Journals watch: Osteoporosis, malaria, olanzapine and warfarin therapy duration

Too busy to read all of the journals? Dr Sally Hope summarises key papers of interest to GPs.

Osteoporosis: Breast cancer patients' bone health should be monitored
Osteoporosis: Breast cancer patients' bone health should be monitored

Managing osteoporosis in breast cancer survivors

Maturitas 2012; 73:275-9

Monitoring the long-term health outcomes of breast cancer survivors is important. As 70% of breast cancers have estrogen and/or progesterone receptors, antihormonal therapies reduce recurrence, but chemotherapy has a negative effect on bone.

According to the Women's Health Initiative's observational study, women with a history of breast cancer had 68.6 more fractures per 10,000 woman-years than controls. This study was when women were treated with tamoxifen rather than aromatase inhibitors.

Women at baseline of breast cancer have a higher bone mineral density (BMD), as they tend to be fatter, so exposed to high estrogen levels.

In premenopausal women, tamoxifen can have a negative effect on bone density, rather like any other cause of amenorrhoea, but in postmenopausal women, BMD increases by 0.5-1% per year of treatment at hip and spine.

All women should receive advice on weight-bearing exercise and adequate calcium (1,200mg per day through diet if possible) and vitamin D intake (800IU to 1,000IU per day). Additional oral bisphosphonates have been shown to preserve or increase BMD in women taking aromatase inhibitors. Denosumab has been shown to increase lumbar spine BMD by 7.6% over 24 months for women on aromatase inhibitors.

Malaria vaccine in African infants

N Engl J Med 2012; 367: 2284-95

The candidate malaria vaccine, RTS,S/AS01, or a comparator vaccine was given to more than 6,500 babies aged six to 12 weeks in seven African countries. They were followed up for a year to monitor episodes of malaria.

The incidence of the first or only episode of clinical malaria in the intention-to-treat population during the 14 months after the first dose of vaccine was 0.31 per person-year in the RTS,S/AS01 group and 0.4 per person-year in the control group. Serious adverse events were similar in both groups. One month after the vaccine, 99.7% of the vaccinated babies were seropositive for anticircumsporozoite antibodies.

This trial vaccine has a 'modest protective effect' against severe malaria in infants. Could this be a ray of hope for the future?

Neural correlates of weight gain with olanzapine

Arch Gen Psychiatry 2012; 69(12): 1226-37

This study took 25 healthy volunteers and used functional MRI studies before and after one week's treatment with olanzapine.

One week of olanzapine treatment caused significant increases in weight and food consumption, and disinhibited eating.

MRI data showed enhanced activation in the inferior frontal cortex, striatum and anterior cingulate cortex to the anticipation of a food reward. Activation in the caudate and putamen was enhanced on receipt of the rewarding food.

There was a decrease in reward responsivity to giving rewarding food in the lateral orbital frontal cortex, a brain area thought to exercise inhibitory control on feeding.

This study concluded that olanzapine treatment enhanced the brain's anticipatory and consummatory responses to food rewards. There must be a clever pharmacologist who could produce a reverse-olanzapine to produce the best slimming drug ever.

Warfarin therapy duration and risk of mortality

JAMA 2012; 308(20): 2118-25

There has been controversy about the need for continued anticoagulation after surgical aortic valve replacement (AVR) with biological prostheses. Thanks to the records of the Danish National Patient Registry, more than 4,000 patients who had undergone AVR with a bioprosthetic valve over 12 years were identified. The mean duration of follow-up was 6.57 years. More patients who had stopped warfarin treatment within six months of bioprosthetic AVR surgery died from cardiovascular causes (adjusted incidence ratios of 3.51).

  • Dr Hope is a GP in Woodstock, Oxfordshire, and a member of our team who regularly review the journals

Reflect on this article and add notes to your CPD Organiser on MIMS Learning

CPD IMPACT: EARN MORE CREDITS

These further action points may allow you to earn more credits by increasing the time spent and the impact achieved.

  • Audit your practice population for the number of patients who have had a bioprosthetic aortic valve replacement who are not on warfarin. Review their cardiology letters to see why they are not.
  • Review your protocols for women on aromatase inhibitors to include a 'bone health review' of dietary calcium intake, discussion on exercise, discussion on vitamin D, and whether they need a DXA scan to consider treatment with bisphosphonates.
  • Perform an audit of all patients who are using warfarin and reasons for anticoagulation, to present to a practice meeting.

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