Maturitas, 1(1979) 165-170 0 Elsevier/North-Holland Biomedical Press

MENOPAUSAL

EFFECTS

16.5

ON RISK FACTORS

FOR ISCHAEMIC HEART DISEASE

CALLE BENGTSSON and OLOF LINDQUIST Department

of Medicine,

University of Gateborg,

Giiteborg, Sweden

(Received 25 July 1978, accepted 6 October 1978)

Women of almost identical age but with a different menopausal state were compared in a population study of women, which was carried out in GGteborg, Sweden. The group of women aged 50 comprised about the same number of still menstruating and postmenopausal women and was, therefore, especially suitable for such a comparison. Serum cholesterol and serum triglycerides were higher in postmenopausal than in premenopausal50-yr-old women and seemed to increase with postmenopausal time. The differences between premenopausal and postmenopausal women were highly significant. Systolic blood pressure was slightly but significantly different (lower in postmenopausal women), while no difference was found for diastolic blood pressure. It seemed that differences in risk factors for ischaemic heart disease could explain part of but not all the association between early menopause and ischaemic heart disease. (Key words: Menopause, Arterial blood pressure, Serum cholesterol, study)

Serum triglycerides,

Population

INTRODUCTION

An association between early menopause and ischaemic heart disease has been reported by us as well as by other investigators [ 11. It is of interest to know whether this association is related to the menopause per se or to menopausal effects on “risk factors” for ischaemic heart disease. A population sample representative of women in Ggteborg, Sweden, which was first studied in 1968-I 969 and then re-studied in 1974-1975, has been very suitable for studying this question. Women in different age strata were studied, which means that women of almost identical age but with different menopausal state could be compared. The age stratum 50 comprised about the same number of still menstruating and postmenopausal women and was, therefore, especially suitable for such comparisons. Smoking is more common in postmenopausal than in premenopausal women of the same age [2]. However, an early menopause seems to be a consequence of smoking and not vice versa. Serum lipids have been found to be higher in postmenopausal than in premenopausal women of the same age [ 1,3]. However, an early menopause seems to be a

Correspondence to: Docent S-413 45 Gijteborg, Sweden.

Calle Bengtsson,

Department

of Medicine,

Sahlgrenska

sjukhuset,

166 Smoking

-

_ Early menoDouse

Feqzpa,,pause Elevated blood lipids

Fig. 1, Probable relationships between early menopause on the one hand and smoking and elevated blood lipids on the other.

cause of elevated blood lipids and not a consequence as illustrated in Fig. 1. There are two main purposes of the present paper. One is to discuss the methods which have been used in order to study the influence of the menopause. The other is to show what happens with risk factors for ischaemic heart disease such as elevated serum lipids and arterial blood pressure before and after the menopause. MATERIAL AND METHODS

A population sample of altogether 1462 women was studied during the years 19681969 [4]. The women were sampled in a way which assured that they were representative of the women in Gijteborg in the age strata studied. A high participation rate was a further guarantee for such a representativeness. The women were in age strata between 38 and 60 yr of age as shown in Table I, in which the number of participants in the various age strata and the participation rate are also shown. The use of age strata instead of age groups means that premenopausal and postmenopausal women of almost identical age could be compared. The numbers of premenopausal (still menstruating) and postmenopausal women aged 46, 50 and 54 are shown in Table II. The age stratum 50 comprised about the same number of premenopausal and postmenopausal women. In the age stratum 46 the postmenopausal and in the age stratum 54 the premenopausal women were rather few. This means that conclusions about the influence of the menopause in these two age strata must be drawn with caution. The results presented wiIl be confined to women aged 50. Premenopausal women were defined as those who had had menstruations during the last month. Postmenopausal women were defined as women who had had no menstrua-

TABLE I Participants in the population study of women in GGteborg, Sweden in 1968-1969. Age 38 46 50 54 60 Total

Participants

Participation rate (%)

312 431 398 180 81

91.4 90.1 91.0 88.6 83.5

1462

90.1

167 TABLE 11 Numbers of premenopausal and spontaneously postmenopausal ing in the population study of womenin Gijteborg 1968-1969. Age (yr)

Premenopausal

Postmenopausal

46 50 54

349 168 10

39 161 146

women aged 46,SO and 54 participat-

tions during a period of 26 mth. Women who had their latest menstruation 2-5 mth before the examination were excluded as it was considered uncertain whether their menstruations had really stopped or not [5]. Those with a hysterectomy or bilateral oophorectomy were also excluded. Included are four women who received oestrogen therapy. More detailed information about menopausal state including numbers of hysterectomized and oophorectomized women has been presented in another paper [S]. Serum cholesterol was determined according to Levine and Zak [6] and serum triglyc erides according to Loftland [7]. Blood pressure was measured in the seated position by means of a mercury manometer. The examinations were performed in the morning with the participants in the fasting state. The population sample was re-studied during the years 1974-1975 [8]. Altogether 1302 women participated on this second occasion which means a participation rate of 89.1% of those examined in 1968-1969. In this follow-up study new information was obtained about the menopausal state. In women who lost their menstruations during the period between the two studies, the time of the last menstruation was noted. In this way the remaining premenopausal time of the women when studied in 1968-1969 could be calculated. RESULTS

Serum cholesterol and serum triglyceride values were found to be higher in postmenopausal than in premenopausal 50-yr-old women as shown in Table III. The differences were statistically significant. Opposite to serum lipids systolic blood pressure was found TABLE III Serum cholesterol, serum triglycerides pausal SO-yr-old women.

Serum cholesterol (mmol/l) Serum triglycerides (mmol/l) Systolic blood pressure (mm Hg) Diastolic blood pressure (mm Hg)

and arterial blood pressure in premenopausal

Premenopausal

Postmenopausal

Mean

SD

Mean

SD

6.90 1.14 140 88

0.95 0.50 22 10

7.43 1.34 135 88

1.19 0.64 21 11

and postmeno-

Significance difference

P < 0.001 P

Menopausal effects on risk factors for ischaemic heart disease.

Maturitas, 1(1979) 165-170 0 Elsevier/North-Holland Biomedical Press MENOPAUSAL EFFECTS 16.5 ON RISK FACTORS FOR ISCHAEMIC HEART DISEASE CALLE B...
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