Table 3.

Multivariable Linear Regression Model for the Relationship of Insulin Resistance with Selected Plasma Metabolites in HIV-Positive Subjects

Outcome variable	Regression coefficient (95% CI)	p
BCAA
Isoleucine	0.07 (−0.02 to 0.16)	.13
Leucine	0.04 (−0.05 to 0.14)	.36
Valine	0.05 (−0.04 to 0.15)	.29
Aromatic amino acids
Phenylalanine	0.04 (−0.02 to 0.11)	.19
Tyrosine	0.12 (0.06 to 0.18)	<.001
Gluconeogenic amino acids
Alanine	0.0008 (−0.07 to 0.07)	.98
Glutamine	−0.01 (−0.09 to 0.06)	.69
Glutamic acid	0.13 (0.05 to 0.21)	.001
BCAA metabolism acylcarnitinesa
Propionyl (C3)	0.12 (0.03 to 0.21)	.01
Isovaleryl (C5)	0.08 (−0.02 to 0.18)	.12
2-Methylbutyryl (C5)	0.009 (−0.07 to 0.09)	.83
Acetyl-carnitine (fully oxidized degradation product)
C2	−0.06 (−0.12 to −0.006)	.03
C2:C3+C5 ratio	−0.11 (−0.19 to −0.03)	.006
Medium and long-chain acylcarnitines
C10	−0.05 (−0.10 to −0.004)	.04
C10-OH	−0.07 (−0.12 to −0.03)	.003
C12	−0.05 (−0.10 to −0.004)	.03
C14	−0.06 (−0.14 to 0.009)	.08
C14:1	−0.06 (−0.12 to 0.008)	.03
C14:2	−0.05 (−0.11 to 0.004)	.07
C16	−0.08 (−0.14 to −0.009)	.03
C16:2	−0.003 (−0.06 to 0.05)	.91
C18	−0.10 (−0.18 to −0.02)	.01
C18:1	−0.11 (−0.17 to −0.04)	.002
C18:2	−0.06 (−0.14 to 0.02)	.16
Acylcarnitine-to-FFA ratio
C14 acylcarnitine:C14FFA	−0.02 (−0.09 to 0.05)	.61
C16 acylcarnitine:C16 FFA	−0.09 (−0.17 to −0.008)	.03
C18 acylcarnitine:C18FFA	−0.09 (−0.15 to −0.04)	.002

Multivariable model adjusted for age, sex, CD4⁺ count at enrollment (square root transformed), duration of antiretroviral treatment, smoking status, and fat mass index. The dependent variable (HOMA2) was log-transformed. Regression coefficients represent the change in log(HOMA2) from the 25th to the 75th percentile of the metabolite. p-Values <.05 are shown in bold.

The results for all measured metabolites are shown in Supplementary Table S2.

^aC5 valeryl was excluded from the multivariable analyses as 29 subjects (41%) had a level below the 0.0025 μM limit of detection.

CI, confidence interval; FFA, free fatty acid.