Abstract
Age at menopause and the risk of chronic illness
Calculations of age at menopause vary with ethnicity, country and definition. However, by applying the most common definition (of NICE and WHO, for example) a woman is recognised as postmenopausal from one year after her last menstrual period – and the mean age of women at menopause remains 51 years. A global consortium study of more than 500,000 women published last year found a mean age at natural menopause of 50.5 years, but no trend change over time. 1 In 2013 the SWAN study (Study of Women’s Health Across the Nation) after following-up more than 3000 pre- and perimenopausal women from five ethnic groups reported a median age at final menstrual period of 52.5 years, with the higher ages found among women who did not smoke, reported better health at baseline, had more education, had higher baseline weight, or had previously used oral contraceptives. 2
However, all studies seem to suggest that this age has remained fairly constant throughout recent generations and time periods, unlike age at menarche which has seen a small but clear decrease in birth cohorts. However, a population study of 312,656 women born in Norway between 1936 and 1964 has found that their mean age at natural menopause did indeed increase – by more than two years over the study period, rising from 50.31 years in those born during 1936–1939 to 52.73 years in those born during 1960–1964. 3
If this temporal change is real and evident elsewhere, does it matter? Certainly, while age at menopause is considered a marker of age-related morbidity and mortality risk in several specific conditions in postmenopausal life (cardiovascular disease, diabetes, osteoporosis, dementia), a new study has now broadened this association to the development of multiple chronic conditions. 4 And age at menopause is important because the earlier it is, the greater the risk of multimorbidity in later life.
The study was a prospective cohort study of 11,258 Australian women aged 45–50 years in 1996, who were followed from 1996 to 2016. Among those who reported their age at natural menopause (n = 5107) 2.3% had premature menopause (≤40 years) but more than 50% developed multimorbidity (defined in the study as two or more of 11 specific conditions). And what the study emphatically showed was that those with premature menopause had twice the risk of multimorbidity by age 60 (and three times more in their 60s) than women with menopause at age 50–51 years. Women with premature menopause also experienced a higher incidence of most individual chronic conditions.
Researcher Xiaolin Xu, formerly of the University of Queensland, said in a press statement: We found that 71% of women with premature menopause had developed multimorbidity by the age of 60 compared with 55% of women who experienced menopause at the age of 50–51. In addition, 45% of women with premature menopause had developed multimorbidity in their 60s compared with 40% of women who experienced menopause at the age of 50–51.
By way of background to the study they note that multiple chronic conditions affect more than 60% of elderly women, with multimorbidity recognised as a common ‘chronic condition’ in older people and a ‘focus for women’s postmenopausal health’.
References
Further confirmation of the long-term benefits of a healthy lifestyle for postmenopausal women
There’s little doubt that modifiable lifestyle factors affect both total life expectancy and incidence of chronic diseases. Indeed, the majority of premature deaths seem attributable to smoking, inactivity, poor diet and heavy alcohol consumption, although there is little research to tell us how a combination of multiple lifestyle factors may relate specifically to life expectancy free from major disease.
Now, an analysis from two long-running cohort studies in the USA, the evergreen Nurses’ Health Study and the Health Professionals Follow-Up Study, collectively comprising well over 100,000 subjects, has cross-linked life expectancy free of cancer, diabetes and cardiovascular disease with adherence to five healthy lifestyle factors and found that the ‘healthy’ epithet really does apply, especially in women. 1
When women in the study adopted none of the five defined low risk lifestyle factors – never smoking, body mass index 18.5–24.9, moderate to vigorous physical activity for at least 30 min a day, moderate alcohol intake, and a high quality diet – their disease-free life expectancy at age 50 was 23.7 years. However, when they followed four or five of the healthy lifestyle factors disease-free life expectancy at age 50 increased by more than a decade, to 34.4 years.
As expected with subject numbers so high, much self-reporting and multiple scoring parameters, this was a complicated study, but one which, the authors state, gains its strength from the big numbers and repeated measurements of lifestyle factors from the 1980s onwards.
Not on the disease-free risk-list of this study was osteoporosis and fracture, but the association of physical activity and sedentary behaviour with fracture incidence among postmenopausal women was the subject of a new study of subjects from the Women’s Health Initiative trial. 2 This time, 77,206 postmenopausal women from the WHI cohort (mean age 63 years) were assessed over a mean follow-up of 14 years to find that total physical activity was inversely associated with the multivariable-adjusted risk of hip fracture. Even mild activity and walking were associated with lower hip fracture risk, a finding, say the authors, with important public health implications ‘because these activities are common in older adults’. Indeed, 33.1% of the eligible WHI cohort reported at least one fracture. Results showed that women in the highest total activity tertile had an 18% lower risk of hip fracture, although benefits were evident in ‘non-recreational’ activity such as household chores and gardening. However, not all fracture types seemed amenable to prevention. Thus, while hip fracture in this study was inversely associated with physical activity, the risk of vertebral fracture in later life seemed only reduced by mild and not intense physical activity. Noting that ‘mild physical activity and walking account for the majority of daily activity time in WHI participants’, the authors stress that these lower-intensity activities ‘are more easily adopted by older individuals and should be recommended when such activity is not contraindicated’.
References
More than ten lifetime sexual partners linked to heightened cancer risk
A study reported in the recently titled BMJ Sexual & Reproductive Health (formerly the Journal of Family Planning and Reproductive Health Care) suggests that sexual history – or more precisely the number of sexual partners – should now be added to the list of indicators for cancer risk in older people. 1 So far, say the authors of this study, the only interest in the back-list of one’s sexual partners has been in younger people and the risk of sexual infection, particularly the human papilloma virus. But now, this study has found, a higher lifetime number of sexual partners is associated with a higher chance of reported cancer later in life. Behind the study lies the hypothesis that, because many STIs go unreported, the number of sexual partners might provide a more accurate proxy measure of sexual risk behaviour.
The sample studied comprised more than 5000 subjects (male and female) from the English Longitudinal Study of Ageing in which participants reported the number of sexual partners they had had in their lifetime. Using logistic regression analysis, these numbers were associated with three self-reported long-standing illnesses, cancer, coronary heart disease and stroke. And results showed that having had ten or more lifetime sexual partners was – in both men and women – associated with statistically significant higher odds of diagnosed cancer than having had no or one sexual partners, especially in women (OR men 1.69 vs. OR women 1.91). This higher risk in women was extended to risk of any limiting long-standing illness, which was not evident in men.
All subjects in the study were aged over 50, with survey data collected from 2002 onwards ‘via computer-assisted personal interview and self-completion questionnaires. However, in women the differences between those reporting 2–4 and 5–9 sexual partners and those reporting 0–1 sexual partners were not statistically significant; but those who had had 10 or more lifetime sexual partners had 91% higher odds of reporting a diagnosis of cancer than those with 0–1.
While this was an observational study (and reliant mostly on self-reporting), the authors do implicate STIs as the likely explanatory factor in the association. But an explanation for the gender difference in long-term risk, they write, remains ‘elusive’, especially given that men tend to have more lifetime sexual partners than women, while women are more likely than men to see a doctor when they feel ill, so potentially limiting the associated consequences for their long-term health. And on such sensitive matters, could we always expect honest answers?
Reference
Women have steeper BP trajectories than men, even from an early age
It’s a long held view that women have greater cardio-protection than men in their earlier years, but, when the protective effect of estrogen declines with the menopause, women’s blood pressure levels and cardiovascular risk catch up. But a new study suggests that such a view may not be quite accurate and that there is a fundamental difference in cardiovascular pathophysiology between the sexes which demands consideration.
With blood pressure readings noted as the single most accessible measure of vascular ageing and increased BP the largest contributor to cardiovascular risk, a study based on BP trajectories over a life course from four community cohorts has found that from as early as their third decade women actually experience steeper increases in blood pressure than do men. 1
‘In contrast with the notion that important vascular diseases in women lag behind men by 10 to 20 years,’ they write, ‘our findings indicate that certain vascular changes not only develop earlier but also progress faster in women than in men. In effect, sex differences in physiology, starting in early life, may well set the stage for later-life cardiac as well as vascular diseases that often present differently in women compared with men’. If a clinician sees two patients of the same age and similarly elevated blood pressure, but one male and one female, before this paper we would think they should receive the same kind of intervention. But now we know that in order for the woman to have reached a level of 140, her BP has risen earlier and faster than is the case for the man. I would say that of these two patients, the woman is likely to be at higher risk of blood-pressure-related outcomes than the man.
References
BMS describes disruption to HRT supply as ‘unacceptable’
The British Menopause Society, in a joint statement with the RCOG (Royal College of Obstetricians and Gynaecologists) and the Faculty of Sexual and Reproductive Healthcare, has described the continuing disruption to supplies of hormone therapies as ‘unacceptable’ and harmful to women. 1 Many supplies, says the statement, have been unavailable for the past year, and in response the BMS has published an update on the availability of every preparation following discussion with manufacturers. 2 The update advises that equivalent preparations might be considered, whose contents might be checked on the BMS’s ‘practical prescribing’ chart. 3 The update, effective on 27 January, lists some products as ‘available’, but many are out of stock, notably Indivina and Estorel, whose manufacturers, says the update, have announced restored and stable stocks in the coming months. The shortage, said the BMS, ‘seems to be unique to the UK’.
Edward Morris, joint editor of this journal and newly elected President of the RCOG, said it was his understanding that ‘the HRT supply situation should begin to improve from February 2020’ – though some products, he added, could remain unavailable until the end of the year. It remains unclear why the situation has arisen, he said, and ‘the lack of transparency around why these shortages have occurred is extremely frustrating’.
The joint statement was preceded by a letter to health secretary Matt Hancock (dated 5 February) calling for a working group to examine the situation. The news prompted several newspapers to report that many women were ‘shopping around’ online for HRT, ‘some paying over the odds in the process’. According to the Daily Telegraph, ‘one Bristol pharmacy has been reported as selling three months’ supply of FemSeven HRT patches – available for £18 from the NHS – for £68.97’. The Daily Mail had a catalogue of similar outrages.
Haitham Hamoda, chair of the BMS, said that the BMS website will keep its list of product availabilities updated and continue its advice on alternative treatments.