Endocrine system alternations have been increasingly linked to the pathogenesis of Alzheimer disease (AD). Tan et al followed 1864 cognitively intact participants of the Framingham Heart Study for 12.7 years and examined the relationship between thyrotropin levels and the risk of developing AD. The investigators found that women in the lowest (thyrotropin <1.0 mIU/L) and highest (thyrotropin >2.10 mIU/L) tertiles of serum thyrotropin levels had over twice the risk of developing AD. In contrast, thyrotropin levels were not related to AD risk in men. This study challenges the traditional thinking of thyroid dysfunction as a potentially reversible cause of cognitive impairment.
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A randomized clinical study was undertaken to examine the dose of physical activity that would elicit a significant and sustained weight loss over a period of 24 months in overweight women. A behavioral intervention was implemented that included continuous intervention contact, a reduction in energy intake, and an increase in moderate to vigorous physical activity. This intervention was effective at significantly reducing body weight. Moreover, the adoption and maintenance of an additional 275 min/wk of physical activity contributed to the ability to sustain a loss of 10% or more of initial body weight at 24 months. These results clarify the dose of physical activity needed for long-term weight loss, suggesting that interventions to facilitate the adoption and maintenance of this level of physical activity are needed.
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Hersh et al used the National Ambulatory Medical Care Survey and National Hospital Ambulatory Medical Care Survey to investigate trends in visit rates and antibiotic therapy for skin and soft-tissue infections during the emergence of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA). The overall rate of ambulatory visits doubled between 1997 and 2005 and nearly tripled among patients younger than 18 years and in emergency departments, while the use of antibiotics with activity against CA-MRSA increased from 7% to 28% of visits during this period. The incidence of skin and soft-tissue infections has rapidly increased nationwide during the CA-MRSA era.
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Despite the significance of hearing impairment, recent, accurate estimates of the magnitude of the problem in the United States and its distribution in the population are lacking. Agrawal et al probed databases on Americans over the past 20 years and found that hearing loss is more prevalent among US adults than previously reported: 16% of Americans aged 20 to 69 years had hearing loss, corresponding to 29 million Americans. Alarmingly, in the youngest age group (20-29 years), 8.5% already exhibited hearing loss. Prevalence appears to be accelerating particularly in this age group, possibly due to the increasing use of personal listening devices. Male subjects were 5.5-fold more likely to have hearing loss, while whites were at a 3.3-fold increased risk. The authors also observed that increases in hearing loss prevalence occurred earlier among participants with cigarette smoke exposure and cardiovascular risks, as well as with noise exposure.
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The potential benefits of a diet rich in fruit and vegetables for diabetes prevention were highlighted in a large population-based prospective study reported by Harding et al. A strong inverse association was found between plasma vitamin C concentrations, a biomarker of fruit and vegetable intake, and the risk of type 2 diabetes mellitus. Among 21 831 healthy men and women, individuals in the top quintile of plasma vitamin C level had a 62% reduction in the risk of developing diabetes compared with those in the bottom quintile, after adjusting for demographic, lifestyle, and anthropometric variables. These findings highlight a potentially important public health message on the benefits of fruit and vegetable intake.
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In This Issue of Archives of Internal Medicine. Arch Intern Med. 2008;168(14):1484. doi:10.1001/archinte.168.14.1484