Different measurements of the sagittal abdominal diameter and waist perimeter in the prediction of HOMA-IR.

BACKGROUND The correlation between the increase in visceral fat and insulin resistance makes the sagittal abdominal diameter and the waist perimeter as potential tools for the prediction of insulin resistance. OBJECTIVE To assess the reproducibility of different measurements of the sagittal abdominal diameter and the waist perimeter and analyze the discriminating power of the measurements when predicting insulin resistance. METHODS A total of 190 adult males were studied. The sagittal abdominal diameter (smallest girth, larger abdominal diameter, umbilical level and midpoint between the iliac crests) and the waist perimeter (umbilical level, smallest girth, immediately above the iliac crest and midpoint between the iliac crest and the last rib) were measured at four different sites. Insulin resistance was assessed by the homeostasis model of assessment-insulin resistance (HOMA-IR) index. RESULTS All measurements presented an intraclass correlation of 0.986-0.999. The sagittal abdominal diameter measured at the smallest girth (r=0.482 and AUC=0.739+/-0.049) and the waist perimeter measured at the midpoint between the last rib and the iliac crest (r=0.464 and AUC=0.746+/-0.05) presented the highest correlations with the HOMA-IR and the best discriminating power for HOMA-IR according to the ROC analysis (p<0.001). CONCLUSION The sagittal abdominal diameter and waist perimeter showed to be highly reproducible and the sagittal abdominal diameter (smallest girth) and waist perimeter (midpoint between the iliac crest and the last rib) presented the best performance when predicting HOMA-IR. Further studies in other groups of the Brazilian population must be carried out to allow the use of these indicators of insulin resistance in the population as a whole, following standardized procedures.