News in brief

Cervical cancer rates skewed by hysterectomies
USING cervical cancer data that include women who are not at risk of developing invasive cervical cancer because of previous hysterectomy underestimates the true incidence of the disease in the US and results in misleading race- and age-specific comparisons, according to research published in Cancer. Researchers have found that the incidence of cervical cancer among all women with an intact cervix does not decline after menopause, but continues to increase until at least age 69 years, particularly in African American women. The researchers, using data on the incidence of cervical cancer collected by the US National Cancer Institute and estimates from the Behavioral Risk Factor Surveillance System, found the prevalence of hysterectomy in women aged 20 years and older was 20.1%. Although the average annual age-standardised rate of cervical cancer was 11.7 cases per 100 000 (95% confidence interval [CI], 11.5–11.8), after correcting the data based on the prevalence of hysterectomy, the rate was 18.6 per 100 000 (95% CI, 18.3–18.9). The uncorrected incidence rates of cervical cancer increased up to, and plateaued at, age 40‒44 years (15.6 per 100 000 women) but corrected data indicated a steady increase in the incidence up to ages 65‒69 years (27.4 per 100 000 women), after which the rates decreased slightly. “The current recommendations on age for cessation of routine cervical cancer screening might be re-evaluated in light of these new results”, the researchers wrote. “The higher rates of cervical cancer after correction for hysterectomy highlights the fact that although a large proportion of cervical cancer has been prevented through early detection and treatment, it remains a significant problem and further emphasizes the need for broad uptake of prophylactic [human papillomavirus] vaccination in the United States.”

Questions over asthma–antibiotic link in infants
A LONGITUDINAL cohort study has found that the association between antibiotic use in early life and asthma might arise through a complex confounding of several factors, including increased susceptibility to viral infections because of impaired antiviral immunity and genetic variants. The study authors speculated that both these factors may increase the likelihood of early life antibiotic prescription as well as later asthma. The research, published in The Lancet Respiratory Medicine, included 916 children followed from birth to age 11 years using antibiotic prescription, wheeze and asthma exacerbations information from medical records, and skin reaction tests to show sensitivity to allergens. At age 11, blood was collected from children who had received at least one course of antibiotics in the first year of life and from those who had not, to compare immune-system cell response to rhinovirus and respiratory syncytial virus (RSV) and bacteria. Genetic testing also looked at the links between common genetic variations on 17q21, and antibiotic prescription. The researchers found a significantly higher risk of both physician-confirmed wheezing, and severe wheeze or asthma exacerbation after antibiotic prescription. In children who wheezed, the hazards of exacerbations and admissions to hospital were significantly increased in the 2 years after the first antibiotic prescription. Children who received antibiotics in infancy had significantly lower induction of cytokines in response to RSV and rhinovirus, but no differences in antibacterial responses. An accompanying commentary said the present study “does not really help” in prescribing antibiotics. The proposal for a randomised control trial of antibiotic use was “worthy of some consideration”, the commentary said.

J-shaped curve for exercise heart risk
TWO studies published in Heart have found high intensity exercise might impact negatively on heart health. One prospective cohort study of more than 1000 patients with stable coronary heart disease found the highest risk of major cardiovascular (CV) events, CV mortality and all-cause mortality was in the least active patients but also observed significantly increased adverse outcomes in those who reported participating in intense physical activity daily. “A potential explanation of our finding of worse prognosis in the most frequently physically active group could be that vigorous exercise increases the risk of ventricular arrhythmias and sudden cardiac death during or after exertion, especially in adults with heart conditions”, the researchers wrote. The second study included more than 44 000 men aged 45‒79 years free of atrial fibrillation (AF) who completed a questionnaire on leisure time exercise in 1997. At follow-up (to diagnosis of AF, death, or the end of 2009, whichever came first), it was found that men who exercised more than 5 hours a week at a younger age had an increased risk of AF in later life. “Physical inactivity and a sedentary lifestyle is a far bigger health problem for the general population [than] excessive physical activity”, the researchers wrote. “However, frequent high-intensity exercise could be associated with a negative health impact.” An accompanying editorial said that “a thin line separates accurate information and unnecessary alarmism leading to inactivity and consequent heart disease”. “The beneficial effects of exercise are definitely not to be questioned; on the contrary, they should be reinforced. The studies reviewed here and future studies will serve to maximise benefits obtained by regular exercise while preventing undesirable effects — just like all other drugs and therapies”, it said.

Disease risks identified by simple questionnaire
AN Australian-designed family history questionnaire (FHQ) has shown “good performance” in identifying primary care patients at increased risk of seven chronic diseases because of their family history. The development and validation of the FHQ, reported in Annals of Family Medicine, included six general practices in Perth, WA, and 526 patients aged 20‒50 years. The FHQ developers used a three-generation pedigree as a reference standard, which included information about ethnicity, disease status of each relative, and age at diagnosis, collected by a genetic counsellor. Disease risk for each condition in the FHQ was based on national risk assessment criteria and classified as either population risk or increased risk. If there was uncertainty because of a more complex family history, a clinical geneticist reviewed the pedigree. The participants met with a research genetic counsellor and completed the FHQ as part of the appointment. The researchers said they had shown that a set of nine simple questions could accurately screen for increased risk of seven common, potentially preventable, serious conditions — heart disease, type 2 diabetes, melanoma, colorectal cancer, prostate cancer, ovarian cancer and breast cancer. “This tool could be applied to identify populations in primary care who could benefit from more detailed assessment and discussion of their disease risk and its management”, they wrote. “The challenge now is how best to implement the systematic application of the FHQ in clinical practice.”

Zinc supplements work in malnourished children
THE benefits of preventive zinc supplementation to reduce diarrhoea and infections in children outweigh the harms in low- and middle-income countries where the risk of zinc deficiency is relatively high, according to a review published in The Cochrane Library. The researchers said the meta-analysis included 80 studies with 205 923 children, who were evaluated for mortality, morbidity, growth and adverse event outcomes. They wrote that the review presented strong evidence for the effectiveness of preventive zinc supplementation on most of the outcomes analysed. However, they did find that the supplements were associated with an increased risk of vomiting. The researchers called for further research to determine optimal intervention characteristics, such as supplement dose. “On the basis of our review findings, policymakers may wish to consider preventive zinc supplementation as one of the public health and nutrition interventions offered to children at risk in low- and middle-income countries”, they wrote. “However, preventive zinc supplementation is not a sufficient or long-term solution to the nutrition and health challenges facing children in resource-scarce settings. Children ultimately need well-balanced diets, and poverty is often a risk factor for undernutrition and pathogen exposure. Unfortunately, until these issues are effectively addressed, zinc deficiency (and the mortality, morbidity, and growth deficits associated with it) will likely remain.”

Second trimester increases car crash risk
THE risk of a serious motor vehicle crash significantly increases during the second trimester of pregnancy, according to research published in CMAJ. The researchers found that the increased risk extended to diverse populations, varied obstetrical cases and different crash characteristics. They found that the increased risk was greatest in the early second trimester and compensated for by the third trimester. They did not observe any increased risk in intentional injury, inadvertent falls or self-reported risky behaviours among the study participants. The population-based, self-matched cohort analysis included 507 262 women who gave birth in Ontario, Canada, between 2006 and 2011. The researchers followed the women for 5 years and found the women accounted for 6922 motor vehicle crashes as drivers during the 3-year baseline interval before pregnancy (177 crashes per month) and 757 crashes during the second trimester (252 per month), equivalent to a 42% relative increase (95% confidence interval, 32%–53%; p < 0.001). They said the absolute risk of a crash during the second trimester was similar in magnitude to the risk associated with sleep apnoea. “These findings suggest that pregnancy might contribute to the risk of a serious motor vehicle crash”, the researchers wrote. “These findings underscore the importance of prevention and suggest that prenatal care guidelines for pregnant women should include safe driving.”