The lowdown on lipodystrophy. Special report from the 2nd International Workshop on Adverse Drug Reactions and Lipodystrophy

A major underlying theme of this meeting was complexity, and the realization that the time has come to individualize therapy, including decisions about when to start therapy and what to use. Our knowledge in this regard is rudimentary. The availability of HAART has led to therapeutic optimism in the U.S., with nearly universal access to the best regimen possible at any given time. Factoring in all of the possible individual and therapeutic variations, to compare risk to benefit, is not possible, although two web sites will be identified through which we can start to quantify cardiac risk. However, we are clearly moving in the direction of individualizing therapy.

Lipodystrophy, metabolic disorders, and human immunodeficiency virus infection: Aquitaine Cohort, France, 1999. Groupe d'Epidémiologie Clinique du Syndrome d'Immunodéficience Acquise en Aquitaine

The objective of this study was to estimate the prevalence of and risk factors for clinical lipodystrophy (LD) and metabolic disorders in human immunodeficiency virus (HIV) type 1-infected patients. A cross-sectional survey of the Aquitaine Cohort was performed in January 1999. The clinical diagnosis of LD was categorized as fat wasting (FW), peripheral fat accumulation (FA), and mixed syndromes (MS). Of the 581 patients studied, 61% were treated with protease inhibitors. The overall prevalence of LD was 38% (95% confidence interval [CI], 32-42): prevalence of FW was 16% (95% CI, 13-18); of FA, 12% (95% CI, 10-15); and of MS, 10% (95% CI, 8-13). The prevalences of metabolic abnormalities were 49% (95% CI, 44-53) for lipid disorders and 20% (95% CI, 17-23), for glucose disorders. Factors associated with LD were age (for FW and MS), male sex (for FW), AIDS stage (for MS), body mass index (for FW and FA), waist-to-hip ratio (for FA and MS), and duration of antiretroviral treatment (for FW).

Association of severe insulin resistance with both loss of limb fat and elevated serum tumor necrosis factor receptor levels in HIV lipodystrophy

HIV-lipodystrophy (HIV-LD) is characterized by the loss of body fat from the limbs and face, an increase in truncal fat, insulin resistance, and hyperlipidemia, factors placing affected patients at increased risk for vascular disease. This study evaluated insulin sensitivity and inflammatory status associated with HIV-LD and provides suggestions about its etiology. Insulin sensitivity and immune activation markers were assessed in 12 control subjects and 2 HIV-positive groups, 14 without and 15 with LD syndrome. Peripheral insulin sensitivity (mostly skeletal muscle) was determined with the hyperinsulinemic-euglycemic clamp. Circulating insulin-like growth factor (IGF) binding protein-1 (IGFBP-1) and free fatty acid (FFA) levels, and their response to insulin infusion were indicative of insulin responsiveness of liver and adipose tissue, respectively. Serum levels of soluble type 2 tumor necrosis factor-alpha (TNF-alpha) receptor (sTNFR2) were used as an indicator of immune activation. HIV-LD study subjects had significantly reduced (twofold) peripheral insulin sensitivity, but normal levels of FFA and reduced levels of IGFBP-1, relative to the nonlipodystrophy groups, indicating that the loss of insulin sensitivity was more pronounced in skeletal muscle than in liver or fat. The significant loss of peripheral fat in the HIV-LD group (34%; p <.05) closely correlated with the reduced peripheral insulin sensitivity (p =. 0001). Levels of sTNFR2 were elevated in all HIV-infected study subjects, but they were significantly higher in those with lipodystrophy than without, and sTNFR2 levels strongly correlated with the reduction in insulin sensitivity (p =.0001). Loss of peripheral fat, normal levels of FFA, and reduced levels of IGFBP-1 indicate that insulin resistance in HIV-LD is distinct from type 2 diabetes and obesity. The relationship between the degree of insulin resistance and sTNFR2 levels suggests an inflammatory stimulus is contributing to the development of HIV-associated lipodystrophy.

Partial lipodystrophy and renal disease

Partial lipodystrophy is a rare disorder with both autosomal recessive and familial forms. The cutaneous findings, which are often subtle, consist of a gradual loss of subcutaneous fat from the face and upper body. Low levels of C3, occasionally low C5 and the presence of the nephritic factor help to identify these patients. Associated systemic abnormalities include the development of mesangiocapillary glomerulonephritis and an increased incidence of autoimmune diseases. Recognition of this unusual disorder is essential for diagnosis and treatment of underlying potentially life- threatening disease.

Sonographic assessment of regional fat in HIV-1-infected people

The routine clinical assessment of lipodystrophy in HIV-1-infected patients is hindered by the absence of easy and reliable methods to measure regional fat. We used sonography to measure subcutaneous fat thickness at three reference skin points (periumbilical, brachial, and malar) and intra-abdominal fat thickness in HIV-1-infected patients with and without lipodystrophy and in healthy controls. Patients without lipodystrophy had less subcutaneous fat than uninfected controls. Sonographic assessment of subcutaneous malar and brachial fat in patients with lipodystrophy was more sensitive and specific than that of intra-abdominal fat in the diagnosis of abnormal fat distribution.

Lipoatrophic lesions preceded by pain and erythema - a new clinical entity?

A 46-year-old female patient presented with deeply depressed lesions on the abdominal wall after slight pain and erythema, without a history of trauma or injection. No general symptoms were noted. There was a marked decrease of subcutaneous fatty tissue with minimal inflammatory cell infiltration. We found three similar cases in the literature. Differential diagnoses were performed, but our case and the other three cases do not fit any of the heretofore described lipoatrophic diseases, and might be a new clinical entity.

Hyperandrogenemia in human immunodeficiency virus-infected women with the lipodystrophy syndrome

A novel lipodystrophy syndrome characterized by insulin resistance, hypertriglyceridemia, and fat redistribution has recently been described in human immunodeficiency virus (HIV)-infected men and women. Women with the HIV lipodystrophy syndrome exhibit a marked increase in waist-to-hip ratio and truncal adiposity; however, it is unknown whether androgen levels are increased in these patients. In this study, we assessed androgen levels in female patients with clinical lipodystrophy based on evidence of significant fat redistribution in the trunk, extremities, neck and/or face (LIPO: n = 9; age, 35.7+/-1.7 yr; BMI, 24.7+/-0.8 kg/m2) in comparison with age- and BMI-matched nonlipodystrophic HIV-infected females (NONLIPO: n = 14; age, 37.6+/-1.1 yr; BMI, 23.4+/-0.6 kg/m2) and healthy non-HIV-infected control subjects (C: n = 16; age, 35.8+/-0.9 yr; BMI, 23.1+/-0.4 kg/m2). Fasting insulin, lipid levels, virologic parameters, and regional body composition using dual energy x-ray absorptiometry were also assessed. Total testosterone [ LIPO, 33+/-6 ng/dL (1.1+/-0.2 nmol/L); NONLIPO, 17+/-2 ng/dL (0.6+/-0.1 nmol/L); C, 23+/-2 ng/dL (0.8+/-0.1 nmol/L); P < 0.05 LIPO vs. C and LIPO vs. NONLIPO] and free testosterone determined by equilibrium dialysis [LIPO, 4.5+/-0.9 pg/mL (16+/-3 pmol/L); NONLIPO, 1.7+/-0.2 pg/mL (6+/-1 pmol/L); C, 2.4+/-0.2 pg/mL (8+/-1 pmol/L); P < 0.05 LIPO vs. C and LIPO vs. NONLIPO] were increased in the lipodystrophic patients. Sex hormone-binding globulin levels were not significantly different between LIPO and C, but were significantly lower in the LIPO vs. NONLIPO patients (LIPO 84+/-7 vs. NONLIPO 149+/-17 nmol/L, P < 0.05). The LH/FSH ratio was significantly increased in the LIPO group compared with the NONLIPO and C subjects (LIPO, 2.0+/-0.6; NONLIPO, 1.1+/-0.1; C, 0.8+/-0.1; P < 0.05 LIPO vs. NONLIPO and LIPO vs. C). Body fat distribution was significantly different between LIPO and C subjects. Trunk to extremity fat ratio (1.46+/-0.17 vs. 0.75+/-0.05, LIPO vs. C, P < 0.05) was increased and extremity to total fat ratio decreased (0.40+/-0.03 vs. 0.55+/-0.01, LIPO vs. C, P < 0.05). In contrast, fat distribution was not different in the NONLIPO group vs. control subjects. Among the HIV-infected patients, free testosterone correlated with percent truncal fat (trunk fat/trunk mass) (r = 0.43, P = 0.04). These data suggest that hyperandrogenemia is another potentially important feature of the HIV-lipodystrophy syndrome in women. Additional studies are necessary to determine the clinical significance of increased androgen levels and the relationship of hyperandrogenism to fat redistribution and insulin resistance in this population of patients.

A new missense mutation in the calcium-sensing receptor in familial benign hypercalcaemia associated with partial lipoatrophy and insulin resistant diabetes

We studied two patients (a 54-year-old woman and her 16-year-old son) with familial benign hypocalciuric hypercalcaemia (FBHH) associated with severe insulin resistant diabetes in the context of a partial lipodystrophic syndrome. Sequencing of the entire coding sequence of the calcium-sensing receptor (CaR) gene revealed a novel heterozygous mutation at codon 395, leading to the substitution of a cysteine by an arginine residue (Cys395Arg) in the extracellular ligand-binding domain. This mutation was absent in two normocalcaemic relatives and in 54 control subjects. It was recently shown, in transfection studies, that the substitution of this amino acid results in incomplete receptor processing, a severe decrease in cell surface expression and altered signal transduction (Fan et al., 1998). This mutation is therefore likely to be responsible of the FBHH phenotype. A pathophysiological link between this mutation and insulin resistance remains unclear.

"Switch" studies for people with lipodystrophy

Many people are considering or have already switched to a regimen without protease inhibitors in hopes of reversing fat redistribution, or lipodystrophy syndrome(s), and/or to lower cholesterol and triglyceride levels that have been associated with using anti-HIV therapy. The studies below suggest that this strategy may be somewhat effective in reducing triglyceride and cholesterol levels. But there is conflicting information on whether it is effective in reversing fat redistribution.

[Heavy and swollen legs]

Painful sensation of heavy or swollen legs are non-specific symptoms frequently associated with chronic venous insufficiency. Clinical evaluation is the first step in defining the cause of the complaint and offering adequate treatment. When a heavy or swollen leg is associated with oedema, venous insufficiency, lymphatic or systemic disease must be considered. If symptoms occur during walking a vascular or nervous disease must be suspected. Associated erythema suggests infection (erysipelas). If clinical data are the cornerstone of diagnosis, difficulty may arise from the high frequency of superficial venous insufficiency and the readiness of linking too quickly any non specific complaint to this particular venous disease.