Perception of higher frequency of daily hot flashes in 50-year-old women today: a study of trends over time during 48 years in the Population Study of Women in Gothenburg, Sweden.

OBJECTIVE: The aim of this study was to examine if there are any differences in the prevalence of daily hot flashes in 50-year-old women in a longitudinal perspective (from 1968 to 2017). METHODS: Cohort comparisons of four population-based samples of 50-year-old women born in 1918, 1930 (earlier-born cohorts), 1954, and 1966 (later-born cohorts) from the Prospective Population Study of Women in Gothenburg examined in 1968-1969, 1980-1981, 2004-2005, and 2016-2017. Questions about frequency of hot flashes have been formulated in the same way throughout all follow-up examinations. Changes between four generations of 50-year-old women were studied. RESULTS: In the unadjusted model, we found an increased prevalence of daily hot flashes in 50-year-old women born in 1954 and 1966 compared with 50-year-old women born in 1918 and 1930 (odds ratio, 1.74; 95% confidence interval, 1.37-2.22). When considering potential predictors for daily hot flashes (smoking, perceived level of high stress, BMI, waist-to-hip ratio, hormone therapy, and hormonal contraceptives) in the adjusted model, there was a notable difference; odds ratio increases from 1.74 to 1.92 (95% confidence interval, 1.46-2.52). Smoking frequency was substantially lower in the later-born cohorts, 39% compared with 17%. CONCLUSIONS: In this prospective longitudinal study of 50-year-old women, we found nearly twice as high odds of reporting daily hot flashes in the later-born women compared with earlier-born. When controlling for potential predictors, there was still an obvious difference, which cannot be explained in our study. These findings have not earlier been described, and there is a need for further longitudinal population studies investigating the prevalence of hot flashes over time. Moreover, additional research is required exploring the underlying mechanism of hot flashes, as well as studies that take into account potential risk factors in the environment and societal development over time, that is, impacts of endocrine-disrupting chemicals changes in lifestyle, environmental, and dietary factors, as well as working conditions.

Is it possible to investigate menopausal age? A comparative cross-sectional study of five cohorts between 1968 and 2017 from the Population Study of Women in Gothenburg, Sweden.

OBJECTIVE: The aim of this study was to examine if the previously found trend of increasing menopausal age is continuing, taking into consideration hormonal use and surgical menopause in both 38- and 50-year-old women of today. METHODS: Cohort comparisons of five generations of population-based samples of 38- and 50-year-old women from the Prospective Population Study of Women in Gothenburg with start in 1968/1969, and with follow-ups in 1980/1981, 1992/1993, 2004/2005, and 2016/2017. Across the time periods newly recruited women as well as earlier participants were included. Use of hormonal contraceptives, estrogen plus progestogen therapy (EPT), and time for menopause was registered. Changes between different generations of 38- and 50-year-old women from 1968/1969 until today were studied. The overall sample size across the time periods was 1,873 individuals. RESULTS: The prevalence of oral contraceptives in 38-year-old women was about 10% in 1968/1969, increasing from 16% in 2004/2005 to almost 22% in 2016/2017. From 2004/2005 the use of hormonal intrauterine contraceptive method (the Levonorgestrel-releasing intrauterine system [LNG-IUS]) increased from about 11% to 14% in 2016/2017. The same pattern was found in 50-year-old women using LNG-IUS, increasing from 6% to 15.5% between 2004/2005 and 2016/2017. The total hormonal use, including LNG-IUS, oral contraceptives, and EPT, was 28% in 50-year-old women in 2016/2017. The total proportion of hormone use in 50-year-old women increased over the years and together with surgical menopause it reached over 37% in the 2016/2017 survey. CONCLUSIONS: This study has shown an increase in the hormonal use, in both 38- and 50-year-old women, making it difficult to determine when the actual menopause occurs. Thus, the previously found increasing secular trend in menopausal age will be more complicated to assess in female generations of today and tomorrow.

Secular trends in cardiovascular risk factors with a 36-year perspective: observations from 38- and 50-year-olds in the Population Study of Women in Gothenburg.

OBJECTIVES: To study secular trends in cardiovascular risk factors in four different cohorts of women examined in 1968-1969, 1980-1981, 1992-1993 and 2004-2005. DESIGN: Comparison of four representative cohorts of 38- and 50-year-old women over a period of 36 years. SETTING: Gothenburg, Sweden with approximately 450,000 inhabitants. SUBJECTS: Four representative samples of 38- and 50-year-old women were invited to free health examinations (participation rate 59-90%, n =1901). MAIN OUTCOME MEASURES: Body mass index (BMI), systolic and diastolic blood pressure (SBP, DBP), leisure time exercise, use of antihypertensive medication, smoking, levels of haemoglobin, b-glucose, s-cholesterol, s-triglycerides and HDL-cholesterol. RESULTS: There was no significant difference in mean BMI from 1968-1969 versus 2004-2005. Mean leisure time exercise was significantly higher in later born cohorts; in 1968, around 15% were physically active compared with 40% in 2004. SBP and DBP, mean s-cholesterol and s-triglyceride levels were significantly lower in both 38- and 50-year-old cohorts in 2004-2005 versus 1968-1969. HDL-cholesterol (not measured until 1992-1993), showed a significantly higher mean level in 2004-2005. Reduction of risk factors was apparent in women with a high as well as low level of physical activity. Smoking declined most in women with high levels of physical activity. CONCLUSIONS: Several cardiovascular risk factors related to lifestyle have improved in middle-aged women from the 1960s until today. Most of the positive trends are observed in women with both low and high physical activity.

Reproducibility of self-reported menopause age at the 24-year follow-up of a population study of women in Göteborg, Sweden.

OBJECTIVE: To study the reproducibility of self-reported age at natural menopause, reported by women in their 70s, compared with menopause age reported in the initial postmenopausal period. DESIGN: A prospective study conducted in Göteborg, Sweden, based on a random sample of the total female population, started in 1968-1969, with follow ups in 1974-1975, 1980-1981, and 1992-1993. A total of 1,009 women born in 1922, 1918, or 1914 (participation rate 90.3%), representative of women of the respective ages in the general population, participated in the initial examination in 1968-1969. Of those women reporting natural menopause some time between 1968 and 1981, 565 women recalled their menopause age in 1992. RESULTS: The mean interval between the first and second reports was 18.3 years. The mean difference between first-reported and recalled menopause was 0.05 years. When menopause age was recalled in 1992-1993, 55.6% of the women with a natural menopause recalled their age at menopause correctly within 1 year, 22.6% underestimated their menopause age by more than 1 year, and 21.8% overestimated their menopause age by more than 1 year. Women undergoing early menopause (<45 years) tended to overestimate menopause age, whereas women undergoing late menopause (>55 years) tended to underestimate menopause age. These differences could not be explained by age, interval since menopause, smoking, exercise, education, or socioeconomic status. CONCLUSIONS: Menopause ages reported at an interval of almost 20 years showed a significant correlation. However, a regression tendency of the values toward the mean was observed, suggesting that strong correlation at the group level does not imply precision at the extremes.

Evidence for a secular trend in menopausal age: a population study of women in Gothenburg.

OBJECTIVE: To describe secular trends in age of natural menopause. DESIGN: A prospective study based on a random sample of the total female population in Gothenburg, Sweden, started in 1968 with follow-ups in 1974-75, 1980-81, 1992-93, and 2000-02. PARTICIPANTS: 1,462 women born in 1930, 1922, 1918, 1914, and 1908 (participation rate, 90.1%) representative of women of the same ages in the general population. Information regarding menopausal age was provided by 1,373 of the 1,462 women (93.9%). The number was further reduced to 1,017 after exclusion of women who had taken hormones, undergone a surgical menopause, or both. RESULTS: The mean age at natural menopause showed a steady increase across birth cohorts. Trends were similar in women who had smoked and women who had never smoked, even after adjusting for different covariates. The upward trend was 0.1 years per birth year (SE 0.020, P < 0.0001). Interestingly, women with earlier menarche had a somewhat earlier age at menopause, independent of the cohort effect. When hormone users were included in the sample, the cohort effect was also found to be independent of oral contraceptive use and hormone therapy. CONCLUSIONS: This study has shown that, independent of variations in socioeconomic status, smoking status, oral contraceptive use, or hormone therapy use, as well as other potential confounders, there was a highly significant secular trend of increase in menopausal age. The observation of a positive association between menarche and menopausal age has, to our knowledge, not previously been described.

Women's sleep: longitudinal changes and secular trends in a 24-year perspective. Results of the population study of women in Gothenburg, Sweden.

STUDY OBJECTIVES: To present observational data on the frequency of sleep problems, sleep duration, and sleep medication in an urban female population. DESIGN: A prospective population study, initiated in 1968-69, with follow-ups in 1974-75, 1980-81, and 1992-93. SETTING: Göteborg, Sweden, with around 445,000 inhabitants. PARTICIPANTS: 1462 women born in 1908, 1914, 1918, 1922, 1930, and 205 women born in 1942 and 1954, a representative selection of women of the respective age in the general population. INTERVENTIONS: NA. MEASUREMENTS: Reported number of hours slept per night, sleep problems, use of sleeping pills, and sleep satisfaction. RESULTS: The frequency of sleep problems increased with age, as did consultations for sleep problems and the use of sleep medication, while no major differences in these parameters could be discerned in a 24-year secular trend analysis of 38- and 50-year-old women, except a lower sleeping pill use in 50-year-old women in 1992-93. An interesting finding was also that the significant reduction of the proportion of 38-year-old women sleeping more than 8 hours per night between 1968-69 and 1980-81 was not accompanied by a secular deterioration in sleep satisfaction in that age group. CONCLUSIONS: Sleep duration decreased by approximately 0.4 hours per night between the ages of 38 and 66. The frequency of sleep problems increased by around 30% between the ages of 38 and 84. The use of sleeping pills also increased, except in the 50-year-old cohort.

A longitudinal study of the treatment of hot flushes: the population study of women in Gothenburg during a quarter of a century.

OBJECTIVE: To describe the prevalence and treatment of hot flushes in premenopausal and postmenopausal women from the 1960s to the 1990s. DESIGN: This prospective study, based on a random sample of the total female population of 430,000 in Gothenburg, Sweden, was started in 1968, with follow-ups in 1974, 1980, and 1992. The participants were 1,462 women born in 1930, 1922, 1918, 1914, and 1908 (participation rate 90.1%) who were representative of women of the same age in the general population. For the purpose of analyzing secular trends, we included 122 participants who were 38 years old and 47 who were 50 years old in 1980-1981. RESULTS: The prevalence of hot flushes increased from approximately 11% at 38 years to a maximal prevalence of approximately 60% at 52 to 54 years of age, then declined successively from approximately 30% at 60 years of age to approximately 15% at 66 years of age, and then to approximately 9% at 72 years of age. The predominant type of medication being prescribed changed during the observation period from sedatives/anticholinergic drugs in the 1960s to hormone replacement therapy in the 1980s. Hormone replacement therapy was considered to be an effective form of treatment for hot flushes by 70% to 87% of the women. CONCLUSIONS: Hot flushes were a common symptom, with a maximal prevalence of 64% at 54 years of age. Medical consultation and treatment did not increase in 50-year-old women from 1968-1969 to 1980-1981. Treatment changed and became more effective during the observation period.