HIV enteropathy and 'Slim disease': Historical and current perspectives

OBJECTIVES

Chronic diarrhoea and severe wasting associated with HIV infection were first described in East African patients as slim disease (SD) in 1985. The main histological features are flattening of the villi (villous atrophy) and crypt hyperplasia (elongated crypts), i.e., HIV enteropathy (HIVE). Selective loss of mucosal clusters of differentiation 4 (CD4)+ T helper (Th)17+ lymphocytes is the immunological hallmark of HIVE. This review explores (i) the historical background of HIVE and SD, (ii) the relationship between gut mucosal CD4+ Th17+ and intestinal-resident intra-epithelial gamma delta (IRIE) T lymphocytes in pathogenesis of HIVE, (iii) the role of cytokines in regulation of intestinal epithelial proliferation, and (iv) the role of antiretroviral therapy in HIVE.

METHODS

Recent studies have highlighted the role of IRIE T lymphocytes, mostly CD8+, in regulating gut epithelial regeneration. CD4+Th17+ and IRIE T cells are necessary to maintain intestinal barrier integrity and mucosal antimicrobial immune defence. However, the immunological cross-talk between such lymphocyte sub-sets culminating in HIVE is uncertain. We undertook a narrative literature review under the headings 'HIVE', 'SD', and 'Highly active antiretroviral therapy (HAART). Relevant studies were located using the electronic search engines Google Scholar and PubMed from 1984 to 2022.

RESULTS

Depletion of Th17+ cells in the lamina propria, attributed to low-level viraemia, is accompanied by concomitant increase in the density of gut mucosal IRIE T lymphocytes in AIDS. The latter express a broad range of cytokines (interferon-gamma, tumor necrosis factor-alpha, interleukin-17) and chemokines e.g., keratinocyte growth factor, post exposure to HIV-infected cells. Keratinocyte growth factor induces epithelial proliferation mainly in the crypts, leading to functional immaturity of enterocytes, reduced gut absorptive surface area and malabsorption in animal experiments. Of note, the absence of IRIE T cells is associated with a reduction in epithelial cell turnover. Patients with HIVE receiving early HAART show enhanced expression of mucosal repair genes and improvement of gut symptoms.

CONCLUSION

Multiple lines of enquiry suggest HIVE is directly related to HIV infection and is a consequence of perturbations in mucosal CD4+Th17+ and IRIE T lymphocytes. The pathological result is enterocyte immaturity and dysfunction. SD whose main features are malabsorption, diarrhoea and weight loss, is a severe clinical expression of HIVE. A better understanding of immuno-pathogenesis of HIVE opens a window of opportunity for the potential use of immunotherapy in HIV disease and other T cell-mediated enteropathies.

Changes in Facial Fat in HIV-Related Lipoatrophy, Wasting, and Weight Gain Measured by Magnetic Resonance Imaging

BACKGROUND

Changes in facial fat occurring over time in patients with HIV-related lipoatrophy have not been properly quantified. We aimed to define the longitudinal changes in facial fat compartments in patients with lipoatrophy and to compare these with changes accompanying wasting or weight gain.

METHOD

Facial MRI scans were performed at baseline and repeated after a median of 10 months in 24 patients, of whom 12 had moderate to severe lipodystrophy continuing antiretroviral therapy, 5 lost weight, and 7 gained weight (more than 10% weight change).

RESULTS

Superficial facial fat decreased by a median of 5.2 mL (p = .03) in patients with lipoatrophy, and 8 of 12 individuals showed more than 15% decrease (all of whom were taking stavudine). The decrease was mainly cheek fat. Superficial facial fat decreased by 6.0 mL in patients with weight loss (p = .04) and increased by 20.2 mL (p = .02) in patients with weight gain, and changes occurred in cheek fat, temporal fat, and masseter muscle and temporalis muscle compartments.

CONCLUSION

MRI can detect substantial ongoing changes in facial fat in patients with facial lipoatrophy. A characteristic pattern of compartmental change distinguishes lipoatrophy from wasting and weight recovery. MRI should be considered for use in clinical trials of interventions to prevent or treat lipoatrophy and may be useful for documenting changes in individual patients during clinical follow-up.

Skeletal and cardiac myopathy in HIV-1 transgenic rats

The mechanism by which human immunodeficiency virus (HIV)-1 infection in humans leads to the erosion of lean body mass is poorly defined. Therefore, the purpose of the present study was to determine whether transgenic (Tg) rats that constitutively overexpress HIV-1 viral proteins exhibit muscle wasting and to elucidate putative mechanisms. Over 7 mo, Tg rats gained less body weight than pair-fed controls exclusively as a result of a proportional reduction in lean, not fat, mass. Fast- and slow-twitch muscle atrophy in Tg rats did not result from a reduction in the in vivo-determined rate of protein synthesis. In contrast, urinary excretion of 3-methylhistidine, as well as the content of atrogin-1 and the 14-kDa actin fragment, was elevated in gastrocnemius of Tg rats, suggesting increased muscle proteolysis. Similarly, Tg rats had reduced cardiac mass, which was independent of a change in protein synthesis. This decreased cardiac mass was associated with a reduction in stroke volume, but cardiac output was maintained by a compensatory increase in heart rate. The HIV-induced muscle atrophy was associated with increased whole body energy expenditure, which was not due to an elevated body temperature or secondary bacterial infection. Furthermore, the atrophic response could not be attributed to the development of insulin resistance, decreased levels of circulating amino acids, or increased tissue cytokines. However, skeletal muscle and, to a lesser extent, circulating insulin-like growth factor I was reduced in Tg rats. Although hepatic injury was implicated by increased plasma levels of aspartate and alanine aminotransferases, hepatic protein synthesis was not different between control and Tg rats. Hence, HIV-1 Tg rats develop atrophy of cardiac and skeletal muscle, the latter of which results primarily from an increased protein degradation and may be related to the marked reduction in muscle insulin-like growth factor I.

Eyelid retraction and incomplete eyelid closure secondary to human immunodeficiency virus-associated muscle wasting

Human immunodeficiency virus (HIV)-associated weight loss remains a significant problem, even in the era of highly active antiretroviral therapy. This interventional case report describes eyelid retraction and poor eyelid closure caused by orbicularis atrophy in the setting of HIV-associated muscle wasting. A 65-year-old HIV-infected man sought treatment for chronic ocular irritation. On examination, he was thin with marked temporal wasting. Corneal epithelial defects were present bilaterally. There was 2 mm of superior scleral show in the right eye and trace inferior scleral show bilaterally. With attempted closure, lagophthalmos approached 1 cm in the right eye and was 3 mm in the left eye. The remainder of the examination was unremarkable. Gold weight placement achieved symptomatic improvement with adequate eyelid closure. Biopsy demonstrated fibrous tissue with an absence of identifiable muscle fibers. In the setting of HIV-associated muscle wasting, orbicularis oculi muscle atrophy may result in eyelid retraction, lagophthalmos, and ocular surface disease.

Wasting and body composition of adults with pulmonary tuberculosis in relation to HIV-1 coinfection, socioeconomic status, and severity of tuberculosis

OBJECTIVE

To examine the impact of HIV coinfection, socioeconomic status (SES) and severity of tuberculosis (TB) on the body composition and anthropometric status of adults with pulmonary TB.

DESIGN

Cross-sectional study.

SETTING

Five TB clinics in Dar es Salaam, Tanzania.

SUBJECTS

A total of 2231 adult men and women diagnosed with pulmonary TB, prior to the initiation of anti-TB therapy.

METHODS

We compared the distribution of anthropometric characteristics including body mass index (BMI), mid-upper arm circumference (MUAC), triceps skin-fold (TSF), and arm muscle circumference (AMC) by HIV status, SES characteristics, and indicators of TB severity (bacillary density in sputum and Karnofsky performance score). Similar comparisons were carried out with body composition variables from bioelectrical impedance analysis and albumin concentrations, in a subsample of 731 subjects.

RESULTS

In multivariate analysis, HIV infection was significantly associated with lower MUAC and AMC in both men and women, but not with BMI or TSF. Compared to HIV-uninfected women, those who were HIV infected had lower body cell mass (BCM) (adjusted difference = -0.85 kg, P = 0.04), intracellular water (-0.68 l, P = 0.04), and phase angle (-0.52, P = 0.02). Albumin concentrations were significantly lower in both men and women infected with HIV. Among HIV-infected men, CD4 cell counts <200/mm(3) were related to lower intracellular water, BCM, fat-free mass and phase angle. Independent of HIV infection, BMI and MUAC were positively related to SES indicators and the Karnofsky performance score; and inversely related to bacillary density.

CONCLUSIONS

HIV infection is associated with indicators of low lean body mass in adults with TB; socioeconomic factors and TB severity are important correlates of wasting, independent of HIV.

SPONSORSHIP

The National Institute of Allergy and Infectious Diseases (UO1 AI 45441-01).

Skeletal muscle involvement in human immunodeficiency virus (HIV)-infected patients in the era of highly active antiretroviral therapy (HAART)

Skeletal muscle involvement can occur at all stages of human immunodeficiency virus (HIV) infection, and may represent the first manifestation of the disease. Myopathies in HIV-infected patients are classified as follows: (1) HIV-associated myopathies and related conditions, including HIV polymyositis, inclusion-body myositis, nemaline myopathy, diffuse infiltrative lymphocytosis syndrome (DILS), HIV-wasting syndrome, vasculitic processes, myasthenic syndromes, and chronic fatigue; (2) muscle complications of antiretroviral therapy, including zidovudine and toxic mitochondrial myopathies related to other nucleoside-analogue reverse-transcriptase inhibitors (NRTIs), HIV-associated lipodystrophy syndrome, and immune restoration syndrome related to highly active antiretroviral therapy (HAART); (3) opportunistic infections and tumor infiltrations of skeletal muscle; and (4) rhabdomyolysis. Introduction of HAART has dramatically modified the natural history of HIV disease by controlling viral replication, but, in turn, lengthening of the survival of HIV-infected individuals has been associated with an increasing prevalence of iatrogenic conditions.

Immunohistochemical study of apelin, the natural ligand of receptor APJ, in a case of AIDS-related cachexia

Apelin, a peptide first isolated from bovine stomach extracts, was discovered as an endogenous ligand for the APJ receptor. APJ has been shown to be a co-receptor for human and simian immunodeficiency virus (HIV and SIV). Apelin specifically inhibited the entry of primary T-tropic and dualtropic HIV-1 isolated from different clones expressing antiviral CD4 and APJ. On the basis of these results, we decided to compare the apelin expression level between normal and AIDS-infected tissues by immunohistochemistry. We found that apelin expression was less intense in AIDS-infected tissues compared to normal tissues, in particular in the pancreas, kidney, adrenal glands and lymphoid organs. These results suggest an involvement of this peptide in immunodeficiency and in the immune response to AIDS.

Facial atrophy in HIV-related fat redistribution syndrome: anatomic evaluation and surgical reconstruction

The use of highly active antiretroviral therapy (HAART) with protease inhibitors can result in a syndrome of peripheral wasting, facial fat atrophy, and central adiposity in as many as 64% of patients infected with human immunodeficiency virus (HIV) who are treated with this regimen for 1 year. In this study the authors evaluated 9 consecutive patients who presented with this disease to define further its anatomic features and to explore techniques for surgical correction. Three of these patients presented with severe facial atrophy, and underwent surgical exploration and reconstruction with submalar silicone implants. Two patients required additional soft-tissue augmentation with synthetic fillers and/or autologous fat. Outcomes were determined through clinical impressions of the patient and surgeons, and comparison of pre- and postoperative photographs. No extrusion or infection was encountered, although 1 patient required repositioning on one side. Both surgeons and patients were satisfied with the results at the long-term follow-up. Detailed anatomic evaluation revealed the presence of a fat pad of Bichat in all patients. Facial atrophy in HIV-related fat redistribution syndrome (HARS) is secondary to atrophy of the subcutaneous fat, but not of the deeper fat pads, as has been described. Durable surgical reconstruction is achieved with a combination of submalar silicone implantation and augmentation of the nasolabial fold. HARS causes noticeable disfigurement that stigmatizes the HIV-infected patient. Given the overall benefit of decreased morbidity and prolonged survival associated with HAART therapy, it is beneficial to attempt surgical correction of these debilitating sequelae before discontinuation of these drugs.

Treatment of HIV-associated wasting with recombinant human growth hormone: monitoring of body composition changes by bioelectrical impedance analysis (BIA)

INTRODUCTION

Recombinant human growth hormone (r-hGH) has demonstrated efficacy in treating HIV-associated wasting (HAW), however, HAW has become less prominent since the introduction of highly active antiretroviral therapy (HAART). Recent studies suggest that patients receiving HAART may still experience HAW. We investigated the nature of HAW and the efficacy of r-hGH in these patients.

METHODS

We treated 27 HIV-positive patients receiving HAART who had either recent loss of >5% body weight or weight <90% lower limit of normal with 12 weeks of r-hGH (6 mg given either daily or every other day). Body composition changes were monitored using bioelectrical impedance analysis (BIA). RESULTS were assessed for all patients and for a subgroup meeting more stringent definitions of wasting (BIA phase angle a<5.6 degrees, n = 14). -

RESULTS

Significant increases from baseline in weight and body cell mass (BCM) occurred in the full population (medians: 2.0 kg weight, 1.5 kg BCM). Patients with phase angle alpha<5.6 degrees also showed increases in weight and BCM (medians: 2.5 kg weight, 1.95 kg BCM), and 10 of 14 showed improvements in the ratio of extracellular mass (ECM) to BCM. At follow-up there was a trend towards loss of the weight and BCM gained on treatment. Treatment was well tolerated.

CONCLUSION

Patients receiving HAART continue to experience wasting, and respond well to r-hGH therapy as monitored by BIA.

Effects of testosterone and exercise on muscle leanness in eugonadal men with AIDS wasting

Loss of lean body and muscle mass characterizes the acquired immunodeficiency syndrome (AIDS) wasting syndrome (AWS). Testosterone and exercise increase muscle mass in men with AWS, with unclear effects on muscle composition. We examined muscle composition in 54 eugonadal men with AWS who were randomized to 1) testosterone (200 mg im weekly) or placebo and simultaneously to 2) resistance training or no training in a 2 × 2 factorial design. At baseline and after 12 wk, we performed assessments of whole body composition by dual-energy X-ray absorptiometry and single-slice computed tomography for midthigh cross-sectional area and muscle composition. Leaner muscle has greater attenuation. Baseline muscle attenuation correlated inversely with whole body fat mass ( r = −0.52, P = 0.0001). This relationship persisted in a model including age, body mass index, testosterone level, viral load, lean body mass, and thigh muscle cross-sectional area ( P = 0.02). Testosterone ( P = 0.03) and training ( P = 0.03) increased muscle attenuation. These data demonstrate that thigh muscle attenuation by computed tomography varies inversely with whole body fat and increases with testosterone and training. Anabolic therapy in these patients increases muscle leanness.

Effects of testosterone and progressive resistance training in eugonadal men with AIDS wasting. A randomized, controlled trial

BACKGROUND

Substantial loss of muscle mass occurs among men with AIDS wasting.

OBJECTIVE

To investigate the independent effects of testosterone therapy and progressive resistance training in eugonadal men with AIDS wasting.

DESIGN

Randomized, controlled trial.

SETTING

University hospital.

PATIENTS

54 eugonadal men with AIDS wasting (weight < 90% ideal body weight or weight loss > 10%).

INTERVENTION

In a 2 x 2 factorial design, patients were assigned to receive testosterone enanthate (200 mg/wk) or placebo injections and progressive resistance training (three times weekly) or no training for 12 weeks.

MEASUREMENTS

Cross-sectional muscle area and other indices of muscle mass.

RESULTS

Cross-sectional muscle area increased in response to training compared with nontraining (change in arm muscle mass, 499 +/- 349 mm2 vs. 206 +/- 264 mm2 [P = 0.004]; change in leg muscle mass, 1106 +/- 854 mm2 vs. 523 +/- 872 mm2 [P = 0.045]) and in response to testosterone therapy compared with placebo (change in arm muscle mass, 512 +/- 371 mm2 vs. 194 +/- 215 mm2 [P< 0.001]; change in leg muscle mass, 1,236 +/- 881 mm2 vs. 399 +/- 729 mm2 [P = 0.002]). Levels of high-density lipoprotein cholesterol decreased in response to testosterone therapy compared with placebo (-0.03 +/- 0.13 mmol/L vs. 0.05 +/- 0.13 mmol/L [-1 +/- 5 mg/dL vs. 2 +/- 5 mg/dL]; P= 0.011) and increased in response to training compared with nontraining (0.05 +/- 0.13 mmol/L vs. 0.00 +/- 0.16 mmol/L [2 +/- 5 mg/dL vs. 0 +/- 6 mg/dL]; P = 0.052).

CONCLUSIONS

In contrast to anabolic therapies that may have adverse effects on metabolic variables, supervised exercise effectively increases muscle mass and is associated with significant positive health benefits in eugonadal men with AIDS wasting.

Contribution of nucleoside analogue reverse transcriptase inhibitors to subcutaneous fat wasting in patients with HIV infection

BACKGROUND

Progressive subcutaneous fat wasting, fat accumulation, dyslipidaemia and insulin resistance in HIV-infected patients on antiretroviral therapy has been attributed to the long-term toxicity of HIV protease inhibitors (PI). More recently, fat wasting has been observed in patients who have never taken a PI, implicating an independent effect of nucleoside analogue reverse transcriptase inhibitor (NRTI) therapy.

OBJECTIVES

To determine the relative contribution of NRTI and PI, as well as any other factors, to fat wasting in HIV-infected patients.

DESIGN

Longitudinal cohort study involving 277 participants of the Western Australian HIV Cohort Study.

METHODS

The time to onset of clinically apparent fat wasting in patients receiving different antiretroviral regimens was compared using standardized clinical criteria. Regional fat measured by dual energy X-ray absorptiometry (DEXA) in 161 patients was also compared. The average rate of percentage fat reduction was estimated in 70 patients who had consecutive DEXA scans at approximately 6-monthly intervals. Multiple confounding factors were considered in the analyses.

RESULTS

Progressive subcutaneous fat wasting, indistinguishable from that described in PI-treated patients, does occur in PI-naive, NRTI-treated patients. In patients taking triple combination antiretroviral therapy, age (relative risk = 1.052 per year; P < 0.0001), white race (relative risk = 3.9; P = 0.023), longer duration of dual NRTI therapy prior to addition of PI (relative risk = 1.021 per month; P = 0.0046) and increased cumulative time on stavudine-containing regimens compared with time on zidovudine-containing regimens (relative risk = 1.085 per month; P < 0.0001) are associated with increased risk of fat wasting. Stavudine increases the risk of fat wasting by 265% per year compared with zidovudine. However PI therapy is associated with faster progression to clinically apparent wasting compared with dual NRTI therapy without PI. The results of DEXA scanning supports these clinical data and suggest a non-linear decline in fat over time.

CONCLUSIONS

NRTIs do have an independent contribution to fat wasting, but PI are the predominant influence and may act synergistically with NRTIs. NRTIs appear to predispose individuals to slowly progressive fat loss, which is markedly accelerated when a PI and NRTIs are combined. Of the NRTIs, stavudine leads to an earlier onset of clinically apparent fat wasting compared with zidovudine. Fat wasting associated with NRTI use may be a manifestation of mitochondrial toxicity, which may be exacerbated by PI use.

Correlation between increased cortisol:DHEA ratio and malnutrition in HIV-positive men

Malnutrition in HIV-infected patients is characterized by a loss of both fat-free mass (FFM) and fat mass (FM). Glucocorticoids and androgens change during the course of the infection and may play a key role in the protein balance. The serum concentrations of cortisol, adrenal (DHEA and DHEA sulfate) and gonadal androgens (androstenedione, testosterone, and dihydrotestosterone) of HIV-positive men were measured and compared with several parameters of body composition as a function of body weight loss (BWL). The patients were assigned to one of five groups according to their BWL: group I (controls, n = 10) < 5%, group II (n = 7) 5-10%, group III (n = 8) 10.1-16%, group IV (n = 9) 16.1-24%, and group V (n = 4) > 24.1%. Correlation analysis showed significant positive or negative relationships between several markers of malnutrition and adrenal androgens and the cortisol:DHEA ratio, but not with cortisol. BWL was negatively correlated with DHEA (r = -0.69, P < 0.0001), DHEA sulfate (r = -0.58, P < 0.0001) and testosterone (r = -0.34, P < 0.03), but positively with the cortisol:DHEA ratio (r = 0.61, P < 0.0001). In contrast, BCM was positively correlated with DHEA (r = 0.34, P < 0.04) and DHEA sulfate (r = 0.36, P < 0.03) and negatively with the cortisol:DHEA ratio (r = -0.58, P < 0.0001). The cortisol:DHEA ratio was also negatively correlated with BMI (body mass index) (r = -0.56, P < 0.01), fat-free mass (r = -0.48, P < 0.004), fat mass (r = -0.39, P < 0.02), and BCM:weight ratio (r = -0.47, P < 0.005) and positively with the extracellular:intracellular water ratio (r = 0.54, P < 0.001). These data indicate that the steroid hormone environment of patients, particularly their cortisol:DHEA ratio, is linked to the malnutrition associated with HIV infection. The decreased DHEA and increased cortisol in patients with the advanced stages of disease could be associated with increased protein catabolism.

Effects of nandrolone decanoate therapy in borderline hypogonadal men with HIV-associated weight loss

Serum testosterone concentrations are frequently in the low-normal range (lowest quartile, <500 ng/dl) in men with AIDS-wasting syndrome (AWS) and in other chronic wasting disorders. The response of patients in this group to androgen treatment has not been determined, however. Eighteen men with AWS (mean +/- standard error [SE]: 87% +/- 1% usual body weight; CD4 count 90 +/- 24) and borderline low serum testosterone concentrations (382 +/- 33 ng/dl) completed a 21-day placebo-controlled inpatient metabolic ward study comparing intramuscular (i.m.) placebo (n = 7) with low-dose (65 mg/week; n = 4) and high-dose (200 mg/week; n = 7) nandrolone decanoate, a testosterone analogue. Nitrogen balance, stable isotope-mass spectrometric measurement of de novo lipogenesis (DNL), resting energy expenditure, and gonadal hormone levels were measured. Both low-dose and high-dose nandrolone resulted in significant nitrogen retention (33-52 g nitrogen/14 days, representing gains of 0.5 to 0.9 kg lean tissue/week) compared with placebo (loss of 11 g nitrogen/week). This was reflected biochemically in a borderline significant reduction of high DNL (p < .06). Serum testosterone and gonadotropins were suppressed whereas resting energy expenditure was unchanged by nandrolone treatment. In 10 study subjects completing a 12-week open-label follow-up phase, body weight increased by 4.9 +/- 1.2 kg, including 3.1 +/- 0.5 kg lean body mass, and treadmill exercise performance also improved. In summary, nandrolone decanoate therapy in the absence of an exercise program in borderline hypogonadal men with AWS caused substantial nitrogen retention compared with placebo, similar in extent to the nitrogen retention previously achieved with recombinant growth hormone. It is reasonable to expand the criteria for androgen treatment in AWS to include at least patients in the lowest quartile of serum testosterone.

Wasting in cancer

Progressive weight loss is a common feature of many types of cancer and is responsible not only for a poor quality of life and poor response to chemotherapy, but also a shorter survival time than is found in patients with comparable tumors without weight loss. Although anorexia is common, a decreased food intake alone is unable to account for the changes in body composition seen in cancer patients, and increasing nutrient intake is unable to reverse the wasting syndrome. Although energy expenditure is increased in some patients, cachexia can occur even with a normal energy expenditure. Various factors have been investigated as mediators of tissue wasting in cachexia. These include cytokines such as tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), interferon-gamma (IFN-gamma) and leukemia inhibitory factor (LIF), as well as tumor-derived factors such as lipid mobilizing factor (LMF) and protein mobilizing factor (PMF), which can directly mobilize fatty acids and amino acids from adipose tissue and skeletal muscle respectively. Induction of lipolysis by the cytokines is thought to result from an inhibition of lipoprotein lipase (LPL), although clinical studies provide no evidence for an inhibition of LPL in the adipose tissue of cancer patients. Instead there is an increased expression of hormone sensitive lipase, the enzyme activated by LMF. Protein degradation in cachexia is associated with an increased activity of the ATP-ubiquitin-proteasome pathway. The biological activity of both the LMF and PMF was shown to be attenuated by eicosapentaenoic acid (EPA). Clinical studies show that this polyunsaturated fatty acid is able to stabilize the rate of weight loss and adipose tissue and muscle mass in cachectic patients with unresectable pancreatic cancer. Knowledge of the mechanism of cancer cachexia should lead to the development of new therapeutic agents.

Quantitative assessment of cross-sectional muscle area, functional status, and muscle strength in men with the acquired immunodeficiency syndrome wasting syndrome

The acquired immunodeficiency syndrome wasting syndrome (AWS) in men is characterized by the loss of lean body mass out of proportion to weight. Although the wasting syndrome has been thought to contribute to reduced functional capacity, the relationships among lean body mass, muscle size, functional status, and regional muscle strength have not previously been investigated in this population. In this study, 24 eugonadal men with the AWS (weight <90% of the ideal body weight or weight loss >10% from preillness maximum) underwent determination of body composition by dual energy x-ray absorptiometry (DXA), 40K isotope analysis, urinary creatinine excretion, and quantitative computed tomographic analysis of cross-sectional muscle areas of the midarm and thigh. Overall exercise functional capacity was evaluated using the 6-min walk test, and performance of upper and lower extremities was determined with the quantitative muscle function test. Subjects were 37 +/- 1 yr of age and weighed 95.5 +/- 3.0% of ideal body weight, with a body mass index of 21.9 +/- 0.7 kg/m2 and an average weight loss of 15 +/- 1%. The mean CD4 count among the subjects was 354 +/- 70 cells/mm3, and viral load was 58,561 +/- 32,205 copies. Sixty-two percent of subjects were receiving protease inhibitor therapy. The subjects demonstrated 90% of the expected muscle mass by the creatinine height index method. Overall performance status on the Karnofsky scale was highly correlated to weight (r = 0.51; P = 0.018; by body mass index), lean body mass (r = 0.46; P = 0.036; by DXA), and body cell mass (r = 0.47; P = 0.037; by 40K isotope analysis). Cross-sectional muscle area of the upper extremity was the best predictor (P < 0.001) of Karnofsky score, accounting for 52% of the variability in a stepwise regression analysis. Upper body muscle strength was most significantly predicted by lean body mass (by DXA; r2 = 0.78; P < 0.0001), whereas lower body strength and performance on the 6-min walk test were best predicted by lower extremity cross-sectional muscle area (r2 = 0.70; P < 0.0001 and r2 = 0.26; P = 0.030, respectively). These data demonstrate that cross-sectional muscle area is highly predictive of functional status and muscle strength in men with the AWS.

Enteropathy in Zambians with HIV related diarrhoea: regression modelling of potential determinants of mucosal damage

BACKGROUND

AIDS is characterised by small intestinal mucosal damage, but its aetiopathogenesis is poorly understood. Enteric infections in Africa differ from those in northern countries, where protozoan infections have been associated with severe enteropathy in AIDS patients.

AIMS

To characterise enteropathy in Zambian AIDS patients compared with local controls, and to assess relative contributions of enteric infection, nutritional impairment, and immune dysfunction.

METHODS

Computer aided mucosal morphometry of small intestinal biopsy specimens from 56 HIV infected Zambians with persistent diarrhoea and 26 diarrhoea free controls, followed by regression modelling.

RESULTS

Patients with HIV related diarrhoea had reduced villous height and increased crypt depth compared with controls. There was no difference between HIV positive and negative controls. In regression models applied to AIDS mucosal measurements, villous height and crypt depth were related to nutritional parameters and to serum soluble tumour necrosis factor receptor p55 concentration. Crypt depth was also related to lamina propria plasma cell count. Intestinal infection was found in 79%, which consisted predominantly of microsporidia in 34%, Isospora belli in 24%, and Cryptosporidium parvum in 21%, but detection of these enteropathogens was not related to severity of enteropathy.

CONCLUSIONS

Nutritional and immune disturbances were associated with enteropathy, accounting for over one third of the variation in mucosal morphometric parameters.

Skeletal muscle studies in patients with HIV-related wasting syndrome

Previous reports have suggested that HIV-related wasting syndrome may be considered as a form of myopathy. The aim of the present study was to investigate histopathological muscle changes in HIV-related wasting syndrome in order to know if there is a common substrate and whether muscle plays a primary or secondary role in its development. Patients with wasting syndrome diagnosed by Centers for Disease Control (CDC) criteria were prospectively evaluated. Clinical, analytical, nutritional, anthropometrical and muscular data were recorded. The patients were subdivided into two groups: group A was constituted by patients in whom wasting syndrome was the AIDS-defining illness, and group B by patients in whom AIDS diagnosis was previously made. In all cases muscle biopsy was performed and processed for conventional stainings and histochemical reactions. Thirty patients were included (group A, 12; group B, 18). Clinical, analytical, nutritional and anthropometrical data did not essentially differ between the two groups. All patients were malnourished with respect to controls. Histopathological findings in muscle biopsy were heterogeneous and similar in both groups, except for HIV-related myopathies, which were more frequently seen in the patients from group A (P=0.05). In five cases (17%) an unsuspected and potentially treatable myopathy was diagnosed. Patients with polyarteritis nodosa (two) or polymyositis (one) were treated with prednisone, which improved their wasting syndrome. By contrast, patients with AZT-myopathy (two) did not improve when the drug was discontinued. We conclude that in most cases the wasting syndrome cannot be considered as a true myopathy, and probably metabolic and/or nutritional factors may account for wasting development. However, in a subset of patients muscle biopsy allows the diagnosis of a treatable myopathy leading to the improvement of wasting syndrome.

Body composition in clinically stable men with HIV infection

Clinically stable HIV-infected men (N = 106) receiving investigational antiretrovirals were recruited. Subjects were divided into three HIV disease severity groups by CD4+ cell count. Standard measures of body composition were assessed, as well as serum measures of visceral protein stores and kilocalorie intake. Group 1 subjects (CD4+ T cells < 200) had significantly lower measures of body fat as compared with Group 2 (CD4 between 200 and 600) and Group 3 (CD4 > 600) despite adequate kilocalorie intake. Group 2 and Group 3 were not significantly different from each other. Our entire cohort had significantly lower muscle mass compared to norms. Our data demonstrate that people with advanced HIV disease have reduced muscle and fat.

Loss of lean body and muscle mass correlates with androgen levels in hypogonadal men with acquired immunodeficiency syndrome and wasting

The acquired immunodeficiency syndrome (AIDS) wasting syndrome (AWS) is a devastating complication of human immunodeficiency virus infection characterized by a disproportionate decrease in lean body mass. The pathogenesis of the AWS is unknown, but recent data suggest that endogenous secretion of the potent anabolic hormone, testosterone; is decreased in 30-50% of men with AIDS. However, it is unknown whether decreased androgen levels are associated with decreased lean body mass and/or functional decreases in muscle strength and aerobic capacity in hypogonadal men with the AWS. In addition, testosterone is known to have stimulatory effects on GH secretion, and the loss of these effects on the GH-insulin-like growth factor I (IGF-I) axis may be an additional mechanism of decreased lean body mass in this population. Twenty hypogonadal subjects (free-testosterone < 12 pg/mL) with weight loss > 10% of preillness weight or absolute weight < 90% ideal body weight (IBW) were enrolled in the study. None of the subjects were receiving Megace. Lean body mass and fat-free mass were determined by potassium-40 isotope analysis (40K) and dual-energy x-ray absorptiometry, respectively, and analyzed with respect to gonadal function by linear regression analysis. Muscle mass was determined by urinary creatinine excretion, and exercise functional capacity was assessed by a 6-min walk test, a sit-to-stand test, and a timed get-up-and-go test. Results also were compared with gonadal function by regression analysis. IGF-I and mean overnight GH levels, determined from frequent sampling (q20 min from 2000-0800 h), were compared with results obtained from age- and sex-matched normal controls. Subjects were 26-58 yr of age (39 +/- 7 yr, mean +/- SD) with a CD4 cell count of 150 +/- 186 cells/mm3. Serum levels of FSH were elevated in 30% of the subjects. Muscle mass was significantly reduced, compared with expected mass for height (23.3 +/- 5.5 vs. 29.3 +/- 1.7 kg, P = 0.0001) and was decreased disproportionately to weight (77% of expected value for muscle mass vs. 93% of expected value for weight). Free-testosterone levels were correlated with total body potassium (R = 0.45, P < 0.05) and muscle mass (R = 0.45, P < 0.05). Total-testosterone levels were correlated with exercise functional capacity (R = 0.64, P = 0.01 for the sit-to-stand test and R = 0.53, P < 0.05 for the 6-min walk test). Mean GH levels were significantly increased (3.03 +/- 1.76 vs. 0.90 +/- 0.37 ng/mL, P < 0.001) and IGF-I levels decreased (167 +/- 66 vs. 225 +/- 69 ng/mL, P < 0.01), compared with age- and sex-matched eugonadal controls. GH levels were inversely correlated with caloric intake (R = -0.60, P = 0.02) and percent fat mass by dual-energy x-ray absorptiometry (R = 0.58, P = 0.02). Six additional hypogonadal subjects receiving Megace for AIDS wasting were analyzed separately. Nutritional status and parameters of body composition were compared in the Megace and non-Megace-treated subjects. No significant differences in caloric intake, lean body mass, fat mass, or muscle mass were demonstrated. These data demonstrate that changes in body composition, including loss of lean body and muscle mass, and deterioration in exercise functional capacity are highly correlated with androgen levels in hypogonadal men with the AWS. Furthermore, our data demonstrate significantly increased GH levels and decreased IGF-I in association with low weight in this population. These data suggest that androgen deficiency combined with classical GH resistance may contribute to the critical loss of lean body and muscle mass in hypogonadal men with the AWS. These data are the first to link muscle and lean body wasting with progressive gonadal dysfunction among the large percentage of men with AIDS wasting who are hypogonadal. This demonstrates the need for additional studies to determine the efficacy of gonadal steroid replacement to increase lean body mass in this population.

Serum hormones in men with human immunodeficiency virus-associated wasting

Weight loss is commonly associated with increased morbidity and mortality in individuals with human immunodeficiency virus (HIV) infection. We performed a nested case-control study of 26 HIV-infected subjects recruited from a cohort of gay men enrolled in the Multicenter Acquired Immunodeficiency Syndrome Cohort Study. To test the hypothesis that hormonal changes precede and may induce the wasting syndrome, we performed a nested case-control study and analyzed serum gonadal steroids and GH in samples of HIV-infected men with or without weight loss, uncomplicated by diarrhea or ever having an opportunistic infection. We studied 13 cases (mean age +/- SD, 45 +/- 7.2 yr) with a mean weight loss of 13 +/- 3.6%, considered to have the wasting syndrome by Centers for Disease Control criteria (weight loss of > 10%) and 13 controls matched for age and duration of follow-up. Serum bioavailable testosterone (T) levels decreased in the case group (P < 0.05) before the definition of wasting was attained, although weight loss had already begun. More impressive declines occurred in serum T (P = 0.012), free T (P = 0.0025), and bioavailable T (P < 0.0001) during the 6 months immediately before documentation of wasting. These changes were concurrent with an increase in serum FSH (P = 0.0135) without a change in serum LH. We conclude that a decline in bioavailable T occurs early in the course of events leading to wasting, suggesting that changes in gonadal hormones may contribute to the multifactorial etiology of the wasting syndrome.

Circadian growth hormone secretion in asymptomatic human immune deficiency virus infection and acquired immunodeficiency syndrome

Although anabolic effects of GH supplementation have been reported in acquired immune deficiency syndrome (AIDS) patients, the effects of human immunodeficiency virus (HIV) infection per se on GH secretion are unknown. Therefore, we evaluated the characteristics of GH secretion in eight asymptomatic HIV-infected men, eight clinically stable male AIDS patients, and eight healthy controls. Wasting AIDS patients were not included to circumvent the confounding effects of opportunistic disease on GH secretion. Samples for GH analysis were taken at 10-min intervals over 24 h. GH was measured by immunoradiometric assay (detection limit, 0.08 mU/L). Insulin-like growth factor I (IGF-I) and IGF-binding protein-3 were measured every 6 h. The pulsatile secretion of GH was evaluated by Cluster and DESADE analyses. No differences in number of peaks, peak amplitude, peak length, peak interval, or GH secretion per 24 h were found among the studied groups. IGF-I and IGF-binding protein-3 concentrations were not different among groups. Circadian GH secretion in asymptomatic HIV infection and AIDS without wasting is not different from that in healthy subjects. Therefore, anabolic effects documented in clinical trials with recombinant human GH in AIDS patients are not merely explained by alterations in the GH/IGF-I axis induced by HIV infection per se.