SEE 3.8 cm), adjusted for age 21 y, is as follows