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Practice Short cuts

What's new in the other general journals

BMJ 2006; 333 doi: (Published 20 July 2006) Cite this as: BMJ 2006;333:192
  1. Alison Tonks (, associate editor

    Active elderly people live longer

    Yet more evidence has emerged that staying active in old age is linked to prolonged survival. In a study of 302 elderly US adults, burning more energy was associated with a significantly lower risk of death over a mean follow-up of six years—every extra 1.2 MJ (287 kcal) a day cutting the risk by about 30%. The most active participants were substantially and significantly less likely to die during follow-up than the least active (hazard ratio comparing top and bottom thirds of energy expenditure, 0.33 (95% CI 0.15 to 0.74)) even accounting for age, sex, race, weight, height, percentage of body fat, sleep duration, smoking habit, education, and health.

    Credit: JAMA

    The authors used doubly radiolabelled water to measure energy expenditure, then computed a figure for energy burnt during activity by subtracting the basal metabolic rate and allowing for the thermic effects of eating. The most active participants burnt 603 more “activity” calories a day than the least active. Less than half the difference was due to extra exercise. They burnt the rest simply moving around, fidgeting, and generally getting on with life.

    Credit: JAMA

    Although these results are fairly striking, they don't translate easily into specific public health messages, writes a linked editorial (pp 216-8). Next time, researchers should try to record the intensity of people's activity too, preferably using an objective method such as accelerometry.

    One per cent of children in a UK cohort have an autistic spectrum disorder

    Twenty years ago, most people accepted that childhood autism was a rare developmental disorder with a prevalence of about four or five per 10 000 children. Japanese researchers were the first to notice an increase in the late 1980s. Europeans and Americans followed suit a decade later, and the prevalence has continued to rise since then, with 116 per 10 000, or more than 1%, of children having an autistic spectrum disorder in …

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