metabolic complications of hiv infection and antiretroviral therapy (art) christopher behrens, md...
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Metabolic Complications of HIV Infection and Antiretroviral
Therapy (ART)
Christopher Behrens, MD
University of Washington
Metabolic Complications of HIV Infection and ART
• Lactic Acidemia
• Lipodystrophy
• Dyslipidemia
• Insulin Resistance
• Cardiovascular Disease
• Bone Mineralization Disorders
Lactic Acidemia & Lactic AcidosisDefinitions
• Lactic Acidemia: serum lactate level greater than 2.0 mmol/L in conjunction with a normal serum pH– Common in HIV-infected patients on ART– Varying degrees of severity– Often asymptomatic
• Lactic Acidosis: serum lactate level greater than 2.0 mmol/L in conjunction with a serum pH less than 7.30– Reflects most serious form of lactic acidemia– Rare but potentially fatal– Common signs & symptoms include lethargy, fatigue, weight loss,
nausea, abdominal pain, and dyspnea– Concomitant hepatotoxicity common with hepatomegaly, hepatic
steatosis, and even ascites and encephalopathy
Schambelan M et al. JAIDS 2002;31:257-75
Classification of Lactic Acidemia
*Symptoms and signs that suggest lactic acidemia consist of nausea, vomiting, abdominal pain, weight loss, fatigue, myalgias, abdominal distention, abdominal pain, dyspnea, and cardiac dysrhythmias.
Source: HIV Web Study (www.hivwebstudy.org); Schambelan M et al. JAIDS 2002;31:257-75
Proposed Pathophysiology of Lactic Acidemia
NRTI-induced mitochondrial toxicity
CELL
glucose
pyruvatelactate
Acetyl CoA Krebscycle
NADHFADH2
OxidativephosphorylationATP
NRTI-induced mitochondrial toxicity
Proposed Pathogenesis
MITOCHONDRION
Fatty Acids
CELL
glucose
pyruvatelactate
Acetyl CoA Krebscycle
NADHFADH2
OxidativephosphorylationATP
NRTI-induced mitochondrial toxicity Proposed Pathogenesis
MITOCHONDRION
mtDNADNA pol γ
Fatty Acids
CELL
glucose
pyruvatelactate
Acetyl CoA Krebscycle
NADHFADH2
OxidativephosphorylationATP
MITOCHONDRION
mtDNADNA pol γ
Fatty Acids
NRTIs
NRTI-induced mitochondrial toxicity Proposed Pathogenesis
CELL
glucose
pyruvatelactate
Acetyl CoA Krebscycle
NADHFADH2
OxidativephosphorylationATP
NRTI-induced mitochondrial toxicity
Proposed Pathogenesis
MITOCHONDRION
mtDNADNA pol γ
Fatty Acids
NRTIs
CELL
glucose
pyruvatelactate
Acetyl CoA Krebscycle
NADHFADH2
OxidativephosphorylationATP
NRTI-induced mitochondrial toxicity
Proposed Pathogenesis
MITOCHONDRION
mtDNADNA pol γ
Fatty Acids
NRTIs
CELL
glucose
pyruvatelactate
Acetyl CoA Krebscycle
NADHFADH2
OxidativephosphorylationATP
NRTI-induced mitochondrial toxicity Proposed Pathogenesis
MITOCHONDRION
mtDNADNA pol γ
Fatty Acids
NRTIs
CELL
glucose
pyruvatelactate
Acetyl CoA Krebscycle
NADHFADH2
OxidativephosphorylationATP
NRTI-induced mitochondrial toxicity
Proposed Pathogenesis
MITOCHONDRION
mtDNADNA pol γ
Fatty Acids
NRTIs
CELL
glucose
pyruvatelactate
Acetyl CoA Krebscycle
NADHFADH2
OxidativephosphorylationATP
NRTI-induced mitochondrial toxicity
Proposed Pathogenesis
MITOCHONDRION
mtDNADNA pol γ
Fatty Acids
NRTIs
NRTIs have different levels of mitochondrial toxicity
• Rank: ddC/ddI/d4T > 3TC > ZDV > ABC for effects on mitochondrial DNA polymerase gamma1
• Tenofovir has low affinity for mitochondrial polymerase gamma2
• However, cases of severe hyperlactatemia have been reported in association with all NRTIs3
1. Kakuda TN. Clin Ther 2000 Jun;22(6):685-7082. Johnson AA et al. J Biol Chem 2001 Nov 2;276(44):40847-57 3. Schambelan M et al. JAIDS 2002;31:257-75
Risk Factors for the Development of Lactic Acidemia in Persons Taking NRTIs
*Most cases have involved stavudine**Especially with the use of stavudine plus didanosine
Source: HIV Web Study (www.hivwebstudy.org)
Hyperlactatemia & Lactic AcidosisMeasuring Serum Lactate Levels
No vigorous exercise for 24 hours prior
Draw without tourniquet and fist clenching
Use pre-chilled gray top (fluoride-oxalate) tube
Place on ice and promptly send to lab; process within 4
hours
If increased, confirm with repeat measurement
Arterial pH measurement if frank acidosis suspected
Schambelan M et al. JAIDS 2002;31:257-75.
Recommendations for the Management of Lactic Acidemia
Source: HIV Web Study (www.hivwebstudy.org); Carr A. Clin Infect Dis 2003;36 (Suppl 2):S96-100.
Case• 44 year old male with C3 AIDS, well-controlled on ART
regimen of d4T/3TC/efavirenz• Develops severe lactic acidosis and is admitted to the ICU• Recovers with discontinuation of ART and supportive care,
but CD4 count now 290 cells/mm³, HIV viral load 66,000 copies/mL
• What are your recommendations regarding antiretroviral therapy?
1. Do not resume ART – continue to monitor2. Resume ART with efavirenz + lopinavir/ritonavir 3. Resume ART with TDF + 3TC + efavirenz4. Resume prior ART regimen, supplemented with L-
carnitine5. I don’t know; just tell me the answer and get on with the
talk
Resumption of Antiretroviral Therapy after Lactic Acidosis
• NRTI-sparing regimen? – Promising early results from trials of efavirenz +
lopinavir/ritonavir1
• Addition of mitochondrial-supporting compounds as prophylaxis against recurrent lactic acidosis?– Limited evidence of benefit in hastening recovery of
patients with lactic acidosis, but efficacy in preventing the condition has not been established2-4
• Re-initiation of therapy using ‘mitochondria-sparing’ NRTIs (tenofovir, abacavir, 3TC, AZT)? – Reasonably safe in two studies5,6
1. Allavena C et al. JAIDS 2005;39(3):300-306. 2. Fouty B et al. Lancet. 1998;352:291-2. 3. Lenzo NP et al. AIDS. 1997;11:1294-6.
4. Schramm C et al. Eur J Anaesthesiol. 1999;16:733-5. 5. Lonergan JT et al. AIDS. 2003;17:2495-9.6. ESS40010 Study Team. JAIDS. 2004;36:935-42.
Case• 44 year old male with C3 AIDS, well-controlled on ART
regimen of d4T/3TC/efavirenz• Develops severe lactic acidosis and is admitted to the ICU• Recovers with discontinuation of ART and supportive care,
but CD4 count now 290 cells/mm³, HIV viral load 66,000 copies/mL
• What are your recommendations regarding antiretroviral therapy?
1. Do not resume ART – continue to monitor2. Resume ART with efavirenz + lopinavir/ritonavir 3. Resume ART with TDF + 3TC + efavirenz4. Resume prior ART regimen, supplemented with L-
carnitine5. I don’t know; just tell me the answer and get on with the
talk
Lipodystrophy
Case 1
• 41 year old HIV-infected man on PI-based ART presents for routine follow-up
• Complains of recent weight gain, especially in the abdomen
• “It’s the protease paunch!”
Case 1 continued
• PMH: – HIV infection x 5 years
• Well-controlled on ART
• CD4 nadir = 140 cells/mm³, most recent = 360
• No OIs, though radiology studies have suggested HIV encephalopathy
– Hypertension
• Medications:– d4T + 3TC + lopinavir/ritonavir (Kaletra) x 2 years
– Enalapril 10mg qd
Case 1 continued
• PE: obese abdomen, otherwise unremarkable
What intervention would you recommend?
A. Ask his wife to padlock the fridge and get him a treadmill
B. Discontinue lopinavir/ritonavir, substitute an NNRTI such as efavirenz or nevirapine
C. Start metformin 500mg bidD. LiposuctionE. None of the above have been demonstrated
to improve HIV-associated visceral fat accumulation
HIV/ART Toxicities: Lipodystrophy
• Constellation of body habitus changes– Fat accumulation (lipohypertrophy): central (esp. visceral)
fat, dorso-cervical fat pad (buffalo hump), breasts, lipomata, within muscle & liver
– Fat wasting (lipoatrophy): face, extremities, buttocks, and trunk
• Lack of clear case definition has hampered clinical research: wide variation in reported prevalence
• Increasing evidence that lipoatrophy and lipohypertrophy are distinct entities, though can occur simultaneously
• Hyperlipidemia and insulin resistance also variably present
Facial lipoatrophy
Central adiposity
Peripheral lipoatrophy
Breast enlargement
Dorsocervical Fat Pad
FRAM Study: Defining Lipodystrophy
Study Outline• Aim: compare randomly selected HIV-infected
subjects and healthy controls to identify statistically significant differences and any linkages between lipodystrophic body changes
• Three types of evaluation:– Self-report re: body habitus changes
– Clinical evaluation of presence/degree of visible lipoatrophy
– Body composition measures including whole-body MRI and DEXA scanning
Grunfeld C. XIV International AIDS Conference, 2002, Abstract TuOr158.
FRAM: Defining Lipodystrophy• N = 565 men 33-45 years old
– 412 HIV+ w/o OIs in past month– 153 HIV-negative controls from
CARDIA study
• Examined fat loss/deposition in peripheral sites (cheeks, face, arms, legs, buttocks) and central sites (waist, abdomen, neck, chest, upper back)
• Peripheral and central lipoatrophy more common in HIV+ subjects
• Central lipohypertrophy more common in HIV-negative subjects
• Lack of concordance between lipoatrophy and lipohypertrophy
0
10
20
30
40
50
60
peripherallipoatrophy
centrallipoatrophy
central fatdeposition
HV positive
HIV negative
p < 0.05 for all
Results for concordant self-report & exam
% o
f pa
tien
ts
Gripshover B et al. 10th CROI, Boston, 2003, Abstract 732.
Lipodystrophy in Women: WIHS
• Women’s Interagency HIV Study (WIHS): prospective, multi-site study of progression of HIV infection in women
• 1,057 HIV-infected and HIV-uninfected women evaluated every 4 months over an 18-month period beginning in 1999
• Over 18 months, mean weight and total body fat increased slightly in HIV-negative women but remained stable in HIV-positive women
• Incidence of peripheral and central lipoatrophy in HIV-positive women was double that of HIV-negative women
• Incidence of central lipohypertrophy was similar in HIV-positive vs HIV-negative women
Tien PC et al. 10th CROI, Boston, 2003. Abstract 736.
Lipohypertrophy
Risk Factors
Pathophysiology
Interventions
Lipohypertrophy: Risk Factors
• Duration of antiretroviral therapy
• Use of protease inhibitors
• Markers of disease severity
• Age
• Female gender
Lichtenstein KA. JAIDS 2005;39:395-400.
Incidence & Size of Buffalo Humps
0
5
10
15
20
25
incidence of buffalo hump (%)
HIV-infected
HIV-negative
0
10
20
30
40
50
60
70
80
buffalo hump size (cm2)
HIV-infected
HIV-negative
N = 421 HIV(+) men vs 151 matched HIV(-) controls (FRAM cohort)
% o
f pa
tien
ts
Zolopa A et al. 10th CROI, Boston 2003, Abstract 734.
p = NS p <0.001
Lipohypertrophy: Pathophysiology
Lipohypertrophy: Treatment Options
• Diet/exercise1-4
1. Jones SP et al. AIDS 2001 Oct 19;15(15):2049-51 2. Roubenoff R et al. Clin Infect Dis 2002 Feb 1;34(3):390-33. Roubenoff R et al. AIDS. 1999;13:1373-1375.4. Thoni GJ et al. Diabetes Metab. 2002;28:397-404.
Lipohypertrophy: Treatment Options
• Diet/exercise
• Switching protease inhibitors out of ART regimen: inconsistent results
Drechsler H, Powderly WG. Clin Infect Dis. 2002;35:1219-1230.
Lipohypertrophy: Treatment Options
• Diet/exercise
• Switching protease inhibitors out of ART regimen: inconsistent results
• Diabetes agents?– Patients with lipodystrophy often
demonstrate insulin resistance as well
• N = 26 patients on ART with insulin resistance and fat redistribution
• Randomized to metformin or placebo for 12 weeks
1191
-1115-1500
-1000
-500
0
500
1000
1500
Placebo
Metformin
Hadigan C et al. JAMA 2000;284:472-7.
p = 0.08
Metformin Therapy for Lipohypertrophy?
Mea
n ch
ange
in v
isce
ral a
bdom
inal
fat
, mm
3
Lipohypertrophy: Treatment Options
• Diet/exercise
• Switching protease inhibitors out of ART regimen: inconsistent results
• Diabetes agents?
• Plastic surgery?
Surgical Correction ofBuffalo Hump?
• Liposuction or surgical excision a reasonable option, esp. if pain or functional limitations
• Only small studies to date• Generally well-tolerated
with favorable initial results • Conflicting data regarding
recurrence: one study found a recurrence rate of just 5% (1/18 patients)1 while another study reported a recurrence rate of 50% (5/10 patients)2
1. Gervasoni C et al. 10th CROI, Boston, 2003. Abstract 723.2. Piliero PJ et al. 10th CROI, Boston, 2003. Abstract 724.
What intervention would you recommend?
A. Ask his wife to padlock the fridge and get him a treadmill
B. Discontinue lopinavir/ritonavir, substitute an NNRTI such as efavirenz or nevirapine
C. Start metformin 500mg bidD. LiposuctionE. None of the above have been demonstrated
to improve HIV-associated visceral fat accumulation
Case 2: Lipoatrophy
• 43 year old woman with history of PCP now doing well on ART: d4T/3TC/lopinavir/ ritonavir
• She complains that her cheeks appear sunken and the veins in her arms and legs are more prominent
What intervention would you recommend for her condition?
A. Discontinue lopinavir/ritonavir, substitute atazanavir or an NNRTI
B. Discontinue d4T, substitute abacavir or tenofovir
C. Initiate rosiglitazone therapy
D. Plastic surgery: facial injections
E. None of these interventions is likely to help
Lipoatrophy: Risk Factors• Antiretroviral therapy
– ART, esp. 2 NRTIs plus PI– d4T, esp. when used with ddI– Hierarchy: d4T/ddI/ddC > AZT > TDF/ABC/3TC
• Prior AIDS diagnosis• Lower CD4 nadir• Lower body weight before ART• Caucasian race• Male gender• Older age
Grinspoon S et al. N Engl J Med 2005;352:48-62.Podzamczer D et al. 11th CROI, 2004, Abstract 716.
Lichtenstein KA et al. JAIDS 2003;32:48-56.Joly V et al. AIDS 2002;16:2447-2454.
Dube M et al. 4th Int’l Workshop on Adverse Drug Reactions and Lipodystrophy in HIV, 2002, abstract 27.Shlay J et al. XV International AIDS Conference, 2004, Abstract ThOrB1360.
J Acquir Immune Defic Syndr 2002 February 1;29(2):117-121
? Etiology of Lipoatrophy: Evidence of Mitochondrial Toxicity in Adipocytes
These are your mitochondria These are your mitochondria on ARVs
Lipoatrophy: Treatment Options
• Switching d4T out of regimen: evidence for slow reversal of lipoatrophy
Abacavir substitution for patients with subcutaneous lipoatrophy (LA): MITOX
• 111 patients with subjective LA on stable AZT- or d4T- containing ART randomized to substitute abacavir or continue current regimen1
• Limb fat mass measured by DEXA and by subjective physician assessment
• Statistically significant increase in limb fat mass by DEXA at 104 weeks of follow-up2
• Similar findings from other studies3,4,5
1. JAMA 2002;288(2): 207-15.2. AIDS 2004;18:1029-36.3. CID 2004;38:263-270.
4. JAIDS 2003;33:22-8.5. JAIDS 2003;33:29-33.
Mean change in limb fat mass (intention-to-treat analysis)
Lipoatrophy: Treatment Options
• Switching d4T out of regimen: evidence for slow reversal of lipoatrophy
• Diabetes agents?
- Rosiglitazone increases subcutaneous fat in type 2 diabetic patients and reverses the block of adipocyte differentiation induced by ART in vitro
Rosiglitazone for Lipoatrophy?Discouraging results to date
• N=108 HIV-1-infected adults with LA on ART randomized to rosiglitazone 4 mg twice daily (n=53) or matching placebo (n=55) for 48 weeks1
• Limb fat increased by 0.14 kg in the rosiglitazone group and 0.18 kg in the placebo group (p=NS)
• Two other similar studies:– One showed no
improvement2
– One showed modest benefit3
1. Carr A et al. Lancet. 2004;363:429-438. 2. Sutinen J et al. Antivir Ther 2003;8:199-207. 3. Hadigan C et al. Ann Intern Med 2004;140:786-794.
Change in limb fat by DEXAwww.clinicaloptions.com
Lipoatrophy: Treatment Options
• Switching d4T out of regimen: evidence for slow reversal of lipoatrophy
• Diabetes agents?
• Facial injections?– Intradermal injections of
polylactic acid
Valantin MA et al. AIDS 2003, 17:2471–2477
VEGA: 96 week results
Valantin MA et al. AIDS 2003, 17:2471–2477
What intervention would you recommend for her condition?
A. Discontinue lopinavir/ritonavir, substitute atazanavir or an NNRTI
B. Discontinue d4T, substitute abacavir or tenofovir
C. Rosiglitazone
D. Plastic surgery: facial injections
E. None of these interventions are likely to help
Dyslipidemia
Dyslipidemia: Case continued
• He returns for followup 3 months later and reports some improvement with increased physical activity
• You check a fasting lipid panel
Case continued
• Fasting lipid panel• Total cholesterol = 320 mg/dL• Triglycerides= 870 mg/dL• HDL cholesterol = 32 mg/dL• LDL cholesterol: could not be calculated
What intervention(s) would you recommend to improve his lipid profile?
A. Discontinue lopinavir/ritonavir, substitute atazanavir
B. Discontinue d4T, substitute tenofovir
C. Ask his employer to replace the donuts in the vending machine with granola
D. Start simvastatin
E. Start gemfibrozil
F. Nothing needs to be done; dyslipidemia associated with HIV/ART is not associated with an increase in CAD
• Decreased levels of HDL & LDL (especially HDL) and elevated triglycerides seen in HIV-infected patients prior to introduction of ART
• Most protease inhibitors have been associated with marked elevations in triglycerides and LDL but little effect on HDL levels
• NNRTIs and stavudine also associated with dyslipidemic effects
• HIV infection and PI-based ART each associated with pro-atherogenic profile dyslipidemia
• Substantial evidence that PI-based ART increases risk of coronary artery disease (CAD)2-4
HIV/ART Toxicities: Dyslipidemia
1. Schambelan M et al. JAIDS 2002; 31(3):257-75.2. 11th CROI, 2004, Abstract 739.
3. 11th CROI, 2004, Abstract 736.4. 11th CROI, 2004, Abstract 737.
The DAD Study Group, N Engl J Med 2003;349:1993-2003
Incidence of Myocardial Infarction According to the Duration of Exposure to Combination Antiretroviral Therapy
Risk Factors for MI in patients on ART: DAD
Use of ART (per additional year) 1.26**
Age (per additional 5 yrs) 1.38
Male Sex 1.99
Current or former smoker 2.17
Prior history of CAD 5.84
Risk Factor Relative Risk of MI*
The DAD Study Group, N Engl J Med 2003;349:1993-2003
* Multivariate analysis** revised to 1.17 on further follow-up
• Often improves with removal of offending agents from regimen
• Treatment with fibrates and/or statins often indicated
• Beware of drug interactions, risk of myositis
ART- associated Dyslipidemia: Treatment
Switch ART regimen or initiate lipid-lowering pharmacotherapy?
Trend of mean plasma triglyceride levels of 130 evaluable patients switched from protease inhibitor to nevirapine (arm A) or efavirenz (B), or treated with pravastatin (C) or bezafibrate (D), at baseline and after 3, 6, 9 and 12 months of follow-up. Calza L et al. AIDS 2005: 19(10), 1051-8.
Switch ART regimen or initiate lipid-lowering pharmacotherapy?
Trend of mean plasma total cholesterol levels of 130 evaluable patients switched from protease inhibitor to nevirapine (arm A) or efavirenz (B), or treated with pravastatin (C) or bezafibrate (D), at baseline and after 3, 6, 9, and 12 months of follow-up.
Calza L et al. AIDS 2005: 19(10), 1051-8.
Lipid-Lowering Agents and ARV Therapy:Potentially Dangerous Drug Interactions
Agent
Pravastatin
Atorvastatin
Lovastatin
Simvastatin
Gemfibrozil
Fenofibrate
Niacin
Bile sequestrants
No dose adjustment
Dose titration
Avoid
Avoid
No dose adjustment
No dose adjustment
Associated with insulin resistance
Avoid
Recommendation
Dube MP et al. Clin Infect Dis 2000;31:1216-24.
What intervention(s) would you recommend to improve his lipids?
A. Discontinue lopinavir/ritonavir, substitute atazanavir
B. Discontinue d4T, substitute tenofovir
C. Ask his employer to replace the donuts in the vending machine with granola
D. Start simvastatin
E. Start gemfibrozil
F. Nothing needs to be done, as studies have failed to document an increase in CAD in patients on ART
Insulin Resistance
Insulin Resistance (IR)
• Defined as condition in which increased levels of insulin are required to exert normal biologic response1
• Typically associated with increased fasting insulin levels, but clinically relevant thresholds of insulin levels have not been defined
• IR should be suspected in setting of elevated fasting blood glucose levels or impaired glucose tolerance
1. Olefsky JM. Ellenberg & Rifkin’s Diabetes Mellitus (1997):513-52.
American Diabetic Association: Prediabetes & DiabetesPre-diabetes
Diabetes mellitusImpaired fasting
glucoseImpaired glucose
tolerance
Fasting glucose 100-125 mg/dL
2-hour post-load glucose 140-199 mg/dL during OGTT
Fasting glucose ≥126 mg/dL or 2 hr post-load glucose ≥200mg/dL during OGTT, or symptoms of diabetes with random glucose ≥200mg/dL
Adapted from: http://clinicaloptions.com/2004lipo
HIV/ART Toxicities: Insulin Resistance
• Direct mechanism: medication-induced– PIs can have a direct effect on glucose metabolism1
– Indinavir leads to decreased insulin sensitivity in both HIV-infected and uninfected subjects2
– Amprenavir may not share this class effect3
– Efavirenz, but not nevirapine, implicated as well4
– NRTIs also recently identified as risk factor5
– Mechanism: • inhibition of an insulin-regulated glucose transporter GLUT4 ? 6
• Inhibition of peroxisome proliferator-activated receptor gamma? 7,8
1. Dube MP et al. JAIDS 2000;27:130-4.2. Noor MA et al. AIDS 2001;15:4.3. Dube MP et al. Antivir Ther 2001;6(4):11. Abst 14.4. Mehta et al, 9th CROI, 2002, Abstract 679.
5. Brown TT et al. AIDS 2005, 19:1375–13836. Murata H et al. J Biol Chem 2000;275:251-4.7. Caron M et al. Diabetes 2001;50:1378–888. Miserez AR et al. AIDS 2002;16:1587–94.
HIV/ART Toxicities: Insulin Resistance
• Indirect mechanism: via changes in body fat composition (lipohypertrophy, lipoatrophy) 1-4
1. Hadigan C et al. Clin Infect Dis 2001;32:130–9.2. Mynarcik DC et al. J Acquir Immune Defic Syndr 2000;25:312–21.3. Kosmiski LA et al. AIDS 2001;15:1993–2000.4. Meininger G et al. Am J Clin Nutr 2002;76:460–5.
www.clinicaloptions.com
Currier et al, 9th CROI, February 2002, abstract 677-T
Insulin resistance is associated with increased risk of CAD in non-HIV infected patients
www.clinicaloptions.com
Despres JP et al. N Engl J Med. 1996;334:952-957.
Insulin Resistance: Treatment
• Consider avoiding implicated PIs for patients with pre-existing diabetes or significant risk factors
• Substitution of PI with NNRTIs1,2 or abacavir3, if regimen potency can be maintained
• Treatment of diabetes mellitus: similar to that for HIV-uninfected individuals
• Screen for and treat insulin resistance?1. Martinez E et al. AIDS 1999;13:805–10.2. Martinez E et al. Clin Infect Dis 2000;31:1266–73.3. Walli RK et al. Eur J Med Res 2001;6:413–21.
Bone Mineralization Disorders associated with HIV and/or ART
Osteonecrosis
Osteopenia
Avascular Necrosis of the Femoral Head
Higher Prevalence of Osteonecrosis
in HIV-Infected Adults • Screening MRIs performed on 339 asymptomatic
HIV-infected adults and 118 age- and sex-matched HIV-negative controls
• Osteonecrosis of the femoral head identified in 15 of 339 (4.4%) HIV-infected patients compared to 0/118 controls (p<0.05)
• Comparison of HIV-infected patients with or without osteonecrosis showed no difference by age, sex, race, risk factor, CD4 cell count, viral load, antiretroviral therapy, blood lipids or CBC.
• The risk was increased for those who had received corticosteroids, lipid-lowering agents or testosterone.
Miller KD et al. Ann Intern Med 2002 Jul 2;137(1):17-25.
• Other studies of HIV-infected patients have found similar associations with steroid use and hyperlipidemia but not with the use of specific antiretroviral agents1,2
• Implication: consider this diagnosis in HIV-infected patients with shoulder, groin, or hip pain
1. Scribner AN et al. JAIDS 2000;25:19-25.2. Glesby MJ et al. JID 2001;184:519-23.
Higher Prevalence of Osteonecrosis in HIV-Infected Adults
Study Sample Prevalence* Risk Factors
Carr, 2001
Australia
221 HIV+ men,
Wt. 70-75 kg
25% Lactate level
low weight
Huang, 2001
Boston, MA
41 HIV+ men, BMI 25
18 HIV- men, BMI 25
BMD reduced in HIV+ men w/ high visceral fat
Historical low weight;
high visceral fat
McDermott, 2001
New England
203 HIV+ men, BMI 24
62 HIV+ women, BMI 25
BMC reduced in men on ART
ART use and duration
Knobel 2001
Spain
58 HIV+ men, 22 HIV+ women, BMI 23 overall
100 HIV- controls, BMI 23
89% in HIV+
30% in HIV-
Weight, BMI
Nolan, 2001
Australia
183 HIV+ men
BMI 23-24
56% in PI-treated;
49% in PI-naïve
Low pre-ART BMI;
Indinavir protective
Gold, 2002
Australia
110 HIV+ men
lean mass 57 kg
55% Age, lean body mass, duration of NRTI use
Mondy, 2003
St. Louis, MO
108 HIV+ men, 17 HIV+ women; BMI 25
46% BMI, smoking, wt loss, steroids
Arnsten, 2003
New York, NY
200 HIV+ women: BMI 28
205 HIV- women: BMI 32
30% in HIV+ 24% in HIV-
Age, race, BMI;
PI use >1 year protective
Studies on Osteopenia in HIV
Adapted from Arnsten JH et al, 10th CROI, Boston 2003, Abstract 103
* combined prevalence of osteopenia and osteoporosis
Alendronate for HIV-associated osteopenia: 48 week results
• N=31 HIV-infected subjects on ART with lumbar spine BMD t-scores less than -1.0
• 87% male, 80% Caucasian, 29% smokers, mean age 44 yo; mean BMI 25kg/m2
• Median CD4 count 561 cells/mm³; 84% had VL <400 copies/mL
• Randomized to alendronate 70 mg weekly (n=15) or placebo (n=16)
• All patients received calcium 1g daily and vit D 400 IU daily
• No serious adverse events
0
1
2
3
4
5
6
Spine Hip
placeboalendronate
p = 0.005
% c
han
ge f
rom
bas
elin
e in
BM
D
Mondy K et al. 10th CROI, Boston, 2003. Abstract 134.
p = NS
Metabolic Complications of HIV and ART
Summary & Conclusions
Hyperlactatemia/Lactic Acidosis
• Potentially fatal syndrome linked to prolonged NRTI use, especially ddI, d4T
• Signs and symptoms often subtle, nonspecific
• Venous lactate level useful in diagnosis
• Discontinuation of ART indicated for symptomatic hyperlactatemia/lactic acidosis
• Resumption of ART that includes NRTIs is controversial
Lipodystrophy• Lipoatrophy more common in HIV-infected individuals
and has been linked to markers of HIV disease severity and to d4T
• Switching out the offending agent appears to improve lipoatrophy, but very slowly
• Buffalo humps may be no more common in HIV-infected patients, but may be larger when they do occur
• Central fat deposition less common in HIV-infected individuals
• Diet, exercise are the most effective treatments for central fat accumulation
• Plastic surgery: short-term benefit; long term - ?
Dyslipidemia & ART
• Many antiretrovirals, especially protease inhibitors, associated with dyslipidemia
• ART-induced dyslipidemia may contribute to risk of coronary artery disease, though short-term absolute risk appears to be small
• Discontinuation of dyslipidemia-inducing agents will generally improve lipid profile
• ART-induced dyslipidemia can be treated with fibrates and/or statins, but response is often sub-optimal and potential drug interactions need to be considered carefully
• Linked to many protease inhibitors, efavirenz, and possibly some NRTIs
• Also linked to presence of lipodystrophy
• Progression to frank diabetes mellitus possible
• Monitor with fasting glucose values
• Improvement may or may not be seen with switching out of the offending agents
Insulin Resistance
HIV & Bone Disease
• Patients with HIV infection, especially Caucasian men, appear to be at increased risk of osteopenia
• Etiology not known at this time
• Role of ART overall and of individual ARV agents is unclear
• Routine screening not recommended
• Intervention warranted for modifiable risk factors such as smoking, alcohol, steroid use, hyperlipidemia, wasting, sedentary lifestyle, low calcium intake
• HIV-infected patients also at increased risk of osteonecrosis
• Consider diagnosis of osteonecrosis in patients with unexplained shoulder/hip/groin pain
The End