Human Plasma High-Density Lipoprotein Composition during the Menstrual Cycle

Changes in atherogenic lipids and lipoproteins during natural and hyperstimulated cycles in healthy women

OBJECTIVE

To compare changes in the concentrations of Lp(a) lipoprotein and other atherogenic lipids and lipoproteins in natural and hyperstimulated ovarian cycles.

DESIGN

Open, prospective study.

SETTING

Academic department in a teaching hospital.

PATIENT(S)

Normal ovulatory women served as controls and the treatment group consisted of women undergoing ovarian hyperstimulation.

INTERVENTION(S)

The treatment group received hMG on a fixed regimen.

MAIN OUTCOME MEASURE(S)

Measurements of serum lipids and lipoproteins were made in both natural and hyperstimulated cycles.

RESULT(S)

There was a significant increase in the median concentration of Lp(a) lipoprotein from 10.1 to 10.7 mg/dL in the luteal compared with the proliferative phase of unstimulated cycles. In hyperstimulated cycles, there was a significant increase in the median concentration of Lp(a) lipoprotein from 9.7 mg/dL in the proliferative phase to 11.3 mg/dL in the luteal phase. Reductions in concentrations of total cholesterol and low-density lipoprotein cholesterol were found in the luteal phase of hyperstimulated cycles.

CONCLUSION

Concentrations of Lp(a) lipoprotein increase during the luteal phase of both natural and hyperstimulated ovarian cycles.

Plasma pattern of growth hormone regulates sexual differentiation of phosphatidylcholine in rat plasma

The effects of continuous and intermittent administration of human growth hormone (hGH) in the regulation of plasma phosphatidylcholine fatty acid composition was studied in adult hypophysectomized male and female Sprague-Dawley rats. Human GH was given for 7 days, either continuously by means of Alzet osmotic minipumps implanted s.c. or intermittently by means of s.c. injections at 12-h intervals. The 'masculinizing' effect of hypophysectomy on the fatty acid composition of plasma phosphatidylcholine in female rats, i.e. an increase in the proportions of palmitic and linoleic acids and a decrease in the proportions of stearic and arachidonic acids, was to a large extent reversed by continuous administration of hGH, while intermittent administration had no consistent effect. This effect of continuous hGH administration similar effect of continuous administration of hGH was also observed in hypophysectomized male rats. Prolactin had no effect on the fatty acid composition of phosphatidylcholine. Replacement therapy with thyroid hormones and glucocorticoids had a small effect on the proportions of palmitic and stearic acids in plasma phosphatidylcholine. It is concluded that the more continuous secretory pattern of GH in female rats is involved in the sexual differentiation of the fatty acid composition of plasma phosphatidylcholine.

Effect of menstrual stress on serum lipid levels

The effect of menstrual stress on serum lipid levels has been investigated in 28 healthy unmarried student nurses aged between 19 and 25 years, with histories of regular 26-30 day menstrual cycles. There were definite and similar patterns of changes in serum cholesterol, phospholipids and triglycerides during different phases of the menstrual cycle.

Total serum cholesterol, triglycerides and phospholipids during the normal menstrual cycle

Ten healthy women (mean age, 29 years) with regular menstrual cycles of 26 to 29 days were tested for levels of total serum cholesterol, triglycerides, phospholipids, and estradiol three times during one menstrual cycle-during menstruation, at ovulation, and in the luteal phase. All studies were performed simultaneously. Lipid variations during the menstrual cycle were minimal. Total serum cholesterol, triglycerides, and phospholipids did not correlate with changes in the serum estradiol levels.