• Most self-test blood pressure devices found to be inaccurate
• Mid-range cholesterol level found to be healthiest for elderly
• Reviparin superior to standard heparin for DVT
• Risk of death reduced by eating just one serving of fruit or vegetables a day
• Once-a-week fluoxetine approved in US
• Incidence of stroke not changed by HRT, trial results suggest
• MS drug may also have use in glaucoma
• Study shows benefit of continuing antiretrovirals in drug-resistant HIV
• Imaging technique shows plaque reversal in Alzheimer’s disease
• PHLS recommends longer antibiotic courses for URTIs
• Ion transportation: determining the severity of cystic fibrosis
• Elderly patients unable to use zanamivir inhaler

Most self-test blood pressure devices found to be inaccurate

Only five out of 23 validated devices for self-measurement of blood pressure can be recommended, according to the European Society of Hypertension.

Members of the society's working group on blood pressure monitoring reviewed the validation of a total of 54 blood pressure monitoring devices and found that the majority could not be recommended because they were inaccurate.

As part of the review, the working party surveyed devices designed for self-measurement of blood pressure at the upper arm and wrist. Devices that measure blood pressure by occluding a digital artery in the finger were not included in the review as this technique is no longer recommended, they say.

None of the devices for measuring blood pressure at the wrist could be recommended for their accuracy by the working party. They comment: “Since these devices become inaccurate if the arm is not kept at heart level during measurement, the working party is reluctant to recommend them, regardless of accuracy.”

Of the 23 devices for self-measurement of blood pressure at the upper arm, five were recommended. The working party comment: “There is a large market for blood pressure measuring devices, not only in clinical medicine but also among the public where the demand for self-measurement is growing rapidly... Most devices have not been evaluated for accuracy independently...Too often accuracy has been sacrificed for technological ingenuity.”

The devices reviewed in the study had been validated using protocols from the Association for the Advancement of Medical Instrumentation (AAMI) and the British Hypertension Society (BHS). A device was recommended if it fulfilled the AAMI criteria for both systolic and diastolic pressures and if it achieved at least grade B (where A denotes greatest agreement with mercury standard and D least agreement) under the BHS protocol.

The study is published in the British Medical Journal (2001;322:531).

Recommended devices The devices for self-measurement of blood pressure recommended by the working party are: Omron HEM-705CP, Omron HEM-722C, Omron HEM-735C, Omron HEM-713C and Omron HEM-737 Intellisense.

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Mid-range cholesterol level found to be healthiest for elderly

Research suggests that elderly patients with mid-range cholesterol levels are less likely to develop coronary heart disease (CHD) than those with high or low levels.

American researchers studied 2,424 men, aged between 71 and 93, for six years. They found that men with total cholesterol levels between 5.2 and 5.7mmol/L were least likely to develop coronary heart disease. Compared with this group, men with cholesterol levels above 6.2mmol/L had a 90 per cent greater chance of developing CHD and, more surprisingly, men with levels below 4.2mmol/L had a 55 per cent greater risk of developing CHD, they say.

Presenting the results at the American Heart Association’s 41st annual conference on cardiovascular disease epidemiology and prevention on March 2, the researchers commented: “The study indicates that, in the elderly, it is not good to have a cholesterol too high, and it is not good to have it too low.”

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Reviparin superior to standard heparin for DVT

Reviparin, a low-molecular-weight heparin, is more effective than unfractionated heparin for the initial treatment of deep-vein thrombosis (DVT), a study has shown. According to research led by Dr Hans Klaus Breddin (International Institute of Thrombosis and Vascular Diseases, Frankfurt, Germany), reviparin is also more effective in preventing the recurrence of venous thromboembolism (New England Journal of Medicine 2001;344:626).

Patients with acute DVT of the legs were assigned to receive either unfractionated heparin for five to seven days, reviparin twice daily for five to seven days or reviparin once daily for 28 days. The researchers found that a reduction in thrombus size was evident in 40.2 per cent of patients (129 out of 321) receiving unfractionated heparin, compared with 53.4 per cent (175 out of 328) of those receiving reviparin twice daily and 53.5 per cent (167 out of 312) receiving reviparin once daily. They comment that reviparin once daily, which was given without a vitamin K antagonist for the first 21 days of treatment, could be a safe and effective alternative for the treatment of DVT in patients with a contraindication to oral anticoagulant therapy.

Reviparin (Clivarine) is licensed in the United Kingdom for the prevention of thrombosis and thromboembolism (PJ, February 5, 2000, p230).

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Risk of death reduced by eating just one serving of fruit or vegetables a day

Increasing fruit and vegetable intake by as little as one serving each day may reduce the risk of death by 20 per cent, say Professor Kay-Tee Khaw and colleagues (school of clinical medicine, University of Cambridge).

“Those who ate the most fruit and vegetables gained the most benefit”, Professor Khaw told The Journal on March 7. She added that people should still be encouraged to eat the recommended five servings each day.

The researchers examined the relationship between plasma vitamin C concentration and subsequent death in 19,496 men and women aged between 45 and 79 years. They measured plasma ascorbic acid concentrations, and participants completed a health and life-style questionnaire and a seven-day diet diary. Participants were followed up for causes of death for about four years.

The researchers found that the risk of death among those with the highest plasma ascorbic acid concentrations was about half that of those with the lowest concentrations. The inverse relationship was shown for death from all causes, death from cardiovascular disease and ischaemic heart disease in both men and women, and for death from cancer in men. That ascorbic acid concentration was inversely related to cancer mortality in men but not in women might be because the relationship was specific to cancer types that are more common in men, they suggest.

A third of men and half the women participating in the study reported use of some sort of supplement but the researchers say that there was no association between supplement use and mortality. “Whether ascorbic acid supplements are beneficial remains to be seen,” they say. “Plasma ascorbic acid might indicate the intake of foods that are rich in other nutrients ... that might confer health benefits.”

The researchers conclude that their findings could have clinical and public health implications and suggest that “small and feasible shifts within the normal population intake [of fruit and vegetables] could have a substantial effect on mortality risk” (Lancet 2001;357:657).

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Once-a-week fluoxetine approved in US

A once-weekly formulation of the selective serotonin reuptake inhibitor fluoxetine (Prozac) has just been licensed in the United States. The Food and Drug Administration has approved the product for treatment of the continuation phase of long-term depression (ie, patients whose depressive symptoms have stabilised, and who require continuing treatment to prevent a relapse or return of symptoms).

A spokeswoman for Lilly (manufacturer of Prozac) in the United Kingdom told The Journal on March 6 that Prozac Weekly contained 90mg of fluoxetine and was an enteric-coated, modified-release formulation that was taken once a week.

An application for a licence for once-weekly fluoxetine had been made to the Medicines Control Agency and the company was awaiting its decision, she said.

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Incidence of stroke not changed by HRT, trial results suggest

Hormone replacement therapy (HRT) does not alter the risk of stroke in postmenopausal women with heart disease, according to American researchers.

In the Heart and Estrogen/progestin Replacement Study (HERS), Dr Joel Simon (University of California, San Francisco) and colleagues found that 7 per cent of women who had been assigned HRT suffered a stroke compared with 5 per cent of those receiving placebo. This difference was not significant, they say.

The HERS trial was primarily designed to determine whether a combination of oestrogen and progestin would prevent recurrent heart attacks or worsening of angina in postmenopausal women with heart disease (PJ, August 29, 1998, p300). A total of 2,763 women were enrolled into the study and received either an oestrogen-progestin combination or placebo. The women were followed up for an average of 4.1 years.

One of the secondary goals of the study was to determine the effect of this hormone combination on the incidence of stroke and transient ischaemic attacks. Of the participants, 149 suffered a total of 165 strokes, of which 85 per cent were ischaemic strokes. The researchers found that the women treated with hormone therapy were at neither an increased nor a decreased risk of stroke.

Commenting on the results, Dr Simon said: “The decision to use or not use hormone therapy should be based on its known risks and benefits, and not on any presumed effect on stroke.” The study is published in Circulation (2001;103:638).

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MS drug may also have use in glaucoma

Glatiramer acetate (Copaxone), a drug used to treat multiple sclerosis, may be a potential therapy for glaucoma, researchers from Israel have shown.

Professor Michal Schwartz and colleagues (the Weizmann Institute of Science, Rehovot) showed that 4.3 per cent of nerve cells died in the glaucoma-affected eye of rats given a single injection of glatiramer, compared with 27.8 per cent in the eyes of rats that were not.

The researchers say that although the initial damage to the optic nerve observed in glaucoma is caused by increased intraocular pressure, it is secondary factors triggered by the initial damage that contribute to ongoing degeneration. One such factor is the neurotransmitter glutamate, which is released from damaged nerve cells.

The researchers say that glatiramer protects these cells from glutamate toxicity and could be developed “to reduce the neuronal toxicity associated with glutamate”. They add that, because glaucoma can progress even when intraocular pressure remains within the normal range, treatment for this disease should include neuroprotective therapy.

The study is published in the Proceedings of the National Academy of Sciences (2001;98:3398).

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Study shows benefit of continuing antiretrovirals in drug-resistant HIV

Continuing treatment against drug-resistant HIV infection provides sustained clinical benefit despite reducing drug susceptibility, according to American researchers.

In a small, randomised study, led by Dr Steven Deeks (University of California, San Francisco), 16 patients with persistent viraemia were assigned either to continue (five patients) or discontinue (11 patients) treatment with their antiretroviral regimens. Treatment was resumed at 12 weeks from baseline.

The researchers found that continuing therapy with a regimen containing protease inhibitors lowered the capacity of viruses to replicate. Discontinuing therapy for 12 weeks resulted in a greater decrease in CD4 cell counts and a greater increase in plasma HIV RNA than did continuing therapy.

The researchers say that plasma HIV RNA levels increased immediately after therapy was discontinued, suggesting that, even though there was viral drug resistance during treatment, antiretrovirals had some degree of activity. (New England Journal of Medicine 2001;344: 472.)

In an accompanying leading article, Dr Lisa Frenkel and Dr James Mullins (University of Washington School of Medicine, Seattle) comment that the benefit of continued drug therapy in patients with drug-resistant infection might be because of continued suppression of drug-sensitive viruses (ibid, p520).

They add that the strategy of continuing treatment “will need to be compared with other strategies, such as those aimed at detecting drug resistance early, at a time when a change of therapy might suppress replication to an undetectable level”.

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Imaging technique shows plaque reversal in Alzheimer’s disease

A new imaging technique has been used to show the clearance of plaques present in Alzheimer's disease from the brains of live mice.

American researchers have developed an imaging technique which, they say, allows visualisation of distinct structures in living brain and might allow early diagnosis of the disease.

The researchers, from the Alzheimer's disease research laboratory at Massachusetts general hospital, used antibodies to amyloid-b (the protein which makes up the plaques) to treat mice with Alzheimer’s disease and imaged the plaques before and after treatment. Repeat imaging showed that few or none of the amyloid-b deposits that were present at the initial imaging remained.

The study supports the idea that existing plaques can be cleared by immunotherapy, say the researchers. They add: “Direct imaging of these lesions in the living brain would revolutionise early diagnosis of Alzheimer’s disease.” Currently, diagnosis can only be confirmed post-mortem.

The study is published in Nature Medicine (2001;7:369).

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PHLS recommends longer antibiotic courses for URTIs

Upper respiratory tract infections may need to be treated for up to seven days to prevent relapse, according to draft guidance from the Public Health Laboratory Service.

The guidance overturns the Standing Medical Advisory Committee guidelines, which suggest that courses of antibiotics for otitis media and sinusitis should last only three days. The guidance can be found on the PHLS website (www.phls.co.uk).

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Ion transportation: determining the severity of cystic fibrosis

A theory to explain the differences in the degree of severity of cystic fibrosis (CF) has been suggested by researchers. The transportation of chloride ions across cells is known to be reduced in CF but the new research indicates that reduced transportation of bicarbonate ions may also be important.

CF is a disease caused by mutations in the CF transmembrane conductance regulator (CFTR). Dr Joo Young Choi (department of physiology, University of Texas, United States) and colleagues say that some CFTR mutations cause CF without reducing chloride transportation and that this indicates that other factors could also be involved. They compared the activity of normal CFTR with disease-causing mutants and found that bicarbonate transportation was critical for normal tissue physiology.

In CF, acidic fluids, rather than normal alkaline fluids, are secreted by CFTR-expressing tissues, they say. This acidic fluid secretion may lead to precipitation of mucins, plugging of ductal systems, facilitation of bacterial infections and pancreatic insufficiency. The researchers say that correcting chloride ion transportation alone is unlikely to ameliorate symptoms of CF and that enhancing bicarbonate transportation should also be considered (Nature 2001;410:94).

In a leading article, Dr Paul Quinton (school of medicine, University of California, San Diego) summarises the findings and says that the degree of CF severity correlates with bicarbonate rather than chloride transportation. Patients with mild CF have diminished, but present, bicarbonate ion transportation, and patients with severe CF have no bicarbonate transportation, he says (Nature Medicine 2001;7:292).

Mr Andrew Whitehead (lead adult CF pharmacist, Leeds Teaching Hospitals NHS trust) told The Journal on March 7 that the results were an important finding for the future understanding of the disease and may well lead to future treatment options. However, at the moment the results were of scientific rather than clinical importance.

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Elderly patients unable to use zanamivir inhaler

Most elderly people cannot use the zanamivir (Relenza) inhaler, according to researchers from the Mayday hospital, Croydon. Dr Paul Diggory and colleagues say that treatment with zanamivir is unlikely to be effective in elderly people unless the delivery system used is improved.

Seventy-three patients, aged over 65 years, were given placebo devices of either zanamivir Diskhaler or a Turbohaler.

The researchers found that 50 per cent of patients allocated the Diskhaler were unable to load and prime the device after 15 minutes of inhaler technique tuition and more patients, 66 per cent, were unable to do so 24 hours later. In comparison, inability to load and prime the Turbohaler was observed with two patients immediately after tuition and one after 24 hours.

They comment that the patients in the study were in the recovery stage of their illnesses and that it was likely that elderly patients with influenza would have greater difficulty using the Diskhaler. (British Medical Journal 2001;322:577.)

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