[Proportion of low insulin responders to glucose among the offspring of maturity-onset diabetics (author's transl)].

The insensitivity of B cells to glucose, a characteristic of mild essential glucose intolerance may be estimated in a given individual by the comparison of the immediate plasma insulin response to glucose (0 to 10' plasma insulin area or iG) with that to Tolbutamide (iT). It was shown that iG/iT clearly differentiates between nondiabetics and diabetics, whatever their body weight. All the diabetics had an iT/iT lower than 0,65. A high proportion of the offspring of diabetics had an iG/iT ratio in the diabetic range, whether or not they were diabetic. Among these subjects aged from 10 to 49 and weighing between 90 and 144% of their ideal body weight, the iG/iT ratio was not correlated with age nor with relative body weight while the K value was negatively correlated with age. We were thus able to look for the frequency of a "diabetic" iG/iT ratio in the offspring of diabetics, For this in sibships in which all the sibs had been tested, one subject was selected by randomisation. A "diabetic" iG/iT ratio was observed in 7 of 41 subjects with no family history of diabetes, in 27 of 50 with one parent having clinical, maturity-onset diabetes melitus, and in 15 of 19 subjects with two diabetic parents. These results are not compatible with the hypothesis of recessive transmission of the "low insulin response to glucose" characteristic.