Publications

BACKGROUND & AIMS

Capsule endoscopy (CE) and double-balloon enteroscopy (DBE) allow complete small-bowel examination but consume additional health care resources. A cost-minimization analysis determined the optimal initial management strategy for obscure occult gastrointestinal bleeding (OGIB).

METHODS

We compared 5 strategies: initial small-bowel follow-through, enteroclysis, push enteroscopy (PE), CE, or DBE. Incorporation of multiple tests was allowed with costs taken from a third-party payer perspective. We modeled medically refractory disease with 2 separate model end points in which treatment or definitive diagnosis was necessary and in which visual diagnosis was sufficient to suspend testing. Sensitivity analyses included variations in parameter estimates, Monte Carlo simulation, and structural variations in the model in which DBE was not available as an initial strategy.

RESULTS

When treatment or definitive diagnosis was necessary, the optimal strategy was initial DBE at a cost of $3824. An initial CE strategy costs an incremental $440. CE was preferred when DBE exceeded $1849 or when the sensitivity of DBE decreased to less than 68%. If DBE was unavailable as an initial test then CE was preferred to PE unless CE exceeded $1190, capsule retention was greater than 3%, or 64% of lesions were within reach of PE. When visual diagnosis was sufficient, initial CE was preferred.

CONCLUSIONS

For OGIB, initial DBE may be the least expensive strategy when treatment or definitive diagnosis is necessary and initial CE may be preferred when visual identification is sufficient. In settings where DBE is not available as an initial test, initial CE may be the preferred strategy.

Under the heading "How tobacco protects you against the flu", the German chemical industry portrays a tobacco grower in an idyllic tobacco plantation. Despite the recent ban of transnational tobacco advertising within the European Union, using tobacco to promote another industry and potential societal health benefits might indirectly promote the social acceptability of tobacco to social leaders. The tobacco control community should thus monitor the use of other industries as a new method to circumvent the tobacco advertising ban and to support the social acceptability of tobacco by associating it with potential health benefits.

BACKGROUND

Studies in persons without HIV infection have compared percentage body fat (%BF) and waist circumference as markers of risk for the complications of excess adiposity, but only limited study has been conducted in HIV-infected subjects.

OBJECTIVE

We compared anthropometric and magnetic resonance imaging (MRI)-based adiposity measures as correlates of metabolic complications of adiposity in HIV-infected and control subjects.

DESIGN

The study was a cross-sectional analysis of 666 HIV-positive and 242 control subjects in the Fat Redistribution and Metabolic Change in HIV Infection (FRAM) study assessing body mass index (BMI), waist (WC) and hip (HC) circumferences, waist-to-hip ratio (WHR), %BF, and MRI-measured regional adipose tissue. Study outcomes were 3 metabolic risk variables [homeostatic model assessment (HOMA), triglycerides, and HDL cholesterol]. Analyses were stratified by sex and HIV status and adjusted for demographic, lifestyle, and HIV-related factors.

RESULTS

In HIV-infected and control subjects, univariate associations with HOMA, triglycerides, and HDL were strongest for WC, MRI-measured visceral adipose tissue, and WHR; in all cases, differences in correlation between the strongest measures for each outcome were small (r

CONCLUSION

Relations of simple anthropometric measures with HOMA, triglycerides, and HDL cholesterol are approximately as strong as MRI-measured whole-body adipose tissue depots in both HIV-infected and control subjects.

Protease inhibitors (PIs) are widely assumed to be associated with a syndrome of insulin resistance accompanied by hyperlipidemia and fat redistribution. Insulin resistance in HIV infection has numerous other causes, however, which include not only the direct effects of antiretroviral drugs but also factors such as aging and restoration to health accompanied by fat accumulation. Studies of PIs in HIV-infected and noninfected patients indicate that some of these drugs are associated with reduced insulin sensitivity (greater acute versus chronic effects) that may be due to direct blockade of the insulin-sensitive glucose transporter in muscle and fat cells. Other studies have shown that insulin levels increase over time with antiretroviral therapy, likely the result of improved health, fat accumulation, and aging, and that increases in visceral fat and upper trunk fat are associated with a higher risk of insulin resistance in HIV-infected and -uninfected individuals alike. This article summarizes a presentation on insulin resistance in HIV infection made by Carl Grunfeld, MD, PhD, at the 10th Annual Ryan White HIV/AIDS Program Clinical Update in Phoenix in June 2007.