A criterion for evaluation of obesity based on the relationship between percent body fat and medical examination parameters / 体力科学

ABSTRACT

A study was conducted to examine the relationship between percent body fat (%fat) and medical examination parameters. The subjects were 250 women aged 17 to 68 years, who neither drank nor smoked. The results obtained were as follows:<BR>After controlling for the effects of age and maximal oxygen intake per kilogram body weight (VO<SUB>2</SUB>max/wt), %fat showed a significant correlation with high-density lipoprotein cholesterol (HDL-C), total cholesterol/HDL-C ratio (TC/HDL-C), β-lipoprotein (β-L), glutamic oxaloacetic transaminase (GOT), glutamic pyruvic tansaminase (GPT), uric acid (UA), white blood cell count (WBC), red blood cell count (RBC), systolic blood pressure (SBP), and diastolic blood pressure (DBP) . Values of %fat calculated from each regression equation when HDL-C=38mg/dl, TC/HDL-C=4.9, β-L=500 mg/dl, GOT=41mu/ml, GPT=46 mu/ml, UA=5.7mg/dl, WBC=8500/mm3, RBC=520×104/mm3, SBP=159 mmHg, and DBP=94 mmHg were 32.2%, 31.9%, 30.8%, 35.4%, 36.4%, 31.8%, 30.7%, 35.0%, 33.8% and 32.6%, respectively.<BR>The subjects were then divided into 2 groups, above (above group) or below (below group) 30%, 31%, 32%, 33%, 34% or 35% body fat. Wherever the subjects were divided into 2 groups at these values of %fat, the above group showed a significantly higer occurrence of abnormal values for medical parameters than the below group.<BR>The subjects were further divided into 3 groups: 154 subjects with %fat below 29.9% (N group), 47 subjects with %fat between 30% and 34.9% (MO group), and 49 subjects with %fat above 35% (O group) . The O group showed significantly higher occurrence of abnormal values for medical parameters than the MO and N groups. The O group also showed a significantly higher mean value of DBP than the MO and N groups. Furthermore, the O group showed a significantly lower mean value of HDL-C and significantly higher mean values of TC/HDL-C, UA, GOT, GPT, SBP, FBS than the N group. There was no significant difference between the N and MO groups in the occurrence of abnormal values for medical parameters. However, the MO group showed a significantly lower mean value of HDL-C and significantly higher mean values of TC/HDL-C, UA and β-L.<BR>These results suggest that the values of medical parameters become poorer when %fat exceeds 30%, a level widely used in Japan as a criterion for evaluation of obesity.<BR>The subjects were further divided into 3 groups: 50 subjects who were non-obese and fit (NF group) ; 104 subjects who were non-obese and unfit (NU group) ; 88 subjects who were obese and unfit (OU group) . There were significant differences in the occurrence of abnormal values for medical parameters among these groups. The NF group showed the lowest values, followed by the NU and OU groups. Thus, it seems preferable to evaluate individuals using a combination of %fat and VO<SUB>2</SUB>max/wt.