Metabolic complications associated with use of protease inhibitors

The potency of highly active antiretroviral therapy, including protease inhibitors have led to declining morbidity and mortality in patients with HIV infection. However the use of protease inhibitors is associated with onset of morphologic and metabolic disorders. A syndrome of lipodystrophy has been described. It is characterized by fast wasting of the face and limbs, and a central adiposity, breast hypertrophy and buffalo neck. The prevalence of lipodystrophy in patients treated with protease inhibition is about 60%. The principal metabolic disorders are lipid abnormalities, principally hypertriglyceridemia. New onset of diabetes mellitus is less frequent. The pathogenesis of these abnormalities unknown. Insulin resistance seems to be a common feature of protease inhibitor associated metabolic an morphologic side-effects.     

Leptin in relation to the lipodystrophy-associated metabolic syndrome

Leptin, an adipocyte-secreted hormone, regulates energy homeostasis as well as reproductive, neuroendocrine, immune and metabolic functions. Subjects with decreased amounts of fat in their adipose tissue, i.e., lipoatrophy, have low leptin levels. In the context of open-label, uncontrolled studies leptin administration, in physiological replacement doses, has been shown to have metabolically salutary effects in the rare patients with the syndrome of congenital lipodystrophy accompanied by leptin deficiency. Much more patients with lipodystrophy suffer from lipodystrophy and the metabolic syndrome associated with the use of highly active antiretroviral therapy. In this so called highly active antiretroviral therapy (HAART)-associated lipodystrophy and metabolic syndrome, patients demonstrate fat maldistribution with dyslipidemia, insulin resistance, and other metabolic complications. Leptin administration has been shown to decrease central fat mass and to improve fasting insulin/glucose levels and insulin sensitivity in human immunodeficiency virus-infected hypoleptinemic patients with HAART induced lipodystrophy and the metabolic syndrome. By contrast, the results of leptin treatment in leptin replete or hyperleptinemic obese individuals with glucose intolerance and diabetes mellitus have been minimal or null, presumably due to leptin tolerance or resistance that impairs leptin action. In this review, we present the emerging clinical applications and potential therapeutic uses of leptin in humans with lipodystrophy and the metabolic syndrome.     

Dysregulation of glucose metabolism in HIV patients: epidemiology, mechanisms, and management

HIV-infected patients on highly active antiretroviral therapy (HAART) have increased prevalence of a number of chronic metabolic disorders of multifactorial but unclear etiology. These include disorders of lipid metabolism with or without lipodystrophy, insulin resistance, and an increased prevalence of impaired glucose tolerance, diabetes mellitus, and cardiometabolic syndrome. While much attention has been focused on the lipid and cardiovascular disorders, few investigations have attempted to characterize the prevalence, incidence, etiology, mechanisms, and management of glycemic disorders in HIV patients. In this review, we have focused specifically on a comprehensive assessment of dysglycemia in the context of HIV infection and HAART.     

Metabolic and cardiovascular complications of highly active antiretroviral therapy for HIV infection

Highly active antiretroviral therapy (HAART) regimens, especially those including protease inhibitors have been shown to cause, in a high proportion of HIV-infected patients, a metabolic syndrome (lipodystrophy/lipoatrophy, dyslipidemia, type 2 diabetes mellitus, insulin resistance) that may be associated with an increased risk of cardiovascular disease. A careful stratification of the cardiovascular risk of HIV-infected patients under HAART is needed according to the most recent clinical guidelines.     

Lipodystrophy in patients with juvenile dermatomyositis--evaluation of clinical and metabolic abnormalities

OBJECTIVE: Lipodystrophy and associated metabolic abnormalities are being increasingly recognized as complications of juvenile dermatomyositis (JDM). We investigated the prevalence of lipodystrophy and the extent of metabolic abnormalities related to lipoatrophic diabetes mellitus in patients with JDM. METHODS: Twenty patients with JDM were evaluated for evidence of lipodystrophy and associated lipoatrophic diabetes mellitus. All patients underwent clinical assessment, laboratory investigations, and metabolic studies (oral glucose tolerance test, lipid studies, insulin antibodies). RESULTS: We found clinical evidence of lipodystrophy and lipoatrophic diabetes mellitus in 4 of 20 patients with JDM and metabolic abnormalities known to be associated with lipodystrophy in another 8 patients. The 20 patients with JDM were categorized as follows: Group 1 (Patients 1-4) consisted of patients with lipodystrophy and either diabetes mellitus (2 patients) or impaired glucose tolerance (2 patients); Group 2 (Patients 5-12): no lipodystrophy but abnormal glucose and/or lipid studies; Group 3 (Patients 13-20): no lipodystrophy and no abnormalities of glucose and lipid studies. CONCLUSION: We found 25% of patients with JDM have lipodystrophy, and 50% present with hypertriglyceridemia and insulin resistance. Screening for metabolic abnormalities in JDM should be included in routine followup because of the effect of lipodystrophy on longterm prognosis.     

Diabetes and HIV: Current Understanding and Future Perspectives

Diabetes mellitus is a chronic disease with a higher risk of associated infections. HIV infection severely affects diabetic patients and acts as a significant health concern. Highly active antiretroviral therapy (HAART) has changed HIV from an acute infection to a chronic infection with associated significant metabolic abnormalities such as insulin resistance, impaired glucose tolerance, metabolic syndrome, diabetes, dyslipidemia, obesity, and lipodystrophy. These metabolic disturbances add complexity to the standards of care in HIV infection and further increase the risk for cardiovascular disease and renal complications. The co-association of diabetes and HIV needs to be managed appropriately to prevent mortality and morbidity and improve patient outcome. The current understanding of diabetes and other metabolic abnormalities along with management strategies in HIV infected patients are summarized in this article. The review also focuses on recent challenges in the diagnosis and management of co-existent diabetes and HIV infection.     

Lipodystrophy and metabolic disorders as complication of antiretroviral therapy of HIV infection.

Peripheral lipodystrophy, central adiposity, hyperlipidaemia, insulin resistance, and diabetes mellitus, in varying constellations, are frequent complications of highly active antiretroviral therapy in HIV1-infected patients. The pathogenetic significance of protease inhibitors toxicity has been demonstrated by the partial reversal of metabolic disorders after switching to other antiretroviral regimens. The therapeutic and prognostic implications of these metabolic disorders are not yet clear. The dramatic improvements in the prognosis and quality of life of people with HIV since the introduction of highly active antiretroviral therapy call for evidence based concepts for the management of treatment-related metabolic disturbances.     

Clinical impact of HIV-related lipodystrophy and metabolic abnormalities on cardiovascular disease

Metabolic complications and altered fat distribution associated with HIV infection and antiretroviral therapy may lead to accelerated coronary artery disease (CAD). The high prevalence of multiple cardiovascular risk factors in a significant number of HIV patients is a cause for concern in both patients and physicians. Non-invasive strategies to measure subclinical CAD have been inconclusive. Long-term studies are underway to determine cardiac event rates, intervention strategies and consequences for the clinical management of HIV disease. In the present paper, we summarize the most prevalent risk factors in individuals with HIV infection receiving highly active antiretroviral therapy by focusing on the clinical implications of metabolic abnormalities and HIV-related lipodystrophy on CAD.     

Association of the metabolic syndrome and insulin resistance with silent myocardial ischemia in patients with type 2 diabetes mellitus

Metabolic syndrome is associated with elevated morbidity and mortality for overt coronary artery disease (CAD). In diabetic patients, CAD is often silent. The relation between metabolic syndrome and silent CAD has never been studied. We investigated whether metabolic syndrome is associated with silent CAD in patients with type 2 diabetes mellitus. We evaluated the prevalence of metabolic syndrome in 169 patients with uncomplicated diabetes and angiographically verified silent CAD and in 158 diabetic patients without myocardial ischemia on exercise electrocardiography, 48-hours ambulatory electrocardiography, and stress echocardiography. The groups were comparable for gender, age, glycemic control, and diabetes duration. Metabolic syndrome was defined according to the National Cholesterol Education Program criteria. To estimate insulin resistance in patients treated with diet alone or oral agents (122 patients with CAD and 115 patients without CAD), the Homeostasis Model Insulin-Resistance Assessment (HOMA) was used. The prevalence of metabolic syndrome (59.8% vs 44.3%, p = 0.005) and HOMA (5.4 +/- 2.1 vs 4.9 +/- 2.8, p = 0.044) were significantly higher in those with CAD than in those without CAD. Multiple logistic regression analysis showed that the metabolic syndrome was associated with silent CAD (odds ratio 2.44, 95% confidence interval 1.19 to 5.02, p = 0.015). Among patients on diet alone or oral agents, the HOMA was the strongest predictor of silent CAD (odds ratio 10.16, 95% confidence interval 2.60 to 39.63, p < 0.001). In conclusion, our data have shown an independent association of metabolic syndrome and insulin resistance with silent CAD in patients with type 2 diabetes mellitus. Other studies are needed to establish whether metabolic syndrome and HOMA are reliable markers to identify diabetic patients for additional screening for silent CAD.     

Adverse effects of antiretroviral therapy. Aspects of pathogenesis

Highly active antiretroviral therapy has resulted in remarkable reduction of morbidity and mortality of HIV infection. With increasing duration of therapy metabolic alterations such as hyperlipidemia, diabetes mellitus type 2 and lipodystrophy are encountered which considerably reduced quality of life for the patients. These adverse events are most likely due to protease inhibitors and nucleoside analogues with synergistic effects. The pathogenesis is related to metabolic alterations of the adipocytes with cellular insulin resistance and enhanced apoptosis of these cells caused by adipocytic cytokines such as adiponectin, leptin, TNF-alpha and interleukin 2. Switch of therapy regimens with elimination of the most suspicious substances and certain protease inhibitors can lead to improvement of deranged metabolism. Also symptomatic therapy is possible to cope with hyperlipidemia and diabetes, although no effective treatment is available to reverse already existing lipodystrophy. Our knowledge about the pathogenesis of these alterations might lead to new concepts and causal therapy in the future.     

Insulin resistance in treated HIV infection

Insulin resistance (IR) was one of the first metabolic complications reported with highly active antiretroviral therapy for HIV infection. It continues to be of concern despite the introduction of newer antiretrovirals with safer metabolic profiles and is associated with inflammation and the development of diabetes mellitus. As the HIV-infected population ages, the prevalence of IR is likely to rise. Specific antiretrovirals can increase insulin resistance through two principal mechanisms, either directly by interfering with insulin signalling at the cellular level or indirectly as a consequence of defects in lipid metabolism (lipotoxocity) arising from antiretroviral toxicities such as the IR observed in those with HIV-associated lipodystrophy. There is considerable overlap between different antiretrovirals in their propensity to cause IR making it more difficult to attribute development of IR to a particular antiretroviral medication. In addition, in the setting of a generalised epidemic of obesity that exists in many populations worldwide, HIV-infected patients may be more prone to the consequences of antiretroviral-induced insulin resistance and diabetes mellitus. Optimal screening and treatment strategies for IR in treated HIV infection have not been established. In this article we review current opinion on insulin resistance in HIV and identify potential areas for future research.     

Application of recent definitions of the metabolic syndrome to survey data from the National Cholesterol Education Program Evaluation Project Utilizing Novel E-Technology (NEPTUNE II)

This was a post hoc analysis of data collected in the National Cholesterol Education Program (NCEP) Evaluation Project Utilizing Novel E-Technology II (NEPTUNE II) survey conducted in 2003. Among 4885 dyslipidemic patients receiving lipid management in the United States, estimates of the prevalence of the metabolic syndrome according to the 2001 NCEP Third Adult Treatment Panel (ATP III), the 2005 American Heart Association/National Heart, Lung, and Blood Institute Scientific Statement, and the 2005 International Diabetes Federation definitions were 55%, 62%, and 63%, respectively. Metabolic syndrome prevalence among patients with coronary heart disease and risk equivalents was 69%, 74%, and 74%, according to these respective definitions. Notably, in the coronary heart disease and risk equivalents category, the prevalence was similar to that of the multiple risk factor category when patients with diabetes mellitus were excluded from the analysis (46% by ATP III). The metabolic syndrome is common in patients receiving lipid-lowering therapy in an office-based setting. Three recent definitions resulted in similar estimates of its prevalence.     

Peroxisome proliferator activating receptor alpha and gamma polymorphisms and metabolic abnormalities in HIV-infected patients receiving highly active antiretroviral therapy: the ANRS CO8 APROCO-COPILOTE study

Highly active antiretroviral therapy (HAART) is associated with fat redistribution and metabolic disorders. The present study was undertaken to evaluate the association between peroxisome proliferator activated receptor (PPAR)α and PPARγ polymorphisms, two genes involved in lipid metabolism and adipocyte differentiation, and elements of the metabolic syndrome, lipodystrophy, or carbohydrate metabolism abnormalities in patients receiving HAART. The frequency distribution of rare alleles for PPARα (L162V) and PPARγ (P12A and H449H) was compared using the chi square test in 363 HIV-1-infected patients classified according to the presence or absence of the metabolic syndrome after 48 months of follow-up on their first PI-containing regimen. The P12A rare g allele was present in 12% patients with normal glucose metabolism, 11% patients with impaired glucose tolerance or impaired fasting glucose, and 35% patients with diabetes (p=0.014). The rare g allele for L162V was present in 14% of patients free of hypertriglyceridemia and in 7% patients with hypertriglyceridemia (p=0.04). The rare g allele for L162V was found in 15% of patients free of any sign of lipodystrophy and 8% with at least one sign of lipodystrophy (p=0.04) and the rare t allele for H449H was found in 14% of patients free of any sign of lipodystrophy and 23% of patients with at least one sign of lipodystrophy (p=0.05). There was no convincing association between any polymorphism of PPARα and PPARγ and each individual component of the metabolic syndrome, except for the relationship of the P12A polymorphism with diabetes. Confirmatory studies on a larger number of individuals are needed.     

Nebenwirkungen der antiretroviralen Therapie

Highly active antiretroviral therapy has resulted in remarkable reduction of morbidity and mortality of HIV infection. With increasing duration of therapy metabolic alterations such as hyperlipidemia, diabetes mellitus type 2 and lipodystrophy are encountered which considerably reduced quality of life for the patients. These adverse events are most likely due to protease inhibitors and nucleoside analogues with synergistic effects. The pathogenesis is related to metabolic alterations of the adipocytes with cellular insulin resistance and enhanced apoptosis of these cells caused by adipocytic cytokines such as adiponectin, leptin, TNF-alpha and interleukin 2. Switch of therapy regimens with elimination of the most suspicious substances and certain protease inhibitors can lead to improvement of deranged metabolism. Also symptomatic therapy is possible to cope with hyperlipidemia and diabetes, although no effective treatment is available to reverse already existing lipodystrophy. Our knowledge about the pathogenesis of these alterations might lead to new concepts and causal therapy in the future.     

HIV lipodystrophy

Combined antiretroviral therapy results in extraordinary decrease of morbidity and mortality of HIV-infected patients and in an essential change of the HIV/AIDS disease prognosis. However, long-term intake of antiretroviral medicaments is related to occurrence of metabolic and morphological abnormalities, of which some have been combined into a new syndrome--the so called HIV lipodystrophy. The HIV lipodystrophy syndrome covers metabolic and morphological changes. Metabolic changes include dyslipidaemia with hypercholesterolaemia and/or hypertriglyceridaemia, insulin resistance with hyperinsulinaemia and hyperlaktataemia. Morphological changes have the nature of lipoatrophia (loss of subcutaneous fat--on the cheeks, on extremities, on buttocks and marked prominence of surface veins) or lipohypertrophia (growth of fat tissue--on the chest, in the dorsocervical area, lipomatosis of visceral tissues and organs, fat accumulation in the abdominal area). Several HIV lipodystrophy features are very similar to the metabolic syndrome of the general population. That is why this new syndrome represents a prospective risk of premature atherosclerosis and increase of the cardiovascular risk in young HIV positive individuals. The article mentions major presented studies dealing with the relation of antiretroviral treatment and the cardiovascular risk. The conclusions of the studies are not unequivocal--this is, among others, given by the reason that their length is short from the viewpoint of atherogenesis. The major risk of subclinical atherosclerosis acceleration seems to be related to the deep immunodeficiency and low number of CD4+ lymphocytes and florid, uncontrolled HIV infection with a high number of HIV-1 RNA copies actually circulating in the plasma. The question, whether metabolic and morphological changes related to HIV and cART carry a similar atherogenic potential as in the general population, remains open for future.     

Clinical review 153: Lipodystrophy in human immunodeficiency virus-infected patients

Human immunodeficiency virus (HIV) infection is a major global health problem. Recently, combination therapy including HIV-1 protease inhibitors (PIs) has dramatically improved the long-term survival of HIV-infected patients. However, such therapy is associated with a lipodystrophy syndrome characterized by selective loss of sc fat from the face and extremities and, in some patients, accumulation of fat around the neck, dorsocervical region, abdomen, and trunk. Lipodystrophy in HIV-infected patients (LDHIV) is associated with insulin resistance and its metabolic complications such as impaired glucose tolerance, diabetes, hypertriglyceridemia and low serum high density lipoprotein cholesterol levels. PIs appear to be the strongest link to LDHIV; however, fat loss has been reported in some patients taking non-PI antiretroviral drugs. Other factors, such as duration of HIV infection, age, and gender, may also contribute to the risk of development of LDHIV. The molecular basis of LDHIV remains unknown. There is no specific therapy for LDHIV. Avoiding weight gain by reducing energy intake and increasing physical activity may be beneficial in reducing fat accumulation as well as improving metabolic complications. Antihyperglycemic drugs may be used to treat diabetes. Management of dyslipidemia may require lipid-lowering drugs; however, the safety and efficacy of such intervention require further studies. Substitution of PIs with other antiretroviral drugs can mitigate dyslipidemia and glucose intolerance, but whether reversal of lipodystrophy occurs remains unknown. Future research is needed to discover the biochemical and molecular markers of lipodystrophy in HIV patients and develop PIs or other antiretroviral agents that are free of metabolic toxicity.     

Clinical review#: Lipodystrophies: genetic and acquired body fat disorders

CONTEXT: Lipodystrophies are heterogeneous, genetic or acquired disorders characterized by selective loss of body fat and predisposition to insulin resistance. The extent of fat loss determines the severity of associated metabolic complications such as diabetes mellitus, hypertriglyceridemia, and hepatic steatosis. EVIDENCE ACQUISITION AND SYNTHESIS: Both original and review articles were found via PubMed search reporting on clinical features and management of various types of lipodystrophies and were integrated with the author's knowledge of the field. CONCLUSION: The autosomal recessive congenital generalized lipodystrophy and autosomal dominant familial partial lipodystrophy (FPL) are the two most common types of genetic lipodystrophies. Mutations in AGPAT2, BSCL2, CAV1, and PTRF have been reported in congenital generalized lipodystrophy and in LMNA, PPARG, AKT2, and PLIN1 in FPL. CIDEC is the disease gene for autosomal recessive, FPL and LMNA and ZMPSTE24 for autosomal recessive, mandibuloacral dysplasia-associated lipodystrophy. Recently, an autosomal recessive autoinflammatory lipodystrophy syndrome was reported to be due to PSMB8 mutation. Molecular genetic bases of many rare forms of genetic lipodystrophies remain to be elucidated. The most prevalent subtype of acquired lipodystrophy currently occurs with prolonged duration of protease inhibitor-containing, highly-active antiretroviral therapy in HIV-infected patients. The acquired generalized and partial lipodystrophies are mainly autoimmune in origin and display complement abnormalities. Localized lipodystrophies occur due to drug or vaccine injections, pressure, panniculitis, and other unknown reasons. The current management includes cosmetic surgery and early identification and treatment of metabolic and other complications with diet, exercise, hypoglycemic drugs, and lipid-lowering agents.     

老年代谢综合征患病情况及特点

目的　 调查老年干部代谢综合征的患病情况及特点。　 方法　通过体检的方法 ,测定血糖、血脂、血压、心电图、身高、体重、腰围、臀围、眼底等 ,并详细对受检人员询问病史。　 结果 　 1615名老年干部中发现代谢综合征 198例 ,发生率为 12 2 6% ;10 0 4名中年干部中发现 65例 ,发生率仅为 6 47% (P <0 0 1)。老年干部糖尿病、高血压的发生率分别为 2 1 67%、5 7 71% ,较中年干部的发生率 13 5 5 %、2 9 5 8%有明显增高 (P <0 0 1)。老年代谢综合征者冠心病、腹型肥胖、眼底动脉硬化的发生率分别为 5 4 0 4%、63 64%和 40 91% ;而非老年代谢综合征者为 2 6 15 %、44 61%和 2 9 2 3% ,明显低于老年代谢综合征者 (P <0 0 1)。　 结论　老年代谢综合征发病率较高 ,其主要原因是糖尿病和高血压的高发病率。老年代谢综合征伴有高冠心病、动脉硬化发病率 ,是威胁老年人身体健康的主要疾病     

Hypertension among HIV patients: prevalence and relationships to insulin resistance and metabolic syndrome

OBJECTIVES: Metabolic syndrome is a cluster of risk factors, such as central obesity, dyslipidemia, glucose intolerance, hypertension, related to insulin resistance. In HIV patients insulin resistance and several metabolic abnormalities of the metabolic syndrome have been described, but few and conflicting studies have investigated the behaviour of blood pressure. The aims of the present study were to evaluate the prevalence of hypertension in a large group of HIV-patients on highly active antiretroviral therapy (HAART) and to investigate the relationship between hypertension, metabolic syndrome and insulin resistance. DESIGN: Case control study. METHODS: We enrolled 287 HIV-positive patients on HAART (mean age 41.1 +/- 7.5 years) and 287 age- and sex-matched controls. Insulin resistance was estimated by the homeostasis model insulin resistance assessment (HOMA) index. Metabolic syndrome was defined according to the European Group for the Study of Insulin Resistance. RESULTS: HIV patients showed a prevalence of subjects with hypertension (34.2 versus 11.9%; P < 0.0001) and metabolic syndrome (33.1 versus 2.4%; P < 0.0001) higher than controls. HOMA was higher in HIV-patients than controls (3.3 +/- 1.2 versus 2.0 +/- 0.9; P < 0.0001). HOMA (3.7 +/- 1.0 versus 3.1 +/- 1.2; P < 0.001) and the prevalence of subjects with the metabolic syndrome (64.3 versus 16.9%; P < 0.0001) were greater in HIV-patients with than in those without hypertension. Multiple logistic regression analysis showed that family history of hypertension (odds ratio [(OR): 8.73; 95% confidence interval (CI): 4.31-17.70; P < 0.0001], metabolic syndrome (OR: 6.79; 95% CI: 3.27-14.10; P < 0.0001), lipodystrophy (OR: 4.80; 95% CI: 2.43-9.85; P < 0.0001) and HOMA (OR: 4.13; 95% CI: 1.14-14.91; P < 0.05) were predictors of hypertension in HIV-patients. CONCLUSIONS: The present study shows that hypertension is frequent in HIV patients on HAART and that hypertension appears to be linked to insulin resistance; in particular, hypertension seems to be a part of the metabolic syndrome.