431
Atherosclerosis, 34 (1979) 431-436 Scientific Publishers, Ltd. @ Elsevier/North-Holland
SEX HORMONES AND HIGH DENSITY LIPOPROTEINS IN HEALTHY MALES
ARNE NORDOY,
ASBJQRN
AAKVAAG
and DAG THELLE
Department of Medicine, University Hospital, !l’rome&,and the Hormone and Isotope Labomtory, Aker Hospital, Oslo (Norway) (Received 21 May, 1979) (Revised, received 9 July, 1979) (Accepted 10 July, 1979)
summary The serum concentrations of testosterone *, androstenedione, oestradiol and total low polar oestrogens, mainly oestradiol and oestrone, were measured in 26 healthy male subjects. The subjects were divided into two groups each of them with low (1.56 mmol/l) levels of serum HDL cholesterol. The group with high HDL cholesterol had significantly higher testosterone than the other group. Positive correlations were established between HDL cholesterol and testosterone and total cholesterol and testosterone concentration in serum. Key words:
High density lipoproteins -Sex
hormones
Introduction A possible relation between sex hormones and coronary risk factors is of interest for several reasons. There is a well documented difference in the occurrence of coronary heart disease (CHD) between the two sexes, a difference which is significantly reduced after the menopause [ 1,2]. Women who have undergone the menopause have also a higher incidence of cardiovascular disease than woman at the same age who are still menstruating [3]. These associations have led to the concept that oestrogens might protect against CHD. Both in men and women, however, the use of oestrogens has been associated * Trivial names: Testosterone, androst-4en-l7~-ol-3-one: oestradiol, oestratri-1,3,6(10)2ne-3 oestrone. 0estratri-1.3.6(10)en-3-o1-17-one; androstenedione, androst-4-ene-3.17~dione.
17&diol;
432
with increased mortality from CHD [ 4-61. A recent study has also shown higher plasma-oestradiol levels in male survivors of myocardial infarction than in age-matched controls [ 71. The sex-related differences in CHD mortality rates cannot be explained by differences in the accepted cardiovascular risk factors. Recent studies have established a striking inverse correlation of high density lipoprotein (HDL) to the incidence of coronary heart disease [8,9]. A lower HDL cholesterol in males than in females in the age group 30-39 years has been reported [lo] and for women a slight decrease in the level from age 50 to age 80 years has been observed [ 91. We have measured plasma levels of testosterone, androstenedione, oestradiol and total low polar oestrogens, representing the sum of oestradiol and oestrone, in healthy male subjects aged 36-50 years with low and high levels of serum HDL cholesterol. Subjects
and Methods
Twenty-six healthy male subjects, aged 36-51 years, were studied. They were selected on the basis of low (1.56 mmol/l) HDL cholesterol serum concentration, determined in a family study on HDL cholesterol in 1975 [lo]. They had taken no drugs the previous week and had fasted 10 h prior to blood collection. None had used lipid-lowering drugs ever. Their smoking habits were recorded. After collection of venous blood, serum was prepared and aliquots were stored frozen and assayed in one batch. Triglycerides and total cholesterol were measured in a GSA II selective analyzer “Greiner” with reagents from Boehringer (Mannheim, F.R.G.). High density lipoprotein cholesterol (HDL, d = 1.063-1.21 g/ml) was measured in the supernatant after preincubation of very low and low density lipoproteins (d < 1.063 g/ml) as described by Burstein et al. [ll]. Oestradiol and total low polar oestrogens were determined as described by Fosd et al. [ 121, and testosterone according to Naess et al. [13]. The method for the determination of androstenedione has not yet been published. Briefly, the method utilizes an antiserum raised against ll-hydroxy-androstene-dione ll-succinyl coupled to bovine serum albumin. In order to obtain adequate specificity, paperchromatographic isolation of androstenedione in the system hexane : benzene (1 : 1, v/v) with formamide as stationary phase was employed of the ether extract of 1 ml of serum. Individual correction for recovery was done on the basis of addition of [ 1,2-‘Hlandrostenedione to the samples prior to extraction. The samples were incubated overnight in a refrigerator, and separation between free and bound androstenedione was achieved with 1 ml of 0.125% charcoal suspension (Norit A, Neutral Pharmaceutical Grade, Amend Drug and Chemical Co.) and 0.0125% Dextrane-70 (Pharmacia Fine Chemicals) for 30 min in ice water followed by centrifugation at 4°C. The significance of the observed differences between the two groups with low and high serum HDL cholesterol levels were tested by Student’s t-test. The product-moment correlation coefficiences were calculated between the lipid and the sex hormone concentrations.
433
TABLE SEX
1
HORMONES
HIGH (>1.56
LEVELS
mm&I)
IN TWO
GROUPS,
AND LOW (
Atherosclerosis, 34 (1979) 431-436 Scientific Publishers, Ltd. @ Elsevier/North-Holland
SEX HORMONES AND HIGH DENSITY LIPOPROTEINS IN HEALTHY MALES
ARNE NORDOY,
ASBJQRN
AAKVAAG
and DAG THELLE
Department of Medicine, University Hospital, !l’rome&,and the Hormone and Isotope Labomtory, Aker Hospital, Oslo (Norway) (Received 21 May, 1979) (Revised, received 9 July, 1979) (Accepted 10 July, 1979)
summary The serum concentrations of testosterone *, androstenedione, oestradiol and total low polar oestrogens, mainly oestradiol and oestrone, were measured in 26 healthy male subjects. The subjects were divided into two groups each of them with low (1.56 mmol/l) levels of serum HDL cholesterol. The group with high HDL cholesterol had significantly higher testosterone than the other group. Positive correlations were established between HDL cholesterol and testosterone and total cholesterol and testosterone concentration in serum. Key words:
High density lipoproteins -Sex
hormones
Introduction A possible relation between sex hormones and coronary risk factors is of interest for several reasons. There is a well documented difference in the occurrence of coronary heart disease (CHD) between the two sexes, a difference which is significantly reduced after the menopause [ 1,2]. Women who have undergone the menopause have also a higher incidence of cardiovascular disease than woman at the same age who are still menstruating [3]. These associations have led to the concept that oestrogens might protect against CHD. Both in men and women, however, the use of oestrogens has been associated * Trivial names: Testosterone, androst-4en-l7~-ol-3-one: oestradiol, oestratri-1,3,6(10)2ne-3 oestrone. 0estratri-1.3.6(10)en-3-o1-17-one; androstenedione, androst-4-ene-3.17~dione.
17&diol;
432
with increased mortality from CHD [ 4-61. A recent study has also shown higher plasma-oestradiol levels in male survivors of myocardial infarction than in age-matched controls [ 71. The sex-related differences in CHD mortality rates cannot be explained by differences in the accepted cardiovascular risk factors. Recent studies have established a striking inverse correlation of high density lipoprotein (HDL) to the incidence of coronary heart disease [8,9]. A lower HDL cholesterol in males than in females in the age group 30-39 years has been reported [lo] and for women a slight decrease in the level from age 50 to age 80 years has been observed [ 91. We have measured plasma levels of testosterone, androstenedione, oestradiol and total low polar oestrogens, representing the sum of oestradiol and oestrone, in healthy male subjects aged 36-50 years with low and high levels of serum HDL cholesterol. Subjects
and Methods
Twenty-six healthy male subjects, aged 36-51 years, were studied. They were selected on the basis of low (1.56 mmol/l) HDL cholesterol serum concentration, determined in a family study on HDL cholesterol in 1975 [lo]. They had taken no drugs the previous week and had fasted 10 h prior to blood collection. None had used lipid-lowering drugs ever. Their smoking habits were recorded. After collection of venous blood, serum was prepared and aliquots were stored frozen and assayed in one batch. Triglycerides and total cholesterol were measured in a GSA II selective analyzer “Greiner” with reagents from Boehringer (Mannheim, F.R.G.). High density lipoprotein cholesterol (HDL, d = 1.063-1.21 g/ml) was measured in the supernatant after preincubation of very low and low density lipoproteins (d < 1.063 g/ml) as described by Burstein et al. [ll]. Oestradiol and total low polar oestrogens were determined as described by Fosd et al. [ 121, and testosterone according to Naess et al. [13]. The method for the determination of androstenedione has not yet been published. Briefly, the method utilizes an antiserum raised against ll-hydroxy-androstene-dione ll-succinyl coupled to bovine serum albumin. In order to obtain adequate specificity, paperchromatographic isolation of androstenedione in the system hexane : benzene (1 : 1, v/v) with formamide as stationary phase was employed of the ether extract of 1 ml of serum. Individual correction for recovery was done on the basis of addition of [ 1,2-‘Hlandrostenedione to the samples prior to extraction. The samples were incubated overnight in a refrigerator, and separation between free and bound androstenedione was achieved with 1 ml of 0.125% charcoal suspension (Norit A, Neutral Pharmaceutical Grade, Amend Drug and Chemical Co.) and 0.0125% Dextrane-70 (Pharmacia Fine Chemicals) for 30 min in ice water followed by centrifugation at 4°C. The significance of the observed differences between the two groups with low and high serum HDL cholesterol levels were tested by Student’s t-test. The product-moment correlation coefficiences were calculated between the lipid and the sex hormone concentrations.
433
TABLE SEX
1
HORMONES
HIGH (>1.56
LEVELS
mm&I)
IN TWO
GROUPS,
AND LOW (
