ackground : First-degree relatives of non-insulin dependent diabetes mellitus are enerally accepted to be high risk group for development of non-insulin dependent dianetes mellitus. So we are intended to identify the early metabolic defects in
the
young
first-degree relatives of non-insulin dependent diabetes mellitus.
Methods : Ten offsprings of non-insulin dependent diabetes mellitus and ten healthy men
were included in this study. They were all third decade male subjects and matched well with
age and body mass indices. Both groups were not different in anthropometric measurements
(IBW, BMI, WHR), dilay calorie intake and total energy consumptions (total energy
expenditure, physical activity).
Results :
1) Oral glucose tolerance test showed normal responses of plasma glucose levels and
C-peptide levels in both groups.
2) There were statistically significant differences (p<0.05) in plasma glucose, C-peptide
and insulin levels at 60 minutes between two groups (Glucose 100±19 vs. 77±19 mg/dl;
C-peptide 5.47±1.7 vs. 3.32±1.88 ng/ml; Insulin 90.3±41.3 vs. 38.6±29.4 uU/ml).
3) The result of euglycemic hyperinsulinemic clamp study showed that offsprings of
non-insulin dependent diabetes mellitus had significantly diminished rates of insulin-mediated
glucose disposal compared to the control group (5.61±1.01 vs. 8.87±0.92 mg/kg B.W/min,
p<0.01).
4) Simple linear regression analysis showed a good correlation between peripheral glucose
utilization rates and the lean mass composition measured by body composition analyzer
(Futrex-5000, Futrex Co., USA). As the lean mass percentage increases, peripheral glucose
utilization rate also increases with positive linear relationship (rE2=0.49, p<0.05)
5) By the method of restriction fragment length polymorphism, we found two polymorphic
Kpn I sites of 6.5 kb and 5.8 kd as described previously without any new polymorphism for
GLUT4 gene DNA in botn groups. We also used other two restriction endonucleases, Bam HI
and Eco RI, but did not discover polymorphism at GLUT4 gene locus.
Conclusion : This study supports the genetic tendency of non-insulin dependent diabetes
mellitus and showed that the early metabolic defect in the young offsprings is expressed as
insulin resistance rather than pancreatic beta-cell dysfunction. The insulin resistance is in the
negative linear relationship with the lean mass composition and seems to arise from the
skeletal muscle tissue. For preventing the development of glucose intolerant status and overt
diabetes, the avoidance of obesity and maintenance of muscle mass by means of careful diet
control and continuous exercise program may be helpful.
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