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Increased brain fatty acid uptake in metabolic syndrome.

Karmi A, Iozzo P, Viljanen A, Hirvonen J, Fielding BA, Virtanen K, Oikonen V, Kemppainen J, Viljanen T, Guiducci L, Haaparanta-Solin M, Någren K, Solin O, Nuutila P - Diabetes (2010)

Bottom Line: Both total and nonoxidized fractions of fatty acid uptake were associated with BMI.Rapid weight reduction decreased brain fatty acid uptake by 17%.Both fatty acid uptake and accumulation appear to be increased in MS patients and reversed by weight reduction.

View Article: PubMed Central - PubMed

Affiliation: Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland.

ABSTRACT

Objective: To test whether brain fatty acid uptake is enhanced in obese subjects with metabolic syndrome (MS) and whether weight reduction modifies it.

Research design and methods: We measured brain fatty acid uptake in a group of 23 patients with MS and 7 age-matched healthy control subjects during fasting conditions using positron emission tomography (PET) with [(11)C]-palmitate and [(18)F]fluoro-6-thia-heptadecanoic acid ([(18)F]-FTHA). Sixteen MS subjects were restudied after 6 weeks of very low calorie diet intervention.

Results: At baseline, brain global fatty acid uptake derived from [(18)F]-FTHA was 50% higher in patients with MS compared with control subjects. The mean percentage increment was 130% in the white matter, 47% in the gray matter, and uniform across brain regions. In the MS group, the nonoxidized fraction measured using [(11)C]-palmitate was 86% higher. Brain fatty acid uptake measured with [(18)F]-FTHA-PET was associated with age, fasting serum insulin, and homeostasis model assessment (HOMA) index. Both total and nonoxidized fractions of fatty acid uptake were associated with BMI. Rapid weight reduction decreased brain fatty acid uptake by 17%.

Conclusions: To our knowledge, this is the first study on humans to observe enhanced brain fatty acid uptake in patients with MS. Both fatty acid uptake and accumulation appear to be increased in MS patients and reversed by weight reduction.

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Related in: MedlinePlus

Left: Graphs show the results of brain white and gray matter uptake of [18F]-FTHA and [11C]-palmitate in the MS group before and after VLCD. P values were calculated using paired Student t test. *P value < 0.02; **P value of 0.009; NS, not significant; black bars, before VLCD; white bars, after VLCD. Right: Results from the voxel-based mapping analysis. Results are rendered on an anatomical brain model; red areas illustrate brain regions where [18F]-FTHA uptake was significantly reduced after dieting among MS patients (Tmax = 4.21 at (−66, −22, 48), kE = 161,315, cluster-level corrected P < 0.0005). (A high-quality digital representation of this figure is available in the online issue.)
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Figure 3: Left: Graphs show the results of brain white and gray matter uptake of [18F]-FTHA and [11C]-palmitate in the MS group before and after VLCD. P values were calculated using paired Student t test. *P value < 0.02; **P value of 0.009; NS, not significant; black bars, before VLCD; white bars, after VLCD. Right: Results from the voxel-based mapping analysis. Results are rendered on an anatomical brain model; red areas illustrate brain regions where [18F]-FTHA uptake was significantly reduced after dieting among MS patients (Tmax = 4.21 at (−66, −22, 48), kE = 161,315, cluster-level corrected P < 0.0005). (A high-quality digital representation of this figure is available in the online issue.)

Mentions: There was a substantial reduction in the brain uptake of [18F]-FTHA in patients with MS after VLCD (Fig. 3). The mean percentage decrease was −17.5% in the white matter and −17.6% in the gray matter. In the rmANOVA, the main effect of repetition was statistically significant (P = 0.010), whereas the repetition × region interaction was not (P = 0.099). The latter suggests that the decrease in tracer uptake was uniform across brain regions. Therefore, to avoid type 1 errors, regional changes were not formally assessed. This result was confirmed using a voxel-based mapping analysis (Fig. 3). The change in [11C]-palmitate uptake was highly variable between individuals, with the average across regions ranging from −37% to +210% and the average across individuals being +32% (SD 74%). The rmANOVA did not show any significant change in [11C]-palmitate uptake after VLCD (Fig. 3, main effect of repetition: P = 0.712, repetition × region interaction: P = 0.676). The change in [18F]-FTHA uptake versus change in [11C]-palmitate correlated positively in all brain areas, and all of the correlations were statistically significant. For the hypothalamus, the correlation r value was 0.56 (P < 0.05).


Increased brain fatty acid uptake in metabolic syndrome.

Karmi A, Iozzo P, Viljanen A, Hirvonen J, Fielding BA, Virtanen K, Oikonen V, Kemppainen J, Viljanen T, Guiducci L, Haaparanta-Solin M, Någren K, Solin O, Nuutila P - Diabetes (2010)

Left: Graphs show the results of brain white and gray matter uptake of [18F]-FTHA and [11C]-palmitate in the MS group before and after VLCD. P values were calculated using paired Student t test. *P value < 0.02; **P value of 0.009; NS, not significant; black bars, before VLCD; white bars, after VLCD. Right: Results from the voxel-based mapping analysis. Results are rendered on an anatomical brain model; red areas illustrate brain regions where [18F]-FTHA uptake was significantly reduced after dieting among MS patients (Tmax = 4.21 at (−66, −22, 48), kE = 161,315, cluster-level corrected P < 0.0005). (A high-quality digital representation of this figure is available in the online issue.)
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2927939&req=5

Figure 3: Left: Graphs show the results of brain white and gray matter uptake of [18F]-FTHA and [11C]-palmitate in the MS group before and after VLCD. P values were calculated using paired Student t test. *P value < 0.02; **P value of 0.009; NS, not significant; black bars, before VLCD; white bars, after VLCD. Right: Results from the voxel-based mapping analysis. Results are rendered on an anatomical brain model; red areas illustrate brain regions where [18F]-FTHA uptake was significantly reduced after dieting among MS patients (Tmax = 4.21 at (−66, −22, 48), kE = 161,315, cluster-level corrected P < 0.0005). (A high-quality digital representation of this figure is available in the online issue.)
Mentions: There was a substantial reduction in the brain uptake of [18F]-FTHA in patients with MS after VLCD (Fig. 3). The mean percentage decrease was −17.5% in the white matter and −17.6% in the gray matter. In the rmANOVA, the main effect of repetition was statistically significant (P = 0.010), whereas the repetition × region interaction was not (P = 0.099). The latter suggests that the decrease in tracer uptake was uniform across brain regions. Therefore, to avoid type 1 errors, regional changes were not formally assessed. This result was confirmed using a voxel-based mapping analysis (Fig. 3). The change in [11C]-palmitate uptake was highly variable between individuals, with the average across regions ranging from −37% to +210% and the average across individuals being +32% (SD 74%). The rmANOVA did not show any significant change in [11C]-palmitate uptake after VLCD (Fig. 3, main effect of repetition: P = 0.712, repetition × region interaction: P = 0.676). The change in [18F]-FTHA uptake versus change in [11C]-palmitate correlated positively in all brain areas, and all of the correlations were statistically significant. For the hypothalamus, the correlation r value was 0.56 (P < 0.05).

Bottom Line: Both total and nonoxidized fractions of fatty acid uptake were associated with BMI.Rapid weight reduction decreased brain fatty acid uptake by 17%.Both fatty acid uptake and accumulation appear to be increased in MS patients and reversed by weight reduction.

View Article: PubMed Central - PubMed

Affiliation: Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland.

ABSTRACT

Objective: To test whether brain fatty acid uptake is enhanced in obese subjects with metabolic syndrome (MS) and whether weight reduction modifies it.

Research design and methods: We measured brain fatty acid uptake in a group of 23 patients with MS and 7 age-matched healthy control subjects during fasting conditions using positron emission tomography (PET) with [(11)C]-palmitate and [(18)F]fluoro-6-thia-heptadecanoic acid ([(18)F]-FTHA). Sixteen MS subjects were restudied after 6 weeks of very low calorie diet intervention.

Results: At baseline, brain global fatty acid uptake derived from [(18)F]-FTHA was 50% higher in patients with MS compared with control subjects. The mean percentage increment was 130% in the white matter, 47% in the gray matter, and uniform across brain regions. In the MS group, the nonoxidized fraction measured using [(11)C]-palmitate was 86% higher. Brain fatty acid uptake measured with [(18)F]-FTHA-PET was associated with age, fasting serum insulin, and homeostasis model assessment (HOMA) index. Both total and nonoxidized fractions of fatty acid uptake were associated with BMI. Rapid weight reduction decreased brain fatty acid uptake by 17%.

Conclusions: To our knowledge, this is the first study on humans to observe enhanced brain fatty acid uptake in patients with MS. Both fatty acid uptake and accumulation appear to be increased in MS patients and reversed by weight reduction.

Show MeSH
Related in: MedlinePlus