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Life expectancy gap between women and men getting smaller

Life expectancy estimates in England and Wales based on “Bayesian spatiotemporal” models conclude that female babies born today can expect to live to 83.3 years, with males slowly closing the gender gap and expected to live to 79.5 years. ¹ Indeed, male catch-up seems now to be moving at an accelerated pace: between 1981 and 2012, life expectancy increased by 8.2 years for men and 6.0 years for women, thereby closing the female–male gap from 6.0 to 3.8 years.

The study also predicted that male babies born in 2030 could live to an average age of 85.7 years, and females to an average of 87.6 years. These, according to one or two news reports, are higher life expectation predictions than official estimates, with inevitable repercussions for healthcare and social services. “Present forecasts underestimate the expected rise in life expectancy,” the investigators write, “especially for men, and hence the need to provide improved health and social services and pensions for elderly people in England and Wales.”

The study, which was funded by the UK Medical Research Council and Public Health England, also found striking variations within the national statistics according to location, health and socioeconomic inequalities. For example, the study estimated that life expectancy in the affluent London borough of Kensington and Chelsea would be five to six years higher than the working class area of Tower Hamlets.

Data for all deaths in England and Wales between 1981 and 2012 (more than 17 million records) were supplied by the Office for National Statistics (ONS), with age, sex, date of death and postcode of residence available for each record. This “district life expectancy” model for 2012 revealed a life expectancy range from 75.2 to 83.4 years for men, and from 80.2 to 87.3 years for women. Life expectancy was lowest in urban northern England and southern Wales, and highest in southern England and some of London’s more affluent districts.

The investigators note that life expectancy trends “should not be attributed solely to changes in health status of individuals” but they do insist that these trends are “largely due to changes in population health”. These inequalities, in life expectancy and in health, are predicted to continue, and even accelerate. For example, in 1981 women in districts with the highest life expectancies could expect to live 4.5 years longer than those in districts with the lowest life expectancies but by 2012 this difference in female life expectancy had increased to 5.6 years.

And on the question of life expectancy estimates higher than the ONS, the investigators conclude that “pensions will have larger pay-outs than those currently planned, and health and social services will have to serve an even older population, with chronic and comorbid disorders, than that currently planned”.

Cochrane review finds little evidence for cardioprotection from HRT, though some support for the “timing hypothesis”

Hormone replacement therapy (HRT) has been described as a “complicated health issue” in an updated Cochrane review of cardiovascular disease and HRT. ¹ Indeed, the report was said by no less than the editor-in-chief of the Cochrane Library to add “a few more pieces to a complicated jigsaw of evidence relating to the use of HRT”.

The complications, according to the editor, are found in a mixed bag of benefits and harm which might apply to one woman and not another. Thus, when the reviewers looked at the timing hypothesis as applied to the age of the woman or years since menopause,

we found that if 1000 women under 60 years old started hormone therapy we would expect six fewer deaths, eight fewer cases of heart disease, and five extra blood clots over about seven years, compared to 1000 similar women who did not start hormone therapy.

Such findings, he added, “need to be carefully considered”.

Since 1996, systematic reviews and meta-analyses prepared and maintained by the Cochrane Collaboration and published in The Cochrane Library have been considered among the strongest pillars of evidence-based medicine. Yet, the fact is that such systematic reviews are only as strong as the studies analysed, and this latest Cochrane update makes it quite clear that “the findings are dominated by the three largest trials” (two from the Women’s Health Initiative, WHI, of 2002 and 2004 and the HERS trial of 1998). These three studies contributed around three-quarters of the subjects in the 19 trials reviewed (a total of 40,410 postmenopausal women), with most participants living in the USA and most, as in the WHI studies, aged over 60.

Patient age, however, was additionally important in this review, because the study had a secondary aim to assess the impact of time since menopause (≥10 years vs. <10 years), and, where these data were not available, to use age at baseline as a proxy (≥60 years of age vs. <60 years of age).

With the WHI so dominating the data, it was no surprise to find with HRT that “both primary and secondary prevention conferred no protective effects for all-cause mortality, cardiovascular death, non-fatal myocardial infarction, angina, or revascularisation”. In addition, there was an increased risk of stroke in HRT subjects for combined primary and secondary prevention (RR 1.24, 95% CI: 1.10–1.41) and of venous thromboembolism (RR 1.92, 95% CI: 1.36–2.69).

However, the subgroup analyses did show that those who started HRT less than 10 years after the menopause did have lower mortality (RR 0.70, 95% CI: 0.52–0.95) and less coronary heart disease (RR 0.52, 95% CI: 0.29–0.96) than those on placebo or no treatment – though they were still at increased risk of venous thromboembolism.

The review’s first author, Henry Boardman from the Department of Cardiovascular Medicine at the University of Oxford, acknowledged that the evidence “provides some support for the so-called ‘Timing Hypothesis’, but we should bear in mind the size of this effect”. He thus concluded that HRT “remains a valid treatment option for women who are significantly troubled by menopausal symptoms; however, the risks and benefits of such treatment vary according to age and medical history”. But the overall conclusion remained a stubborn echo of the original WHI findings that

our review findings provide strong evidence that treatment with hormone therapy in post-menopausal women overall, for either primary or secondary prevention of cardiovascular disease events has little if any benefit and causes an increase in the risk of stroke and venous thromboembolic events.

And one assumes that as a result of this update the guidelines of the regulatory authorities and the learned colleges remain as before – that, as noted for example by the American College of Obstetricians and Gynecologists in 2013, “menopausal [hormone therapy] should not be used for the primary or secondary prevention of coronary heart disease at the present time” (even though “recent analyses suggest that HT does not increase CHD risk for healthy women who have recently experienced menopause”). ²

Oophorectomy benefits in breast cancer patients with BRCA1 mutation

Oophorectomy has been associated with a 62% reduction in breast cancer death in women carrying a BRCA1 gene mutation in a Canadian study. ¹ The study was a retrospective analysis of 676 patients selected by pedigree review with stage I or II breast cancer and a BRCA1 or BRCA2 mutation. They were followed-up for up to 20 years after receiving a diagnosis between 1975 and 2008. Survival experience was compared for women who did (n = 345) and did not (n = 331) have oophorectomy.

As background to the study, the investigators reported that women who carry a mutation in either the BRCA1 or BRCA2 gene face a lifetime risk of breast cancer of up to 70%. Once diagnosed with breast cancer, they face further high risks of both second primary breast and ovarian cancers. However, several studies of BRCA gene mutation carriers have reported reduced mortality associated with oophorectomy for women with a history of breast cancer.

Results of this study showed that 20-year survival for the entire patient cohort was 77.4%. However, there was a 56% reduction in breast cancer death associated with oophorectomy in the entire group. More specifically, oophorectomy was associated with a significant reduction in breast cancer death in women with a BRCA1 mutation (HR 0.38, 95% CI: 0.19–0.77), but not in women with a BRCA2 mutation, where the 43% rate reduction was not statistically significant.

Oophorectomy was performed in this study population, a mean of 6.1 years after diagnosis. However, for the 70 BRCA1 carriers who had oophorectomy within two years of their breast cancer diagnosis, the hazard ratio was 0.27 (95% CI: 0.11–0.66) compared with women without oophorectomy.

There were in addition nine deaths from ovarian cancer recorded in the non-oophorectomised group, and the study revealed a 65% reduction in all-cause mortality associated with oophorectomy. The authors noted that the protective effect of oophorectomy on deaths from breast cancer was apparent immediately after diagnosis and lasted for 15 years.

In an editorial commentary on the study, the editor of JAMA Oncology writes that the results “provide a validation of the role of oophorectomy in conveying both a disease-free and overall survival benefit for BRCA1 mutation carriers”, adding that the data are “compelling” and suggest that oophorectomy should become part of the treatment discussion at the time of diagnosis for BRCA mutation carriers with early-stage breast cancers. ²

As for the investigators, they suggest that oophorectomy should be discussed with the patient shortly after diagnosis, and “recommend that the operation be performed in the first year of treatment to maximize the benefit”.

Incidence of falls among older women in Finland unaffected by vitamin D or exercise

Neither exercise training nor vitamin D supplementation had any effect on the overall rate of falls in a two-year randomised trial performed in more than 400 elderly women living in community dwellings in Finland. ¹ Fall rates, in each of four groups studied, were 118.2 per 100 person-years in those taking placebo without exercise, 132.1 (vitamin D without exercise), 120.7 (placebo and exercise) and 113.1 (vitamin D and exercise).

However, the study did find as a secondary outcome that the rate of injurious falls was cut by more than half among exercisers with or without vitamin D, and that vitamin D helped maintain bone mineral density in the femoral neck.

As background to the study, the authors noted that falls are the leading cause of unintentional injuries and fractures in older adults. However, results from clinical trials of the role of vitamin D in reducing falls and fractures in older adults and in improving physical functioning have been inconclusive.

Given that fall risk appears multifactorial, the investigators suggest that exercise may still be the most effective and feasible strategy for preventing injurious falls in community-dwelling older women (with good levels of vitamin D).

It was further emphasised in an accompanying commentary that the subjects in this study were European, and that vitamin D is the “sunshine vitamin”. No doubt mindful of Finland’s winter daylight (to say nothing of sunshine), they question whether the results of this study are applicable in the USA, where official recommendations are still that those at risk of falling should take vitamin D. And even if this study does keep a small question mark hanging over vitamin D, the results still reminds us “that the strongest and most consistent evidence for prevention of serious falls is exercise”.