1650. Trimethylamine N-oxide (TMAO) levels do not correlate with CD4+ cell count or HIV-1 RNA in HIV+ individuals
Session: Poster Abstract Session: HIV: Cardiovascular Disease in HIV
Saturday, October 10, 2015
Room: Poster Hall
Background:

HIV is associated with premature coronary artery disease (CAD). Recently, a gut microbiome-dependent phosphatidylcholine metabolite, trimethylamine N-oxide (TMAO), has been associated with CAD and mechanistically linked with CAD pathogenesis. However, the relationship between TMAO and both HIV indices and immunosuppression are uncertain.

Methods:

In this prospective study, we assessed demographic, HIV, and fasting metabolic indices. TMAO was analyzed with mass spectrometry. In 42 subjects, carotid intima media thickness (IMT) was measured by ultrasound.

Results:

We assessed 100 consenting HIV+ patients at Cleveland Clinic. The median (IQR) age was 48 (37.4, 52.9). 52 were black; 89 were male. The CD4+ cell counts were median (IQR) 480 (330, 1902) cells/ mm3. HIV-1 RNA were ≤50 copies/mL in 48 subjects and < 200 copies/mL in 74 subjects. Nadir CD4+ cell counts were median (IQR) 196 (64.5, 319.3) cells/ mm3.

TMAO levels were a mean (SD) of 5.06 (7.35) µM. TMAO levels did not correlate with CD4+ cell counts, nadir CD4+ cell count, or log HIV-1 RNA . TMAO levels correlated significantly (r=0.25, p=0.01) with C-reactive protein (hsCRP).  Mean (SD) total cholesterol, LDLc, and triglycerides were 187.2 (40.4), 115.0 (36.5), and 147.4 (74.6) mg/dL, respectively. TMAO did not correlate with total cholesterol, LDLc, or triglycerides. In the carotid IMT subgroup, mean (SD) IMT was 0.68 (+/-0.18) mm. 12 of 42 patients (29%) had plaque present; TMAO did not significantly differ between those with and without plaque.

The TMAO levels in the 7 subjects not receiving antiretroviral therapy (ART) tended to be higher than in the 93 subjects receiving ART, but did not reach statistical significance:  [mean (SD) =11.0 (22.7) vs. 4.6 (4.6) µM; P=0.49].

Conclusion:

In this pilot study of an HIV+ population that is not severely immunosuppressed; TMAO levels did not correlate with CD4+ cell counts or viral load. A trend towards higher levels of the gut-flora dependent CAD marker TMAO in untreated patients would be consistent with reported increased CAD risk with advanced HIV disease. Evaluation of TMAO levels in a larger or more immunosuppressed population, particularly with longitudinal outcome data for incident CAD risks, may add information regarding the microbiome’s effect on CAD risk in HIV+ individuals.

Marisa Tungsiripat, MD1, WH Wilson Tang, MD2, Byungwoo Choi, MD1, Jacqueline Fox, RN3 and Stanley L Hazen, MD, PhD4, (1)Cleveland Clinic Foundation, Cleveland, OH, (2)Cardiovascular Medicine, Cleveland Clinic, Cleveland, OH, (3)Medicine, Cleveland Clinic, Cleveland, OH, (4)Cell Biology, Cleveland Clinic, Cleveland, OH

Disclosures:

M. Tungsiripat, None

W. W. Tang, None

B. Choi, None

J. Fox, None

S. L. Hazen, None

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