What's new in the other journals?
- These snippets are extracts from a monthly service called the Journal Article Summary Service. It is a service that summarises all that is new in obstetrics and gynaecology over the preceding month. If you would like to know the details of how to subscribe, please email the editor Athol Kent at firstname.lastname@example.org or visit the website www.getjass.com.
The Lancet has recently published the most comprehensive report ever on the Global Burden of Disease. This monumental work is like a census of disease, injuries and risks throughout the world in recent decades.
There are over 200 pages of figures, graphs, tables and text on all conditions in all countries which will delight Public Health workers.
The following are the top ten causes of death globally in order of prevalence: ischaemic heart disease, stroke, chronic obstructive pulmonary disease, respiratory infections, lung cancer, AIDS, diarrhoea, road accidents, diabetes and tuberculosis.
The leading countries in the longevity stakes are Japan, Switzerland, Iceland, Sweden, Australia and Israel, where men live to a mean age of nearly 80 years and women outlive them by about 5 years. At the other end of the scale are the Central African Republic, Haiti, Lesotho and Swaziland with life expectancies of 45–50 years.
Survival rates are crude measurements of health, with Disability-Adjusted Life-Years (DALYs) a more sophisticated means of calculating national wellbeing. DALYs count the years of healthy life lost due to premature death or illness. Obviously to measure DALYs one has to know the country's mean survival so the statistics provided by the data in The Lancet's pages are of crucial value. The work done by Murray and his team (Lancet 2012;380:2055–7) is a milestone in the metrics of medicine.
Exercise and longevity
Articles appear regularly extolling the virtues of exercise but seldom are they as clear-cut as the latest offering by Moore et al. (PLoS Med 2012;9:e1001335). The authors say that moderate exercise for half an hour, three times a week will increase your life expectancy by 2 years. More exercise is more beneficial with a brisk walk 7 days a week resulting in a 4 year extension of longevity. If this is coupled with a lean Body Mass Index then one stands to gain 7 years compared with someone who is obese and inactive. It is all carefully calculated taking into account metabolic equivalent hours per week.
The data were gathered from over 650 000 individuals up to the age of 90 years and the dose-related response strongly suggests a cause-and-effect explanation. It would seem prudent to reflect on this well-supported research.
Aspirin keeps popping up as a useful medication in fields other than its basic analgesic or antipyretic role. Apart from its counter-malignancy properties it also has antithrombotic activity, which is useful in preventing arterial and venous thromboembolism (VTE).
Low-dose aspirin (<100 mg/day) is known to protect against arterial vascular events and against VTE in people undergoing surgery, so its effectiveness in preventing the recurrence of VTE after primary anticoagulation is not a surprise (Brighton et al. N Engl J Med 2012;367:1979–87). People who had been anticoagulated following an unprovoked VTE were given aspirin or placebo after 3 months of conventional therapy and the aspirin proved superior in reducing recurrent VTE and cardiovascular-related events. The number of bleeding episodes or serious adverse effects did not increase with aspirin use.
Should everyone over the age of 50 be taking it prophylactically?
There are certain measures that can be taken to reduce one's risk of cancer. Some are general behaviours, like avoiding being overweight, not smoking, and exercising regularly, which appear to decrease overall risk and over which individuals have some control.
There are specific associations of particular cancers with particular actions, like promiscuity and a raised risk of cervical cancer or having children and a lowered risk of breast cancer or even the decreased risk of ovarian cancer related to taking oral contraceptives. Certainly the last words on the protective effects of hormones in the postmenopausal era have not been written so the recipe for a long and healthy life may well become firmly established in the first decades of the twenty-first century.
Certain medications can also change the odds, for example low-dose aspirin reduces the dangers of developing colorectal malignancies (and probably other cancers) and now a new contender may have appeared. Nielsen et al. from Denmark (N Engl J Med 2012;367:1792–802) argue that as cholesterol is a fundamental structural component of cell membranes and is critical in cellular proliferation, a reduction in its availability may inhibit rapid cell division and growth.
As statins reduce cholesterol availability perhaps they can be used to lower cancer risks. To test this hypothesis the researchers compared statin users in the whole of Denmark with nonstatin users and came up with intriguing results. They found that statin users had hazard ratios of 0.85 (95% CI 0.83–0.87) for death from any cause or death from cancer compared with people who never used statins.
There was not a dose-related response nor was any particular type of cancer more or less closely associated with statin use than any other. Maybe a whole new area of cancer prevention research has yet to be explored?
Hormone replacement therapy in perspective
A Danish study in the BMJ (Schierbeck et al. 2012;345:e6409) reports what has long been suspected, that hormone replacement therapy started recently after the menopause is good for women. The research involved 17β-estradiol plus norethisterone acetate versus placebo in women aged 45–58 years and looked at deaths from cardiovascular disease following treatment for a decade and follow up for a further 6 years.
Fewer women died in the group taking the hormones than in the control group (hazard ratio 0.48, 95% CI 0.26–0.87; P = 0.015). Stroke, venous thromboembolism and all cancer rates showed no significant differences over the full 16 years.
Although the numbers were small, just over 1000 participants, the results are encouraging for those wishing to enjoy the benefits of hormone therapy—like freedom from menopausal symptoms, lifestyle advantages and osteoporosis protection—without previously described harms.
Perhaps these data will allow the cycle of drug use to reach equilibrium. Often treatments swing from unbridled enthusiasm, through complete rejection to finding the correct medication, for the right group, at the appropriate time, via the optimal route, for a reasonable duration to derive maximal benefit.
Vitamins, cardiovascular disease and cancer
About half of us will be personally affected by cardiovascular disease (CVD) in our lifetimes. One-third of us will die from CVD. It is therefore unsurprising that, as doctors, we seek to reduce our (and our patients') risk of developing CVD. The concept of ‘risk factors’ was created half a century ago and the critical factors pertaining to CVD are well known; smoking, untreated hypertension, overweight and obesity, diabetes, abnormal cholesterol levels and a lack of exercise.
These are also contributors to cancer, depression, arthritis, renal disease and cognitive decline, so it would be logical for intelligent, informed people (like us) to eat healthily, exercise regularly, avoid smoking and take effective medications where necessary. By and large we do, at least our male American colleagues do, judging from the profile of volunteers to the US Physicians' Health Study recently reporting on vitamin supplements (Sesso et al. JAMA 2012;308:1751–60 and Lonn et al. JAMA 2012;308:1802–3).
Over 14 000 physicians took a multivitamin or placebo for more than 10 years and had themselves monitored for CVD and cancer. It was impressive reading the descriptive data of the men accepted into the study. Their mean Body Mass Index was 26, less than 4% smoked, most exercised weekly and ate healthily. Their rates of cardiovascular events were excellent–about 10 per 1000 person-years–but whether they took multivitamins or not made no difference.
Taking extra vitamins hardly made any difference to cancer occurrence (Gaziano et al. JAMA 2012;308:1871–80 and Bach and Lewis JAMA 2012;308:1916–17). The point is made statistically and pertinently by all the authors involved in these well-conducted studies that ingesting multivitamins is not the answer and they should not be used as an option to risk avoidance. Taking tablets is not an easy way out so a balanced diet plus exercise remain lifestyle priorities. We have to preach and practice positive health.
Pertussis vaccine in pregnancy
The US Center for Disease Control and Prevention (CDC) is advising pertussis vaccination in every pregnancy. They recommend the combined tetanus, diphtheria and pertussis (Tdap) vaccine to all pregnant women irrespective of previous exposure or vaccination.
This approach offers the advantage of passive antibody transfer to the fetus before neonatal vaccination starting at 2 months old. The US authorities suggest five doses of diphtheria, tetanus and pertussis to children by 4 years of age. All mothers not vaccinated antenatally should receive their injections immediately postpartum (Kuehn JAMA 2012;308:2126–2132).