Total energy expenditure and carbohydrate oxidation are increased in the human immunodeficiency virus lipodystrophy syndrome

Patients living with HIV have quantitatively inadequate food consumption

Objective

The objective of the current study was to estimate energy expenditure and compare it with the usual food consumption of PLWH, and to determine whether duration of high-potency antiretroviral therapy (HAART) influenced nutritional intake and adequacy.

Materials and methods

Anthropometric measurements and bioelectrical impedance analysis (BIA) provided data for estimating resting energy expenditure (REE) using Melchior's equations. Dietary Reference Intakes (DRIs) and 24-Hour Recall were used to verify if reported food intake aligned with energy, macro and micronutrient recommendations.

Results

Sixty one patients with a mean age of 52 ± 9.4 years and who had a high frequency of diabetes mellitus (24.5%), hypertension (54%), and dyslipidemia (90.1%) were evaluated. Estimated REE of female and male patients with less than 10 years of HAART was 1791 (1717.5; 1887.2) and 1941 (1808; 2335.6), and their estimated energy intake was 900.5 (847;1221.9) and 2095.4 (1297.5; 2496.4), respectively. The estimated REE for female and male patients with more than 10 years of HAART was 1796.20 (1598.9;1820.7) and 2105 (1913.4; 2308), and their estimated energy intake was 1566 (1353.1; 1764.3) and 1999.7 (1706.5; 2508.1), respectively. Being on HAART for more than 10 years was associated with increased energy intake (533 (95% CI 3; 1063) kcals), but not with meeting energy requirements.

Conclusion

Patients had an atherogenic metabolic profile, inadequate dietary pattern, and a similar REE, regardless of HAART duration, contributing even more to the increased risk of cardiovascular diseases.

Immunometabolic Reprogramming in Response to HIV Infection Is Not Fully Normalized by Suppressive Antiretroviral Therapy

Background: HIV infection results in immunometabolic reprogramming. While we are beginning to understand how this metabolic reprogramming regulates the immune response to HIV infection, we do not currently understand the impact of ART on immunometabolism in people with HIV (PWH). Methods: Serum obtained from HIV-infected (n = 278) and geographically matched HIV seronegative control subjects (n = 300) from Rakai Uganda were used in this study. Serum was obtained before and ~2 years following the initiation of ART from HIV-infected individuals. We conducted metabolomics profiling of the serum and focused our analysis on metabolic substrates and pathways assocaited with immunometabolism. Results: HIV infection was associated with metabolic adaptations that implicated hyperactive glycolysis, enhanced formation of lactate, increased activity of the pentose phosphate pathway (PPP), decreased β-oxidation of long-chain fatty acids, increased utilization of medium-chain fatty acids, and enhanced amino acid catabolism. Following ART, serum levels of ketone bodies, carnitine, and amino acid metabolism were normalized, however glycolysis, PPP, lactate production, and β-oxidation of long-chain fatty acids remained abnormal. Conclusion: Our findings suggest that HIV infection is associated with an increased immunometabolic demand that is satisfied through the utilization of alternative energetic substrates, including fatty acids and amino acids. ART alone was insufficient to completely restore this metabolic reprogramming to HIV infection, suggesting that a sustained impairment of immunometabolism may contribute to chronic immune activation and comorbid conditions in virally suppressed PWH.

People Living With HIV, Lean Mass, and Sarcopenia: A Systematic Review and Meta-Analysis

This systematic review aims to estimate the prevalence of sarcopenia in people living with HIV (PLHIV) and to assess whether there is a difference between the muscle mass of PLHIV and people living without HIV. A systematic review of randomized controlled trials, cohort studies, cross-sectional and case-control studies was carried out. PLHIV over 18 years of age and that had their muscle mass evaluated by dual-energy X-ray absorptiometry were included. Overall, 4,376 studies were found, of which 118 had their full texts evaluated. A total of 5,532 people living with HIV and 2,986 people living without HIV were identified in 41 studies. The frequency of sarcopenia defined by low muscle mass (Baumgartner's operational definition) alone was 30.3% (95%CI 24.3%, 37.1%) and the frequency of sarcopenia defined by low muscle mass with low muscle strength (EWGSOP definition) was 4.5% (95%CI 1.3%, 13.9%), p-value = 0.0006. The standardized mean differences of muscle mass between PLHIV and controls was -0.211 units of standard deviation (95%CI -0.419, -0.003). In the meta-regression analysis muscle mass mean difference was associated with BMI, CD4, percentage of subjects on ART, and study design. PLHIV have a lower muscle mass when compared to people living without HIV. This difference appears to be attenuated by higher BMI, CD4 levels, and the percentage of subjects using ART. Furthermore, the frequencies of sarcopenia assessed by the operational definition of Baumgartner and the EWGSOP are not comparable and cannot be interchanged in PLHIV.

Nutritional Issues and Positive Living in Human Immunodeficiency Virus/AIDS

Nutritional counseling has been shown to improve dietary intake in individuals with human immunodeficiency virus (HIV)/AIDS. Registered dietitians/nutritionists can individualize diet interventions to optimize effectiveness in treating metabolic consequences of the HIV infection or highly active antiretroviral therapy. Nutrition management for individuals infected with HIV can be helpful in maintaining lean body weight, combating oxidative stress, reducing complications from hyperglycemia and hyperlipidemia, and managing gastrointestinal function. Consideration should be given to including the expertise of a registered dietitian/nutritionist.

Doubly Labeled Water Method and Accelerometer for the Measurement of Energy Expenditure in Human Immunodeficiency Virus-Infected Patients

BACKGROUND

Several studies have reported increased resting energy expenditure (REE) in human immunodeficiency virus (HIV)-infected patients with HIV-associated lipodystrophy syndrome (HALS). However, limited data exist on the total energy expenditure (TEE). This study was aimed at evaluating the REE and TEE of HIV-infected patients with and without HALS by using the doubly labeled water (DLW) technique and the activity monitor based on accelerometry system (AM), and comparing the results obtained using both methods.

METHODS

Evaluated total of 45 HIV+ men undergoing antiretroviral therapy, including 18 LIPO- (without lipodystrophy) and 27 LIPO+ (with lipodystrophy) individuals were evaluated. Habitual physical activity patterns were measured by using the ActivPAL™ AM system, REE by indirect calorimetry, and TEE by DLW and AM.

RESULTS

No significant differences were found between LIPO- and LIPO+ in REE (1,433 ± 196 vs. 1,510 ± 203 kcal), TEE-DLW (2,691 ± 856 vs. 2,618 ± 415 kcal) and TEE-AM (2,560 ± 458 vs. 2,594 ± 456 kcal), respectively. RQ was a predictor of REE in LIPO+. TEE estimated by the AM had a moderate correlation with DLW, but there was a wide variance in the intra-subject results.

CONCLUSIONS

TEE is not increased in HIV-infected patients with HALS. AM should be used with caution for TEE evaluation during clinical practice.

Physical activity and capacity at initiation of antiretroviral treatment in HIV patients in Ethiopia

SUMMARY We described levels of habitual physical activity and physical capacity in HIV patients initiating antiretroviral treatment in Ethiopia and assessed the role of HIV and nutritional indicators on these outcomes. Physical activity energy expenditure (PAEE) and activity levels were measured with combined heart rate and movement sensors. Physical capacity was assessed by grip strength, sleeping heart rate and heart rate economy. Grip strength data was also available from a sex- and age-matched HIV-negative reference group. Median PAEE was 27.9 (interquartile range 17.4-39.8) kJ/kg per day and mean ± s.d. grip strength was 23.6 ± 6.7 kg. Advanced HIV disease predicted reduced levels of both physical activity and capacity; e.g. each unit viral load [log(1+copies/ml)] was associated with -15% PAEE (P < 0.001) and -1.0 kg grip strength (P < 0.001). Grip strength was 4.2 kg lower in patients compared to HIV-negative individuals (P < 0.001). Low body mass index (BMI) predicted poor physical activity and capacity independently of HIV status, e.g. BMI <16 was associated with -42% PAEE (P < 0.001) and -6.8 kg grip strength (P < 0.001) compared to BMI ≥18.5. The study shows that advanced HIV and malnutrition are associated with considerably lower levels of physical activity and capacity in patients at initiation of antiretroviral treatment.

Nutrition and the HIV-associated lipodystrophy syndrome

HIV-associated lipodystrophy syndrome (HALS), comprising metabolic and morphological alterations, is a known side effect of highly active antiretroviral therapy (HAART). Evidence for the role of nutrition in the management of the systemic parameters of HALS is currently limited. In the present paper we review the current knowledge base surrounding HALS, focusing particularly on the role of nutrition in mitigating the systemic parameters of the syndrome. Reported prevalence of HALS was found to vary from 9 to 83 % due to lack of a standardised definition, as well as variations in assessment methods and in the study population used. HALS is associated with both morphological (lipoatrophy, lipohypertrophy) and metabolic (dyslipidaemia, glucose intolerance, diabetes, hypertension, endothelial dysfunction and atherosclerosis) alterations, which may occur singly or in combination, and are associated with an increased risk of CVD. HAART-induced adipocyte inflammation, oxidative stress and macrophage infiltration, as well as altered adipocyte function and mitochondrial toxicity, have been shown to be central to the development of HALS. The adipocyte, therefore, represents a plausible target for treatment. Pharmacological and surgical treatment interventions have shown effect. However, their use is associated with numerous adverse effects and complications. Targeted lifestyle interventions may provide a useful alternative for managing HALS owing to their safety and tolerability. A Mediterranean-style diet has been found to be effective in improving the systemic parameters of HALS. Furthermore, the effects of n-3 PUFA supplementation are encouraging and future randomised controlled trials investigating the beneficial effects of n-3 PUFA in HALS are justified.

Hypermetabolism and altered substrate oxidation in HIV-infected patients with lipodystrophy

OBJECTIVE

Human immunodeficiency virus type 1 (HIV)-associated lipodystrophy syndrome compromises body composition and produces metabolic alterations, such as dyslipidemia and insulin resistance. This study aims to determine whether energy expenditure and substrate oxidation are altered due to human HIV-associated lipodystrophy syndrome.

METHODS

We compared energy expenditure and substrate oxidation in 10 HIV-infected men with lipodystrophy syndrome (HIV+LIPO+), 22 HIV-infected men without lipodystrophy syndrome (HIV+LIPO-), and 12 healthy controls. Energy expenditure and substrate oxidation were assessed by indirect calorimetry, and body composition was assessed by dual-energy X-ray absorptiometry. The substrate oxidation assessments were performed during fasting and 30 min after eucaloric breakfast consumption (300 kcal).

RESULTS

The resting energy expenditure adjusted for lean body mass was significantly higher in the HIV+LIPO+ group than in the healthy controls (P = 0.02). HIV-infected patients had increased carbohydrate oxidation and lower lipid oxidation when compared to the control group (P < 0.05) during fasting conditions. After the consumption of a eucaloric breakfast, there was a significant increase in carbohydrate oxidation only in the HIV+LIPO- and control groups (P < 0.05), but there was no increase in the HIV+LIPO+ group.

CONCLUSION

Hypermetabolism and alteration in substrate oxidation were observed in the HIV+LIPO+ group.

Energy expenditure in HIV infection

Energy intake recommendations for adults should be based preferably on direct measurements of total daily energy expenditure (TDEE) in corresponding populations who are maintaining healthy body weight and satisfactory physical activity levels. During adolescence, pregnancy, and lactation, energy requirements should be based on TDEE plus the additional energy required to advance these physiologic states. With illness, energy expenditure and energy intake change, but nutritional intervention is not necessarily beneficial. This article reviews data on energy expenditure in HIV infection with a focus on adults, adolescents aged ≥14 y, and pregnant and lactating women. Resting energy expenditure (REE) in adults with untreated asymptomatic HIV is ~ 10% higher than in healthy control subjects. In asymptomatic adults receiving antiretroviral therapy, REE may be similarly increased. HIV wasting and secondary infections are also associated with increased REE. In contrast, TDEE is typically normal in asymptomatic HIV and decreased in HIV wasting and secondary infection. No direct measurements of REE or TDEE are available in adolescents or in pregnant or lactating women with HIV. On the basis of current data, energy intake may need to increase by ~ 10% in adults with asymptomatic HIV to maintain body weight. In adolescents and in pregnant and lactating women with asymptomatic HIV, energy requirements should approximate recommendations for their uninfected counterparts until further data are available. In the resource-rich world, the energy expenditure changes associated with HIV are unlikely to contribute to significant weight loss. More data are needed on energy expenditure in HIV-infected populations from developing nations, where concurrent malnutrition and coinfections are common.

Brown fat activity is not apparent in subjects with HIV lipodystrophy and increased resting energy expenditure

The HIV lipodystrophy (LD) syndrome is associated with increased resting energy expenditure (REE), but the basis of this hypermetabolism has not been determined. The objective of this pilot study was to determine if brown fat is activated in subjects with HIV LD and increased REE. In this descriptive study of four subjects with HIV LD and marked hypermetabolism, REE was measured by indirect calorimetry and brown fat activity was determined by (18)F-fluorodeoxyglucose (FDG) positron-emission tomography (PET) combined with anatomic computed tomography (CT). Brown fat activity was not apparent in any subject with HIV LD and resting hypermetabolism. Therefore, brown fat activation is unlikely to be the principal cause of the increased REE associated with the HIV LD syndrome. Evidence of adaptive thermogenesis has been demonstrated in this syndrome, but this study suggests that tissues other than brown adipose tissue (BAT) are responsible. Further understanding of the chronic hypermetabolism associated with HIV LD could provide new insights into the regulation of energy balance.

Dual-energy X-ray absorptiometry modeling to explain the increased resting energy expenditure associated with the HIV lipoatrophy syndrome

BACKGROUND

The HIV lipoatrophy syndrome is characterized by loss of subcutaneous fat and is associated with increased resting energy expenditure (REE). Recently, dual-energy X-ray absorptiometry (DXA) modeling of organ-tissue mass combined with specific organ-tissue metabolic rates has been used to gain further insight into the relation of the lean body mass to REE and to better understand differences in REE between groups.

OBJECTIVE

This study examined the organ-tissue basis of the increased REE shown in HIV lipoatrophy.

DESIGN

REE was measured in 29 HIV-infected patients with lipoatrophy and in 29 HIV-infected and 19 healthy control subjects. Five organ-tissue mass components (brain, bone, skeletal muscle, adipose tissue, and residual mass) were calculated with the use of DXA modeling and body weight.

RESULTS

DXA modeling showed no significant differences in predicted REE between the 3 groups. However, measured REE was significantly greater in subjects with lipoatrophy than in control subjects. Measured REE remained significantly greater in lipoatrophy subjects after routine adjustment for lean body mass and after adjustment for each organ-tissue mass component. Finally, DXA and regression modeling of REE suggests that increased energy expenditure in skeletal muscle may account for the resting hypermetabolism of patients with HIV lipoatrophy.

CONCLUSIONS

Increased REE in subjects with HIV lipoatrophy cannot be explained by differences in organ-tissue mass as modeled by DXA. Instead, DXA and regression modeling of REE suggests that skeletal muscle is hypermetabolic in patients with HIV lipoatrophy. This may be a form of adaptive thermogenesis in response to an inability to store triglyceride fuel in a normal manner.

Fat distribution and longitudinal anthropometric changes in HIV-infected men with and without clinical evidence of lipodystrophy and HIV-uninfected controls: a substudy of the Multicenter AIDS Cohort Study

BACKGROUND

Fat abnormalities are common among HIV-infected persons, but few studies have compared regional body fat distribution, including visceral fat, in HIV-infected and HIV-uninfected persons and their subsequent trajectories in body composition over time.

METHODS

Between 1999 and 2002, 33 men with clinical evidence of lipodystrophy (LIPO+), 23 HIV-infected men without clinical evidence of lipodytrophy (LIPO-), and 33 HIV-uninfected men were recruited from the four sites of the Multicenter AIDS Cohort Study (MACS). Participants underwent dual-energy x-ray absorptiometry, quantitative computerized tomography of the abdomen and thigh, and circumference measurements of the waist, hip and thigh. Circumference measurements at each semi-annual MACS visit between recruitment and 2008 were used to compare average annual anthropometric changes in the 3 groups.

RESULTS

Body mass index (BMI) was lower in LIPO+ men than in the LIPO- men and the HIV- uninfected controls (BMI: 23.6 +/- 0.4 vs 26.8 +/- 1.5 vs 28.7 +/- 0.9 kg/m(2), respectively, p < 0.001). The average amount of visceral adipose tissue (VAT) was similar in all three groups (p = 0.26), but after adjustment for BMI, VAT was higher in the LIPO+ group (169 +/- 10 cm(2)) compared to the LIPO- men (129 +/- 12 cm(2), p = 0.03) and the HIV-uninfected group (133 +/- 11 cm(2), p = 0.07). Subcutaneous adipose tissue (thigh, abdomen) and total extremity fat were less in the HIV-infected men (LIPO+ and LIPO-) than in the HIV-uninfected men. Over an average of 6 years of follow-up, waist circumference increased at a faster rate in LIPO+ group, compared to the LIPO- men (0.51 cm/year vs 0.08 cm/year, p = 0.02) and HIV-uninfected control men (0.21 cm/year, p = 0.06). The annual changes in hip and thigh circumferences were similar in all three groups

CONCLUSION

Subcutaneous lipoatrophy was observed in HIV-infected patients, even those without clinical evidence of lipodystrophy, compared to age-matched HIV-uninfected men. Despite markedly lower BMI, HIV-infected men with lipodystrophy had a similar amount of VAT as HIV-uninfected men and tended to have more rapid increases in waist circumference over 6 years of follow-up. These longitudinal increases in waist circumference may contribute to the development of cardiovascular risk in HIV-infected patients with lipodystrophy.

Dysregulated Energy Expenditure in HIV-Infected Patients: A Mechanistic Review

Metabolic abnormalities are common in patients with human immunodeficiency virus (HIV) infection and range from protein catabolism to lipodystrophy and dyslipidemia associated with the use of highly active antiretroviral therapy. One abnormality is increased resting energy expenditure, which even occurs in clinically stable HIV-infected patients. Increased resting energy expenditure may aggravate the tendency towards weight loss and wasting, which are independent predictors of mortality. Despite much investigation, the factors associated with altered resting energy expenditure remain unclear; viral load, CD4 cell count, use of antiretroviral drugs, body composition, hormones, and proinflammatory cytokines have been imputed. Mechanisms that could explain increased resting energy expenditure include the HIV accessory protein viral protein R, antiretroviral drugs that affect mitochondrial function, and futile cycling within adipocytes. Other components of energy expenditure are also important to overall energy balance and may also be affected. Identifying unifying mechanisms will be an important step to finding effective treatments for HIV-related alterations in energy expenditure and to reversing metabolic risks in patients with HIV infection.

Increased resting energy expenditure, fat oxidation, and food intake in patients with highly active antiretroviral therapy-associated lipodystrophy

Highly active antiretroviral therapy (HAART) is associated with metabolic adverse events such as lipodystrophy in human immunodeficiency virus (HIV)-infected patients. The objective of the present study was to evaluate the effects of HAART-associated lipodystrophy on resting energy expenditure and caloric intake. In this cross-sectional study we compared resting energy expenditure (REE) and energy intake in 30 HAART-treated patients with lipodystrophy (HAART+LD+) with 13 HAART-treated patients without lipodystrophy (HAART+LD-). REE was measured using indirect calorimetry, and energy intake was recorded as a 3-day diary of food intake. REE (5,180+/-160 vs. 4,260+/-150 J/min, P<0.01) and also REE expressed per fat-free mass (86+/-1 vs. 78+/-2 J.kg fat-free mass-1.min-1, P<0.01) were significantly higher in the HAART+LD+ than the HAART+LD- group. Rate of lipid oxidation was significantly higher in the HAART+LD+ than the HAART+LD- group. Total energy and fat intakes were significantly increased in the HAART+LD+ compared with the HAART+LD- group. These results imply that HAART-associated lipodystrophy is associated with increased REE and lipid oxidation and with increased caloric and fat intake.

Short-term energy restriction reduces resting energy expenditure in patients with HIV lipodystrophy and hypermetabolism

We have previously shown that resting energy expenditure (REE) is increased in patients with HIV lipodystrophy. This hypermetabolism could be the result of an inadequate storage capacity for lipid fuel secondary to atrophy of the subcutaneous adipose tissue depot. Therefore, energy restriction may be able to alleviate this hypermetabolism. To test this hypothesis, we measured REE in HIV-infected patients with lipodystrophy and hypermetabolism and in HIV-infected and healthy controls. Measurements were taken during the overnight fasted state after 3 days on a eu-energetic diet and again after 3 days on a diet of similar composition but reduced in energy by 50%. After 3 days of eu-energetic feeding, REE was significantly higher in HIV-infected patients with lipodystrophy compared with healthy controls (139.5 +/- 1.3 vs 117.2 +/- 1.3 kJ/kg lean body mass, P < .001) and tended to be higher compared with HIV-infected subjects without lipodystrophy (139.5 +/- 13 vs 127.3 +/- 1.4 kJ/kg lean body mass, P = .06). Furthermore, energy restriction caused a significant decline in REE in patients with HIV lipodystrophy (P < .001). This dietary manipulation did not lead to a significant reduction in REE in either HIV-infected or healthy controls. This suggests that energy intake and REE may be uniquely coupled in patients with lipodystrophy as a means to dissipate energy that cannot be stored in a normal manner. A better understanding of this coupling would have important implications for weight regulation in general.

Effects of transgenic expression of HIV-1 Vpr on lipid and energy metabolism in mice

HIV infection is associated with abnormal lipid metabolism, body fat redistribution, and altered energy expenditure. The pathogenesis of these complex abnormalities is unclear. Viral protein R (Vpr), an HIV-1 accessory protein, can regulate gene transcription mediated by the glucocorticoid receptor and peroxisome proliferator-activated receptor-gamma and affect mitochondrial function in vitro. To test the hypothesis that expression of Vpr in liver and adipocytes can alter lipid metabolism in vivo, we engineered mice to express Vpr under control of the phosphoenolpyruvate carboxykinase promoter in a tissue-specific and inducible manner and investigated the effects of dietary fat, indinavir, and dexamethasone on energy metabolism and body composition. The transgenic mice expressed Vpr mRNA in white and brown adipose tissues and liver and immunoaffinity capillary electrophoresis revealed that they had free Vpr protein in the plasma. Compared with wild-type (WT) animals, Vpr mice had lower plasma triglyceride levels after 6 wk (P < 0.05) but not after 10 wk of a high-fat diet and lower plasma cholesterol levels after 10 wk of high-fat diet (P < 0.05). Treatment with dexamethasone obviated group differences, whereas indinavir had no significant independent effect on lipids. In the fasted state, Vpr mice had a higher respiratory quotient than WT mice (P < 0.05). These data provide the first in vivo evidence that HIV-1 Vpr expressed at low levels in adipose tissues and liver can 1) circulate in the blood, 2) regulate lipid and fatty acid metabolism, and 3) alter fuel selection for oxidation in the fasted state.

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.