[Effect of a combined diet-training program on the insulin sensitivity of obese persons with normal or disordered...

The majority of the obese persons is characterized by a disturbed glucose tolerance and an increased insulin secretion. The cause of this apparent contradiction lies in the existence of an insulin resistance. In 23 obese persons (relative weight greater than 120% according to Möhr and Johnson) with normal or disturbed glucose tolerance the effect of a diet restriction lasting 4 weeks (700 kcal/die) or of a combined diet training programme on the body weight, serum lipids, state of conditioning (PWC170) and insulin sensitivity in vivo was investigated. The insulin sensitivity was characterized by means of 1 h insulin infusion test. At comparable peripheral steady state insulin levels the relative decrease of the plasma glucose and free fatty acid concentration is a measure of the insulin sensitivity in vivo. In 9 obese persons with disturbed glucose tolerance observations of the course over 1 year are existing. The finding demonstrate that only a combined diet training programme leads to a significant improvement of the insulin sensitivity and prevails a unique dietary treatment. The measure of the improved insulin effectivity directly correlates with the effect of conditioning. The reduction of the body weight obtained is about double as large in a combined diet conditioning treatment as after a unique restriction of the diet (18% or 10% of the relative weight). Triglyceride and cholesterol levels significantly decrease, the HDL-cholesterol increases in tendency. On the other hand, the results are unsatisfactory after one year. The therapy regime is a promising strategy for the reduction of the insulin resistance in adiposity as a preventive medical measure, provided a good cooperation and motivation on the side of the patient is present.