Age at natural menopause in Iran

Objectives: Estimation of mean and median age at menopause among Iranian women using a cumulative distribution by region. Methods: The number of 8194 women aged between 30 and 65+ who enrolled in National Health Survey in the year 2000 in Iran through cluster sampling were studied and according to their age and the onset of their menopause (12 month consecutive menstrual cessation), the pattern of age at natural menopause has been described using a cumulative distribution. Results: The median age of menopause has been calculated to be 49.9, 49.2, and 49.6 years in urban, rural, and total population, respectively. While the mean age at menopause in total population was 50.4 years (S.D.=4.3). As it has been shown, the median age of menopause in rural areas (49.2) is earlier than urban areas (49.9). This difference is statistically significant (95% CI: 1.00066, 1.03363). Conclusion: There are different factors influencing age at natural menopause but there are not certain and homogenous results about those factors in different studies. Therefore, it is obvious that exploring these factors in different regions in Iran merit to be done.     

Age at natural menopause and cognition

OBJECTIVES: To examine associations between age at natural menopause, childhood IQ and cognition at age 65 years. To determine if lower age at menopause partly mediates the effect of childhood IQ on cognition at age 65 years. METHODS: Data were provided by a sub-cohort of women participating in a longitudinal study of brain ageing and health. Main variables were childhood IQ from a 1947 national survey of children born in 1936, age at natural menopause and five cognitive tests measured in 2000-2001. RESULTS: Age at menopause was associated with childhood IQ (r = 0.221, P = 0.008) and with general cognitive function age 65 years (r = 0.246, P = 0.004). Multiple regression showed 44.4% of the reliable variance in cognitive ability age 65 years is contributed by IQ at an age of 11 years to which, years of education contributed an additional 3.9%. Structural equation modelling suggested that childhood IQ differences contribute 4.8% of the variance to age at natural menopause and that the relation between age at menopause and cognition at age 65 years was accounted for by childhood IQ. CONCLUSION: Childhood IQ and age at menopause each have significant relations with general cognitive function age 65 years but the link between cognition age 65 years and age at menopause might be wholly explained by childhood IQ. The association between childhood IQ and age at menopause may be attributed to central neural mechanisms or, as argued here, to the effects of childhood IQ on adult general health.     

Age at menopause and its relation to osteoporosis

As one phase of a comprehensive population study of women, bone density was determined in the third lumbar vertebra by dual photon absorptiometric technique. The method involves the use of two radionuclides, which both emit gamma radiation but with different energies (241Am with 59.6 keV and 137Cs with 662 keV). Women in three age strata were studied: 46, 54 and 62 yr. All women aged 46 were still menstruating, while the age strata 54 and 62 were subdivided into two groups: those who still menstruated or had been postmenopausal for a short time and those who had been postmenopausal for many years. The bone mineral content was higher in premenopausal or recently postmenopausal 54-yr-old women than in women of the same age who had been postmenopausal for a long time (P less than 0.01). A similar trend was found for women aged 62 (P less than 0.10). The differences could not be explained by differences in other factors studied, such as body weight, body height, smoking habits or physical activity. No significant differences were found when women with similar menopausal status in different age groups were compared.     

Age at menopause as a marker of reproductive ageing

Ages of menopause and of the preceding reproductive events such as the beginning of subfertility and infertility, are likely to be dictated by the process of follicle depletion leading to loss of oocyte quantity and quality. To some extent this process is influenced by lifestyle factors like smoking, and possibly also by the use of oral contraceptives. Genetic factors and possibly also events during intrauterine life, probably play a more important role in the age-dependent decrease of female fertility.     

Age at natural menopause in Yazd, Islamic Republic of Iran

OBJECTIVE: With increasing life expectancy, menopause is an increasingly important aspect of women's health. Although research suggests that age at menopause varies in different ethnic groups, data on age at menopause among Iranian women are limited. We recorded the age at natural menopause among women in a population-based study in Yazd, Islamic Republic of Iran, in 2006. DESIGN: This cross-sectional study estimates age at natural menopause among a sample of 346 menopausal women through cluster sampling and according to their age and the onset of menopause (12 months of consecutive menstrual cessation). RESULTS: We found that the mean (SD) age at menopause was 47.39 (5.089) years (95% CI: 46.85-47.92) and the median age was 48 years. The Iranian women demonstrated a moderate to high frequency of reporting four symptoms in vasomotor, vaginal, sleep-related, emotional, and somatic categories. Physical factors (height, weight, body mass index, handedness) and sociodemographic factors (educational level, income) were not significantly related to early mean age at menopause. CONCLUSIONS: This study provides an estimate of age at menopause for Iranian center women, which is similar to the overall estimates previously reported for Iranian populations. Different factors influence age at natural menopause; however, there has not been a study in which this factor has been confirmed as a significant factor.     

Age at menopause in women with type 2 diabetes mellitus.

OBJECTIVE: Considering that chronic diseases such as diabetes mellitus (DM) may determine premature ovarian failure by various mechanisms, we studied the age at menopause in women without diabetes and in women with type 2 DM. DESIGN: We studied 409 women without diabetes and 404 patients with type 2 DM, selected from 45 to 55 years of age, for analysis with the status quo method. The age at menopause was calculated with a logistic regression on the proportions of menopausal women for each age group. RESULTS: In the groups, 172 women without diabetes and 207 women with diabetes had menopause. The regression procedure gave a median age of 49.7 +/- SD 1.7 years for the whole group, 49.6 +/- 1.6 years for the nondiabetic group, and 49.8 +/- 1.7 years for women with diabetes. Women without diabetes were 1.4 years younger, but this factor did not have an influence on the results. Smoking habits, vegetarianism, and somatometric variables were similar in both groups, except for waist/hip and abdomen/hip ratios, larger in the group of women with diabetes. The mean for years since diagnosis in patients < 45 years of age was 4.9 years. For older patients, the figure increased to 8.9 years. CONCLUSIONS: No difference for age at menopause was found between women without diabetes and women with type 2 diabetes who were 5 to 8 years since the diagnosis was made.     

Age and symptom experience at menopause in the Selska Valley, Slovenia

OBJECTIVE: To assess age and symptom experience at menopause in a high-altitude population in the Selska Valley of Slovenia. DESIGN: In four mountain villages, all houses were approached and 80% of eligible residents were interviewed. Additional women were interviewed for comparison in the valley below. Age at interview ranged from 32.7 to 85.5 years, with a mean of 58.2 years. The majority of women (62%) were aged 40 to 65 years. RESULTS: Of the 58 women interviewed, 7 had undergone menopause by hysterectomy (12%). Recalled age at natural menopause ranged from 42 to 54, with a mean of 50.3 (SD 2.9). By probit analysis, median age at natural menopause was 52.03. Fifty-five percent of participants reported ever having experienced a hot flash, although only 24% reported hot flashes during the 2 weeks before being interviewed. When the sample was limited to women aged 40 to 65, frequency of hot flashes in the 2 weeks before the interview was 39%. For all participants, the most frequent complaint was lack of energy (66%), followed by backaches (59%), and joint stiffness (53%). CONCLUSIONS: In contrast to expectations, age at menopause was not earlier and hot flash frequency was not significantly lower at higher elevations.     

Age at menopause and determinants of hysterectomy and menopause in a multi-ethnic community: The Hilo Women's Health Study

Objectives

A lifespan approach was used to evaluate age at menopause, and determinants of surgical and natural menopause, in the multi-ethnic community of Hilo, Hawaii.

Study design

Participants aged 40–60 years (n = 898) were drawn from a larger, randomly generated sample recruited by postal questionnaires. Median age at natural menopause was computed by probit analysis. Logistic regression analysis was applied to examine determinants of hysterectomy, and Cox regression analysis was used to examine risk factors for an earlier age at menopause.

Main outcome measures

History of hysterectomy, age at menopause.

Results

Frequency of hysterectomy was 19.2% at a mean age of 40.5 years. The likelihood of hysterectomy increased with older ages, lower education, mixed ancestry, having been overweight at age 30, and married 20 years prior to survey. Median age at natural menopause was 53.0 years. Smoking and not being married 10 years before survey were associated with an earlier age at menopause.

Conclusions

Median age at menopause was later than the national average. Ethnicity and education were determinants of hysterectomy, but not associated with age at natural menopause. Events later in the lifespan (e.g., smoking and not being married 10 years prior to the survey) were more important than earlier events (e.g., childhood residence) in relation to age at menopause. The timing of weight gain and marital status appear to be important in relation to surgical menopause, and the timing of marital status appears to be important in relation to the timing of natural menopause.     

Human norovirus infection in Latin America

Noroviruses are important enteric pathogens involved in non-bacterial gastroenteritis outbreaks worldwide. Noroviruses mainly occur from person to person via the fecal-oral route but also through contaminated food or water; indirect contamination is also possible due to the resistance of the virus in the environment. Latin American countries as a whole cover a vast North-to-South range, which is highly heterogeneous in terms of climate, ecosystem, human population distribution (urban areas with high human densities versus closed communities), economic development and genetic backgrounds resulting from each particular historical context. This review aims to present epidemiological and clinical patterns of human norovirus infections in Latin American countries. Divergent prevalences were observed depending on the country and the surveyed population. In particular, a shift in rotavirus/norovirus ratio in the etiologies of gastroenteritis was detected in some countries and could be attributed partly to rotavirus vaccine coverage in their infant population. While GII.4 noroviruses were seen to constitute the most common genotype, differences in genotype distribution were observed both in the environment (via sewage sampling proxy) and between genotypes circulating in healthy and diarrheic patients. Due to high climatic discrepancies, different patterns of seasonality were observed. Accordingly, this continent may condense the different particular epidemiological features encountered for HuNoV infections worldwide.     

Age at menopause and prevalence of its different types in contemporary Greek women

OBJECTIVE: This study attempted to estimate the mean age at menopause and also characterize and quantify its types and frequencies in Greek women who have recently become postmenopausal. DESIGN: A retrospective analysis of hospital records was used to record the frequency of natural, spontaneous or induced premature, and delayed natural menopause; the mean age at menopause of each group; and their possible interrelationships with major events of reproductive history in 1,747 women visiting an endocrine clinic 1 to 5 years after menopause. A group of 438 postmenopausal women drawn from 4,000 cases from the nongynecological clinics of this hospital comprised the control group. RESULTS: Natural menopause was found in 1,333 (76.3%) women with a median age of 51 (95% CI, 50.8-51.2) and mean +/- SD of 48.7 +/- 3.8 years. Medically induced menopause after the age of 40 was recorded in 204 women (11.7%), spontaneous premature in 127 (7.1%), medically induced premature in 60 (3.7%), and delayed menopause in 26 (1.5%), with mean ages of 43.6 +/- 1.7, 35.1 +/- 3.3, 37.2 +/- 1.6, and 59.6 +/- 2.1 years, respectively. No significant differences in mean age at menopause or its types were noted between the two groups. Furthermore, no significant correlations among the parameters examined could be demonstrated except between smoking and age at menopause in the spontaneous premature menopause subgroup (P < 0.05). Finally, ovarian autoantibodies were found in 6.7% of the tested women with premature menopause. CONCLUSIONS: Natural menopause occurred at a mean age of 48.7 years in Greek women, who displayed an unexpectedly high prevalence of spontaneous or induced premature cessation of menstruation.     

Age at menopause and cause-specific mortality in South Korean women: Kangwha Cohort Study

OBJECTIVE: The purpose of this study was to examine the relation between age at natural menopause and all-cause and cause-specific mortality among women. METHODS: This study used the data of the Kangwha Cohort that was followed up from 1985 to 2001, in particular, for the group of 55 years or older women (n=2658). We calculated the hazard ratio of mortality by the group of age at menopause using the Cox proportional hazards model with adjustment for age, alcohol consumption, education, age at first birth, self-cognitive health level, chronic disease, marital partner, parity, age at menarche, oral contraceptive use and hypertension. RESULTS: The mean (standard deviation) age at menopause was 46.9 (4.9) years, and the median age was 48 years. After adjusting for the relevant variables, the risk of total death in the early menopause group (<40 years at menopause) was 1.32 times higher than that of the reference group (45-49 years at menopause) (95% confidence interval [CI], 1.05-1.66, p=0.02). For the early menopause group, relative to the reference group, the adjusted hazard ratios of death due to cardiovascular disease and cancer were 1.53 (95% CI, 1.00-2.39, p=0.04) and 2.01 (95% CI, 1.06-3.82, p=0.03), respectively. CONCLUSION: Through this study, the age at menopause was found to be different between Asian and Caucasian women and the association of age at menopause with death, particularly caused by cardiovascular disease and cancer, was validated. Our study is one of rare studies regarding the age at menopause of Asian women and their risk of mortality, which could be considered to be meaningful.     

Human metapneumovirus strains circulating in Latin America

The human metapneumovirus (HMPV) is responsible for acute respiratory tract infections in young children, elderly patients, and immunocompromised hosts. In this study, we genetically analyzed the circulating HMPV in Central and South America from July 2008 to June 2009 and characterized the strains present in this region. Samples were collected during an international collaborative influenza like illness surveillance study and then sequenced with specific primers for the HMPV G gene. Our results show that two distinct clusters of HMPV circulated in Central and South America, subtypes A2 and B2 being the predominant strains.