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- Sevastianova, K., et al.
(författare)
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Effect of short-term carbohydrate overfeeding and long-term weight loss on liver fat in overweight humans
- 2012
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Ingår i: American Journal of Clinical Nutrition. - : Elsevier BV. - 0002-9165. ; 96:4, s. 727-734
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Tidskriftsartikel (refereegranskat)abstract
- Background: Cross-sectional studies have identified a high intake of simple sugars as an important dietary factor predicting nonalcoholic fatty liver disease (NAFLD). Objective: We examined whether overfeeding overweight subjects with simple sugars increases liver fat and de novo lipogenesis (DNL) and whether this is reversible by weight loss. Design: Sixteen subjects [BMI (kg/m(2)): 30.6 +/- 1.2] were placed on a hypercaloric diet (>1000 kcal simple carbohydrates/d) for 3 wk and, thereafter, on a hypocaloric diet for 6 mo. The subjects were genotyped for rs739409 in the PNPLA3 gene. Before and after overfeeding and after hypocaloric diet, metabolic variables and liver fat (measured by proton magnetic resonance spectroscopy) were measured. The ratio of palmitate (16:0) to linoleate (18:2n-6) in serum and VLDL triglycerides was used as an index of DNL. Results: Carbohydrate overfeeding increased weight (+/- SEM) by 2% (1.8 +/- 0.3 kg; P < 0.0001) and liver fat by 27% from 9.2 +/- 1.9% to 11.7 +/- 1.9% (P = 0.005). DNL increased in proportion to the increase in liver fat and serum triglycerides in subjects with PNPLA3-148II but not PNPLA3-148MM. During the hypocaloric diet, the subjects lost 4% of their weight (3.2 +/- 0.6 kg; P < 0.0001) and 25% of their liver fat content (from 11.7 +/- 1.9% to 8.8 +/- 1.8%; P < 0.05). Conclusions: Carbohydrate overfeeding for 3 wk induced a >10-fold greater relative change in liver fat (27%) than in body weight (2%). The increase in liver fat was proportional to that in DNL. Weight loss restores liver fat to normal. These data indicate that the human fatty liver avidly accumulates fat during carbohydrate overfeeding and support a role for DNL in the pathogenesis of NAFLD. This trial was registered at www.hus.fi as 235780. Am J Clin Nutr 2012;96:727-34.
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- Bunck, M. C., et al.
(författare)
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Exenatide treatment did not affect bone mineral density despite body weight reduction in patients with type 2 diabetes
- 2011
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Ingår i: Diabetes, obesity & metabolism. - : Wiley. - 1463-1326 .- 1462-8902. ; 13:4, s. 374-377
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Tidskriftsartikel (refereegranskat)abstract
- Preclinical studies suggest that incretin-based therapies may be beneficial for the bone; however, clinical data are largely lacking. We assessed whether the differential effects of these therapies on body weight differed with respect to their effect on bone mineral density (BMD) and markers of calcium homeostasis in patients with type 2 diabetes (T2D). Sixty-nine metformin-treated patients with T2D were randomized to exenatide twice daily (n = 36) or insulin glargine once daily (n = 33). Total body BMD, measured by dual-energy X-ray absorptiometry, and serum markers of calcium homeostasis were assessed before and after 44-week treatment. Exenatide or insulin glargine treatment decreased body weight by 6%. Endpoint BMD was similar in both groups after 44-week therapy (LSmean +/- s.e.m. between-group difference -0.002 +/- 0.007 g/cm(2) ; p = 0.782). Fasting serum alkaline phosphatase, calcium and phosphate remained unaffected. Forty-four-week treatment with exenatide or insulin glargine had no adverse effects on bone density in patients with T2D, despite differential effects on body weight.
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- Lallukka, S., et al.
(författare)
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Adipose tissue is inflamed in NAFLD due to obesity but not in NAFLD due to genetic variation in PNPLA3
- 2013
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Ingår i: Diabetologia. - : Springer Science and Business Media LLC. - 1432-0428 .- 0012-186X. ; 56:4, s. 886-892
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Tidskriftsartikel (refereegranskat)abstract
- The rs738409 C > G single-nucleotide polymorphism in PNPLA3 leads to a missense mutation (I148M) which increases liver fat but does not cause insulin resistance. We hypothesised that patients with non-alcoholic fatty liver disease (NAFLD) due to the PNPLA3 variant ('PNPLA3 NAFLD'aEuro parts per thousand= PNPLA3-148MM) do not have adipose tissue (AT) inflammation in contrast with those with NAFLD due to obesity ('obese NAFLD'). Biopsy specimens of AT were taken, and PNPLA3 genotype and liver fat (H-1-magnetic resonance spectroscopy) were determined in 82 volunteers, who were divided into groups based on either median BMI (obese 36.2 +/- 0.7 kg/m(2); non-obese 26.0 +/- 0.4 kg/m(2)) or PNPLA3 genotype. All groups were similar with respect to age and sex. The PNPLA3 subgroups were equally obese (PNPLA3-148MM, 31.1 +/- 1.3 kg/m(2); PNPLA3-148II, 31.2 +/- 0.8 kg/m(2)), while the obese and non-obese subgroups had similar PNPLA3 genotype distribution. Gene expression of proinflammatory (MCP-1, CD68) and anti-inflammatory (Twist1, ADIPOQ) markers was measured using quantitative real-time RT-PCR. Liver fat was similarly increased in obese NAFLD (9.5 +/- 1.3% vs 5.1 +/- 0.9%, obese vs non-obese, p = 0.007) and PNPLA3 NAFLD (11.4 +/- 1.7% vs 5.3 +/- 0.8%, PNPLA3-148MM vs PNPLA3-148II, p < 0.001). Fasting serum insulin was higher in the obese than the non-obese group (76 +/- 6 vs 47 +/- 6 pmol/l, p < 0.001), but similar in PNPLA3-148MM and PNPLA3-148II (60 +/- 8 vs 62 +/- 5 pmol/l, NS). In obese vs non-obese, MCP-1 and CD68 mRNAs were upregulated, whereas those of Twist1 and ADIPOQ were significantly downregulated. AT gene expression of MCP-1, CD68, Twist1 and ADIPOQ was similar in PNPLA3-148MM and PNPLA3-148II groups. PNPLA3 NAFLD is characterised by an increase in liver fat but no insulin resistance or AT inflammation, while obese NAFLD has all three of these features.
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- Sevastianova, K, et al.
(författare)
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Comparison of Dorsocervical With Abdominal Subcutaneous Adipose Tissue in Patients With and Without Antiretroviral Therapy-Associated Lipodystrophy
- 2011
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Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 60:7, s. 1894-1900
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Combination antiretroviral therapy (cART) is associated with lipodystrophy, i.e., loss of subcutaneous adipose tissue in the abdomen, limbs, and face and its accumulation intra-abdominally. No fat is lost dorsocervically and it can even accumulate in this region (buffalo hump). It is unknown how preserved dorsocervical fat differs from abdominal subcutaneous fat in HIV-1-infected cART-treated patients with (cART+LD+) and without (cART+LD-) lipodystrophy. RESEARCH DESIGN AND METHODS: We used histology, microarray, PCR, and magnetic resonance imaging to compare dorsocervical and abdominal subcutaneous adipose tissue in cART+LD+ (n=21) and cART+LD- (n=11). RESULTS: Albeit dorsocervical adipose tissue in cART+LD+ seems spared from lipoatrophy, its mitochondrial DNA (mtDNA; copies/cell) content was significantly lower (by 62%) than that of the corresponding tissue in cART+LD-. Expression of CD68 mRNA, a marker of macrophages, and numerous inflammatory genes in microarray were significantly lower in dorsocervical versus abdominal subcutaneous adipose tissue. Genes with the greatest difference in expression between the two depots were those involved in regulation of transcription and regionalization (homeobox genes), irrespective of lipodystrophy status. There was negligible mRNA expression of uncoupling protein 1, a gene characteristic of brown adipose tissue, in either depot. CONCLUSIONS: Because mtDNA is depleted even in the nonatrophic dorsocervical adipose tissue, it is unlikely that the cause of lipoatrophy is loss of mtDNA. Dorsocervical adipose tissue is less inflamed than lipoatrophic adipose tissue. It does not resemble brown adipose tissue. The greatest difference in gene expression between dorsocervical and abdominal subcutaneous adipose tissue is in expression of homeobox genes.
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