TY - JOUR
T1 - Characterising metabolically healthy obesity in weight-discordant monozygotic twins
AU - Naukkarinen, J.
AU - Heinonen, S.
AU - Hakkarainen, A.
AU - Lundbom, J.
AU - Vuolteenaho, K.
AU - Saarinen, L.
AU - Hautaniemi, S.
AU - Rodriguez, A.
AU - Frühbeck, G.
AU - Pajunen, P.
AU - Hyötyläinen, Tuulia
AU - Orešič, Matej
AU - Moilanen, E.
AU - Suomalainen, A.
AU - Lundbom, N.
AU - Kaprio, J.
AU - Rissanen, A.
AU - Pietiläinen, K.H.
PY - 2014
Y1 - 2014
N2 - Aims/hypothesis: Not all obese individuals display the metabolic disturbances commonly associated with excess fat accumulation. Mechanisms maintaining this 'metabolically healthy obesity' (MHO) are as yet unknown. We aimed to study different fat depots and transcriptional pathways in subcutaneous adipose tissue (SAT) as related to the MHO phenomenon.Methods: Sixteen rare young adult obesity-discordant monozygotic (MZ) twin pairs (intra-pair difference (Δ) in BMI =3 kg/m2), aged 22.8-35.8 years, were examined for detailed characteristics of metabolic health (subcutaneous, intra-abdominal and liver fat [magnetic resonance imaging/spectroscopy]), OGTT, lipids, adipokines and C-reactive protein (CRP). Affymetrix U133 Plus 2.0 chips were used to analyse transcriptomics pathways related to mitochondrial function and inflammation in SAT.Results: Based on liver fat accumulation, two metabolically different subgroups emerged. In half (8/16) of the pairs (Δweight 17.1 ± 2.0 kg), the obese co-twin had significantly higher liver fat (Δ718%), 78% increase in AUC insulin during OGTT and CRP, significantly more disturbance in the lipid profile and greater tendency for hypertension compared with the lean co-twin. In these obese co-twins, SAT expression of mitochondrial oxidative phosphorylation, branched-chain amino acid catabolism, fatty acid oxidation and adipocyte differentiation pathways were downregulated and chronic inflammation upregulated. In the other eight pairs (Δweight 17.4 ± 2.8 kg), the obese co-twin did not differ from the non-obese co-twin in liver fat (Δ8%), insulin sensitivity, CRP, lipids, blood pressure or SAT transcriptomics.Conclusions/interpretation: Our results suggest that maintenance of high mitochondrial transcription and lack of inflammation in SAT are associated with low liver fat and MHO.
AB - Aims/hypothesis: Not all obese individuals display the metabolic disturbances commonly associated with excess fat accumulation. Mechanisms maintaining this 'metabolically healthy obesity' (MHO) are as yet unknown. We aimed to study different fat depots and transcriptional pathways in subcutaneous adipose tissue (SAT) as related to the MHO phenomenon.Methods: Sixteen rare young adult obesity-discordant monozygotic (MZ) twin pairs (intra-pair difference (Δ) in BMI =3 kg/m2), aged 22.8-35.8 years, were examined for detailed characteristics of metabolic health (subcutaneous, intra-abdominal and liver fat [magnetic resonance imaging/spectroscopy]), OGTT, lipids, adipokines and C-reactive protein (CRP). Affymetrix U133 Plus 2.0 chips were used to analyse transcriptomics pathways related to mitochondrial function and inflammation in SAT.Results: Based on liver fat accumulation, two metabolically different subgroups emerged. In half (8/16) of the pairs (Δweight 17.1 ± 2.0 kg), the obese co-twin had significantly higher liver fat (Δ718%), 78% increase in AUC insulin during OGTT and CRP, significantly more disturbance in the lipid profile and greater tendency for hypertension compared with the lean co-twin. In these obese co-twins, SAT expression of mitochondrial oxidative phosphorylation, branched-chain amino acid catabolism, fatty acid oxidation and adipocyte differentiation pathways were downregulated and chronic inflammation upregulated. In the other eight pairs (Δweight 17.4 ± 2.8 kg), the obese co-twin did not differ from the non-obese co-twin in liver fat (Δ8%), insulin sensitivity, CRP, lipids, blood pressure or SAT transcriptomics.Conclusions/interpretation: Our results suggest that maintenance of high mitochondrial transcription and lack of inflammation in SAT are associated with low liver fat and MHO.
KW - Adipose tissue
KW - diabetes
KW - fatty liver
KW - inflammation
KW - metabolically healthy obesy
KW - obesity
U2 - 10.1007/s00125-013-3066-y
DO - 10.1007/s00125-013-3066-y
M3 - Article
VL - 57
SP - 167
EP - 176
JO - Diabetologia
JF - Diabetologia
SN - 0012-186X
IS - 1
ER -
