341
Int. .I. Gynecol. Obstet.. 1990,31: 341-345 International Federation of Gynecology and Obstetrics
Features of menopause women F.E. Okonofua,
and menopausal
age in Nigerian
A. Lawal and J.K. Bamgbose
Departments of Obstetrics, Gynecology and Perinatology _~ and Community Health and Nutrition, Obafemi Awolowo University (Nigeria) (Received February 13th, 1989) (Accepted March 9th, 1989)
Abstract
The age of menopause and the clinical features of menopause were investigated by questionnaire survey in 563 Nigerian women of Yoruba descent who have been menopausal for at least 5 years. The mean and median ages of menopause were 48.4 and 48.0 years, respectively. No relationship could be established between menopausal age and various biosocial factors such as age of menarche, social class, parity, smoking and place of residence. The commonest menopause related symptoms were joint pains and hot flush and only 42% of them still practiced sexual intercourse. These findings when compared to those from other populations indicate that there is need for more work on menopause in Nigerian women. Keywords:
Menopausal age; Questionnaire; Menarche; Social class; Parity.
Introduction
Numerous studies [8,10,15,16] have highligted the features of menopause in several populations around the world. Such studies have failed to show significant inter-ethnic variation in the age at which women reach menopause. It is however known that the age 0020-7292/90/.$03.50 0 1990 International Federation of Gynecology and Obstetrics Published and Printed in Ireland
of menopause may be affected by several factors such as parity, obesity, years of amenorrhea during reproductive life and smoking D61. Very few studies are available from the African continent on menopause and menopausal age. Although, it was initially suggested that African women may reach menopause later than Caucasian women [16], a more recent study conducted amongst South African blacks [18] actually showed comparable age of menopause for black and Caucasian women. However, clinical experiences in Nigerian women suggests that the age of menopause may be lower in these women (Aimakhu, 1987, pers. commun.). Furtherthat the more, it has been postulated symptoms of menopause may be less severe in Nigerian women as a result of more favorable socio-cultural circumstances in these women. To test the above hypotheses, the present study was designed to determine age of menopause and incidence of menopausal symptoms in Nigerian women. The effect of several factors on menopause were also determined and the findings compared to those from other populations. Methodology
Sample The study
consisted
of 563 randomly Clinical and Clinical Research
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Okonofua et al.
selected postmenopausal women from Oyo State in Nigeria and all of them were from the Yoruba ethnic group. Only women who had stopped menstruating for at least 5 continuous years and had no history suggestive of surgical menopause were recruited for the study. They were approached independently at home and in their places of work and were requested to complete a prepared questionnaire on their experiences of menopause. In addition, some women were recruited from the outpatient departments of Ife State Hospital and Wesley Guild Hospital, Ilesa, Nigeria. A systematic sampling method of choosing every other woman was used but only women who agreed to participate were finally included. The subjects were assured of strict confidentiality of information provided. Questionnaire A questionnaire consisting of two major parts was designed for the study. Section I contained information on biosocial data (age, educational status, smoking habits, etc) and previous menstrual function. In section II of the questionnaire, information sought included (1) age of menopause, (2) years since menopause, (3) symptoms of menopause, and (4) health care practices in relation to menopause. The age of menopause was elicited directly in those who could remember dates correctly. Others were assisted by reference to dates of important events, the date of last confinement, the age of last child and information provided by the husband or close relative. Women whose information were unreliable were excluded from the study. Menopausal complaints specifically asked for were hot flush, bone aches, joint pains, postmenopausal bleeding, dyspareunia and psychological problems. Statistical analysis The mean and median ages of menopause were determined for the entire group and for women from different social backgrounds. Int J Gynecol Obstet 31
Comparison of group means was done using Student’s t-test and analysis of various (ANOVAR) as appropriate. The correlation of menopausal age with menarcheal age and parity were tested with multiple regression analysis. Results Five hundred sixty-three women completed and returned the questionnaires. Their current ages ranged between 44 and 87 years with a mean f SD of 57.7 2 8.4 years. Their mean menarcheal age (MMA) was 16.2 years. Their parity ranged between 0 and 14 with a median of 6 and a mean & SD of 6.4 f 2.8. Social class analysis as determined by the occupation of husbands and years of schooling showed that 71% of them were from the lower social class while 29% were from the upper class. Age of menopause The age of menopause (MPA) for the entire group ranged between 39 and 62 years, with a median of 48 years and a mean + SD of 48.4 + 5.0 years. The effects of social class, place of residence, smoking, alcohol intake, age of menarche and parity on menopausal age were also evaluated. The MPA for women from lower social class was 48.7 -C 4.9 years compared to 47.6 + 5.1 years for upper class women. This difference did not achieve statistical significance (t = 0.89, P > 0.05). Similarly, there was no difference in MPA between rural (MPA = 49.1 -I- 4.9 years) and urban (MPA = 47.5 + 5.1 years) dwellers (t = 1.56, P > 0.05). Only 83 respondents admitted to smoking cigarettes or sniffing tobacco durig their perimenopausal years. The mean f SD MPA in this group of smokers was 47.1 + 5.3 years. This was not significantly different (P > 0.05) from that of non-smokers which was 48.5 f 4.9 years. Similarly, alcohol intake did not seem to affect the age of menopause in this population. Amongst 130 women who admit-
Menopause in Nigerian women Table I.
Incidence women.
menopausal
of
associated
symptoms
No. (To) of women
Joint and bone pains Hot flush
223 (39.6) 169 (30.0) 101 (17.9) 95 (16.9) 49 (8.7) 16 (2.8)
Anxiety Dyspareunia Vaginal discharge Postmenopausal bleeding
only 138 of them had previous medical consultation for these complaints. The types of treatment received were as follows: 101 received analgesics for bone and joint pains, 5 had surgery for postmenopausal bleeding, 6 received hormone replacement therapy, a further 6 were given sedatives and 20 women were reassured by their physicians.
in Nigerian
Symptoms
ted to taking alcohol several years before menopause, the MPA was 48.9 f 3.9 years whereas in non-alcoholics MPA was 48.2 f 5.4 years. This difference was also not statistically significant (t = 0.637, P > 0.05). The effects of menarcheal age and parity on MPA were also ascertained. There was no correlation between age of menarche and MPA(r = 0.09, P > 0.05) and between parity and MPA (r = 0.015, P > 0.05) in this population of women, indicating that both parity and age of menarche have no effect on menopausal age.
Attitude to menopause When the attitude to menopause was analysed, 94% of the respondents indicated that they still felt adequate as women whereas 6% said they felt inadequate. Further analysis showed that of those who felt inadequate, 6 had no living children. Also 58% of the women admitted stopping sexual intercourse after reaching menopause. This was because the majority felt intercourse after menopause can cause disease. Discussion The criterion for menopause used in this study was cessation of menstruation for 5 consecutive years as defined by Masters and Johnson [13]. Other investigators have used amenorrhea lasting 9 months [5] or 1 year [2,3,7] as the basis for defining menopause. We used the longer period in order to be sure that the women were definitely postmenopau-
Menopausal symptoms The number of women who admitted to having specific menopausal symptoms are shown in Table I. The commonest complaint was joint pains followed by hot flushes, bone pains, anxiety and dyspareunia. However,
Table II.
Age of menopause
(means and medians) as reported by previous investigators.
Investigators
Population
Benjamin (1960) [2] Burch and Gunz (1967) [3] Frommer (1964) [5] Jashman et al. (1%9) [7] MacMahon and Worchester Lindquist et al. (1981) [lo] Walker et al. (1984) [18] Abramson
et al. (1960) [1]
Present study (1988)
343
(1966)
[ 1 l]
studied
White South African women New Zealand women English women Netherlands United States Sweden Black South African women Black women in Durbam Nigerian women
Median menopausal age
Mean menopausal age 48.7
50.7 50.1 49.8 50.0
50.1 51.4 47.3 49.1 49.5
48.1
47.7
48.0
48.5
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Okonofua et al.
sal since periods of prolonged amenorrhea are not uncommon in the perimenopausal years. The mean and median ages of menopause in Nigerian women were found to be 48.4 and 48.0 years, respectively. As shown in Table II, our findings are in agreement with those of previous studies in industrialised societies which indicate that the vast majority of women worldwise reach their menopause around the age of 50. This finding suggests that the age of menopause may not be significantly affected by race or environmental factors unlike menarcheal age which may be influenced by some of these factors. Although malnutrition appears to lower age of menopause [17] evidence of severe malnutrition is currently rare in Nigeria. The study also showed lack of effect of social class, place of residence, smoking, alcohol intake, menarcheal age and parity as menopausal age in this population. Of all these factors, only smoking has been postulated to definitely influence the age at which women reach menopause. Smokers are known to attain menopause earlier than nonsmokers [lo] and this effect is unrelated to body weight and number of cigarettes smoked [14]. It has been suggested that smoking may enhance the hepatic metabolism of estrogen, thereby leading to an earlier drop in its levels [6]. Only few women smokers were identified in this study; this factor and the fact that smoking amongst women is a social taboo in Nigeria that is not readily admitted may explain our inability to demonstrate a difference in menopausal age between smokers and non-smokers. The findings in the study on the effect of menarcheal age, social class, place of residence and alcohol intake are consistent with those of other investigators [8,14,16] who found that these factors did not influence menopausal age in their various study, populations. However, the effect of parity has still not been sufficiently clarified. Some workers have found a positive correlation between parity and menopausal age [8,16] while others [ 141found no correlation. On the Int J Gynecol Obstet 31
basis of the increased number of months of amenorrhea in highly parous women, it would have been reasonable to expect menopause to occur later in these women. However, it is possible that oocyte loss through the process of follicular atresia continues during pregnancy. The commonest menopause related symptom complained of by these women was joint pains in contrast to Caucasians where hot flush appear to be the commonest symptom. Furthermore, hot flush was present in 30% of our respondents whereas in a study conducted amongst Caucasian women [9], 100% experienced hot flush after the menopause. The difference may be due to higher level of symptom awareness in Caucasian women. It may also be due to the fact that hot flush may be wrongly attributed to the hot environmental temperature or to the endemic malaria fever in Nigerian women. This point is further supported by the fact that only very few of the respondents compalined of hot flush to their physicians and only two women were on hormone replacement therapy. When the attitude to menopause was analysed, up to 94% of the respondents still felt adequate as women. This degree of adjustment to menopause appears to be better than that reported by Wilbush [19] for Caucasian women. Cultural experience has been postulated to have a modulating effect on the way women adapt to menopause [12] and it is possible that the adult orientation of African societies could be of benefit to postmenopausal women in this population. However, only 42% of the women were still practicing sexual intercourse and this low incidence may again be due to cultural influences. The reasons given for sexual abstinence included lack of interest, death of spouse, presence of younger co-wives who could better satisfy their husband’s sexual needs and loss of interest in the spouse. Also, some felt it was a cultural taboo to have sexual relations after they have had grand children while others thought this could lead to diseases necessitating surgery. These reasons are unlikely to operate in Western
Menopause in Nigerian women
societies and it is well established that in these areas, women continue to have sexual intercourse well into their menopause. In conclusion, the age of menopause in Nigerian women is identical to that published from several populations and is unaffected by menarcheal age, parity or social class. It would appear that the symptoms of menopause are less because more women accept the condition in our society.
10
11
12 13
References 14 Abramson JH, Gampal B, Slome C, Scotch N, Majola CC: Age at menopause of urban zulu women. Science 132: 356,196O. Benjamin F: The age of the menarche and of the menopause in white South African women and certain factors influencing these times. S Afr Med J 34: 416, 1960. Burch PR, Gunz FW: The distribution of menopausal age in New Zealand. An exploratory study. NZ Med J 66: 6, 1967. Daniel1 HW: Osteoporosis of the slender smoker. Arch Intern Med 136: 298,1976. Frommer OJ: Changing age of the menopause. Br Med J 2: 349,1964. Hart D, Farrel CC, Cookslow WC, Powell LW: Enhanced drug metabolism in cigarette smokers. Br Med J 2: 147.1976. Jaszman L, Van Lith ND, Zaat JCA: The age at menopause in the Netherlands. The statistical analysis of a survey. Int J Fertil14: 106, 1969. Kongshavn T, Jenue B, Penderson SH: The influence of various factors on the age for commencement of the menopause. Dncelgeskr Laeg 148: 534, 1986. Lauritzen C: The management of the premenopausal and
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Address for reprints: F.E. Okonofur Department of Obstetrics, Gynecology nod Perinatology Faculty of Heaitb Sciences Ohfemi Awolowo University lie-lfe, Nigeria
Clinical and Clinical Research