Malnutrition and immune dysfunction in patients infected with human immunodeficiency virus

Sex differences in the associations of HIV disease characteristics and body composition in antiretroviral-naive persons

BACKGROUND

Data on associations of body composition with HIV disease characteristics are limited.

OBJECTIVE

We compared sex-specific associations between HIV disease characteristics and body composition in an racially-ethnically diverse cohort of antiretroviral-naive patients.

DESIGN

The study was a cross-sectional analysis of participants enrolled in a metabolic substudy of a multicenter trial. Regional fat was measured, and total body fat (TBF) was derived by using the Durnin-Womersley formula (DWF) and bioelectrical impedance analysis (BIA). Body cell mass (BCM) was measured by BIA.

RESULTS

Among 422 participants, 22% were women, 60% were African American, and 36% had prior AIDS-defining illnesses. Mean (+/-SD) age was 38.2 +/- 9.6 y, CD4+ count was 215 +/- 184 cells/mm3, and HIV RNA log10 was 5.0 +/- 0.8 copies/mL. On multivariate analysis, women with AIDS-defining illness had significantly (P < 0.005) lower regional body fat and TBF (BIA: -9.5 kg; DWF: -7.3 kg) but nonsignificantly lower BCM (-1.3 kg) than did women without such illnesses, whereas men with AIDS-defining illness had significantly (P < 0.005) lower BCM (-1.7 kg) but nonsignificantly lower TBF (BIA: -1.3 kg; DWF: -1.83 kg) than did men without such illnesses (P < 0.05 for sex differences in TBF). Significant negative associations of HIV RNA with BCM (-0.9 kg/log RNA; P = 0.03), TBF by BIA (-1.4 kg/log RNA; P = 0.05) and by DWF (-1.6 kg/log RNA; P = 0.01), and regional fat were observed in men only.

CONCLUSIONS

The effect of prior AIDS illness on body fat differed significantly between the sexes: women with prior AIDS-defining illness had significantly less fat than did women without such illnesses. An independent effect of HIV viremia on BCM and fat was seen in men. These distinctions may be due to inherent biological differences between the sexes.

Investigating heterogeneity in studies of resting energy expenditure in persons with HIV/AIDS: a meta-analysis

BACKGROUND

There is conflict in the literature about the extent of alterations of resting energy expenditure (REE) in persons with HIV.

OBJECTIVE

The study was conducted to ascertain the mean difference in REE (in kJ) per kilogram of fat-free mass (FFM; REE/FFM) between HIV-positive subjects and control subjects and to investigate heterogeneity in the literature.

DESIGN

A meta-analysis comparing classical and Bayesian methods was conducted. Heterogeneity was investigated by using subgroup analysis, metaregression, and a mixed indirect comparison.

RESULTS

Of 58 studies meeting the inclusion criteria, 32 included both HIV-positive and control groups; 24 of these 32 were included. Thirty-seven studies were used in the mixed indirect comparison, and 30 were used in the subgroup comparisons of the HIV-symptomatic, lipodystrophy, weight-losing, and weight-stable subgroups and the healthy (HIV-negative) control group. Mean REE/FFM was significantly higher in 732 HIV-positive subjects than in 340 control subjects [11.93 kJ/kg (95% CI: 8.44,15.43 kJ/kg) and 12.47 kJ/kg (95% CI: 8.19,16.57 kJ/kg), classical and Bayesian random effects, respectively]; the test for heterogeneity was significant (P < 0.001). Both the mixed indirect comparison and the subgroup analysis indicated that REE/FFM was highest in the symptomatic subgroup; however, the small number of studies investigating symptomatic subjects limited statistical comparisons. The presence of lipodystrophy, use of highly active antiretroviral therapy, subject age, and method of body-composition measurement could not explain the heterogeneity in the data with the use of metaregression.

CONCLUSIONS

REE/FFM (kJ/kg) is significantly higher in HIV-positive subjects than in healthy control subjects. Symptomatic HIV infection may contribute to the variations reported in the literature.

Position of the American Dietetic Association and Dietitians of Canada: nutrition intervention in the care of persons with human immunodeficiency virus infection

Infection with the human immunodeficiency virus (HIV) and the development of acquired immunodeficiency syndrome (AIDS) have had a significant impact on domestic and global health, social, political, and economic outcomes. Prevention and treatment efforts to control HIV infection are more demanding than in previous decades. Achieving food and nutrition security, and managing nutrition-related complications of HIV infection and the multiple aspects of disease initiated by or surrounding HIV infection, referred to as HIV disease, remain challenges for patients and for those involved with HIV/AIDS prevention, care, and treatment efforts. Confounding clinical issues include medication interactions, coinfection with other infections and diseases, wasting, lipodystrophy, and others. Dietetics professionals, other health care professionals, and people infected with HIV will need to understand and address multiple complex aspects of HIV infection and treatment to improve survival, body functions, and overall quality of life. Individualized nutrition care plans will be an essential feature of the medical management of persons with HIV infection and AIDS.

Weight gain, improvement in metabolic profile, and CD4 count with insulin administration in an AIDS patient

Malnutrition with muscle wasting, weight loss, and decreased immunogenicity is a hallmark of Acquired Immune Deficiency Syndrome (AIDS). Several anabolic agents have been utilized for retarding or preventing progressive wasting with limited success. However, insulin, with its most effective anabolic properties, has not been tried in an attempt to prevent or reverse cachexia in AIDS or any other wasting disorders. We report here the effect of using subcutaneous (s.c.) daily administration of insulin 0.3 U/kg (BW) for 6 months in a subject with AIDS. We noted a marked weight gain, improvement in metabolic profiles, that is, lowering of triglyceride, liver enzymes, glycohemoglobin concentrations, as well as 24-hour urinary excretion of urea nitrogen, protein, and creatinine suggestive of positive energy balance. Simultaneously, a marked rise in CD4 counts and an improvement in the thyroid hormone profile were also noted. A deterioration in these parameters occurred during the period of insulin withdrawal following completion of the study protocol. Resumption of insulin administration, on patient's request, once again resulted in the marked improvement similar to that noted during the study period. No adverse effects, including hypoglycemic episodes, were noted during either phase of insulin administration. The possibility that insulin administration may improve the wasting associated with AIDS may warrant further evaluation.

A syndrome of peripheral fat wasting (lipodystrophy) in patients receiving long-term nucleoside analogue therapy

OBJECTIVE

To compare body composition, body fat distribution and insulin secretion in patients taking nucleoside reverse transcriptase inhibitor (NRTI) therapy.

DESIGN AND SETTING

Cross-sectional study in three French AIDS clinical centres.

PATIENTS

Forty-three HIV-infected patients on long-term NRTI therapy including stavudine (n = 27) or zidovudine (n = 16) and 15 therapy-naive HIV-infected patients (control group).

MAIN OUTCOME MEASURES

Fat wasting was assessed by physical examination and body composition by bioelectrical impedance. Regional fat distribution was estimated using caliper measurements of skinfold thickness at four sites and evaluated by computed tomography at abdominal and mid-thigh level. Fasting glucose, insulin, C-peptide, triglyceride, cholesterol, free fatty acid, testosterone, follicle stimulating hormone, luteinizing hormone, cortisol levels, CD4 cell count and HIV viral load were determined. Daily total caloric and nutrient intake were evaluated.

RESULTS

The zidovudine group and the control group had similar body composition and regional fat distribution. Stavudine therapy was associated with a significantly lower percentage of body fat (12.9% versus 15.2% in the zidovudine group; P < 0.05), markedly decreased subcutaneous to visceral fat ratio (0.90 +/- 0.63 versus 1.92 +/- 1.34, P < 0.01) and higher mean intake of fat and cholesterol (P < 0.01). Fasting plasma glucose, insulin and C-peptide levels were similar among the three groups. Triglyceride levels were significantly higher in the stavudine group than in the controls (P < 0.05), but did not differ between the stavudine and the zidovudine group or between the zidovudine and the control group. Free fatty acids tended to be higher in the stavudine group but the difference did not reach statistical significance. Lipodystrophy was observed clinically in 17 (63%) patients taking stavudine, and in three (18.75%) patients taking zidovudine after a median time of 14 months. The relative risk of developing fat wasting was 1.95 in the stavudine group as compared with the zidovudine group (95% confidence interval, 1.18-3.22). Five out of 12 patients had a major or mild improvement in their lipodystrophy after stavudine was discontinued.

CONCLUSION

Lipodystrophy may be related to long-term NRTI therapy, particularly that including stavudine.

Body mass index course in asymptomatic HIV-infected homosexual men and the predictive value of a decrease of body mass index for progression to AIDS

Weight loss is a common characteristic of advanced stages of HIV infection. Weight changes during the asymptomatic stage of HIV infection have not been well documented and the possible predictive value of early weight loss for progression to AIDS is unknown. In 122 HIV seroconverters, the natural course of body mass index (BMI) following seroconversion was studied. No BMI decline was seen immediately following seroconversion. In the 56 AIDS cases, however, a steep BMI decline of 1.14 kg/m2 occurred 6 months before AIDS. This BMI decline was more pronounced in those with low CD4+ T cell counts (<100 x 10(6)/L) at the time of AIDS diagnosis (1.8 kg/m2). The relative hazard for progression to AIDS of a BMI decline of 1.14 kg/m2 per 6 months was 3.1, which remained similar after adjustment for CD4 count and p24 antigenemia. We conclude that the course of BMI in HIV-1 infection is biphasic: a relatively stable period is followed by a rapid decline in the 6 months preceding onset of AIDS. Furthermore, we found that this steep BMI decline was associated with faster progression to AIDS.

Effect of malabsorption on nutritional status and resting energy expenditure in HIV-infected patients

OBJECTIVE

To assess the influence of malabsorption on nutritional status and energy expenditure in patients at different stages of HIV infection.

DESIGN AND METHODS

Fifty HIV patients were classified into three groups: Group 1, HIV asymptomatic patients (n=17); Group 2, AIDS without opportunistic infection (n=16); Group 3, AIDS patients with active infection (n=17). Clinically-healthy subjects (n=19) were used as controls. Parameters measured were: anthropometry, body composition by tetrapolar bioelectrical impedance; resting energy expenditure (REE) by open-circuit indirect calorimetry; malabsoption by D-xylose absorption and triolein breath tests.

RESULTS

Malabsorption (defined as abnormality of xylose and/or fat absorption test) was found in 34 (68%) of patients: 9 (53%) Group 1; 11 (69%) Group 2; 14 (82%) Group 3. Twenty-seven (54%) had sugar malabsorption and 21 (42%) fat malabsorption. A significant relationship was observed between malabsorption and weight loss. REE measured was significantly lower in malabsorptive patients than in non-malabsorptive patients and controls (6006.3+/-846.5 versus 6443.4 + 985.5 versus 6802.1+/-862.7 kJ/day, respectively; P < 0.05). The REE adjusted for fat-free mass was lower in malabsorptive than in non-malabsorptive patients and slightly higher than in controls, although the differences were not statistically significant.

CONCLUSIONS

The results suggest that malabsorption is a frequent feature in HIV infection and is related to the HIV-related weight loss. Hypermetabolism is not a constant phenomenon in HIV infection since, in the presence of malabsorption, our patients show an appropriate metabolic response with a compensatory decrease in REE.

Weight gain and increased concentrations of receptor proteins for tumor necrosis factor after patients with symptomatic HIV infection received fortified nutrition support

OBJECTIVE

To determine whether certain nutrients and dietary factors act as modulators of the immune system and improve the nutritional status of immunocompromised patients.

DESIGN

Controlled, double-blind, crossover phase trials of the effects of a fortified formula in patients infected with the human immunodeficiency virus (HIV). Patients consumed a control formula for 4 months and a study formula for 4 months.

SUBJECTS

Ten men with symptomatic HIV infection who were following stable medication regimens and had no malignancies, mycobacteriosis, or additional virus infection requiring systemic treatment.

INTERVENTION

Formula fortified with alpha-linolenic acid (1.8 g/day), arginine (7.8 g/day), and RNA (0.75 g/day) and a standard formula.

MAIN OUTCOME MEASURES

Nutritional status determined by anthropometric, bioelectrical, biochemical, and dietary assessment; energy expenditure determined by indirect calorimetry; disease progression; CD4 lymphocyte counts; HIV p24 antigen plasma concentrations; tumor necrosis factor (TNF) receptor proteins; and compliance control parameters.

STATISTICAL ANALYSES PERFORMED

Student's t tests for paired and unpaired data.

RESULTS

Fortified nutrition resulted in a weight gain (+ 2.9 kg/4 months vs -0.5 kg/4 months with the control formula, P < .05), an incorporation of eicosaenoic acid into erythrocyte cell membranes (+ 47% of baseline values, P < .05), and increased plasma arginine concentrations (96.8 +/- 45.1 vs 51.8 +/- 20.9 mumol/L, P < .01). The serum concentrations of the soluble tumor necrosis factor receptor (sTNFR) proteins increased during the study period (sTNFR 55 = + 0.23 vs -0.40 ng/mL, P < .001; sTNFR 75 = + 0.90 vs -0.36 ng/mL, P < .01), whereas no changes in CD4+ lymphocyte counts were observed.

CONCLUSION

Increasing dietary intakes of n-3 polyunsaturated fatty acids, L-arginine, and RNA increased body weight, possibly by modulating the negative effects of TNF.

Effect of increased protein intake and nutritional status on whole-body protein metabolism of AIDS patients with weight loss

The aim of this study was to investigate nutritional status and protein metabolism during total parenteral nutrition (TPN) in AIDS patients with weight loss. Six patients on treatment for AIDS-associated complications were investigated and reviewed TPN that supplied energy equivalent to 1.5 times the resting energy expenditure (REE). Amino acid (AA) supply increased from 0.6 g/kg body weight (BW)/d on days 1 to 3 and 1.2 on days 4 to 6 to 1.8 on days 7 to 9. Nonprotein energy was given as equicaloric amounts of glucose and fat emulsion. There were repeated measurements of nitrogen balance and whole-body protein turnover (WBPT) using a bolus 15N-glycine method on the morning of days 3, 6, and 9. Principal findings were as follows: (1) increasing the supply of AAs significantly improves nitrogen balance in AIDS patients; (2) there is no simple linear effect of increasing amounts of AAs on WBPT in AIDS patients; (3) WBPT is high and variable in these patients; and (4) mean WBPT of each patient is significantly correlated with body cell mass (BCM) as a proportion of BW (P < .001, r = .92). We conclude that poor nutritional status in AIDS patients with weight loss is associated with high WBPT. However, these patients can attain at least transiently positive nitrogen balance with sufficient protein intake, predominantly through an increase in whole-body protein synthesis (WBPS).

Nutritional support in HIV infection and AIDS

Weight loss and wasting are common features of HIV infection and AIDS. Patterns of weight loss can be acute or chronic which appear to be related primarily to systemic infections and gastrointestinal pathology, respectively. However, weight loss is not inevitable. and periods of weight stability and weight gain have been documented. Reduced food intake appears to be a major cause of weight loss in HIV infection. Since time of death has been associated with degree of wasting, it seems reasonable to suggest that nutritional support may contribute to enhancing survival and quality of life. All patients should have early access to a qualified dietitian such that assessment of individual situations can be made and appropriate dietary advice given, within a multi-disciplinary approach. Choice of nutritional therapy should be made based on an assessment of the causes of weight loss and an assessment of gut function. Treating infections and alleviating symptoms is vital for ensuring effective nutritional support. Enhancing the energy and protein density of foods and use of oral supplements should be considered if a normal diet alone cannot meet nutritional requirements. Unnecessary dietary restrictions should be avoided. Enteral feeding is indicated for patients unable to meet their needs via the oral route, and in cases of inadequate gut function, parenteral nutrition may be necessary. There is currently insufficient clinical evidence to justify the need for special enteral formulae specifically for patients with HIV infection.

Home enteral nutrition in patients with Acquired Immunodeficiency Syndrome

14 patients in advanced stages of HIV infection (1 ARC, 13 AIDS; sex: 1 female, 13 male; age 37.8 +/- 6.3 years; body mass index (BMI): 17.4 +/- 2.4 kg/m(2)) were followed prospectively while receiving home enteral nutrition (observation period: 62 +/- 75 days). Artificial nutrition was indicated because of severe weight loss (9-38 kg within 6-48 months, n = 7) or cerebral toxoplasmosis with eating and swallowing disorders (n = 7). In all patients a defined formula diet (175 +/- 17.7 kJ/kg body weight) was administered through an endoscopically placed gastrostomy tube (PEG). Home enteral nutrition was well tolerated by all patients and no significant PEG-related complications occurred. Enteral nutrition resulted in significant increases in body weight (p < 0.005), body cell mass (BCM, p < 0.05), total body fat (TBF, p < 0.005), serum albumin concentration (p < 0.05), and serum total iron-binding capacity (transferrin, p < 0.01).

CONCLUSION

Home enteral nutrition via PEG is safe and well tolerated in patients with advanced HIV-related immunodeficiency and is capable of improving nutritional state including BCM.

Resting energy expenditure and weight loss in human immunodeficiency virus-infected patients

Resting energy expenditure (REE) and body composition were investigated in 60 clinically stable patients with human immunodeficiency virus (HIV) infection varying with respect to immune impairment. REEs differed significantly from predicted values (> or < 10% of the Harris-Benedict [HB] equation) in 40% of patients. Seven percent of patients showed markedly increased REE (> +20% of HB prediction), whereas REE was decreased in 13% (< -10%). Increased REE was found during all clinical stages of the disease (Walter Reed [WR] 2 through 6) and was not strictly associated with the degree of immune impairment, presence of diarrhea or Kaposi's sarcoma, nutritional state, or anamnestic wasting. Twenty-seven patients were evaluated for a mean period of 319 days; 11 lost more than 5% of their initial body weight during the observation period. Weight-losing patients were normometabolic before but showed a significantly increased REE (+7% of predicted values or +8% when compared with previous measurements) during weight loss. The degree of deviation from estimated REE was strongly associated with the degree of weight loss. We summarize that increased REE is not a constant feature of HIV infection. It is not associated with clinical and laboratory parameters of immune deficiency, but may occur during weight loss. Thus increased REE represents an inadequate adaptation to malnutrition and contributes to wasting.