Insulin resistance and the adiponectin/leptin ratio as a surrogate measure of insulin resistance in Japanese collegiate baseball players.

BACKGROUND

No study has previously investigated insulin resistance in collegiate baseball players. The purposes of this study were to examine: 1) the insulin resistance; and 2) the usefulness of the adiponectin/leptin (A/L) ratio compared with the homeostasis model assessment of insulin resistance (HOMA-IR) for assessing insulin resistance in collegiate baseball players.

METHODS

Twenty collegiate baseball players with abdominal obesity (AO group) defined by a waist circumference (WC) ≥85 cm, 65 lean baseball players with a WC<85 cm (L group), and 20 controls who were sedentary for at least 1 year (C group) were compared. The Body Mass Index, WC, systolic and diastolic blood pressures, fasting plasma glucose, total cholesterol, triglycerides, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol, apolipoprotein B, insulin, leptin, adiponectin, and high-sensitivity C-reactive protein (hs-CRP) were measured.

RESULTS

The AO group had a significantly higher insulin level, HOMA-IR, and leptin level, and lower A/L ratio than the L and C groups. The AO group had a significantly higher prevalence of insulin resistance (50%) than the L (14%) group. The A/L ratio was significantly negatively correlated with body weight, Body Mass Index, WC, triglycerides, triglycerides/HDL-C ratio, apolipoprotein B, hs-CRP, insulin, HOMA-IR, and leptin, and positively correlated with HDL-C, whereas HOMA-IR was significantly positively correlated with body weight, Body Mass Index, WC, systolic and diastolic blood pressures, fasting plasma glucose, and insulin, and negatively correlated with adiponectin and the A/L ratio. In the forward stepwise multiple regression analysis, WC, triglycerides, and hs-CRP were the significant determinants for the A/L ratio, whereas diastolic blood pressure and WC were the significant determinants for HOMA-IR. This model explained 53.7% of the variance in the A/L ratio and 13.6% of the variance in HOMA-IR.

CONCLUSIONS

The present study suggested that the baseball players with abdominal obesity had a significantly higher prevalence of insulin resistance than the lean baseball group. The A/L ratio may be more useful than HOMA-IR to accurately assess insulin resistance in male collegiate baseball players.