In HIV patients with lipoatrophy, antioxidants lead to only modest improvement in LDL cholesterol

Michael Carter
Estimated reading time 2 minutes
This article is more than 21 years old.

The use of antioxidants alongside a pre-existing HAART regimen by patients with lipoatrophy was associated with a trend to lower LDL cholesterol and a slight improvement in waist-to-hip ratio , but may also have led to increased insulin resistance, according to a small US study published in the August 15th edition of the Journal of Acquired Immune Deficiency Syndromes.

Oxidative stress is thought to contribute to lipoatrophy. Accordingly, investigators in Ohio recruited eight HAART-treated patients with lipoatrophy to a 24 week study to see if antioxidants improved body shape and lipids.

The patients all had a HIV viral load below 400 copies/mL, an average age of 42 years and a median CD4 cell count of over 600 cells/mm3. They remained on their existing HAART regimen and were prescribed 800/IU of vitamin E a day, with 1000mg of vitamin C and 600mg of N-acetyl cysteine twice daily.

Glossary

p-value

The result of a statistical test which tells us whether the results of a study are likely to be due to chance and would not be confirmed if the study was repeated. All p-values are between 0 and 1; the most reliable studies have p-values very close to 0. A p-value of 0.001 means that there is a 1 in 1000 probability that the results are due to chance and do not reflect a real difference. A p-value of 0.05 means there is a 1 in 20 probability that the results are due to chance. When a p-value is 0.05 or below, the result is considered to be ‘statistically significant’. Confidence intervals give similar information to p-values but are easier to interpret. 

insulin

A hormone produced by the pancreas that helps regulate the amount of sugar (glucose) in the blood.

cholesterol

A waxy substance, mostly made by the body and used to produce steroid hormones. High levels can be associated with atherosclerosis. There are two main types of cholesterol: low-density lipoprotein (LDL) or ‘bad’ cholesterol (which may put people at risk for heart disease and other serious conditions), and high-density lipoprotein (HDL) or ‘good’ cholesterol (which helps get rid of LDL).

lipoatrophy

Loss of body fat from specific areas of the body, especially from the face, arms, legs, and buttocks.

antioxidant

A vitamin, mineral or drug which can reduce the activity of free radicals, the unpaired electrons produced as a consequence of burning energy in a cell.

Viral load remained undetectable and average CD4 cell counts were unchanged at the end of the study. However, neither the study doctors, study dietitian, not patients noticed any improvement in peripheral fat loss. Nor did fasting triglycerides or HDL cholesterol change significantly. There was however a trend to lower LDL cholesterol, down from 124mg/dL at baseline to 102mg/dL at week 24 (p=0.006).

Hip-to-waist ratio also decreased from 0.94 to 0.92 by week 24 (p=0.05), however, fasting glucose increased significantly from a median of 84mg/dL at baseline to 110mg/dL at the end of the study (p=0.017), and fasting insulin trended upwards (14.2IU/mL at baseline to 54IU/mL at week 24, p=0.1). A homoestatic model for insulin resistance suggested that insulin sensitivity increased significantly, from 2.75 at entry to 7.20 at week 24 (p=0.03).

The investigators comment, “these findings are of concern, and suggest increased insulin resistance.” However, the trend towards lower LDL cholesterol and waist to hip ratio are described as “encouraging.” The investigators acknowledge limitations in their study, not least that they did not use CT or MRI scans to measure body fat, and could therefore have failed to notice small improvements in body shape. They conclude “controlled studies are required to evaluate directly the effects of [antioxidant] agents on lipid and glucose metabolism.”

Further information on this website

Body fat and metabolic changes whilst on treatment - menu of information

Lipodystrophy - factsheets

Lipodystrophy - booklet in the information for HIV-positive people series (pdf)

References

McComsey G et al. Effects of antioxidants on glucose metabolism and plasma lipids in HIV-infected subjects with lipoatrophy. JAIDS 33: 605 – 07, 2003.

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