OBJECTIVESA lower vital capacity (VC) has been reported to be an independent predictor of diabetes in Western countries. The aim of this study was to examine the relationships between VC and diabetes and between VC and metabolic syndrome (MS) in Japanese individuals.

METHODSStepwise multiple linear regressions with fasting glucose as a dependent variable and age, metabolic risk factors, and percentage vital capacity (%VC) as independent variables were performed using data obtained from 1651 men and 957 women. Area under the receiver operating characteristic curve (AUC) of -%VC for diagnosing diabetes, MS, and Japanese MS (JMS) were calculated, and stepwise logistic regressions using diabetes, MS, and JMS as dependent variables were performed.

RESULTSPercentage vital capacity was independently associated with fasting glucose in men, but not in women. The AUC of -%VC for diagnosing diabetes, MS, and JMS were 0.647, 0.606, and 0.598, respectively (all p < 0.0001) in men and 0.639 (p = 0.065), 0.513 (p = 0.732), and 0.668 (p = 0.01), respectively, in women. Age, waist circumference (WC), and %VC in men and WC and %VC in women were independently associated with diabetes. Age and %VC in men and only age in women were independently associated with MS, and age and %VC in both men and women were independently associated with JMS.

CONCLUSIONSAmong a representative Japanese population, a lower VC was significantly associated with diabetes and MS in men, but the relationships were not conclusive in women.