Alterations in glucose metabolism during menstrual cycle in women with IDDM

To examine the hormonal mechanisms underlying the variability in glycemic control during the different phases of the menstrual cycle in women with insulin-dependent diabetes mellitus (IDDM).

Hyperglycemic (11.7 +/- 0.1 mM), hyperinsulinemic (24 +/- 3 mU/L) clamp studies were performed in 16 women with IDDM during the follicular (day 8 +/- 1) and luteal (day 23 +/- 1) phases of the menstrual cycle. Seven of the patients (group 1) experienced worsening glucose control during the luteal phase, whereas nine patients (group 2) did not.

In group 1, glucose metabolism fell from 30.2 +/- 3.8 mumol.kg-1.min-1 during the follicular phase to 24.5 +/- 2.0 mumol.kg-1.min-1 during the luteal phase (P = 0.09), whereas in group 2 it increased from 18.5 +/- 1.2 to 23.2 +/- 2.3 mumol.kg-1.min-1 (P = 0.03). The decrease in glucose metabolism during the luteal phase in patients in group 1 was associated with a significant rise in the serum estradiol levels from the follicular to luteal phase (164 +/- 39 vs. 352 +/- 59 pM, P = 0.006), whereas this rise was not observed in group 2 (334 +/- 156 vs. 423 +/- 74 pM, NS). Changes in other reproductive hormones (progesterone, testosterone, dihydrotestosterone, androstenedione, luteinizing hormone, follicular-stimulating hormone, or prolactin) were not related to the differences in glucose uptake in the two groups.

1) Marked heterogeneity in glucose metabolism is seen throughout the menstrual cycle in women with IDDM, 2) a subgroup of patients exhibits worsening premenstrual hyperglycemia and a decline in insulin sensitivity during the luteal phase, and 3) the deterioration in glucose uptake in this subgroup was associated with a greater increment in estradiol levels from the follicular to the luteal phase.