Nigel Oakley

Effect of combined oral contraceptives on glycosylated haemoglobin.

Glycosylated haemoglobin (HbA), was measured in 164 Caucasian women aged 20-40 years who were using: (1) barrier contraceptive methods; (2) contraceptive pills with 30 micrograms ethinyloestradiol and 150 micrograms laevo-norgestrel; (3) contraceptive pills with 30-35 micrograms ethinyloestradiol and 0.5-1 mg norethisterone. Mean +/- 1 s.d. values for the three groups were 7.64 +/- 0.69, 7.56 +/- 0.56 and 7.27 +/- 0.74 respectively. Groups (1) and (2) did not differ significantly from one another but the mean value for group (3) was significantly lower than for the other groups (P less than 0.01). Age, percentage ideal body weight and smoking did not influence HbA, but the value was higher for parous than for nulliparous women (P = 0.02). These findings can be explained in terms of the known effects of oestrogens and progestogens on fasting blood glucose.

Twice-daily insulin regimens in management of severe diabetes.

Diurnal glucose profiles have been compared in ten insulin dependent diabetics receiving, firstly, a twice-daily soluble insulin (SI): isophane insulin (NPHI) regimen containing a high proportion of SI (mean 73%) and, secondly, Mixtard insulin (30% SI, 70% NPHI). For each patient the two regimens gave similar profiles though nocturnal blood glucose control was better on Mixtard. HbA1 values were similar on the two regimens. The findings show that, using highly purified formulations, small changes in insulin proportions in twice-daily SI: NPHI regimens may be irrelevant to diabetic control; they also suggest that highly purified NPHI may have a substantially shorter duration of action than its older counterpart and that the convenient regimen of twice-daily Mixtard is usually as good as any more complicated ‘tailormade’ regimen of highly purified insulins.