Carbohydrate Metabolism in the Menstrual Cycle

Abstract

Summary Blood sugar, serum insulin and growth hormone levels in response to 100 g. of oral glucose were studied under carefully controlled conditions on days 9, 18 and 27 of the menstrual cycle in 20 healthy women aged 18 to 20 years. The results indicate that blood sugar and serum insulin levels in response to oral glucose loading do not alter significantly in the menstrual cycle. Seven of the women had repeat studies on the same days three cycles later. No significant change in blood sugar or serum insulin levels occurred between cycles. The fasting growth hormone level was highest at the time of impending menstruation in 11 subjects (55 per cent) but the difference in mean values for the group as a whole was not statistically significant. It is concluded that the changes in endogenous hormone levels in a menstrual cycle do not produce significant alterations in carbohydrate metabolism in normal women in this age group. The reported divergence of blood glucose and insulin levels after oral glucose in the menstrual cycle may reflect the interaction of other factors such as age and parity on glucose tolerance. It is suggested that investigations into the metabolic effects of oral contraceptive steroids on these parameters should be performed in nulliparous women in a similar age range.

Changes in Insulin Receptors during Oral Contraception*

“…Thus, this hypothesis cannot be supported from the literature. This is due to the fact that most reports describing the metabolic consequences of combined estrogen/progestagen OC do not take into consideration the day of the cycle used to perform control studies (28)(29)(30)(31)(32), perhaps because some authors have found no difference in glucose tolerance and insulin sensitivity during the menstrual cycle (33,34). In contrast, other investigators have described differences during the cycle, with lower glucose tolerance in the luteal than in the follicular phase (35,36).…”

Alterations in Glucose Metabolism During Menstrual Cycle in Women With IDDM

“…In healthy nondiabetic women, some investigators have reported a worsening in glucose tolerance, as assessed by the oral glucose tolerance test (OGTT), during the luteal phase (4,5). However, other studies that used the OGTT (6,7) or the intravenous glucose tolerance test (8) did not find significant changes in glucose tolerance or insulin concentration as a function of the menstrual cycle phase. Evaluation of insulin sensitivity by means of the euglycemic-hyperinsulinemic clamp technique has also failed to detect alterations during the luteal phase in nondiabetic women (9,10).…”

Glucose Tolerance in Women: The Effects of Age, Body Composition, and Sex Hormones

“…In contrast, studies measuring glucose and insulin responses to an OGTT 30 , 40 or to an IVGTT, 28 , 29 as well as insulin‐mediated glucose disposal using the euglycemic hyperinsulinemic clamp technique, 41 – 43 have shown no differences between follicular and luteal cycle phases in healthy women. Similarly, in the current study, premenopausal women evidenced no luteal phase abnormality in glucose tolerance as assessed by OGTT.…”

“…Previous cross‐sectional reports on glucose metabolism in relation to the menstrual cycle have shown conflicting results. While most studies found no cycle‐related change in fasting glucose values, 28 – 30 Billig 31 noted a decrease, while Okey, in a longitudinal study, 32 found an increase in FPG during the luteal phase. An OGTT‐associated decline in glucose tolerance during the luteal phase of healthy women was reported by Peppler, 33 Jarrett, 34 and Fioretti 35 .…”