A Randomized, Placebo-controlled Trial of Fidaxomicin for Prophylaxis of Clostridium difficile-associated Diarrhea in Adults Undergoing Hematopoietic Stem Cell Transplantation

Background

Clostridium difficile–associated diarrhea (CDAD) is common during hematopoietic stem-cell transplantation (HSCT) and is associated with increased morbidity and mortality. We evaluated fidaxomicin for prevention of CDAD in HSCT patients.

Methods

In this double-blind study, subjects undergoing HSCT with fluoroquinolone prophylaxis stratified by transplant type (autologous/allogeneic) were randomized to once-daily oral fidaxomicin (200 mg) or a matching placebo. Dosing began within 2 days of starting conditioning or fluoroquinolone prophylaxis and continued until 7 days after neutrophil engraftment or completion of fluoroquinolone prophylaxis/clinically-indicated antimicrobials for up to 40 days. The primary endpoint was CDAD incidence through 30 days after study medication. The primary endpoint analysis counted confirmed CDAD, receipt of CDAD-effective medications (for any indication), and missing CDAD assessment (for any reason, including death) as failures; this composite analysis is referred to as “prophylaxis failure” to distinguish from the pre-specified sensitivity analysis, which counted only confirmed CDAD (by toxin immunoassay or nucleic acid amplification test) as failure.

Results

Of 611 subjects enrolled, 600 were treated and analyzed. Prophylaxis failure was similar in fidaxomicin and placebo recipients (28.6% vs 30.8%; difference 2.2% [-5.1, 9.5], P = .278). However, most failures were due to non-CDAD events. Confirmed CDAD was lower in fidaxomicin vs placebo recipients (4.3% vs 10.7%; difference 6.4% [2.2, 10.6], P = .0014). Drug-related adverse events occurred in 15.0% of fidaxomicin recipients and 20.0% of placebo recipients.

Conclusions

While no difference was demonstrated between arms in the primary analysis, results of the sensitivity analysis demonstrated that fidaxomicin significantly reduced the incidence of CDAD in HSCT recipients.

Clinical Trials Registration

NCT01691248

Rethinking Strategies to Select Antibiotic Therapy in Clostridium difficile infection

In recent years, Clostridium difficile infection (CDI) has become a global public health threat associated with increased morbidity, mortality, and economic burden, all of which are exacerbated with disease recurrence. Current guidelines informing treatment decisions are largely based on definitions of disease severity at diagnosis, with subjective components not well delineated across treatment algorithms and clinical trials. Furthermore, there is little evidence linking severity at onset to outcome. However, reducing the risk of recurrence may offer both a better outcome for the individual and decreased downstream economic impact. The authors present data supporting the opinion that patients deemed at low risk for recurrence should receive vancomycin (or metronidazole when cost is an issue), while those at higher risk of recurrence would benefit from fidaxomicin treatment. Although further prospective studies are needed, choosing treatment with the goal of preventing recurrent CDI may offer a better guide than disease severity.

Practice guidelines for the diagnosis and management of skin and soft tissue infections: 2014 update by the Infectious Diseases Society of America

A panel of national experts was convened by the Infectious Diseases Society of America (IDSA) to update the 2005 guidelines for the treatment of skin and soft tissue infections (SSTIs). The panel's recommendations were developed to be concordant with the recently published IDSA guidelines for the treatment of methicillin-resistant Staphylococcus aureus infections. The focus of this guideline is the diagnosis and appropriate treatment of diverse SSTIs ranging from minor superficial infections to life-threatening infections such as necrotizing fasciitis. In addition, because of an increasing number of immunocompromised hosts worldwide, the guideline addresses the wide array of SSTIs that occur in this population. These guidelines emphasize the importance of clinical skills in promptly diagnosing SSTIs, identifying the pathogen, and administering effective treatments in a timely fashion.

John G. Bartlett: Contributions to the discovery of Clostridium difficile antibiotic-associated diarrhea

In 1975 John Bartlett began trials investigating the problem of antibiotic-associated diarrhea and pseudomembranous colitis. His work led the discovery of Clostridium difficile and he identified it as the leading cause of hospital-associated infections.

Effects of proton pump inhibitors and histamine-2 receptor antagonists on response to fidaxomicin or vancomycin in patients with Clostridium difficile-associated diarrhoea

OBJECTIVE

It has been established that use of proton pump inhibitors (PPIs) is associated with an increased risk of acquiring Clostridium difficile-associated diarrhoea (CDAD). However, it is not known whether the use of PPIs or histamine-2 receptor antagonists (H2RAs) concurrently with CDAD-targeted antibiotic treatment affects clinical response or recurrence rates.

DESIGN

In two phase 3 trials, patients with toxin-positive CDAD were randomised to receive fidaxomicin 200 mg twice daily or vancomycin 125 mg four times daily for 10 days. Only inpatients with CDAD (due to complete medication record availability) were included in this post hoc analysis: 701 patients, of whom 446 (64%) used PPIs or H2RAs during study drug treatment or follow-up. Baseline factors that were statistically significant in univariate analyses were analysed in multivariate analyses of effects on clinical response and recurrence.

RESULTS

Multivariate analysis showed that leukocytosis, elevated creatinine and hypoalbuminemia, but not PPI or H2RA use, were significant factors associated with poor clinical responses. Treatment group was the single significant predictor of recurrence; the probability of recurrence after fidaxomicin therapy was half that following vancomycin therapy.

CONCLUSIONS

Acid-suppressing drugs, used by nearly two-thirds of inpatients with CDAD, did not worsen clinical response or recurrence when used concurrently with fidaxomicin or vancomycin. Therefore, development of CDAD does not require discontinuation of anti-acid treatment in patients who have an indication for continuing PPI or H2RA therapy, such as gastro-oesophageal reflux disease and risk of gastrointestinal bleed.

Practice Guidelines for the Diagnosis and Management of Skin and Soft Tissue Infections: 2014 Update by the Infectious Diseases Society of America

A panel of national experts was convened by the Infectious Diseases Society of America (IDSA) to update the 2005 guidelines for the treatment of skin and soft tissue infections (SSTIs). The panel's recommendations were developed to be concordant with the recently published IDSA guidelines for the treatment of methicillin-resistant Staphylococcus aureus infections. The focus of this guideline is the diagnosis and appropriate treatment of diverse SSTIs ranging from minor superficial infections to life-threatening infections such as necrotizing fasciitis. In addition, because of an increasing number of immunocompromised hosts worldwide, the guideline addresses the wide array of SSTIs that occur in this population. These guidelines emphasize the importance of clinical skills in promptly diagnosing SSTIs, identifying the pathogen, and administering effective treatments in a timely fashion.

Whole-genome sequencing demonstrates that fidaxomicin is superior to vancomycin for preventing reinfection and relapse of infection with Clostridium difficile

Whole-genome sequencing was used to determine whether the reductions in recurrence of Clostridium difficile infection observed with fidaxomicin in pivotal phase 3 trials occurred by preventing relapse of the same infection, by preventing reinfection with a new strain, or by preventing both outcomes. Paired isolates of C. difficile were available from 93 of 199 participants with recurrences (28 were treated with fidaxomicin, and 65 were treated with vancomycin). Given C. difficile evolutionary rates, paired samples ≤2 single-nucleotide variants (SNVs) apart were considered relapses, paired samples >10 SNVs apart were considered reinfection, and those 3–10 SNVs apart (or without whole-genome sequences) were considered indeterminate in a competing risks survival analysis. Fidaxomicin reduced the risk of both relapse (competing risks hazard ratio [HR], 0.40 [95% confidence interval {CI}, .25–.66]; P = .0003) and reinfection (competing risks HR, 0.33 [95% CI, 0.11–1.01]; P = .05).

Renal impairment and clinical outcomes of Clostridium difficile infection in two randomized trials

BACKGROUND/AIMS

Patients with chronic kidney disease (CKD) have increased risk for Clostridium difficile infection (CDI) and for subsequent mortality. We determined the effect of CKD on response to treatment for CDI.

METHODS

This is a post hoc analysis of two randomized controlled phase 3 trials that enrolled patients with CDI. Patients received either fidaxomicin 200 mg b.i.d. or vancomycin 125 mg q.i.d. for 10 days. Univariate and multivariate analyses compared end points by treatment received and CKD stage.

RESULTS

At baseline, 27, 21, and 9% of the patients had stage 2 (60-89 ml/min/1.73 m(2)), stage 3 (30-59), and stage 4 or higher (<30) CKD. Cure rates were similar for normal (91%) and stage 2 CKD (92%), but declined to 80% for stage 3 and to 75% for stage 4 CKD (p < 0.001 for trend). Time to resolution of diarrhea (TTROD) increased with stage 3 and stage 4 CKD. CDI recurrence rates 4 weeks after treatment were 16, 20, 27, and 24% for normal, stage 2, stage 3, and stage 4 or higher CKD, respectively. Mortality increased with CKD stage. In multivariate analyses, stage 3 or higher CKD correlated with lower odds of cure, greater chance of recurrence, and lower odds of sustained response 28 days after treatment. Initial cure rates were similar in the vancomycin or fidaxomicin groups; however, the rate of recurrence was higher following vancomycin treatment independent of renal function. The presence of immunosuppression did not alter this effect.

CONCLUSION

Progressive CKD is associated with increased TTROD, lower cure rates, and higher recurrence rates with treatment of CDI.

Effect of age on treatment outcomes in Clostridium difficile infection

OBJECTIVES

To determine the effect of advancing age on the clinical outcomes of Clostridium difficile (CDI) treatment.

DESIGN

Regression modeling of results from two double-blind randomized multicenter studies on the treatment of primary and first recurrent cases of CDI to examine for effects of age and study drug on outcomes of cure (resolution of diarrhea), recurrence within 4 weeks of completing successful therapy, and cure without recurrence.

SETTING

Participants were randomized into studies in the United States, Canada, and Europe.

PARTICIPANTS

Nine hundred ninety-nine individuals with toxin-positive CDI were randomized to receive vancomycin (125 mg 4 times daily) or fidaxomicin (200 mg twice daily) for 10 days.

MEASUREMENTS

The effect of advancing age in those aged 18 to 40 years and in 10-year increments thereafter was examined.

RESULTS

The model predicts a 17% lower clinical cure, 17% greater recurrence, and 13% lower sustained clinical response by advancing decade than in those younger than 40 (P < .01 each). Clinical cure was similar in the fidaxomicin and vancomycin treatment groups, although fidaxomicin was associated with a more than 50% lower relative risk for recurrence than vancomycin (P < .001). Multivariate regression modeling showed that risk factors accounting for poorer outcomes with advancing age include infection with the BI strain type, inpatient status, renal insufficiency, leukocytosis, hypoalbuminemia, and concomitant medication exposure.

CONCLUSION

Measurable and progressive deterioration in CDI treatment outcomes occurred with advancing age in those aged 40 and older, highlighting the need for prevention and treatment strategies. Fidaxomicin treatment was associated with a 60% lower risk of recurrence than vancomycin after adjusting for age, concomitant antibiotics, and C. difficile strain.

Fidaxomicin versus vancomycin for Clostridium difficile infection: meta-analysis of pivotal randomized controlled trials

Two recently completed phase 3 trials (003 and 004) showed fidaxomicin to be noninferior to vancomycin for curing Clostridium difficile infection (CDI) and superior for reducing CDI recurrences. In both studies, adults with active CDI were randomized to receive blinded fidaxomicin 200 mg twice daily or vancomycin 125 mg 4 times a day for 10 days. Post hoc exploratory intent-to-treat (ITT) time-to-event analyses were undertaken on the combined study 003 and 004 data, using fixed-effects meta-analysis and Cox regression models. ITT analysis of the combined 003/004 data for 1164 patients showed that fidaxomicin reduced persistent diarrhea, recurrence, or death by 40% (95% confidence interval [CI], 26%–51%; P < .0001) compared with vancomycin through day 40. A 37% (95% CI, 2%–60%; P = .037) reduction in persistent diarrhea or death was evident through day 12 (heterogeneity P = .50 vs 13–40 days), driven by 7 (1.2%) fidaxomicin versus 17 (2.9%) vancomycin deaths at <12 days. Low albumin level, low eosinophil count, and CDI treatment preenrollment were risk factors for persistent diarrhea or death at 12 days, and CDI in the previous 3 months was a risk factor for recurrence (all P < .01). Fidaxomicin has the potential to substantially improve outcomes from CDI.

Renal failure and leukocytosis are predictors of a complicated course of Clostridium difficile infection if measured on day of diagnosis

Nonsevere Clostridium difficile infection (CDI) and severe CDI, which carries a higher risk than nonsevere CDI for treatment failure and CDI recurrence, are difficult to distinguish at the time of diagnosis. To investigate the prognostic value of 3 markers of severe CDI suggested by recent guidelines (fever, leukocytosis, and renal failure), we used the database of 2 randomized controlled trials, which contained information for 1105 patients with CDI. Leukocytosis (risk ratio [RR], 2.29; 95% confidence interval [CI], 1.63–3.21) and renal failure (RR, 2.52; 95% CI, 1.82–3.50) were associated with treatment failure. Fever, although associated with treatment failure (RR, 2.45; 95% CI, 1.07–5.61), was rare. Renal failure was the only significant predictor of recurrence (RR, 1.45; 95% CI, 1.05–2.02). Different timing of measurements of leukocyte count and serum creatinine level around the CDI diagnosis led to a different severity classification in many cases. In conclusion, both leukocytosis and renal failure are useful predictors, although timing of measurement is important.

Treatment of first recurrence of Clostridium difficile infection: fidaxomicin versus vancomycin

Recurrence of Clostridium difficile infection (CDI) occurs in approximately 25% of successfully treated patients. Two phase 3 randomized, double-blind trials were conducted at 154 sites in the United States, Canada, and Europe to compare fidaxomicin vs vancomycin in treating CDI. Patients with CDI received fidaxomicin 200 mg twice daily or vancomycin 125 mg 4 times daily for 10 days. The primary end point was clinical cure of CDI at end of treatment, and a secondary end point was recurrence during the 28 days following clinical cure. In all, 1164 subjects were enrolled, of which a subgroup of 128 in the per-protocol population had another recent episode of CDI prior to the CDI diagnosis at study enrollment. In the analysis of this subgroup, initial response to therapy was similar for both drugs (>90% cure). However, recurrence within 28 days occurred in 35.5% of patients treated with vancomycin and 19.7% of patients treated with fidaxomicin (−15.8% difference; 95% confidence interval, −30.4% to −0.3%; P = .045). Early recurrence (within 14 days) was reported in 27% of patients treated with vancomycin and 8% of patients treated with fidaxomicin (P = .003). In patients with a first recurrence of CDI, fidaxomicin was similar to vancomycin in achieving a clinical response at end of therapy but superior in preventing a second recurrence within 28 days.

Clinical Trials Registration. NCT00314951 and NCT00468728.

Efficacy of fidaxomicin versus vancomycin as therapy for Clostridium difficile infection in individuals taking concomitant antibiotics for other concurrent infections

Concomitant antibiotic (CA) use compromised initial response to Clostridium difficile infection therapy and durability of that response. Fidaxomicin was significantly more effective than vancomycin in achieving clinical cure in the presence of CAs and preventing recurrence regardless of CA use.

Background. Treatment guidelines recommend stopping all implicated antibiotics at the onset of Clostridium difficile infection (CDI), but many individuals have persistent or new infections necessitating the use of concomitant antibiotics (CAs). We used data from 2 phase 3 trials to study effects of CAs on response to fidaxomicin or vancomycin.

Methods. Subjects with CDI were treated for 10 days with fidaxomicin 200 mg every 12 hours or vancomycin 125 mg every 6 hours, assessed for resolution of symptoms, and followed up for an additional 4 weeks for evidence of recurrence. Rates of cure, recurrence, and global cure (cure without recurrence) were determined for subgroups of subjects defined by CA use and treatment group.

Results. CAs were prescribed for 27.5% of subjects during study participation. The use of CAs concurrent with CDI treatment was associated with a lower cure rate (84.4% vs 92.6%; P < .001) and an extended time to resolution of diarrhea (97 vs 54 hours; P < .001). CA use during the follow-up was associated with more recurrences (24.8% vs 17.7%; not significant), and CA administration at any time was associated with a lower global cure rate (65.8% vs 74.7%; P = .005). When subjects received CAs concurrent with CDI treatment, the cure rate was 90.0% for fidaxomicin and 79.4% for vancomycin (P = .04). In subjects receiving CAs during treatment and/or follow-up, treatment with fidaxomicin compared with vancomycin was associated with 12.3% fewer recurrences (16.9% vs 29.2%; P = .048).

Conclusions. Treatment with CAs compromised initial response to CDI therapy and durability of response. Fidaxomicin was significantly more effective than vancomycin in achieving clinical cure in the presence of CA therapy and in preventing recurrence regardless of CA use.

Polymyxin B-Induced Release of Low-Molecular-Weight, Heat-Labile Enterotoxin from Escherichia coli

Polymyxin B-induced release of enterotoxin from Escherichia coli strain H-10407 was demonstrated. Incubation of E. coli cells derived from 6-h cultures with polymyxin caused the rapid release of enterotoxin with a molecular weight of approximately 20,000, as estimated by the gel filtration technique. The rapidity of the release of enterotoxin indicates that it probably resides in the periplasmic space of the cell. The low-molecular-weight enterotoxin possessed vascular permeability factor and diarrheagenic activities, both of which were found to be heat-labile. The permeability factor activity of this enterotoxin was neutralized by antisera prepared against crude E. coli enterotoxin, Vibrio cholerae enterotoxin (choleragen), and V. cholerae toxoid (choleragenoid), respectively. Supernatant fluids of 6-h E. coli cultures did not contain this molecular form of enterotoxin but did contain very high-molecular-weight, heat-labile enterotoxin. Incubation of cells derived from older (18 h) cultures with polymyxin caused the release of both low- (20,000) and high-molecular-weight forms of enterotoxin. We concluded that either the 20,000-dalton form of heat-labile enterotoxin is not released by E. coli under in vitro growth conditions or that enterotoxin released in this form is rapidly destroyed or inactivated.

Lessons learned from the anaerobe survey: historical perspective and review of the most recent data (2005-2007)

BACKGROUND

The rationale and lessons learned through the evolution of the National Survey for the Susceptibility of Bacteroides fragilis Group from its initiation in 1981 through 2007 are reviewed here. The survey was conceived in 1980 to track emerging antimicrobial resistance in Bacteroides species.

METHODS

Data from the last 11 years of the survey (1997-2007), including 6574 isolates from 13 medical centers, were analyzed for in vitro antimicrobial resistance to both frequently used and newly developed anti-anaerobic agents. The minimum inhibitory concentrations of the antibiotics were determined using agar dilution in accordance with Clinical and Laboratory Standards Institute recommendations.

RESULTS

The analyses revealed that the carbapenems (imipenem, meropenem, ertapenem, and doripenem) and piperacillin-tazobactam were the most active agents against these pathogens, with resistance rates of 0.9%-2.3%. In the most recent 3 years of the survey (2005-2007), resistance to some agents was shown to depend on the species, such as ampicillin-sulbactam against Bacteroides distasonis (20.6%) and tigecycline against Bacteroides uniformis and Bacteroides eggerthii ( approximately 7%). Very high resistance rates (>50%) were noted for moxifloxacin and trovafloxacin, particularly against Bacteroides vulgatus. During that period of study, non-B. fragilis Bacteroides species had >40% resistance to clindamycin. Metronidazole-resistant Bacteroides strains were also first reported during that period.

CONCLUSIONS

In summary, resistance to antibiotics was greater among non-B. fragilis Bacteroides species than among B. fragilis and was especially greater among species with a low frequency of isolation, such as Bacteroides caccae and B. uniformis. The emergence of resistance among the non-B. fragilis Bacteroides species underscores the need for speciation of B. fragilis group isolates and for clinicians to be aware of associations between species and drug resistance.

Clinical indications for probiotics: an overview

Probiotic bacteria are used to treat or prevent a broad range of human diseases, conditions, and syndromes. In addition, there are areas of medical use that have been proposed for future probiotic applications. Randomized double-blind studies have provided evidence of probiotic effectiveness for the treatment and prevention of acute diarrhea and antibiotic-induced diarrhea, as well as for the prevention of cow milk-induced food allergy in infants and young children. Research studies have also provided evidence of effectiveness for the prevention of traveler's diarrhea, relapsing Clostridium difficile-induced colitis, and urinary tract infections. There are also studies indicating that probiotics may be useful for prevention of respiratory infections in children, dental caries, irritable bowel syndrome, and inflammatory bowel disease. Areas of future interest for the application of probiotics include colon and bladder cancers, diabetes, and rheumatoid arthritis. The probiotics with the greatest number of proven benefits are Lactobacillus rhamnosus strain GG and Saccharomyces boulardii.

Risk factors for cardiovascular disease in children infected with human immunodeficiency virus-1

OBJECTIVE

To determine risk factors for cardiovascular disease (CVD) in children infected with human immunodeficiency virus (HIV) compared with nationally representative controls from 2003-2004 National Health and Nutrition Examination Survey (NHANES) data.

STUDY DESIGN

A prospective, longitudinal analysis of CVD risk factors in 42 HIV-infected children compared with NHANES controls, with multivariable modeling of demographic, disease-specific, and treatment-related factors contributing to cardiac risk in the HIV cohort.

RESULTS

The 42 children infected with HIV were initially an average of 10.1 years old; 68% were Centers for Disease Control and Prevention pediatric HIV disease stage B or C, and 76% were receiving highly active antiretroviral therapy (HAART). Compared with age- and sex-adjusted NHANES controls, the children infected with HIV had lower weight (-0.46 standard deviation [SD] vs +0.54 SD; P < .001), height (-0.62 SD vs +0.26 SD; P < .001), and body mass index (-0.09 SD vs +0.51 SD; P < .001), a higher level of triglycerides (136 mg/dL vs 90 mg/dL; P < .001), and a lower level of high-density lipoprotein (HDL) cholesterol (47 mg/dL vs 54 mg/dL; P < .001). Protease inhibitor therapy was independently associated with higher triglyceride (P = .02) and low-density lipoprotein cholesterol levels (P = .04) and lower HDL cholesterol level (P = .02); nonnucleoside reverse-transcriptase inhibitor therapy was associated with lower visceral fat (P = .01) and higher HDL cholesterol level (P = .005).

CONCLUSIONS

Children infected with HIV have adverse cardiac risk profiles compared with NHANES controls. Antiretroviral therapy has a significant influence on these factors.

Changes in macronutrient intake among HIV-infected children between 1995 and 2004

BACKGROUND

Nutritional concerns in HIV-infected children have evolved, from wasting to obesity and insulin resistance. However, little is known about the diet of these children during this evolution.

OBJECTIVE

We analyzed dietary macronutrient intake in HIV-infected children over nearly 10 y.

DESIGN

HIV-infected children underwent periodic longitudinal nutritional assessments between 1995 and 2004. Sex-specific initial and final means or proportions and time trends in macronutrient intakes were estimated with regression analyses.

RESULTS

Three hundred thirty nutritional records from 49 males and 411 from 67 females were analyzed. Caloric intake exceeded the estimated energy requirement (EER) for ideal body weight in 1995 by 62% for males and 39% for females and decreased by 3% of the EER per year in males (P = 0.02) and by 2% in females (P = 0.004). In 2004, caloric intake still remained >19% above the EER in both groups. Protein intake was nearly 400% of the recommended dietary allowance (RDA) for ideal body weight in 1995 among both males and females and decreased by 13% of the RDA per year for males (P = 0.001) and by 21% per year for females (P < 0.001). However, daily protein intake still exceeded the RDA by >60% in both groups in 2004. Females consumed more energy from carbohydrates (P = 0.05) and sugar (P = 0.10) and less from monounsaturated (P = 0.04), polyunsaturated (P = 0.05), saturated (P = 0.03), and total (P = 0.10) fat in 2004 than in 1995.

CONCLUSION

Excessive caloric intake and a shift in dietary composition toward carbohydrates in females suggest that continued monitoring of diet in HIV-infected children is important to avoid increased nutritional risk.

Cystatin C and creatinine in an HIV cohort: the nutrition for healthy living study

BACKGROUND

Human immunodeficiency virus (HIV)-infected persons have an increased risk of chronic kidney disease (CKD). Serum creatinine level may underestimate the prevalence of CKD in subjects with decreased lean body mass or liver disease. Level of serum cystatin C, an alternative kidney function marker, is independent of lean body mass.

STUDY DESIGN

Cross-sectional.

SETTING & PARTICIPANTS

250 HIV-infected subjects on highly active antiretroviral therapy in the Nutrition for Healthy Living (NFHL) cohort; 2,628 National Health and Nutrition Examination Survey (NHANES) 2001-2002 subjects.

PREDICTORS & OUTCOMES

Comparison of serum creatinine levels in NFHL to those in NHANES subjects; comparison of CKD in NFHL subjects ascertained using serum creatinine versus cystatin C levels.

MEASUREMENTS

Standardized serum creatinine, serum cystatin C, glomerular filtration rate (GFR) estimated from serum creatinine and cystatin C levels.

RESULTS

Creatinine levels were lower in NFHL than NHANES subjects despite greater rates of hepatitis, diabetes, and drug use (mean difference, -0.18 mg/dL; P < 0.001 adjusted for age, sex, and race). Of NFHL subjects, only 2.4% had a creatinine-based estimated GFR less than 60 mL/min/1.73 m(2), but 15.2% had a cystatin-based estimated GFR less than 60 mL/min/1.73 m(2).

LIMITATIONS

GFR was estimated rather than measured. Other factors in addition to GFR may affect creatinine and cystatin C levels. Measurements of proteinuria were not available.

CONCLUSIONS

Serum creatinine levels may overestimate GFRs in HIV-infected subjects. Kidney disease prevalence may be greater than previously appreciated.

Drug use and other risk factors related to lower body mass index among HIV-infected individuals

Malnutrition is associated with morbidity and mortality in HIV-infected individuals. Little research has been conducted to identify the roles that clinical, illicit drug use and socioeconomic characteristics play in the nutritional status of HIV-infected patients. This cross-sectional analysis included 562 HIV-infected participants enrolled in the Nutrition for Healthy Living study conducted in Boston, MA and Providence, RI. The relationship between body mass index (BMI) and several covariates (type of drug use, demographic, and clinical characteristics) were examined using linear regression. Overall, drug users had a lower BMI than non-drug users. The BMI of cocaine users was 1.4 kg/m(2) less than that of patients who did not use any drugs, after adjusting for other covariates (p=0.02). The BMI of participants who were over the age of 55 years was 2.0 kg/m(2) less than that of patients under the age of 35, and BMI increased by 0.3 kg/m(2) with each 100 cells/mm(3) increase in CD4 count. HAART use, adherence to HAART, energy intake, AIDS status, hepatitis B and hepatitis C co-infections, cigarette smoking and depression were not associated with BMI in the final model. In conclusion, BMI was lower in drug users than non-drug users, and was lowest in cocaine users. BMI was also directly associated with CD4 count and inversely related to age more than 55 years old. HIV-infected cocaine users may be at higher risk of developing malnutrition, suggesting the need for anticipatory nutritional support.

Metabolic syndrome and subclinical atherosclerosis in patients infected with HIV

BACKGROUND

The present study examines the association between carotid and coronary atherosclerosis and metabolic syndrome in human immunodeficiency virus (HIV)-infected adults.

METHODS

We measured the common and internal carotid intima-media thickness (c-IMT) using B-mode ultrasonography, and we measured coronary artery calcium (CAC) using high-resolution, electrocardiographic, synchronized, computed tomography, for 314 HIV-infected men and women. Metabolic syndrome was defined by National Cholesterol Education Program/Adult Treatment Panel III criteria. We compared the c-IMT measurements and CAC scores of patients with metabolic syndrome with the scores of those without metabolic syndrome using a Wilcoxon test for continuous variables and a chi2 test for categorical variables. To examine the association between surrogate markers and metabolic syndrome, we used logistic regression analysis.

RESULTS

Participants with metabolic syndrome were more likely to have a common c-IMT measurement >0.8 mm than were those without metabolic syndrome (17% vs.7%; P=.009), but both groups were equally likely to have an internal c-IMT measurement >1.0 mm (20% vs. 13%; P=.15). Any positive CAC score was more likely to occur for participants with metabolic syndrome (80.3% vs. 46.7%; P<.0001). In a multivariate model adjusted for sex, age, ethnicity, and smoking status, participants with metabolic syndrome were more likely than those without metabolic syndrome to have an abnormal common c-IMT measurement (odds ratio [OR], 2.9; P=.020) and detectable CAC scores (OR, 4.9; P<.0001) but not a higher internal c-IMT measurement (OR, 1.6; P=.255).

CONCLUSION

Our study demonstrates that HIV-infected individuals with metabolic syndrome may be at increased risk for subclinical atherosclerosis and supports screening for metabolic syndrome among HIV-infected patients at risk for cardiovascular disease.

National survey on the susceptibility of Bacteroides fragilis group: report and analysis of trends in the United States from 1997 to 2004

The susceptibility trends for the species of the Bacteroides fragilis group against various antibiotics from 1997 to 2004 were determined by using data for 5,225 isolates referred by 10 medical centers. The antibiotic test panel included ertapenem, imipenem, meropenem, ampicillin-sulbactam, piperacillin-tazobactam, cefoxitin, clindamycin, moxifloxacin, tigecycline, chloramphenicol, and metronidazole. From 1997 to 2004 there were decreases in the geometric mean (GM) MICs of imipenem, meropenem, piperacillin-tazobactam, and cefoxitin for many of the species within the group. B. distasonis showed the highest rates of resistance to most of the beta-lactams. B. fragilis, B. ovatus, and B. thetaiotaomicron showed significantly higher GM MICs and rates of resistance to clindamycin over time. The rate of resistance to moxifloxacin of B. vulgatus was very high (MIC range for the 8-year study period, 38% to 66%). B. fragilis, B. ovatus, and B. distasonis and other Bacteroides spp. exhibited significant increases in the rates of resistance to moxifloxacin over the 8 years. Resistance rates and GM MICs for tigecycline were low and stable during the 5-year period over which this agent was studied. All isolates were susceptible to chloramphenicol (MICs < 16 microg/ml). In 2002, one isolate resistant to metronidazole (MIC = 64 microg/ml) was noted. These data indicate changes in susceptibility over time; surprisingly, some antimicrobial agents are more active now than they were 5 years ago.

Incidence of metabolic syndrome in a cohort of HIV-infected adults and prevalence relative to the US population (National Health and Nutrition Examination Survey)

BACKGROUND

Metabolic syndrome increases the risk of cardiovascular outcomes and type II diabetes. Most of the metabolic abnormalities defining metabolic syndrome are observed in HIV.

OBJECTIVE

To determine the incidence and risk factors for metabolic syndrome in HIV-infected adults in the Nutrition for Healthy Living (NFHL) study (2000-2003) and prevalence relative to the findings of the National Health and Nutrition Examination Survey (NHANES) (1999-2002).

METHODS

Metabolic syndrome is > or =3 of the following: hypertriglyceridemia, low high-density lipoprotein (HDL) cholesterol, hypertension, abdominal obesity, and high serum glucose. The baseline prevalence of metabolic syndrome in the NFHL study (n = 477) was compared to that in the NHANES (n = 1876), adjusted for age, race, gender, poverty, exercise, and diet.

RESULTS

Almost one quarter of NFHL subjects had metabolic syndrome. Most with metabolic syndrome (77%) had low HDL and hypertriglyceridemia plus > or =1 additional abnormality. The prevalence of metabolic syndrome was significantly lower in HAART and non-HAART users compared with NHANES participants unadjusted for body mass index (BMI). After adjustment for BMI, it was no longer significant but the trend remained. The incidence of metabolic syndrome in the NFHL study was higher with increasing viral load, higher BMI, higher trunk-to-limb fat ratio, and Kaletra (lopinavir/ritonavir) or didanosine (ddI) use and lower among college-educated persons.

CONCLUSIONS

Metabolic syndrome is mostly diagnosed through low HDL and high triglycerides in HIV. The risk of developing the syndrome is related to HIV, specific medications, and body fat.

The effect of drug abuse on body mass index in Hispanics with and without HIV infection

Objective:

There is a widely held view that the lower weight of drug abusers is attributable to diet. However, many studies on the dietary intake of drug abusers have failed to find energy insufficiency, while non-dietary factors have rarely been examined. The purpose of this study was to examine non-dietary factors that could affect the weight of drug abusers with and without HIV infection.

Design:

Participants were recruited into one of three groups: HIV-positive drug abusers (n=85), HIV-negative drug abusers (n=102) and HIV-positive persons who do not use drugs (‘non-drug abusers’, n=98). Non-dietary factors influencing weight included infection with HIV and/or hepatitis, malabsorption, resting energy expenditure and physical activity.

Setting:

The baseline data from a prospective cohort study of the role of drug abuse in HIV/AIDS weight loss conducted in Boston, USA.

Subjects:

The first 286 participants to enrol in the study.

Results:

HIV-positive drug abusers had a body mass index (BMI) that was significantly lower than that of HIV-positive non-drug abusers. The differences in weight were principally differences in fat. In the men, cocaine abuse, either alone or mixed with opiates, was associated with lower BMI, while strict opiate abuse was not. Infection with HIV or hepatitis, intestinal malabsorption, resting energy expenditure and physical activity, as measured in this study, did not explain the observed differences in weight and BMI.

Conclusions:

Drug abuse, and especially cocaine abuse, was associated with lower weight in men. However, infection with HIV and/or hepatitis, malabsorption and resting energy expenditure do not explain these findings.

Dietary intake and body mass index in HIV-positive and HIV-negative drug abusers of Hispanic ethnicity

Objective:

Malnutrition in drug abusers has been attributed to poor diet. However, previous studies are conflicting. Many studies have not considered possible concurrent HIV disease. The purpose of this study was to determine the relationship between drug abuse and dietary intake in Hispanic Americans with and without HIV infection.

Design:

Dietary intake was measured using 3-day food records and 24-hour dietary recalls in three groups: HIV-positive drug abusers, HIV-negative drug abusers and HIV-positive persons who do not use drugs (‘non-drug abusers’).

Setting:

The baseline data from a prospective cohort study of the role of drug abuse in HIV/AIDS weight loss and malnutrition conducted in Boston, Massachusetts, USA.

Subjects:

The first 284 participants to enrol in the study.

Results:

HIV-positive drug abusers had a body mass index (BMI) that was significantly lower than that of HIV-positive non-drug abusers. Reported energy, fat and fibre intakes did not differ between groups. All groups had median reported intakes of vitamin A, vitamin B6, vitamin B12, selenium and zinc that were in excess of the dietary reference values (DRI). Intakes of α-tocopherol were below the DRI, but did not differ from intakes of the general US population. However, increasing levels of drug abuse were associated with lower reported intakes of vitamin B6, vitamin B12, selenium and zinc.

Conclusions:

Overall, this study does not support the notion that dietary intake can explain the lower BMI of HIV-positive drug abusers. Further studies examining non-dietary determinants of nutritional status in drug abusers are warranted.

Risk of cardiovascular disease in a cohort of HIV-infected adults: a study using carotid intima-media thickness and coronary artery calcium score

BACKGROUND

There is concern that human immunodeficiency virus (HIV) infection and the use of highly active antiretroviral therapy lead to accelerated atherosclerosis and increased risk of cardiovascular disease. We measured 2 surrogate markers of subclinical atherosclerosis, carotid intima-media thickness (c-IMT) and coronary artery calcium (CAC) scores, in HIV-infected adults.

METHODS

A cross-sectional analysis of 242 men and 85 women with HIV infection was used. Carotid ultrasonography and coronary computed tomography were performed, and their associations with cardiovascular risk factors were examined.

RESULTS

Among men, the mean (+/- standard deviation [SD]) common c-IMT was 0.62+/-0.2 mm, the mean (+/-SD) internal c-IMT was 0.76+/-0.5 mm, and 136 patients (56.1%) had detectable CAC. Among women, the mean (+/-SD) common c-IMT was 0.59+/-0.2 mm, the mean (+/-SD) internal c-IMT was 0.66+/-0.4 mm, and 40 patients (47.1%) had detectable CAC. Neither the c-IMT nor the CAC score differed by antiretroviral therapy class or individual medications for either sex. For men, age and waist circumference independently predicted common c-IMT; age, systolic blood pressure, and high-sensitivity C-reactive protein level independently predicted internal c-IMT; and age, apolipoprotein B level, and high-sensitivity C-reactive protein level independently predicted CAC score. For women, age and body mass index independently predicted common c-IMT; age independently predicted internal c-IMT; and age and glucose level independently predicted CAC score.

CONCLUSIONS

Our participants had more abnormal surrogate markers than expected at a relatively young age, but those were not associated with use of highly active antiretroviral therapy or protease inhibitors. At present, the positive associations were primarily with traditional and novel cardiovascular risk factors. Some HIV-specific (not treatment-specific) factors were observed; they may become more evident with prolonged HIV infection and treatment.

Probiotics: their role in the treatment and prevention of disease

A probiotic is a "live microbial food ingredients that, when ingested in sufficient quantities, exerts health benefits on the consumer". Probiotics exert their benefits through several mechanisms; they prevent colonization, cellular adhesion and invasion by pathogenic organisms, they have direct antimicrobial activity and they modulate the host immune response. The strongest evidence for the clinical effectiveness of probiotics has been in their use for the prevention of symptoms of lactose intolerance, treatment of acute diarrhea, attenuation of antibiotic-associated gastrointestinal side effects and the prevention and treatment of allergy manifestations. More research needs to be carried out to clarify conflicting findings on the use of probiotics for prevention of travelers' diarrhea, infections in children in daycare and dental caries, and elimination of nasal colonization with potentially pathogenic bacteria. Promising ongoing research is being conducted on the use of probiotics for the treatment of Clostridium difficile colitis, treatment of Helicobacter pylori infection, treatment of inflammatory bowel disease and prevention of relapse, treatment of irritable bowel syndrome, treatment of intestinal inflammation in cystic fibrosis patients, and prevention of necrotizing enterocolitis in premature infants. Finally, areas of future research include the use of probiotics for the treatment of rheumatoid arthritis, prevention of cancer and the treatment of graft-versus-host disease in bone marrow transplant recipients.

Update on Clostridium difficile

The most dramatic change in the past several years has been the increased incidence and severity of Clostridium difficile colitis reported from multiple countries. A number of factors have likely contributed to this. One major event has been the emergence of a fluoroquinolone-resistant clone of C. difficile with enhanced virulence properties that is associated with epidemic disease. Also noteworthy is the apparently decreasing effectiveness of the first-line agent metronidazole in treating this disease. Aggressive treatment of severe C. difficile colitis requires a multifaceted approach, including: 1) cessation of antibiotics where possible; 2) oral vancomycin; 3) if an ileus exists, intravenous administration of metronidazole and possibly intracolonic administration of vancomycin; 4) intravenous immunoglobulin if response to therapy is not rapid, or if there are signs of sepsis; and 5) early surgical consultation. Although it is likely that intravenous immunoglobulin contains antibodies against C. difficile toxins, its benefit remains unproven in rigorous clinical trials. Efforts to actively or passively immunize patients at risk are being explored to prevent the increasing morbidity and mortality associated with this disease. However, defining exactly who is at risk for severe C. difficile-associated disease is complex, as cases are being reported in populations not previously believed to be vulnerable.

Insulin Resistance in HIV-Infected Men and Women in the Nutrition for Healthy Living Cohort

OBJECTIVE

We evaluated insulin resistance (IR) in an HIV-infected cohort and compared our results with those of the National Health and Nutrition Examination Survey III (NHANES III).

METHODS

Using a cross-sectional study design, we determined the Quantitative Insulin Sensitivity Check Index (QUICKI) in 378 nondiabetic participants in the Nutrition for Healthy Living (NFHL) study and evaluated the association of the QUICKI with demographic, socioeconomic, body composition, lipid, liver function, HIV-associated factors (CD4 cell count, viral load, highly active antiretroviral therapy type, and years infected), and injection drug use. The prevalence of IR (QUICKI <0.350) and the mean QUICKI were ascertained for nondiabetic persons aged 25 to 65 years in the NHANES III and compared with those in the NFHL study.

RESULTS

Protease inhibitor (PI) highly active antiretroviral therapy (HAART) and nonnucleoside reverse transcriptase inhibitor (NNRTI) HAART were associated with worse IR in HIV-infected men. Greater waist circumference, triglycerides, age, and alanine aminotransferase were associated with worse IR, and higher high-density lipoprotein, low-density lipoprotein, and smoking were associated with less IR in the NFHL study; CD4 cell count, viral load, and years HIV infected were not associated with IR. There was no significant difference in the prevalence of IR in the NFHL study versus the NHANES III (51% vs. 47%; P = 0.27). NFHL participants were not more IR than NHANES III participants.

CONCLUSIONS

IR in the NFHL study was quite common but not significantly different than in the NHANES III and was associated with similar factors as in the general population. PI HAART and NNRTI HAART were associated with worse IR in men.

Predictors of bone mineral density in human immunodeficiency virus-1 infected children

OBJECTIVES

To compare bone mineral density (BMD) among human immunodeficiency virus (HIV)-infected children with population norms and to determine predictors of BMD in HIV-infected children.

METHODS

Total body BMD was measured by dual energy x-ray absorptiometry in 37 HIV-infected children and nine sibling controls at baseline. Clinical, dietary and anthropometric data were obtained at the time of the dual energy x-ray absorptiometry examination. Age- and gender-adjusted z scores were calculated for BMD, body mass index, weight and height from population standards. Age-adjusted percentiles were determined for dietary intake of calcium and vitamin D. Differences in BMD z scores between HIV-infected children and sibling controls were determined and adjusted for height and weight, as were independent risk factors for lower BMD among infected children. Eighteen HIV-infected children and 5 controls had serial BMD measures.

RESULTS

Compared with population norms, HIV-infected children had significantly lower BMD z scores (-0.51 SD, P = 0.004), in contrast with controls who had normal z scores (0.38 SD, P = 1.0). However, there was no difference in BMD z scores between HIV-infected children and the small number of sibling controls, adjusted for height and weight. Among HIV-infected children, lower BMD z scores were independently associated with lower weight z scores (P < 0.0001), lower height z scores (P = 0.01), advanced (stage B or C) HIV stage (P = 0.01) and age greater than 8 years (P < 0.0001). In the same model, multivitamin use (P = 0.009) and African American race (P = 0.001) were associated with better BMD z scores, with nevirapine use showing borderline positive effect (P = 0.06). All results were adjusted for Tanner stage. Change in BMD z score over time showed that there was no change or an increase in BMD in 100% of controls but in only 44% of the HIV-infected children (P = 0.09).

CONCLUSION

When compared with population norms, HIV-infected children had lower than expected bone mass for their age and gender that may be attributable to delays in growth, sexual maturity, time (length of HIV infection), ethnicity and disease severity. Dietary intake of calcium and vitamin D were not associated with bone loss, but most children had suboptimal intake. However, multivitamin use was strongly associated with better bone mineral density.

Differences in serum sex hormone and plasma lipid levels in Caucasian and African-American premenopausal women

CONTEXT

Risk of coronary heart disease is higher in African-American than in Caucasian women.

OBJECTIVE

The aim of this study was to evaluate the contribution of sex hormone levels, race, and measures of body fat to the variation in plasma lipid levels, a well-established risk factor for coronary heart disease.

DESIGN

This was a cross-sectional study.

SETTING

The study was conducted in the general community.

STUDY PARTICIPANTS

Sixty Caucasian and 117 African-American premenopausal women participated.

MAIN OUTCOME MEASURES

Body weight, body mass index (BMI), and waist to hip circumference ratio (WHR), as well as plasma lipid and serum sex hormone levels, were assessed.

RESULTS

Relative to Caucasian women, African-American women had significantly higher mean BMI (23.92 +/- 3.87 vs. 26.99 +/- 5.87 kg/m2, respectively; P < 0.001), and WHR (0.733 +/- 0.052 vs. 0.757 +/- 0.068; P < 0.03). Also, plasma triglyceride (TG) levels were significantly lower in African-American women (81 +/- 61 vs. 55 +/- 24 mg/dl; P < 0.0001). Serum estrone sulfate (556 +/- 323 vs. 442 +/- 332 pg/ml, Caucasian vs. African-American; P < 0.001), estradiol (E2) (55.1 +/- 43.6 vs. 35.8 +/- 17.7 pg/ml; P < 0.0001), androstenedione (2.6 +/- 0.9 vs. 1.6 +/- 0.7 ng/ml; P < 0.0001), and testosterone (0.36 +/- 0.12 vs. 0.31 +/- 0.19 ng/ml; P < 0.002) levels were significantly lower in African-American women than in Caucasian women. After correction for the effects of age, BMI, and WHR, serum E2 levels were significantly and positively associated with plasma high-density lipoprotein cholesterol levels in all women, and serum estrone sulfate levels with plasma total cholesterol and TG levels in African-American women.

CONCLUSIONS

Our results indicate that race is an important determinant of plasma TG and serum sex hormone levels, even after adjustment for differences in body size. A significant association between endogenous E2 and high-density lipoprotein cholesterol levels exists in premenopausal women, independent of their race.

The Effect of Micronutrient Supplementation on Disease Progression and Death in Simian Immunodeficiency Virus–Infected Juvenile Male Rhesus Macaques

BACKGROUND

We investigated the impact that micronutrient supplementation has on the progression of simian acquired immunodeficiency syndrome (SAIDS).

METHODS

Twenty-four simian immunodeficiency virus-infected juvenile male rhesus macaques were randomized into 2 groups. One group was given certified chow, and the other group was given chow and a supplement that contained 2-3 times the estimated nutritional requirement of micronutrients. Virological, immunological, and body composition measurements were taken every 4 weeks for 120 weeks.

RESULTS

There was no difference between groups in weight gain, body mass index (BMI), crown-heel length, waist circumference, total tissue mass, lean mass, bone mineral content, or bone mineral density. The rhesus macaques on the supplemented diet had a higher death rate (hazard ratio, 2.39; P<.001) than those on the nonsupplemented diet; death in both groups was associated with a higher viral load set point during the early phase of infection. Additionally, higher body weight, BMI, crown-rump length, and lower viral load set point were protective from death in both groups.

CONCLUSIONS

Micronutrient supplementation did not significantly alter the progression of SAIDS with respect to changes in body composition and immunological characteristics. A significantly higher rate of death was observed in rhesus macaques on the supplemented diet.

Predicting CD4 count using total lymphocyte count: a sustainable tool for clinical decisions during HAART use

Understanding the total lymphocyte count (TLC)-CD4 count relationship could aide design predictive instruments for making clinical decisions during antiretroviral therapy, especially in underserved resource-poor settings. We performed multiple regression analyses to assess the prediction of CD4 count using TLC on 771 participants with 4,836 visits. In linear and logistic regression TLC, hemoglobin, gender, history of AIDS, and weight predicted CD4 count and CD4 < 200, respectively, before and after highly active antiretroviral therapy (HAART) use. On HAART, the adjusted odds ratios (OR) for TLC < 1500 (optimal TLC cutoff) were 5.1 (95%CI 4.0, 6.5; P < 0.001), and off HAART, 4.6 (95%CI 3.4, 6.2: P < 0.001) with high predictive power. TLC predicts CD4 count and CD4 < 200 cells/microL well during HAART. Including the additional factors improves performance. TLC is simple and inexpensive and can be used in many ways to develop clinical decision-making tools in underserved resource-poor settings during HAART therapy.

Protease inhibitor-based HAART, HDL, and CHD-risk in HIV-infected patients

OBJECTIVE

To study the effects of HIV-infection and protease inhibitor (PI)-based highly active anti-retroviral therapy (HAART) on the lipid and high-density lipoprotein (HDL) subpopulation profile and to relate the changes to coronary heart disease (CHD)-risk.

METHODS AND DESIGN

The lipid and HDL subpopulation profiles of HIV-positive subjects (n = 48) were studied prospectively by comparing pre- and post-PI-HAART data as well as cross-section by comparing the profiles to HIV-negative subjects with (n = 96) and without CHD (n = 96).

RESULTS

HIV-infected HAART-naïve subjects had lower concentrations of low-density lipoprotein cholesterol (LDL-C) and HDL-C and higher concentration of triglycerides (TG) than healthy controls. After receiving PI-based HAART, LDL-C and TG concentrations increased, while HDL-C concentrations remained unchanged. The HDL subpopulation profiles of HAART-naïve HIV-positive patients were significantly different from those of healthy controls and were similar to those with CHD. Moreover, the HDL subpopulation profile changed unfavorably after PI-based HAART, marked with increased concentrations of the small, lipid-poor pre-beta-1 HDL (32% or 3.9 mg/dl; p < 0.001), and decreased concentration of the large, cholesterol-rich alpha-1 HDL (9% or 1 mg/dl ns).

CONCLUSION

An already unfavorable lipid and HDL subpopulation profile of HIV-positive HAART-naïve subjects further deteriorated after receiving PI-based treatment, which may cause increased CHD-risk in these subjects.

A Comparison of the Clinical and Cost-Effectiveness of 3 Intervention Strategies for AIDS Wasting

OBJECTIVE

To compare oxandrolone (OX) or strength training with nutrition alone (NA) for AIDS wasting.

SUBJECTS

Fifty patients with AIDS; 47 completing the study.

INTERVENTIONS

Randomization to (1) NA with placebo pills, (2) nutrition with 10 mg of OX administered orally twice a day, or (3) nutrition with progressive resistance training (PRT) for 12 weeks.

MAIN OUTCOME MEASURES

Midthigh cross-sectional muscle area (CSMA), physical functioning (PF), costs, and cost-effectiveness in dollars/quality-adjusted life-years (dollars/QALYs).

RESULTS

The OX and PRT subjects had increases in CSMA (7.0% +/- 2.5%, P = 0.01; 5.0% +/- 2.0%, P = 0.04, respectively), although these increases did not differ significantly from the NA arm (NA: 1.0% +/- 1.0%; OX vs. NA: P = 0.09; PRT vs. NA: P = 0.26). Only PRT caused significant improvements in PF (mean +/- SE: 10.4 +/- 3.8 points on a 100-point scale) and 7 measures of strength (P values: 0.04 to <0.001). There were no overall differences between groups in PF change. Among patients with impaired baseline PF, however, OX was significantly less effective than NA and PRT was significantly better than NA. All treatments led to increases in protein intake and performance; NA and PRT also increased caloric intake. The institutional costs per subject in this trial were 983 dollars for NA, 3772 dollars for OX, and 3189 dollars for PRT. At a community-based level of intensity, the institutional costs per QALY were 45,000 dollars (range: 42,000 dollars-64,000 dollars) for NA, 147,000 dollars (range: 147,000 dollars-163,000 dollars) for OX, and 31,000 dollars (range: 21,000 dollars-44,000 dollars) for PRT.

CONCLUSIONS

OX and PRT induce similar improvements in body composition, but PRT improves quality of life more than nutrition or OX, particularly among patients with impaired PF. PRT was the most cost-effective intervention, and OX was the least cost-effective intervention.

The effect of drug abuse on body mass index in Hispanics with and without HIV infection

OBJECTIVE

There is a widely held view that the lower weight of drug abusers is attributable to diet. However, many studies on the dietary intake of drug abusers have failed to find energy insufficiency, while non-dietary factors have rarely been examined. The purpose of this study was to examine non-dietary factors that could affect the weight of drug abusers with and without HIV infection.

DESIGN

Participants were recruited into one of three groups: HIV-positive drug abusers (n=85), HIV-negative drug abusers (n=102) and HIV-positive persons who do not use drugs ('non-drug abusers', n=98). Non-dietary factors influencing weight included infection with HIV and/or hepatitis, malabsorption, resting energy expenditure and physical activity.

SETTING

The baseline data from a prospective cohort study of the role of drug abuse in HIV/AIDS weight loss conducted in Boston, USA.

SUBJECTS

The first 286 participants to enroll in the study.

RESULTS

HIV-positive drug abusers had a body mass index (BMI) that was significantly lower than that of HIV-positive non-drug abusers. The differences in weight were principally differences in fat. In the men, cocaine abuse, either alone or mixed with opiates, was associated with lower BMI, while strict opiate abuse was not. Infection with HIV or hepatitis, intestinal malabsorption, resting energy expenditure and physical activity, as measured in this study, did not explain the observed differences in weight and BMI.

CONCLUSIONS

Drug abuse, and especially cocaine abuse, was associated with lower weight in men. However, infection with HIV and/or hepatitis, malabsorption and resting energy expenditure do not explain these findings.

Understanding the Role of HIV Load in Determining Weight Change in the Era of Highly Active Antiretroviral Therapy

BACKGROUND

In this prospective cohort study, we determined the relationship between human immunodeficiency virus (HIV) RNA load and body weight in patients with HIV infection.

METHODS

Repeated-measures analysis was restricted to patients with >or=2 study visits, 4-9-month intervals between study visits, and complete data on virus load, resting energy expenditure (REE), and highly active antiretroviral therapy (HAART). The outcome was change in body weight across study intervals. The main predictor was virus load. Separate analyses were performed for weight change in patients receiving and patients not receiving HAART.

RESULTS

The eligible sample consisted of 318 participants associated with 1886 study intervals. Sixty-one patients (19%) were women, and 173 (54%) were undergoing HAART at the time of enrollment. There was a significant interaction (P=.01) between virus load and HAART use. In the absence of HAART, each log(10) increase in virus load was associated with a 0.92-kg decrease in body weight (P=.003), but during HAART, virus load was not significantly associated with weight change. During HAART, a CD4(+) cell count decrease of 100 cells/mm(3), rather than a change in the virus load, was associated with a 0.35-kg decrease in body weight (P<.001). REE was independently associated with weight change in both models (P<.001).

CONCLUSIONS

Patients with HIV infection who are losing weight and are not taking HAART should be considered for HAART. Patients who are already receiving HAART and have unsuppressed virus loads may benefit virologically from an intensified regimen, because such a regimen may lead to complete suppression if there is an accompanying increase in CD4(+) cell counts. Further research is needed to understand the strong independent effect of changes in REE among patients receiving and patients not receiving HAART.

Body-composition changes in the simian immunodeficiency virus-infected juvenile rhesus macaque

BACKGROUND

Body-composition changes are common in individuals infected with human immunodeficiency virus. The purpose of the present study was to measure, as a model of wasting in acquired immunodeficiency syndrome (AIDS), longitudinal body-composition changes in macaques infected with simian immunodeficiency virus (SIV).

METHODS

Twelve juvenile macaques were inoculated with SIVmac239. Immunologic, virologic, somatometric, and dual-energy x-ray-absorptiometry measurements were performed prospectively every 4 weeks for 72 weeks and were compared to measurements taken from 8 uninfected control macaques.

RESULTS

During the first 4 weeks, body-fat percentage decreased in the SIV-infected macaques while lean-tissue percentage increased; during weeks 4-72, these macaques lost a greater percentage of total fat tissue but had more subcutaneous-fat deposition than did the uninfected control macaques. Just prior to death, the SIV-infected macaques that died (n=7) had a greater loss in body-mass index, abdominal fat, fat tissue, and lean tissue, compared with that in SIV-infected macaques that survived (n=5).

CONCLUSIONS

Body-composition changes in SIV-infected juvenile macaques exhibit 3 phases: during acute infection, loss of body weight from fat tissue; a compensation period during which macaques grow, but at a reduced rate; and a terminal phase, during which tissue is lost from all body compartments. The SIV-infected juvenile macaque provides a useful model for the investigation of wasting in AIDS, particularly for pediatric AIDS wasting.