Prediction of coronary heart disease risk in HIV-infected patients with fat redistribution

Metabolic syndrome: a major risk factor for atherosclerosis in HIV-infected patients (SHIVA study)

OBJECTIVE

Metabolic syndrome (MetS) is directly related to a high incidence of cardiovascular disease in the general population. The association is more doubtful among HIV-infected patients, although MetS has an elevated prevalence in this population. We explored the impact of MetS on early atherosclerosis markers.

RESEARCH DESIGN AND METHODS

All HIV-infected outpatients followed at the Brest University Hospital were included in this cross-sectional hospital-based study (SHIVA study, France) (n=154). The MetS status (NCEP ATPIII definition, at least three of these five criteria: fasting glucose, triglycerides, HDL-C, waist circumference and hypertension.) of each patient was analyzed (Mann-Whitney test) according to carotid intima-media thickness, number of plaques, and a combined cardiovascular score.

RESULTS

After exclusion of 6 patients treated with statins or insulin or both, MetS status was available for 140 (90.9%) patients and positive for 10 (7.1%). MetS status was due predominantly to blood glucose and triglyceride levels and was strongly correlated with all atherosclerosis markers (p < or = 0.01).

CONCLUSION

The MetS prevalence in this population is low for a group with HIV infection, even after inclusion of the statin-treated patients (11.4%), but remains higher than among the general population. MetS in this population is probably a heterogeneous cluster of side effects of antiretroviral therapy (high triglycerides, lower HDL-C, and hypertension) and direct effects of HIV (glucose disturbances). Because it is strongly linked to the presence of plaque and intimal thickness, it is a pertinent criterion for deciding about cardiovascular prevention.

Exercise training reduces central adiposity and improves metabolic indices in HAART-treated HIV-positive subjects in Rwanda: a randomized controlled trial

As HAART becomes more accessible in sub-Saharan Africa, metabolic syndromes, body fat redistribution (BFR), and cardiovascular disease may become more prevalent. We conducted a 6-month, randomized controlled trial to test whether cardiorespiratory exercise training (CET), improves metabolic, body composition and cardiorespiratory fitness parameters in HAART-treated HIV(+) African subjects with BFR. Six months of CET reduced waist circumference (-7.13 +/- 4.4 cm, p < 0.0001), WHR (-0.10 +/- 0.1, p < 0.0001), sum skinfold thickness (-6.15 +/- 8.2 mm, p < 0.0001) and % body fat mass (-1.5 +/- 3.3, p < 0.0001) in HIV(+)BFR(+)EXS. Hip circumference was unchanged in non-exercise control groups. CET reduced fasting total cholesterol (-0.03 +/- 1.11 mM, p < 0.05), triglycerides (-0.22 +/-0.48 mM, p < 0.05) and glucose levels (-0.21 +/- 0.71 mM, p < 0.05) (p < 0.0001). HDL-, LDL-cholesterol and HOMA values were unchanged after CET. Interestingly, HIV(+) subjects randomized to non-exercising groups experienced increases in fasting plasma glucose levels, whereas HIV seronegative controls did not (p < 0.001). Predicted VO(2) peak increased more in the HIV(+)BFR(+)EXS than in all other groups (4.7 +/- 3.9 ml/kg/min, p < 0.0001). Exercise training positively modulated body composition and metabolic profiles, and improved cardiorespiratory fitness in HAART-treated HIV(+) Africans. These beneficial adaptations imply that exercise training is a safe, inexpensive, practical, and effective treatment for evolving metabolic and cardiovascular syndromes associated with HIV and HAART exposure in resource-limited sub-Saharan countries, where treatment is improving, morbidity and mortality rates are declining, but where minimal resources are available to manage HIVand HAART-associated cardiovascular and metabolic syndromes.

Cardiovascular risk and choice of HIV drug regimen

Since the introduction of combination antiretroviral therapy (cART), there have been many conflicting reports linking its use to the development of cardiovascular disease (CVD). Most antiretroviral drugs have been associated with the development of lipid abnormalities to some degree. However, whereas several large observational studies have reported a link between the use of cART (particularly protease inhibitors) and CVD, evidence linking specific antiretroviral drugs to CVD is limited. Much of the evidence linking cART to the development of dyslipidemia derives from randomized trials. However, given the relative infrequency of CVD in most HIV-positive populations, these may be inadequately powered to demonstrate a link with clinical events. In contrast, large observational studies have greater power to describe the development of clinical events but may be affected by bias. This review will describe the current literature linking cART to CVD as well as the limitations of some of the published studies.

Assistência de enfermagem a um paciente infartado portador de HIV, baseada na teoria do autocuidado: estudo de caso

OBJETIVO: Aplicar a Sistematização da Assistência de Enfermagem (SAE) a um paciente portador de HIV e infartado. MÉTODOS: Trata-se de um estudo de caso realizado em um hospital escola localizado na região metropolitana de São Paulo, em novembro de 2003, utilizando a Sistematização da Assistência de Enfermagem e propondo diagnósticos de enfermagem com base na taxonomia II NANDA bem como as intervenções de enfermagem relacionadas. RESULTADOS: Os principais diagnósticos de enfermagem identificados foram: Risco para controle ineficaz do regime terapêutico, ansiedade, perfusão tissular cardíaca alterada, mobilidade física prejudicada, proteção alterada, risco para infecção, entre outros. CONCLUSÃO: O estudo mostrou a importância da Sistematização da Assistência de Enfermagem e da decisão do paciente em engajar-se no autocuidado a fim de proporcionar uma melhora no padrão de resposta do doente à doença.

Metabolic syndrome, cardiovascular disease and type 2 diabetes mellitus after initiation of antiretroviral therapy in HIV infection

BACKGROUND

Metabolic syndrome (MS) identifies individuals at risk of cardiovascular disease (CVD) and type 2 diabetes mellitus (T2DM). Little is known about MS and its consequences following initiation of antiretroviral therapy (ART).

METHODS

HIV-infected adults (881) initiating ART were evaluated for prevalence and incidence of MS and subsequent diagnosis of CVD and T2DM over a 3-year period. MS was defined by criteria of the National Cholesterol Education Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Third Report; ATP-III) or of the International Diabetes Federation (IDF).

RESULTS

The prevalence of baseline MS was 8.5% and 7.8% (ATP-III and IDF, respectively). During follow-up, 234 (12/100 patient-years) (ATP-III) and 178 (8/100 patient-years) (IDF) progressed to MS. MS at baseline had a borderline association with increased risk of CVD [ATP-III: hazard ratio (HR), 2.56; 95% confidence interval (CI), 0.86-7.60; P = 0.095; IDF: HR, 2.89; 95% CI, 0.98-8.63; P = 0.058] and was significantly associated with an increased risk of T2DM (ATP-III: HR, 4.34; 95% CI, 1.83-10.25; P = 0.001; IDF: HR, 3.33; 95% CI, 1.35-8.17; P = 0.009). Incident MS was significantly associated with an increased risk of both CVD (ATP-III: HR, 2.73; 95% CI, 1.07-6.96; P = 0.036; IDF: HR, 3.05; 95% CI, 1.20-7.75; P = 0.019) and T2DM (ATP-III: HR, 4.89; 95% CI, 2.22-10.78; P < 0.0001; IDF: HR, 4.84; 95% CI, 2.20-10.64; P < 0.0001).

CONCLUSIONS

Substantial progression to MS occurs within 3 years following initiation of ART. Since baseline and incident MS identifies individuals at risk for subsequent CVD and T2DM, it warrants evaluation in patients commencing ART.

Ten-Year Predicted Coronary Heart Disease Risk in HIV-Infected Men and Women

BACKGROUND

Highly active antiretroviral therapy (HAART), in addition to traditional vascular risk factors, may affect coronary heart disease (CHD) risk in individuals with human immunodeficiency virus (HIV) infection.

METHODS

Among HIV-infected (931 men and 1455 women) and HIV-uninfected (1099 men and 576 women) adults, the predicted risk of CHD was estimated on the basis of age, sex, lipid and blood pressure levels, the presence of diabetes, and smoking status.

RESULTS

Among HIV-infected men, 2% had moderate predicted risk of CHD (10-year CHD risk, 15%-25%), and 17% had high predicted risk (10-year CHD risk of > or = 25% or diabetes). Among HIV-infected women, 2% had moderate predicted CHD risk, and 12% had high predicted CHD risk. Compared with users of protease inhibitor-based HAART, the adjusted odds ratio (OR) for moderate-to-high risk of CHD was significantly lower among HAART-naive individuals (OR, 0.57; 95% confidence interval [CI], 0.36-0.89). Users of HAART that was not protease inhibitor based (OR, 0.74; 95% CI, 0.53-1.01) and former HAART users (OR, 0.68; 95% CI, 0.46-1.03) were also less likely than users of protease inhibitor-based HAART to have moderate-to-high CHD risk, although 95% CIs overlapped the null. Low income was associated with increased likelihood of moderate-to-high CHD risk (for annual income < $10,000 vs. > $40,000: OR, 2.32; 95% CI, 1.51-3.56 ). Elevated body mass index (calculated as weight in kilograms divided by the square of height in meters) predicted increased likelihood of moderate-to-high CHD risk (for BMI of 18.5-24.9 vs. BMI of 25-30: OR, 1.41 [95% CI, 1.03-1.93]; for BMI of 18.5-24.9 vs. BMI > or = 30: OR, 1.79 [95% CI, 1.25-2.56]).

CONCLUSIONS

Among HIV-infected adults, in addition to antiretroviral drug exposures, being overweight and having a low income level were associated with increased predicted CHD risk. This suggests a need to target HIV-infected men and women with these characteristics for vascular risk factor screening.

Use of metabolic drugs and fish oil in HIV-positive patients with metabolic complications and associations with dyslipidaemia and treatment targets

BACKGROUND

Highly active antiretroviral therapy (HAART) with protease inhibitors (PI) is successful in suppressing viral replication, but may lead to a range of metabolic abnormalities associated with cardiovascular disease (CVD).

OBJECTIVES

The first objective of the study was to compare baseline demographic and clinical characteristics between PI users and non-PI users referred to a specialized metabolic clinic during 1999-2003. The second objective was to assess the associations of prescription drugs and fish oil with dyslipidaemia and to determine whether or not patients achieved treatment targets during 6 months of treatment.

METHODS

A retrospective analysis was performed using two sets of charts based on standardized forms with entries for personal data, drug treatment and clinical history. Anonymous linkage with the British Columbia HIV/AIDS Drug Treatment Program and the hospital laboratory was performed to gather information about HAART prescriptions and blood work.

RESULTS

In total, 237 patients were included in the study. There were few differences in any demographic or clinical factors between PI users and non-PI users. Compared with controls not taking lipid-lowering drugs or fish oil (n=48), statins appeared to be the only agent that was significantly associated with a reduced total cholesterol concentration (-15.6%; P=0.009). Fibrate treatment was associated with the largest reduction of triglyceride concentration (-37.4%; P=0.012), closely followed by fish oil (n=18;-32%; P=0.027). Six-month treatment success rates ranged between 17 and 43% of patients for total cholesterol (<5.2 mmol/L) and between 15 and 44% of patients for triglycerides (<2.3 mmol/L).

CONCLUSIONS

Despite the apparent lowering of blood lipids with drug and fish oil treatments, a majority of patients in these treatment groups (56.5-83.3%) still had elevated concentrations after 6 months.

Management of antiretroviral treatment-related complications

Antiretroviral therapy for HIV restores immune function, controls viral replication, decreases opportunistic infections, and extends lifespan to near-normal for infected individuals. However, successful HIV therapy has been accompanied by the emergence of treatment-related complications, with an impact not yet fully understood. This article reviews six common complications of antiretroviral therapy, including hyperlactatemia/lactic acidosis, hypersensitivity reactions, abnormal glucose metabolism, dyslipidemia, body composition changes, and cardiovascular disease. A comprehensive approach to management of antiretroviral-related complications includes awareness of (1) risk factors for adverse reactions, (2) clinical syndromes suggestive of an evolving complication, and (3) evidence-based monitoring and treatment strategies. Fluency in options for preventing and managing complications can provide maximal opportunity to balance treatment effects with quality of life.

Incidence and prevalence of the metabolic syndrome in a cohort of naive HIV-infected patients: prospective analysis at 48 weeks of highly active antiretroviral therapy

We undertook a prospective study to assess the prevalence of the metabolic syndrome (MetS) in HIV patients at the start of highly active antiretroviral therapy (HAART), and at 48 weeks, and we also studied its relationship with high-sensitivity C-reactive protein (hs-CRP) in 60 HIV patients who maintained the same regimen during follow-up. The prevalence of MetS rose from 16.6% at baseline to 25% at 48 weeks (P=0.0001). During follow up, 7/50 patients developed MetS, leading an incidence of 14/100 patients/year. The MetS was associated with age, homosexuality, and lower hepatitis C virus prevalence; only age remained significant in the multivariate analysis (for each five-year increase: beta coefficient 4.26, 95% confidence interval, 3.80-4.75; P=0.0039). The hs CRP values were similar in patients with and without the MetS, and they did not increase at 48 weeks of HAART.

A coronary heart disease risk model for predicting the effect of potent antiretroviral therapy in HIV-1 infected men

BACKGROUND

Many HIV-infected patients on highly active antiretroviral therapy (HAART) experience metabolic complications including dyslipidaemia and insulin resistance, which may increase their coronary heart disease (CHD) risk. We developed a prognostic model for CHD tailored to the changes in risk factors observed in patients starting HAART.

METHODS

Data from five cohort studies (British Regional Heart Study, Caerphilly and Speedwell Studies, Framingham Offspring Study, Whitehall II) on 13,100 men aged 40-70 and 114,443 years of follow up were used. CHD was defined as myocardial infarction or death from CHD. Model fit was assessed using the Akaike Information Criterion; generalizability across cohorts was examined using internal-external cross-validation.

RESULTS

A parametric model based on the Gompertz distribution generalized best. Variables included in the model were systolic blood pressure, total cholesterol, high-density lipoprotein cholesterol, triglyceride, glucose, diabetes mellitus, body mass index and smoking status. Compared with patients not on HAART, the estimated CHD hazard ratio (HR) for patients on HAART was 1.46 (95% CI 1.15-1.86) for moderate and 2.48 (95% CI 1.76-3.51) for severe metabolic complications.

CONCLUSIONS

The change in the risk of CHD in HIV-infected men starting HAART can be estimated based on typical changes in risk factors, assuming that HRs estimated using data from non-infected men are applicable to HIV-infected men. Based on this model the risk of CHD is likely to increase, but increases may often be modest, and could be offset by lifestyle changes.

HIV-associated adipose redistribution syndrome (HARS): definition, epidemiology and clinical impact

A segment of the HIV infected population develops abnormal and excessive accumulation of adipose tissue in the trunk, including accumulation of visceral (deep abdominal) adipose tissue. This condition, known as HIV-related adipose redistribution syndrome (HARS), may also be accompanied by fat accumulation in the upper back/neck (dorsocervical region) and/or depletion of subcutaneous adipose tissue from the abdomen, face, limbs, or buttocks. HARS is estimated to occur in up to 32% of patients and is associated with health risks similar to those of metabolic syndrome. Techniques to detect and measure HARS include physician and patient assessments and radiologic or anthropometric methods.

Global cardiovascular risk in patients with HIV infection: concordance and differences in estimates according to three risk equations (Framingham, SCORE, and PROCAM)

To compare cardiovascular risk stratification according to Framingham, PROCAM (Prospective Cardiovascular Münster), and SCORE (Systematic Coronary Risk Evaluation) equations in patients with HIV infection, a cross-sectional study of a well-characterized cohort of 760 HIV-infected adults managed at the outpatient Infectious Disease Unit in 2003 was conducted. Cardiovascular risk score was examined and patients were classified as having low, moderate, or high risk using Framingham and PROCAM (<10%, 10%-20%, and <20%, respectively) and SCORE (<3%, 3%-4%, and >/=5%, respectively) equations. The prevalence of patients with low, moderate and high cardiovascular risk was 76.6%, 15.1%, and 8.3% by the Framingham, respectively, 90.1%, 4.9%, and 5% by the PROCAM, respectively, and 88.6%, 3%, and 8.4% by SCORE, respectively. Concordance between these three risk functions was significant, but globally moderate (Framingham and PROCAM, kappa 0.36, p < 0.0001; Framingham and SCORE, kappa 0.32, p < 0.0001; PROCAM and SCORE, kappa 0.46, p < 0.0001). The Framingham equation categorized a higher proportion of HIV-infected male patients with moderate cardiovascular risk and a lower proportion of those with low risk (p < 0.0001) compared with PROCAM and SCORE. The present study showed a high prevalence of HIV-infected patients at low cardiovascular risk regardless of the assessed coronary risk system used. However, compared with PROCAM and SCORE, Framingham risk equation in HIV-infected patients identified a higher number of male patients with moderate cardiovascular risk.

Increased acute myocardial infarction rates and cardiovascular risk factors among patients with human immunodeficiency virus disease

CONTEXT

Metabolic changes and smoking are common among HIV patients and may confer increased cardiovascular risk.

OBJECTIVE

The aim of the study was to determine acute myocardial infarction (AMI) rates and cardiovascular risk factors in HIV compared with non-HIV patients in two tertiary care hospitals.

DESIGN, SETTING, AND PARTICIPANTS

We conducted a health care system-based cohort study using a large data registry with 3,851 HIV and 1,044,589 non-HIV patients. AMI rates were determined among patients receiving longitudinal care between October 1, 1996, and June 30, 2004.

MAIN OUTCOME MEASURES

The primary outcome was myocardial infarction, identified by International Classification of Diseases coding criteria.

RESULTS

AMI was identified in 189 HIV and 26,142 non-HIV patients. AMI rates per 1000 person-years were increased in HIV vs. non-HIV patients [11.13 (95% confidence interval [CI] 9.58-12.68) vs. 6.98 (95% CI 6.89-7.06)]. The HIV cohort had significantly higher proportions of hypertension (21.2 vs. 15.9%), diabetes (11.5 vs. 6.6%), and dyslipidemia (23.3 vs. 17.6%) than the non-HIV cohort (P < 0.0001 for each comparison). The difference in AMI rates between HIV and non-HIV patients was significant, with a relative risk (RR) of 1.75 (95% CI 1.51-2.02; P < 0.0001), adjusting for age, gender, race, hypertension, diabetes, and dyslipidemia. In gender-stratified models, the unadjusted AMI rates per 1000 person-years were higher for HIV patients among women (12.71 vs. 4.88 for HIV compared with non-HIV women), but not among men (10.48 vs. 11.44 for HIV compared with non-HIV men). The RRs (for HIV vs. non-HIV) were 2.98 (95% CI 2.33-3.75; P < 0.0001) for women and 1.40 (95% CI 1.16-1.67; P = 0.0003) for men, adjusting for age, gender, race, hypertension, diabetes, and dyslipidemia. A limitation of this database is that it contains incomplete data on smoking. Smoking could not be included in the overall regression model, and some of the increased risk may be accounted for by differences in smoking rates.

CONCLUSIONS

AMI rates and cardiovascular risk factors were increased in HIV compared with non-HIV patients, particularly among women. Cardiac risk modification strategies are important for the long-term care of HIV patients.

Long-term complications of antiretroviral therapy: lipoatrophy

The effective use of potent antiretroviral therapy has dramatically improved the life expectancy for HIV-infected individuals. Long-term complications of both HIV-infection and antiretroviral agents are therefore of increasing concern. Lipoatrophy (LA) or fat wasting is a complication most frequently associated with nucleoside reverse transcriptase inhibitors, thymidine analogues particularly. LA can be stigmatising and is associated with psychosocial complication. It can occur in isolation or as part of the 'metabolic' or 'lipodystrophy' syndrome, a triad of LA, fat accumulation and metabolic disturbance (insulin resistance and dyslipidaemia) with a subsequently increased risk of cardiovascular events. We aimed to review the definition, prevalence, pathogenesis, implications and treatment of HIV/highly active antiretroviral therapy-associated fat loss. We performed a review of PubMed, Medline and recent conference abstracts for information on LA. The current treatments available for treating LA are limited. Switching away from thymidine analogues can provide a small benefit but improvement is, at best, slow and partial. Specific medical therapies such as glitazones, metformin and stating have been disappointing to date. Surgical fillers can yield marked results but are costly, time consuming and only of value for facial LA, not other sites. Ultimately, prevention of this condition is the best approach by avoiding thymidine analogues wherever possible or careful monitoring with early switching away from these agents. New therapies to treat pre-existing fat loss are required.

Molecular mechanisms of HIV protease inhibitor-induced endothelial dysfunction

Highly active antiretroviral therapy incorporating protease inhibitors (PIs) is successful in controlling HIV infection and has dramatically improved the prognosis of HIV-infected patients. The therapeutic benefit of long-term use of HIV PIs is compromised by an increased risk of cardiovascular disease, however, including metabolic syndrome and endothelial dysfunction. Although clinical evidence strongly suggests an association of the use of HIV PIs with endothelial dysfunction, the underlying molecular mechanisms have not been fully elucidated yet. In this review, we describe recent advances in the molecular mechanisms of PI-induced endothelial dysfunction. The available evidence demonstrates that certain HIV PIs could induce endothelial dysfunction, including a decrease of endothelium-dependent vasorelaxation, inhibition of the nitric oxide synthase system, increase of oxidative stress, and activation of mitogen-activated protein kinases. HIV infection itself may also induce endothelial dysfunction and injury. These new discoveries provide a better understanding of the molecular mechanisms of the interaction between HIV PIs and vascular cells and may suggest potential approaches to control HIV PI-associated cardiovascular complications.

Longitudinal anthropometric changes in HIV-infected and HIV-uninfected men

BACKGROUND

Although morphologic abnormalities are common among HIV-infected persons receiving highly active antiretroviral therapy (HAART), longitudinal comparative body shape changes among HAART-treated HIV-infected men versus HIV-seronegative men of similar age remain unclear.

METHODS

Since September 1999, men enrolled in the Multicenter AIDS Cohort Study underwent body mass index (BMI) and circumference measurements of the waist, hip, thigh, and arm at each semiannual visit. Changes in these measurements that occurred between 1999 and 2003 among HIV-infected men were compared with measurements of HIV-seronegative men using linear mixed effects regression models. The HIV-infected men were further stratified by treatment group (no antiretroviral therapy [ART], monotherapy or combination [mono/combo] ART, or HAART). Analyses were adjusted for age, nadir CD4 cell count, and BMI (for circumference measurements).

RESULTS

Over the 4-year observation period, mean BMI increased significantly among the 392 HIV-seronegative men (0.12 kg/m/y; P < 0.001) but did not change in the 3 HIV-infected groups (combined n = 661). Mean waist and hip circumferences increased significantly in all groups. Hip circumferences increased more slowly in the HIV-positive HAART-treated group (n = 488) than in the HIV-seronegative group (0.18 vs. 0.49 cm/y; P < 0.001), however, yielding a more rapid increase in the waist/hip ratio in the HIV-positive, HAART-treated group over time (0.005 per year; P < 0.001).

CONCLUSIONS

The increased rate of change in waist/hip ratio in HIV-infected men receiving HAART compared with HIV-seronegative men is attributable to slower increases in hip circumference rather than an increased rate of change in waist circumference. These findings underscore the importance of body fat composition changes in the peripheral compartment relative to the central compartment among HIV-infected men receiving HAART.

Improved triglycerides and insulin sensitivity with 3 months of acipimox in human immunodeficiency virus-infected patients with hypertriglyceridemia

CONTEXT

Metabolic abnormalities such as hypertriglyceridemia remain a challenge for optimizing long-term health in HIV-infected patients.

OBJECTIVE

Elevation of free fatty acids (FFAs) may contribute to hyperlipidemia and insulin resistance in HIV. We evaluated the efficacy and safety of chronic inhibition of lipolysis in HIV-infected men and women with hypertrigyceridemia. We hypothesized that acipimox would lead to significant reductions in triglycerides and improved insulin sensitivity, compared with placebo.

DESIGN

A 3-month, randomized, double-blind, controlled trial of acipimox (250 mg thrice daily) vs. placebo was conducted in 23 HIV-infected men and women with hypertriglyceridemia (>150 mg/dl), abnormal fat distribution, and no current lipid-lowering therapy. The primary outcome variable was triglyceride concentration, and insulin sensitivity measured by hyperinsulinemic euglycemic clamp was a secondary outcome.

SETTING

The study was conducted at an academic medical center.

RESULTS

Acipimox resulted in significant reductions in FFAs [mean change -0.38 (0.06) vs. 0.08 (0.06) mEq/liter with placebo, -68 vs. +17% change from mean baseline, P < 0.0001], decreased rates of lipolysis (P < 0.0001), and a median triglyceride decrease from 238 mg/dl at baseline to 190 mg/dl, compared with an increase from 290 to 348 mg/dl in the placebo group (P = 0.01). Acipimox improved insulin sensitivity [acipimox +2.31 (0.74) vs. placebo -0.21 (0.90) mg glucose per kilogram lean body mass per minute, or +31 vs. -2% change from mean baseline values, P = 0.04]. Improvements in insulin sensitivity were significantly correlated with reductions in FFAs (r = -0.62, P = 0.003) and lipolysis (r = -0.59, P = 0.005).

CONCLUSIONS

Acipimox resulted in significant sustained reductions in lipolysis, improved glucose homeostasis, and significant but modest reductions in triglycerides in HIV-infected individuals with abnormal fat distribution and hypertriglyceridemia. Improvement in overall metabolic profile with acipimox suggests a potential clinical utility for this agent that requires further investigation.

Effects of a lifestyle modification program in HIV-infected patients with the metabolic syndrome

OBJECTIVES

A large percentage of HIV-infected patients receiving HAART develop the metabolic syndrome. In this study, we sought to determine whether lifestyle modification improves metabolic syndrome criteria, including waist circumference, blood pressure, fasting blood sugar, triglycerides, and HDL-cholesterol among HIV-infected patients with the metabolic syndrome.

DESIGN

We conducted a randomized, 6-month study in HIV-infected patients with metabolic syndrome as defined by the National Cholesterol Education Program. Subjects were randomly assigned to an intensive lifestyle modification program, which included weekly one-on-one counseling sessions with a registered dietician, or observation (control group).

METHODS

Metabolic syndrome criteria and cardiovascular parameters, including blood pressure, body composition, submaximal stress testing, lipids and other biochemical parameters were determined.

RESULTS

Thirty-four patients were randomly assigned and 28 subjects completed the study. Compared with the control group, subjects randomly assigned to the lifestyle modification program demonstrated significant decreases in waist circumference (-2.6 +/- 1.1 versus 1.2 +/- 1.0 cm, P = 0.022), systolic blood pressure (-13 +/- 4 versus 4 +/- 4 mmHg, P = 0.008), hemoglobin A1C (-0.1 +/- 0.1 versus 0.2 +/- 0.1%, P = 0.017), lipodystrophy score (-1.2 +/- 0.3 versus 0.9 +/- 0.6, P = 0.006) and increased activity (17.7 +/- 14.3 versus -33.1 +/- 12.7 metabolic equivalents, P = 0.014) as measured by the Modifiable Activity Questionnaire, but lipid levels did not improve.

CONCLUSION

These data demonstrate that intensive lifestyle modification significantly improved important cardiovascular risk indices in HIV-infected patients with the metabolic syndrome. Lifestyle modification may be a useful strategy to decrease cardiovascular risk in this population.

Effects of a supervised home-based aerobic and progressive resistance training regimen in women infected with human immunodeficiency virus: a randomized trial

BACKGROUND

Women infected with human immunodeficiency virus (HIV) increasingly demonstrate abnormalities in fat distribution and metabolism; however, the effects of a home-based exercise regimen in this group have not been investigated.

METHODS

We conducted a 16-week randomized intervention study of a supervised home-based progressive resistance training and aerobic exercise program in 40 HIV-infected women with increased waist-hip ratio and self-reported fat redistribution. Cross-sectional muscle area and muscle attenuation were measured by computed tomography. Cardiorespiratory fitness was determined by calculated maximum oxygen consumption (VO2max) and strength by 1-repetition maximum.

RESULTS

Cardiorespiratory fitness (VO2max) was markedly lower at baseline (median [95% confidence interval], 15.4 [8.3-25.2] mL x kg(-1) x min(-1)) than reported values for healthy female subjects (26-35 mL x kg(-1) x min(-1)). Subjects randomized to exercise had significant improvement in mean +/- SEM VO2max (1.5 +/- 0.8 vs -2.5 +/- 1.6 mL x kg(-1) x min(-1); P<.001) and endurance (1.0 +/- 0.3 vs -0.6 +/- 0.3 minute; P<.001). Strength increased at the knee extensors, pectoralis, knee flexors, shoulder abductors, ankle plantar flexors, and elbow flexors (all P<.001). Total muscle area (6 +/- 1 vs 2 +/- 1 cm2; P = .02) and attenuation (2 +/- 1 vs -1 +/- 1 Hounsfield unit; P = .03) increased in the exercise group. No significant difference was seen in lipid levels, blood pressure, or abdominal visceral fat between the groups, but subjects randomized to exercise reported improved energy and appearance.

CONCLUSIONS

A 16-week, supervised, home-based exercise regimen improved measures of physical fitness in HIV-infected women. The effects on strength were most significant, but improvements in cardiorespiratory fitness, endurance, and body composition were also seen.

Lipodystrophy and metabolic syndrome in HIV-infected patients treated with antiretroviral therapy

Lipodystrophy (lipo) and metabolic derangements associated with an increased cardiovascular risk are observed frequently in human immunodeficiency virus (HIV)-infected patients who receive antiretroviral treatment (ART). The objective of the study was to provide detailed biochemical information about metabolic syndrome in this condition. One hundred forty-six HIV-infected male and female patients on ART for more than 6 months were compared with 156 body mass index (BMI)-matched healthy subjects. Lipodystrophy was diagnosed upon patient and physician concordance. Metabolic syndrome was defined according to the Adult Treatment Panel III criteria. Plasma adiponectin (AD) and leptin were measured by radioimmunoassay. Insulin resistance (IR) was assessed by the homeostasis model assessment (HOMA). The prevalence of metabolic syndrome was higher in HIV-infected patients on ART than in non-HIV-infected healthy controls (15.8% vs 3.2%; P < .001). Patients with metabolic syndrome are older (44.6 +/- 6 vs 39.8 +/- 8 years; P = .004), have an increased BMI (24.9 +/- 3.8 vs 22.9 +/- 9.8 kg/m(2); P = .01), present with a reduced AD-to-leptin ratio log(10) (-0.19 +/- 0.4 vs 0.5 +/- 0.4; P = .04), and show increased IR (HOMA, 5.6 +/- 2.7 vs 3.8 +/- 2.2; P = .001; plasma fasting insulin, 22.9 +/- 9.8 vs 16.6 +/- 9.7 ng/mL; P < .001). In multivariate analysis, the diagnosis of lipo and HOMA were independently and significantly related to metabolic syndrome. In conclusion, the prevalence of metabolic syndrome is significantly increased in HIV-infected patients on ART and its presence is associated with lipo, increased age and BMI, IR, and a reduced plasma AD-to-leptin ratio.

[Metabolic alterations in HIV-associated lipodystrophy syndrome]

The introduction of highly active antiretroviral therapy (HAART) has reduced morbidity and mortality in patients infected with the human immunodeficiency virus (HIV). However, prolonged treatment with combination regimens can be difficult to sustain because of problems with adherence and toxic effects. Treatment with antiretroviral agents--protease inhibitors in particular--has uncovered a syndrome of abnormal fat redistribution, impaired glucose metabolism, insulin resistance and dyslipidemia, collectively termed lipodystrophy syndrome (SLHIV). Nowadays, no clinical guidelines are available for the prevention or treatment of SLHIV, and its cause have yet to be totally elucidated. This review emphasizes the clinical features and the data from previous studies about the SLHIV taking into account that a better understanding of this syndrome for HIV specialists, cardiologists and endocrinologists is fundamental for the disease control.

What a Cardiologist Needs to Know About Patients With Human Immunodeficiency Virus Infection

Patient case: A 48-year-old man with human immunodeficiency virus (HIV) infection developed chronic chest pain that started after a bout of pneumonia. He has hypertension and has smoked cigarettes in the past. His current medications include Kaletra and Combivir. His total cholesterol was 331 mg/L, his HDL cholesterol was 27 mg/L, his triglycerides were 935 mg/L, and his LDL cholesterol could not be calculated. How should this patient be evaluated and managed?

Tolerability and safety of HIV protease inhibitors in adults

Antiretroviral drugs are associated with both short-term and long-term adverse events. Like other HIV drugs, protease inhibitors (PIs) may affect metabolic processes influencing body shape and body tissue composition, appearance, bone integrity, and cardiovascular status. However, numerous confounding variables including age, cigarette smoking, body mass index (BMI), duration of HIV infection, degree of immunodeficiency, concomitant antiretroviral agents, extent of previous treatment, and duration of treatment all blur the relationship between PI use and adverse events. Recent data suggest that the early PIs appear to have greater effects on such surrogate markers of disease risk as insulin resistance and cholesterol and triglyceride levels than the recently developed PIs. These data also suggest that evaluation of PIs as a class should be reconsidered and that it is probably not appropriate to extrapolate safety data obtained from individuals treated with first-generation agents in the era of potent combination antiretroviral therapy to those treated with recently developed PIs. Because PIs remain a critical component of successful antiretroviral therapy, evaluation of potential long-term complications with prolonged PI use is essential, as is delineation of the significant differences in safety profiles among individual PIs.

Antiretroviral Therapy in HIV-Infected Children: The Metabolic Cost of Improved Survival

Although highly active antiretroviral therapy (HAART) has positively altered the morality rates in HIV-infected children, these drugs have the potential to cause significant morbidity. These drugs cause changes in fat distribution, lipid profiles, glucose, homeostasis, and bone turnover. The direct relationship between duration of drug exposure and increased risk of cardiovascular disease is particularly concerning for HIV-infected infants and children, who likely will have longer cumulative exposure to HAART. It is unclear whether the metabolic effects of decades of exposure would be reversible with cessation of therapy. The benefits of HAART in HIV infection are indisputable, but the impetus to find a cure or design more tolerable therapy is clear. Infarction may replace infection as the major cause of morbidity and mortality from HIV.

Premature atherosclerosis in HIV positive patients and cumulated time of exposure to antiretroviral therapy (SHIVA study)

BACKGROUND

With the advent of antiretroviral therapy regimens in HIV positive patients, it is crucial to consider their long-term benefits to risk ratios. The responsibility of treatment in premature atherosclerosis is not clear. Thus, the aim of this study is to evaluate the impact of exposure to reverse transcriptase inhibitors (nucleosidic and non-nucleosidic) and to protease inhibitors on the cardiovascular status of an entire hospital based cohort of patients.

METHODS

154 patients were included. Using a linear analysis, we sought an association between the cumulative time of exposure to these three classes of antiretroviral drugs and the carotid intima-media thickness measured by ultrasonography and a cardiovascular composite score.

RESULTS

The study confirms premature atherosclerosis, which not only correlates with the usual risk factors, such as triglyceride level, but also with protease inhibitor exposure, especially that of lopinavir. Nevertheless as regards current drug exposure, the clinical impact was low: five clinical complications of atherosclerosis and only one out of 35 scintigraphic and ECG exercise tests warranted a coronary angiography which was negative.

CONCLUSION

These data should not lead to the rejection of protease inhibitors but should strengthen the prevention of cardiovascular diseases as an integral part of the management of HIV patients.

A placebo-controlled, dose-ranging study of a growth hormone releasing factor in HIV-infected patients with abdominal fat accumulation

OBJECTIVE

To investigate the effects of TH9507, a novel growth hormone releasing factor, on abdominal fat accumulation, metabolic and safety parameters in HIV-infected patients with central fat accumulation.

DESIGN AND METHODS

Randomized, double-blind, placebo-controlled trial enrolling 61 HIV-infected patients with increased waist circumference and waist-to-hip ratio. Participants were randomized to placebo or 1 or 2 mg TH9507 subcutaneously, once daily for 12 weeks. The primary outcome was change in abdominal fat, assessed by dual energy X-ray absorptiometry and cross-sectional computerized tomography scan. Secondary endpoints included change in insulin-like growth factor-I (IGF-I), metabolic, quality of life, and safety parameters.

RESULTS

TH9507 resulted in dose-related physiological increases in IGF-I (P < 0.01 for 1 mg (+48%) and 2 mg (+65%) versus placebo). Trunk fat decreased in the 2 mg group versus placebo (0.8, -4.6 and -9.2%; placebo, 1 and 2 mg, respectively, P = 0.014 for 2 mg versus placebo), without significant change in limb fat. Visceral fat (VAT) decreased most in the 2 mg group (-5.4, -3.6 and -15.7%; placebo, 1 and 2 mg, respectively) but this change was not significant versus placebo. Subcutaneous fat (SAT) was preserved and did not change between or within groups. Lean body mass and the ratio of VAT to SAT improved significantly in both treatment groups versus placebo. Triglyceride and the cholesterol to high-density lipoprotein ratio decreased significantly in the 2 mg group versus placebo. Treatment was generally well tolerated without changes in glucose.

CONCLUSIONS

TH9507 reduced truncal fat, improved the lipid profile and did not increase glucose levels in HIV-infected patients with central fat accumulation. TH9507 may be a beneficial treatment strategy in this population, but longer-term studies with more patients are needed to determine effects on VAT, treatment durability, and safety.

Increased cardiovascular disease risk indices in HIV-infected women

Little is known regarding cardiovascular disease risk indices in HIV-infected women. This study investigated cardiovascular disease risk indices in 100 consecutively recruited HIV-infected women and 75 healthy female control subjects. Subjects were recruited from hospital- and community-based health care providers. C-reactive protein (CRP), interleukin-6 (IL-6), adiponectin, lipid, and glucose levels were the main outcome measures. CT scan, dual-energy x-ray absorptiometry (DXA), and anthropometry were used to assess body composition. Although similar in age, weight, and racial composition, HIV-infected women demonstrated higher CRP (4.6 +/- 0.7 vs. 2.3 +/- 0.4 mg/L, P = 0.007), IL-6 (2.7 +/- 0.2 vs. 1.8 +/- 0.1 pg/mL, P = 0.02), triglyceride (1.84 +/- 0.21 vs. 0.85 +/- 0.05 mM, P = 0.0002), 2-hour glucose after oral glucose challenge (6.88 +/- 0.22 vs. 5.72 +/- 0.17 mM, P = 0.0003), and fasting insulin (81 +/- 8 vs. 45 +/- 2 pM, P = 0.0002) and lower high-density lipoprotein cholesterol (1.17 +/- 0.03 vs. 1.45 +/- 0.05 mM, P < 0.0001) and adiponectin (5.4 +/- 0.3 vs. 7.6 +/- 0.5 mg/L, P = 0.0001) levels compared with the control population. HIV-infected women had more abdominal visceral fat and less extremity fat by CT and DXA scan and demonstrated a higher waist-to-hip ratio (WHR) than the control population. Within the HIV group, CRP and other indices were significantly related to body composition in stepwise regression models. Among all subjects, WHR, but not HIV status, was significantly related to CRP and other cardiovascular disease risk indices. HIV-infected women demonstrate significantly increased risk factors for cardiovascular disease in association with abnormal fat distribution.

Metabolic syndrome and cardiovascular disease in patients with human immunodeficiency virus

Use of highly active antiretroviral therapy (HAART) for the treatment of human immunodeficiency virus (HIV) infection is associated with the development of cardiovascular risk factors, including dyslipidemia, insulin resistance, fat redistribution, and hypertension. The results of the Data Collection on Adverse Events of Anti-HIV Drugs study showed that HAART therapy is associated with a 26% relative risk increase in the rate of myocardial infarction per year of HAART exposure. A number of studies have shown that insulin resistance often precedes lipodystrophy, suggesting that insulin resistance may be a primary feature of the metabolic syndrome in this population. The rate-limiting step in the uptake of glucose is glucose transport, and the predominant glucose transporter (GLUT) in muscle and fat is GLUT-4. Specific protease inhibitors (PIs) have been associated with decreased GLUT-4-mediated glucose transport and insulin resistance both in vitro and in vivo, whereas newer protease inhibitors may have fewer effects on insulin sensitivity. Data also suggest that endothelial dysfunction, impaired fibrinolysis, and excess inflammation may contribute to increased cardiovascular risk in the population infected with HIV. Moreover, recent data suggest that evidence for coronary atherosclerotic disease can be revealed by means of carotid intimal medial thickness (IMT) assessments in specific groups of HIV patients. Pharmacologic strategies for the prevention and/or treatment of HAART-induced dyslipidemia and abnormal glucose homeostasis include 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins), resins, nicotinic acid, fibrates, and insulin-sensitizing agents. However, newer PIs such as atazanavir may result in less insulin resistance and dyslipidemia and, as part of a HAART regimen, use of atazanavir may reduce the metabolic complications associated with HAART.

Metabolic syndrome among HIV-infected patients: prevalence, characteristics, and related factors

OBJECTIVE

To assess the prevalence in HIV-infected patients of the metabolic syndrome as defined by the National Cholesterol Education Program, i.e., three or more of the following components: abdominal obesity, hypertriglyceridemia, low HDL cholesterol, high blood pressure, and high fasting glucose.

RESEARCH DESIGN AND METHODS

In this cross-sectional study, 710 HIV-infected patients managed at the outpatient clinic of a tertiary hospital during 2003 completed the study protocol consisting of a medical examination and laboratory analysis after a 12-h overnight fast.

RESULTS

Metabolic syndrome prevalence was 17% and increased from 5.1% among HIV-infected patients under age 30 years to 27.0% for those aged 50-59 years. Age (per 10-year increment) (odds ratio [OR] 1.41 [95% CI 1.12-1.77]), BMI (1.27 [1.19-1.36]), past and present protease inhibitor exposure (2.96 [1.03-3.55] and 4.18 [1.4-12.5], respectively) were independently associated with the metabolic syndrome on logistic regression analysis. Furthermore, only stavudine (d4T) (1.74 [1.01-2.98]) and lopinavir/ritonavir (2.46 [1.28-4.71]) were associated with the metabolic syndrome after adjustment for age and BMI.

CONCLUSIONS

The prevalence of metabolic syndrome among these HIV-infected patients is similar to that previously reported in uninfected individuals. Of specific concern is the association of protease inhibitor exposure with the metabolic syndrome and, more specifically, with exposure to stavudine and lopinavir/ritonavir when individual antiretroviral drugs were analyzed.

The effects of low-dose growth hormone in HIV-infected men with fat accumulation: a pilot study

Pharmacologic doses of growth hormone (GH) reduce HIV-associated fat accumulation but may worsen glucose metabolism. We investigated the effects of a low dose of GH (1 mg per day) in HIV-infected men with fat accumulation and found that such treatment reduced total fat and increased lean body mass without significant changes in glucose tolerance or insulin sensitivity. Visceral adipose tissue (VAT) levels did not change significantly for the group as a whole, although a reduction in the VAT level was seen in patients with a greater VAT level at baseline.

Natural history of lipid abnormalities and fat redistribution among human immunodeficiency virus-infected children receiving long-term, protease inhibitor-containing, highly active antiretroviral therapy regimens

OBJECTIVE

To characterize the type and frequency of biochemical lipid abnormalities and physical changes in body composition associated with the use of protease inhibitor (PI)-containing antiretroviral therapy among human immunodeficiency virus-infected children treated for up to 6 years.

METHODS

A retrospective study of human immunodeficiency virus-infected pediatric patients enrolled in research protocols between August 1995 and December 2001 was performed. All patients who had received a PI for > or =2 years as part of their investigational antiretroviral treatment regimens during the study period were eligible. Of the 110 patients identified as having received PI therapy, 94 met the study criteria.

RESULTS

Of the 94 patients evaluated, 9 patients (10%) developed fat redistribution as well as dyslipidemia, 49 patients (52%) developed dyslipidemia without associated physical changes, and 36 patients (38%) exhibited no elevation of lipid levels or physical signs of fat redistribution. For all 9 patients with fat redistribution, the onset of the physical changes was closely associated with changes during pubertal development. Fat redistribution was also associated with lower viral loads and higher, more sustained levels of dyslipidemia. The onset of dyslipidemia and fat redistribution peaked between 10 and 15 years of age.

CONCLUSION

Among pediatric patients receiving PI therapy, there seems to be an age range in which children are at greater risk of developing hypercholesterolemia and subsequent fat redistribution, suggesting that unidentified physiologic changes associated with puberty may predispose pediatric patients treated with PI therapy to developing lipodystrophy.

Fenofibrate is effective in treating hypertriglyceridemia associated with HIV lipodystrophy

OBJECTIVE

To determine the effectiveness of fenofibrate in treating hypertriglyceridemia associated with highly active antiretroviral therapy-associated HIV lipodystrophy syndrome (HLS).

METHODS

The authors recruited from their HIV metabolic clinic 55 adult patients with anthropomorphic changes consistent with HLS together with hypertriglyceridemia. The patients had no prior history of taking lipid-lowering medications and were free of liver and renal disease. They were on various highly active antiretroviral therapy regimens, and these regimens were not altered during the course of the study. Fenofibrate was started at 54 mg a day and the dose increased every 2 weeks to a maximum of 162 mg/day. Fasting lipid concentrations were measured at baseline and 6 months after the intervention.

RESULTS

At baseline, the fasting plasma concentrations of total cholesterol, triglyceride, and high-density lipoprotein (HDL) cholesterol were 259 +/- 11, 886 +/- 172, and 35.7 +/- 2.3 (mean +/- SEM) mg/dL, respectively. After 6 months of fenofibrate treatment, the fasting plasma concentrations were as follows: total cholesterol, 243 +/- 13; triglycerides, 552 +/- 104, and HDL cholesterol, 35.7 +/- 1.8 mg/dL. The decrease in fasting plasma triglyceride concentration was statistically significant (P < 0.05). Fenofibrate was well tolerated, and no subjects dropped out of the study.

CONCLUSION

Fenofibrate is an effective, well-tolerated treatment for hypertriglyceridemia associated with HLS.

Management of Dyslipidaemia in HIV-Infected Patients Receiving Antiretroviral Therapy

Dyslipidaemia associated with the treatment of HIV infection, particularly with the use of protease inhibitors (PIs), can raise cholesterol and triglyceride (TG) levels to the thresholds indicated for intervention. Recent evidence from epidemiological studies has shown that there are correlations between antiretroviral drug use and increased risks for, and incidences of, cardiovascular disease, including myocardial infarction and coronary heart disease. The primary goals of dyslipidaemia therapy for HIV patients are reductions of both low-density lipoprotein cholesterol (LDL-C) and markedly elevated TG levels. Dietary strategies and exercise programs may be tried, although these have shown inconsistent results. The two options for drug therapy are switching anti-retroviral agents and using lipid-lowering drugs. Each approach is associated with advantages and limitations, and the need to maintain viral suppression must be balanced with the need to treat abnormal lipid levels. Most drug switches replace the PI component with drugs from another antiretroviral class. Selection of drug therapy for lipid lowering depends on the type of dyslipidaemia predominating and the potential for drug interactions. The use of the statins pravastatin and atorvastatin is recommended for the treatment of patients with elevated LDL-C levels and gemfibrozil or fenofibrate for patients with elevated TG concentrations. Development of new PIs with more favourable effects on the lipid profile should be of benefit.

Effect of highly active antiretroviral therapy on cardiovascular involvement in children with human immunodeficiency virus infection

The impact of highly active antiretroviral therapy (HAART) on cardiovascular involvement was evaluated in 38 vertically human immunodeficiency virus-infected children followed up for 5 years. This study demonstrates for the first time in a cohort of children the resolution of previous dilated cardiomyopathy after the start of HAART and the absence of cardiovascular events related to metabolic abnormalities during the period of its administration.

HIV-associated lipodystrophy: pathogenesis, prognosis, treatment, and controversies

Potent antiretroviral agents markedly suppress HIV and have dramatically improved the clinical course, prognosis, and survival of HIV-infected patients. Unfortunately, highly active antiretroviral therapy is often compromised by metabolic complications, including insulin resistance, dyslipidemia, and fat redistribution. Together these changes have been termed the HIV-lipodystrophy syndrome, which is estimated to affect a majority of patients treated with potent combination antiretroviral therapy. Routine testing of fasting glucose is recommended for all HIV-infected patients, particularly those who are obese, have a family history of diabetes mellitus, or are receiving protease inhibitor therapy. Preliminary investigations have demonstrated the potential utility of insulin-sensitizing agents and lipid-lowering therapies to ameliorate these metabolic disturbances. Patients with HIV infection who demonstrate fat redistribution and develop hyperinsulinemia and dyslipidemia may be at increased risk of cardiovascular disease. However, the long-term effects on cardiovascular disease have not yet been determined.

Effects of exercise training and metformin on body composition and cardiovascular indices in HIV-infected patients

OBJECTIVE

To determine whether exercise training in combination with metformin improves cardiovascular risk indices and insulin in comparison to metformin alone among HIV-infected patients.

METHODS AND DESIGN

We conducted a prospective, randomized, 3-month study of HIV patients on stable antiretroviral therapy with hyperinsulinemia and fat redistribution. Subjects received metformin alone or metformin and exercise training consisting of 1 h of aerobic and resistance training three times a week. Cardiovascular parameters, including blood pressure and endurance during sub-maximal stress testing, body composition, strength, insulin and other biochemical parameters were determined.

RESULTS

Thirty-seven patients were randomized and 25 subjects completed the study. Subjects receiving exercise training and metformin demonstrated significant decreases in median waist-to-hip ratio [-0.02 (-0.06, -0.01) (median (interquartile range) versus -0.01 (0.03, 0.02), P = 0.026], resting systolic [-12 (-20, -4) versus 0 (-11, 11), P = 0.012] and diastolic blood pressures [-10 (-14, -8) versus 0 (-7, 8), P = 0.001], increased thigh muscle cross-sectional area [3 (-3, 12) versus -7 (-11, 0), P = 0.015], and improved exercise time [3 (0, 4) versus 0 (-1, 1), P = 0.045] compared with subjects receiving metformin alone. Fasting insulin and insulin area under the curve decreased significantly more in the exercise and metformin group (P < 0.05). Lipids and resting lactate did not change significantly between treatment groups.

CONCLUSIONS

These data demonstrate that exercise training in combination with metformin significantly improves cardiovascular and biochemical parameters more than metformin alone in HIV-infected patients with fat redistribution and hyperinsulinemia. Combined treatment was safe, well tolerated and may be a useful strategy to decrease cardiovascular risk in this population.

Metabolic regulation of growth hormone by free fatty acids, somatostatin, and ghrelin in HIV-lipodystrophy

Human immunodeficiency virus (HIV)-lipodystrophy is a syndrome characterized by changes in fat distribution and insulin resistance. Prior studies suggest markedly reduced growth hormone (GH) levels in association with excess visceral adiposity among patients with HIV-lipodystrophy. We investigated mechanisms of altered GH secretion in a population of 13 male HIV-infected patients with evidence of fat redistribution, compared with 10 HIV-nonlipodystrophic patients and 11 male healthy controls similar in age and body mass index (BMI). Although similar in BMI, the lipodystrophic group was characterized by increased visceral adiposity, free fatty acids (FFA), and insulin and reduced extremity fat. We investigated ghrelin and the effects of acute lowering of FFA by acipimox on GH responses to growth hormone-releasing hormone (GHRH). We also investigated somatostatin tone, comparing GH response to combined GHRH and arginine vs. GHRH alone with a subtraction algorithm. Our data demonstrate an equivalent number of GH pulses (4.1 +/- 0.6, 4.7 +/- 0.8, and 4.5 +/- 0.3 pulses/12 h in the HIV-lipodystrophic, HIV-nonlipodystrophic, and healthy control groups, respectively, P > 0.05) but markedly reduced GH secretion pulse area (1.14 +/- 0.27 vs. 4.67 +/- 1.24 ng.ml(-1).min, P < 0.05, HIV-lipodystrophic vs. HIV-nonlipodystrophic; 1.14 +/- 0.27 vs. 3.18 +/- 0.92 ng.ml(-1).min, P < 0.05 HIV-lipodystrophic vs. control), GH pulse area, and GH pulse width in the HIV-lipodystrophy patients compared with the control groups. Reduced ghrelin (418 +/- 46 vs. 514 +/- 37 pg/ml, P < 0.05, HIV-lipodystrophic vs. HIV-nonlipodystrophic; 418 +/- 46 vs. 546 +/- 45 pg/ml, P < 0.05, HIV-lipodystrophic vs. control), impaired GH response to GHRH by excess FFA, and increased somatostatin tone contribute to reduced GH secretion in patients with HIV-lipodystrophy. These data provide novel insight into the metabolic regulation of GH secretion in subjects with HIV-lipodystrophy.