The effect of oral contraceptives on serum lipids

Influence of dietary fats and an oral contraceptive on plasma lipids, high density lipoproteins, gallstones, and atherosclerosis in african green monkeys

Twenty-nine African green monkeys were fed diets for 22 months containing 0.79 mg cholesterol/kcal and 40% of calories as either safflower oil or butter with or without the addition of an estrogen- and progestin-containing oral contraceptive. Plasma cholesterol concentrations ranged from 199 to 250 mg/dl. Animals consuming the safflower oil diet had plasma cholesterol concentrations that averaged 61 mg/dl lower than those consuming butter. At least 72% of this lowering was due to a reduction in low density lipoproteins. Triglyceride concentrations were also slightly lower in animals consuming the safflower oil diet. The oral contraceptive lowered total plasma cholesterol concentrations in both diet groups by an average of 41 mg/dl with 54% of this lowering (22 mg/dl) due to a reduction in high density lipoprotein cholesterol. This effect occurred only during the 3 weeks while the contraceptive was being administered and was not apparent 1 week after stopping the drug. Animals consuming safflower oil had bile that was more lithogenic and had more gallstones than did those consuming butter. Addition of the oral contraceptive caused a slight increase in bile lithogenicity, but this increase was not statistically significant. There was no significant interaction between the oral contraceptive and either of the diets to exacerbate cholelithiasis. At the plasma cholesterol concentrations achieved only minimal amounts of atherosclerosis developed and there were no indications of differences due to diet or oral contraceptive in the extent of atherosclerosis.

Changes in serum high density lipoproteins in women on oral contraceptive drugs

Serum lipids, lipoproteins, and lipoprotein subfractions were measured in a group of 18 women aged 20 through 39 who were users of oral contraceptive drugs, and in 19 age-matched controls. Concentrations of the major lipid and lipoprotein classes were higher in the users, but the elevation was statistically significant only in the case of the high density lipoproteins. This increase was shown to be due to a highly significant increase (275 +/- 9 vs. 223 +/- 9 mg/100 ml, (p less than 0.005) in the denser high density lipoprotein subfraction (HDL3). Levels of the other subfraction (HDL2) were similar in users and controls. Thus, anovulatory steroids have selective effects on individual types of high density lipoproteins. Studies of such specific effects may help to further define the functional properties of the high density lipoproteins such as their apparent protective role in atherosclerosis.

Altered plasma-lipids associated with oral contraceptive or oestrogen consumption. The Lipid Research Clinic Program

Mean plasma cholesterol and triglyceride concentrations were measured in White female users and non-users of oral contraceptives and oestrogens in 10 diverse, demographically defined North American populations. About 50% of the younger women (20-24 years old) were taking oral contraceptives. In these women mean triglyceride concentrations were up to 48% higher and mean cholesterol concentrations were about 5% higher than in non-users. The 95% percentile of the total lipid distribution among non-users was used to define hyperlipidaemia. In young women on oral contraceptives hypercholesterolaemia was up to three times more common and hypertriglyceridaemia was up to five times more common than in non-users. 37% of older women (50-54 years) (presumably intramenopausal and postmenopausal) were hormone users, and in this group there were small, inconsistent alterations in plasma-triglyceride and a modest but consistent reduction in mean cholesterol concentration.

Response of serum cholesterol and triglycerides to hormone treatment and the relation of pretreatment values to mortality in patients with prostatic cancer

Cholesterol and triglycerides were measured in plasma samples from patient with cancer of the prostate before and after 3 months treatment with either Premarin, Provera, Provera and diethylstilbestrol, or diethylstilbestrol alone. Cholesterol was also measured before and after one of three doses of diethylstilbestrol or placebo. Pretreatment cholesterol levels at 196 +/- 1.3 mg per 100 ml (X +/- SE, N = 1093) were significantly lower than these reported for similar age group noncancer controls. Significant increases occurred with some of the estrogen treatments. Pretreatment cholesterol levels showed a significant negative correlation with age in Stage III and IV patients of both studies and a positive correlation with hemoglobin in Stage III patients of both studies. Pretreatment triglyceride levels at 120 +/- 1.9 mg per 100 ml (X +/- SE, N = 1089) were similar to levels reported for noncancer controls of similar age. Estrogen treatment produced a significant increase in triglyceride levels. Serum triglycerides were significantly correlated with hemoglobin, weight, and cholesterol and negatively correlated with age, Analysis of covariance for both cholesterol and triglycerides showed highly significant treatment effects, but no stage effects and no stage-treatment interactions. It showed that the pretreatment value is of extreme importance for predicting or explaining the 3-month value. Death rates were calculated by level of pretreatment cholesterol or pretreatment triglycerides for all Stage II and IV patients, all treatments combined, and for Study 2 and Study 3 separately. No consistent trends were evident for cholesterol. Spearman correlation coefficients between category of initial triglyceride value and rank of death rate were computed to test for a quadratic effect. When the absolute values of the initial triglyceride values minus the overall mean were correlated with the death rate, a significant negative correlation was found for all causes of death and for deaths due to cardiovascular disease and prostatic cancer. These results indicate that the death rate is highest near the overal mean for initial triglyceride values and decreases as the initial values deviate above or below the mean. Initial triglyceride levels appear to have potential as indicators of risk of death in patients with prostatic cancer. The percentage of patients dead at 1 year by initial triglyceride levels, measured only in Study 3, revealed a pattern similar to that observed for the death rate, that is, the highest percentages were associated with values near the overall mean.

Effect of contraceptive steroids on serum lipids

Serum triglycerides, free fatty acids, phospholipids, and cholesterol were estimated in groups of women who were taking either norgestrel, megestrol acetate, daily combination tablet, once-a-month pill, or once-a-month injection as a method of contraception. These estimations were done prior to and during therapy at specific times over a period of 2 years. A significant reduction in serum lipids was observed in women taking norgestrel. The women on megestrol acetate showed practically no changes. All the lipid fractions were significantly elevated in women taking combination pills. Raised serum cholesterol was observed in women receiving once-a-month injection.