Effects of two oral contraceptive combinations, 0.125 mg desogestrel + 0.050 mg ethinylestradiol and 0.125 mg levonorgestrel + 0.050 mg ethinylestradiol on the adrenal function of healthy female volunteers

Effects of two oral contraceptive combinations, 0.125 mg desogestrel + 0.050 mg ethinylestradiol and 0.125 mg levonorgestrel + 0.050 mg ethinylestradiol on the adrenal function of healthy female volunteers

Europ. J. Obstet. Gynec. reprod. Biol., 13 (1982) Elsevier Biomedical Press 259-265 259 EFFECTS OF TWO ORAL CONTRACEPTIVE COMBINATIONS, 0.125 mg DE...

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Europ. J. Obstet. Gynec. reprod. Biol., 13 (1982) Elsevier Biomedical Press

259-265

259

EFFECTS OF TWO ORAL CONTRACEPTIVE COMBINATIONS, 0.125 mg DESOGESTREL + 0.050 mg ETHINYLESTRADIOL AND 0.125 mg LEVONORGESTREL + 0.050 mg ETHINYLESTRADIOL ON THE ADRENAL FUNCTION OF HEALTHY FEMALE VOLUNTEERS

A. RUOKONEN

‘, L. LUND *, S. NUMMI 3, U. ALAPIESSA

4 and L. VIINIKKA

1

’ Department of Clinical Chemistry, University of Oulu, Departments of Gynecology and Obstetrics, 2 Satakunta and 3 Rauma Central Hospitals, SF-90220 Oulu 22, Finland, and 4 Organon Scientific Development Group, Organon, Oss, The Netherlands Accepted for publication

20 January 1982

RUOKONEN, A., LUND, L., NUMMI, S., ALAPIESSA, U. and VIINIKKA, L. (1982): Effects of two oral contraceptive combinations, 0.125 mg desogestrel + 0.050 mg ethinylestradiol and 0.125 mg levonorgestrel + 0.050 mg ethinylestradiol on the adrenal function of healthy female volunteers. Europ. J. Obstet. Gynec. reprod. Biol., 13/d, 259265. The effects of the oral contraceptive combinations of 0.125 mg desogestrel + 0.050 mg ethinylestradiol (EE), and of 0.125 mg levonorgestrel + 0.050 mg EE on serum cortisol and the urinary excretion of l7-oxogenic steroids and free cortisol were studied in 16 healthy females. Adrenal responsiveness was studied by the metyrapone test. Both contraceptive combinations increased (P < 0.001) serum cortisol concentrations but the rhythmic fluctuation at different times of the day remained unchanged. The urinary excretion of 17-oxogenic steroids was lower (P < 0.01) during treatment than before or after treatment with both contraceptive combinations. The metyrapone test showed normal adrenal responsiveness during the treatment cycles. The urinary excretion of free cortisol was unchanged when desogestrel + EE was used, but increased (P < 0.01) during treatment with levonorgestrel + EE. However, even then, the urinary free cortisol was within the normal range of the population. All the test results of hormone determinations normalized soon after finishing the contraceptive treatments. It is suggested that the abnormalities seen were due to an increased serum binding capacity of cortisol induced by EE and not a sign of pathological changes in adrenal function. No major differences in the biological effects of the two combinations tested were seen. 17-oxogenic

steroids; urinary free cortisol; serum cortisol; metyrapone

test; side-effects

INTRODUCTION

It is well established that contraceptive agents can change the concentrations of the hormones of the pituitaryadrenal axis in the blood (Schreiner, 1970; Weindling and Henry, 1974; Givens et al., 1976; Carr et al., 1979) and urine (Weindling and Henry, 1974; Givens et al., 1976). This might result 0029-2243/82/0000-0000/$02.75

@ 1982 Elsevier Biomedical Press

260

from changes in the function of the endocrine glands or from other causes, e.g. changes in plasma proteins. In this study we compared the influences of a daily dose of 0.125 mg of a new contraceptive progestagen, desogestrel (13-ethyl-ll-methylene-18,19dinor-17a-p~egn-4-en-20-yn-l7-o1) (Viinikka, 1978), in combination with 0.050 mg ethinylestradiol (EE) on the adrenal of healthy female volunteers with those of the 0.125 mg levonorgestrel + 0.050 mg EE. MATERIALS

AND METHODS

Subjects

Sixteen healthy, normally menstruating females volunteered for the study after giving informed consent. Their ages were between 19 and 34 yr. During the 3 mth preceding the study no hormonal treatment was allowed. During the study no drug therapy or self-medication was used. Design of the study

This open, randomized, group-comparative study covered 6 cycles. A pretreatment control cycle was followed by 3 treatment cycles, which in turn were followed by 2 posttreatment control cycles. During the treatment cycles 8 volunteers ingested 0.125 mg of desogestrel + 0.050 mg of EE and the remaining 8 volunteers ingested 0.125 mg of levonorgestrel + 0.050 mg of EE on 21 consecutive days starting on the first day of menstrual bleeding. Between the treatment cycles there was a 7day tablet-free period. Samples

and hormone

determinations

Cortisol concentrations were determined in serum samples obtained at 08.00 and 15.00 h on day 19 of the pretreatment cycle, the third treatment cycle and the second posttreatment cycle, as previously described (Apter et al., 1975). Total urinary 17-oxogenic steroids (according to Zimmerman, 1935, after the cleavage of the side chain at carbon 17) and free cortisol (Apter et al., 1975) were determined in 24-h urine samples collected on days 19, 20 and 21 of the pretreatment, the third treatment and the second posttreatment cycles. Metopirone@ (Ciba-Geigy, Basel, Switzerland) was administered orally in six 4-hourly doses of 750 mg on day 20 of the cycles indicated above. Statistics

Comparisons were performed using Student’s t-test. RESULTS

Both 0.125 mg of desogestrel+ 0.050 mg of EE (I) and 0.125 mg of levonorgestrel + 0.050 mg of EE (II), significantly increased serum cortisol concentrations, but the circadian variation remained normal (Table I). During treatment with combination I, serum cortisol at 08.00 h was higher

I

8.00 15.00

8.00 15.00

I

II

0.53 0.29

0.51 0.34

t 0.11 + 0.10

+ 0.18 + 0.16

Pretreatment cycle (1)

8 8

8 8

n

1.28 0.60

1.61 0.82

II

n = number

of subjects

42 2 13 25 k15 37 f 13

II pretreatment cycle 3rd treatment cycle 2nd posttreatment cycle

NS = not significant,

48 -+21 29 k 13 43 f 14

(day 1)

Control

studied.

8 7 7

8 7 7

n

Values

(mean

67 + 22 42 + 17 55 + 16

90 + 52 43 + 15 64k 8

+ 0.14 + 0.11

8 7 7

7 5 4

n

7 7

7 7

n

118+29 70 + 21 82 + 33

94 + 24 58 + 10 102 + 14

Day after metyrapone test (day 3)

8 7 7

7 4 4

n

P < 0.001 P < 0.001

P < 0.001 P < 0.01

1 and 2

Significance

P < 0.001 P < 0.01 P < 0.01

NS P < 0.001 P < 0.001

1 and 2

Significance

DURING

and

P < 0.001 P < 0.001 P < 0.001

P < 0.01 P < 0.01 P < 0.001

1 and 3

PRETREAT-

pmol/i

3

AND ON

NS P < 0.05

NS NS

1

at 8.00 h and <0.55

STEROIDS

h excretion.

OF 17-OXOGENIC

were CO.70 bmoI/I

0.49 + 0.10 0.20 + 0.06

0.54 0.29

2nd posttreatment cycle (3)

+ SD) are given in gmo1/24

Metyrapone test (day 2)

METYRAPONE TEST ON THE URINARY EXCRETION AND POSTTREATMENT CYCLES (SEE TABLE I)

I pretreatment cycle 3rd treatment cycle 2nd posttreatment cycle

Combination

EFFECTS OF THE MENT, TREATMENT

TABLE

7 7

7 7

n

mg DESOGESTREL + 0.050 mg ETHINYLESTRADIOL (I) (II) ON SERUM CORTISOL AND ITS DAILY VARIATION

values for serum cortisol

+ 0.16 + 0.20

+ 0.29 + 0.32

3rd treatment cycle (2)

COMBINATIONS 0.125 mg ETHINYLESTRADIOL

NS = not significant, n = number of subjects studied. Reference at 15.00 h. Values (mean + SD) are given in pmol/l serum.

Sampling time

Combination

EFFECTS OF THE CONTRACEPTIVE 0.125 mg LEVONORGESTREL + 0.050 THE 19th CYCLE DAY

TABLE

k? +

0.11 t 0.03 0.11 + 0.03 0.11 t 0.04

0.09 f 0.03 0.14 + 0.04 0.08 _+0.02

I pretreatment cycle 3rd treatment cycle 2nd posttreatment cycle

II pretreatment cycle 3rd treatment cycle 2nd posttreatment cycle 8 7 7

8 7 7

n

0.05 _+0.03 0.08 + 0.05 0.05 _+0.02

0.08 2 0.03 0.13 f 0.05 0.06 -+ 0.03

Metyrapone test (day 2)

8 7 7

6 5 4

n

0.22 + 0.11 0.24 + 0.10 0.16 z!z0.04

0.18 ? 0.06 0.19 + 0.09 0.17 + 0.17

Day after metyrapone test (day 3)

8 7 7

7 4 4

n

OF FREE CORTISOL

P < 0.05 NS P < 0.001

NS NS P < 0.05

1 and 2

Significance

P < 0.01 P < 0.05 P < 0.001

P < 0.01 P < 0.05 NS

1 and 3

DURING PRETREATMENT,

NS = not significant, n = number of subjects studied. Reference values for urinary excretion of free cortisol was CO.35 pmo1/24 h. Values (mean k SD) are given in pmo1/24 h excretion.

Control (day 1)

Combination

EFFECTS OF THE METYRAPONE TEST ON THE URINARY EXCRETION TREATMENT AND POSTTREATMENT CYCLES (SEE TABLE I)

TABLE III

than when using combination II (P< 0.05, Table I). During the second posttreatment cycles, serum cortisol concentrations were the same as before the treatment with combination I, but lower (P< 0.05) at 15.00 h with combination II (Table I). Urinary excretion of 17-oxogenic steroids was lower (P < 0.01) during treatment cycles than during pre- or posttreatment cycles (Table II). The metyrapone test increased urinary excretion of 17-oxogenic steroids as normal in all experimental conditions, but during treatment cycles steroid excretion constantly remained at lower levels than during pre- or posttreatment cycles. During the second posttreatment cycles, urinary excretion of 17-oxogenic steroids had returned to values very close to those of the pretreatment cycles. The two contraceptive combinations did not differ from each other in their effects on urinary excretion of 17-oxogenic steroids. The side-effects associated with the metyrapone test resulted in the drop-out of 4 volunteers. Combination II, but not combination I, increased (P < 0.01) the urinary excretion of free cortisol (Table III). On the day when metyrapone was given, the urinary excretion of free cortisol usually declined during preand posttreatment cycles but it remained more constant during treatment cycles. A day after the metyrapone test, the urinary excretion of free cortisol usually increased (Table III). DISCUSSION

Contraceptive agents have been shown to influence many hormone tests in vivo (Schreiner, 1970; Weindling and Henry, 1974; Givens et al., 1976; Carr et al., 1979). Because oral contraceptives have been used for years, in addition to the possible physiological significance of these changes, It ii also important to know their influences on clinical chemical determinations in order to avoid possibly misleading interpretations made from laboratory tests. In this study we investigated the influences of 0.125 mg desogestrel + 0.650 mg EE, and 0.125 mg levonorgestrel + 0.050 mg EE on commonly used laboratory tests of adrenal function in 16 normally menstruating females. During the treatment cycles with both combinations, serum cortisol levels increased, the increment being bigger with the combination containing desogestrel, but the rhythmic fluctuation of serum cortisol during treatment cycles suggested normal regulation of adrenal function. It has been shown earlier that estrogens increase the blood concentrations of many proteins, among them the cortisol-binding protein, transcortin (Doe et al., 1964; Barbosa et al., 1971; Binge1 and Benoit, 1973). Because both the protein-bound and free cortisol were measured and because neither of the progestagens alone affect cortisol concentrations (Givens et al., 1976; Viinikka et al., 1976; Viinikka et al., 1977), we suggest that the high cortisol concentrations during the treatment cycles were due to increased transcortin induced by EE. The difference of the increments of plasma total cortisol during the two treatments might also provide an explanation from the changes of plasma

264

cortisol binding activity. Because levonorgestrel has a more potent androgenie activity than desogestrel (Bergink er al., 1981), its androgenicity might have partly overcome the stimulation of transcortin biosynthesis by the estrogen during the ingestion of levonorgestrel + EE. The urinary excretion of 17-oxogenic steroids was lowered during the treatment cycles, but in all experimental conditions the excretion responded well to the metyrapone test, indicating normal adrenal reactivity. A decrease in the excretion of 17-oxogenic steroids during oral contraceptive use, as well as under a simultaneous metyrapone test, has been reported earlier (Dawkjaer-Nielsen et al., 1969). A possible mechanism behing the phenomenon is a decreased clearance rate of cortisol as a result of an increased protein-bound fraction. Although the urinary excretion of free cortisol was increased during treatment with combination II and unchanged with combination I, it was always clearly within normal ranges, indicating that no really major change in adrenal function was caused by either combination. During treatment cycles the urinary excretion of free cortisol was not diminished by metyrapone inhibition as clearly as it was during pre- or posttreatment cycles. It is possible that highly elevated protein-bound cortisol levels during treatment served as a source of urinary free cortisol for a longer time than during preor posttreatment cycles. The increased urinary excretion of free cortisol on the day after the metyrapone test indicated normal adrenal responsiveness to the test under contraceptive treatments. In conclusion, both 0.125 mg desogestrel + 0.050 mg EE, and 0.125 mg levonorgestrel + 0.050 mg EE had noteworthy influences on serum total cortisol concentration and urinary excretion of 17-oxogenic steroids. These changes, however, were not regarded as a sign of pathological adrenal function, but as consequences of increased corticosteroid-binding protein due to the administered estrogen. The changes must be taken into account, however, when these tests are interpreted during contraceptive treatments. This study did not reveal any major differences in the effect of treatments with 0.125 mg of desogestrel + 0.050 mg EE or with 0.125 mg of levonorgestrel + 0.050 mg EE on adrenal function. ACKNOWLEDGEMENT

We wish to thank Mrs. Liisa Ollanketo for her skillful technical assistance. REFERENCES Apter, D., Janne, 0. and Vihko, R. (1975): Lipidex chromatography in the radioimmunoassay of serum and urinary cortisol. Clin. Chim. Acta, 63, 139-148. Barbosa, J., Seal, U.S. and Doe, R.P. (1971): Effect of anabolic steroids on haptoglobin, urosomucoid, plaaminogen, fibrinogen, transferrin, ceruloplasmin, or-antitrypsin, @ glucuronidase, and total serum proteins. J. clin. Endocr. Metan. 33, 389-398. Bergink, E.W., Hamburger, A.D., de Jager, E. and van der Vies, J. (1981): Binding of a contraceptive progestagen Org 2969 and its metabolites to receptor proteins and human sex hormone binding globulin. J. Steroid Biochem., 14, 175-183.

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