["Koshi-heso" (waist-umbilicus) test: A novel screening method for visceral fatty obesity]

To evaluate the screening performance and validity of the "Koshi-heso" (waist-umbilicus) test for visceral fatty obesity in elderly diabetic patients.

Subjects were diabetic patients ≥65 years old visiting our outpatient clinic. As a "Koshi-heso" test, the distance between the umbilicus and the superior border of the iliac crest (waist) was measured with the patient's own finger. When the index finger reached the umbilicus and there was a gap between the finger and the abdominal wall, the patient was classified as "smaller"; when the index finger reached the umbilicus and there was no gap between the finger and the abdominal wall, the patient was classified as "just fit"; and when the index finger did not reach the umbilicus, the patient was classified as "bigger". Abdominal circumference was used to assess visceral fat obesity, with a cut-off value of ≥85 cm for men and ≥90 cm for women. Visceral fat mass and body fat percentage were evaluated by the multi-frequency bioelectrical impedance method. The sensitivity and specificity of the waist-umbilical test for visceral fat obesity were calculated. Pearson's correlation coefficients between the "Koshi-heso" test and visceral fat mass and body fat percentage were calculated to evaluate the validity of the test. Furthermore, the association between the "Koshi-heso" test and risk factors for vascular disease, microvascular complications and cardiovascular disease was assessed by a logistic analysis.

A total of 221 patients were included in the analysis population of the study. The cut-off values of "just fit" in men (sensitivity 0.96, specificity 0.62) and "bigger" in women (sensitivity 0.76, specificity 0.78) were optimal. Furthermore, the "Koshi-heso" test was significantly correlated with abdominal visceral fat mass and body fat percentage as well as with vascular disease risk factors and microvascular complications.

The "Koshi-heso" test was able to be used as a screening method for visceral fatty obesity in elderly diabetic patients.