24 October 2016
Journal round up: Microbes, caffeine and dementia
TMR has scanned the top medical journals for research relevant to GPs over the past two weeks. Here’s what we found:
Beware of the bedmates
Patients who occupy a hospital bed may be more susceptible to Clostridium difficile (C. diff) infection if its previous occupant received antibiotics.
A retrospective cohort study of more than 100,000 pairs of patients showed a 22% relative increase in risk of C. diff for these patients, after adjusting for potential confounders.
The association was independent of the prior bed occupant’s Clostridia status.
Antibiotics might promote C. diff proliferation and the number of C. diff spores that were shed into the local environment, the authors said.
…and go easy on the zinc
A high concentration of dietary zinc may increase susceptibility to Clostridium difficile (C. diff) infection by causing changes to the gut’s microbiome.
A study shows zinc changes the gut’s microbial organisms in a way that mimics antibiotic treatment, which is the primary risk factor for C. diff infection.
Multi-vitamin supplements and cold therapies which contain high levels of zinc should be avoided by patients who are hospitalised or taking antibiotics, unless they have a particular nutritional deficit, the study authors say.
C. diff is the most common cause of hospital-acquired infections.
Non-obese OSA treatment
Normal-to-overweight patients with obstructive sleep apnoea (OSA) require a different approach to treatment, according to Australian researchers.
While obesity is an established risk-factor for sleep apnoea, the study of 163 patients in diagnostic sleep studies found that one quarter of those diagnosed with OSA had a normal BMI and just over half were in the non-obese range.
They also found that more non-obese patients had a low respiratory arousal threshold compared with obese OSA patients (86% vs 60%).
CPAP is less effective in non-obese patients, so clinicians may need therapies that target causes other than upper airway anatomy, such as sleep promotion aids, to allow for deeper more stable sleep and breathing, the study authors say.
J Clin Sleep Med 2016; online 13 September
Caffeine and dementia
The potential of coffee in warding off cognitive decline is supported by findings from a US analysis of more than 6400 women aged 65 or older.
Compared with women with low-caffeine intakes, those who consumed more than 261mg a day were at a 36% reduced risk of diagnosis of probable dementia or cognitive impairment. The intake was equal to two to three cups of coffee or five to six cups of black tea.
The authors did not claim a direct link between caffeine and reduced dementia risk but believe the study raises understanding of how caffeine might benefit cognitive health.