John Stansell

AIDS AND THE LUNG

Respiratory symptoms are common in HIV-infected persons. The challenge facing clinicians is to determine whether these respiratory symptoms are due to an opportunistic infection or to a chronic process, such as asthma, chronic bronchitis, bronchiectasis, or emphysema. This article reviewed the clinical presentation, diagnosis, and treatment of two important opportunistic infections, PCP and bacterial pneumonia. It also reviewed the current data on obstructive lung diseases as they relate to HIV.

Quantification of insulin-mediated glucose disposal in HIV-infected individuals: comparison of patients treated and untreated with protease inhibitors.

To describe the distribution of insulin sensitivity and glucose tolerance in HIV-infected patients, the authors measured insulin-mediated glucose disposal (IMGD) in 51 subjects (24 protease inhibitor (PI)-treated subjects and 27 non-PI-treated subjects). IMGD was determined by measuring the steady-state plasma glucose (SSPG) concentration during the last 30 minutes of a 180-minute intravenous infusion of octreotide, glucose, and insulin. In addition, oral glucose tolerance testing was performed. SSPG concentrations varied six-fold in both groups, and the mean values +/- SEM did not differ between PI-treated and non-PI-treated groups (8.7 +/- 0.9 vs. 8.0 +/- 0.7 mmol/L, respectively). The mean fasting plasma glucose concentration +/- SEM was higher in the PI-treated subjects than in the non-PI-treated subjects (5.44 +/- 0.11 vs. 5.05 +/- 0.11 mmol/L, respectively; p =.01), whereas fasting plasma insulin concentrations did not differ. PI-treated patients also had significantly higher plasma glucose (p =.001) and insulin (p =.03) responses to the oral glucose challenge. However, whereas the incremental plasma glucose response during the first 30 minutes was significantly higher in PI-treated patients, the incremental insulin response in the two groups was identical. In conclusion, insulin sensitivity varies widely in HIV-infected patients irrespective of PI treatment, and the adverse effect of PIs on insulin sensitivity is likely to be of modest magnitude. Finally, PI treatment may have an inhibitory effect on insulin secretion.

Methods for quantifying insulin resistance in human immunodeficiency virus-positive patients ☆

Various indirect indices have been used in human immunodeficiency virus (HIV)-infected individuals to assess insulin resistance, but the validity of these measures has not been rigorously assessed by comparison with physiologic methods of quantifying insulin-mediated glucose uptake (IMGU). We directly measured IMGU in 50 nondiabetic HIV-positive subjects by determining the steady-state plasma glucose (SSPG) concentration in response to a 3-hour continuous infusion of insulin, glucose, and somatostatin. Because steady-state plasma insulin concentrations were similar (approximately 60 microU/mL) in all subjects, the SSPG concentrations provided direct assessments of insulin action. Relationships between SSPG levels and various surrogate measures of IMGU derived from the 75-g oral glucose tolerance test (OGTT) were determined. The indirect measure of IMGU most closely related to SSPG concentrations was the total integrated insulin response to a 75-g glucose load (r=0.78, P<.01), accounting for approximately two thirds of the variability in SSPG (r2=0.61). Other indirect measures of IMGU, including the homeostasis assessment for insulin resistance (HOMA-IR), were also significantly related to SSPG values, but had lower magnitudes of correlation (r=0.43 to 0.61), thereby possessing limited ability to predict SSPG variability (r2=0.18 to 0.37). In conclusion, indirect measures of IMGU need to be applied with caution when evaluating insulin action in HIV-infected patients.

Discrepancy between sex- and water-associated risk behaviors for cryptosporidiosis among HIV-infected patients in San Francisco

OBJECTIVE Potential transmission of cryptosporidiosis through drinking water supplies has been highly publicized; however, it is unknown whether this reporting has increased patient awareness or reduced other risk behaviors for exposure to this organism, such as high-risk sexual behavior. METHODS Consecutive patients presenting for initial evaluation to the Gastroenterology AIDS Clinic completed a questionnaire that assessed knowledge about cryptosporidiosis, perceived risk of infectious diarrhea, drinking water sources, and high-risk sexual behavior. RESULTS Fifty-one patients completed the questionnaire (82% male; 86% homosexual; mean age, 38 years; median CD4 count, 136 x 10(6) cells/L). Most respondents (31 of 44; 70%) believed they were at risk for infectious diarrhea. Awareness of cryptosporidiosis was high (31 of 45; 69%) as was avoidance of tap water (26 of 51; 51%) and exclusive or frequent use of bottled or boiled water (40 of 51; 78%). Respondents who used bottled water reported spending an average of

Relative Effects of Insulin Resistance and Protease Inhibitor Treatment on Lipid and Lipoprotein Metabolism in HIV-Infected Patients

331.76 U.S. annually. However, high-risk sexual behavior remained common: 21 (41%) of the 51 subjects reported unprotected anal intercourse or oral-anal sexual contact. High-risk sexual behavior was prevalent even among subjects who drank exclusively boiled or bottled water. CONCLUSIONS Awareness of risk for infectious diarrhea and cryptosporidiosis is high among patients infected with HIV in San Francisco. Patients perceive drinking water to be a substantial risk factor for infectious diarrhea and incur significant expense to avoid tap water. However, high-risk sexual behaviors remain prevalent in this population and should be the focus of future education efforts.

High-resolution CT in the evaluation of clinically suspected Pneumocystis carinii pneumonia in AIDS patients with normal, equivocal, or nonspecific radiographic findings.

Abstract Background: The relationship between insulin resistance, dyslipidemia, HIV infection, and antiretroviral therapy remains unclear, and the atherogenic nature of lipid and lipoprotein profiles in HIV-infected patients has not been fully characterized. Method: We measured plasma lipid and lipoprotein subfractions using Vertical Auto Profile-II methodology and directly measured insulin-mediated glucose disposal in 45 protease inhibitor (PI)-treated and non-PI-treated HIV-infected patients. Results: PI-treated patients had higher total, LDL, and narrow-density LDL cholesterol (p < .05) and a trend toward higher triglycerides, whereas HDL cholesterol and LDL particle characteristics were unrelated to PI use or history of lipodystrophy. Insulin sensitivity did not differ on the basis of PI therapy, but decreased insulin sensitivity was associated with lower HDL and HDL-3 cholesterol (p < .01); elevated triglyceride (p < .01), VLDL 1+2, and VLDL 3a+3b lipoproteins (p < .01); and smaller, denser (more atherogenic) LDL particle characteristics (p < .01). Thus, the lipoprotein abnormality associated with PI use was increased LDL cholesterol, whereas changes in TG and HDL metabolism were associated with insulin resistance, independent of PI use. Conclusion: The variables of PI-treatment, dyslipidemia, lipodsytrophy, and insulin resistance do not always cluster together in HIV-infected patients, which suggests that the metabolic phenotype emerging in treated patients results from a complex interplay of drug effects, immune restoration, and baseline insulin sensitivity.