| 1. |
|
|
| 2. |
- Goedecke, Julia H, et al.
(författare)
-
Ethnic differences in serum lipoproteins and their determinants in South African women
- 2010
-
Ingår i: Metabolism. - : Elsevier BV. - 0026-0495 .- 1532-8600. ; 59:9, s. 1341-1350
-
Tidskriftsartikel (refereegranskat)abstract
- The objective of the study was to characterize ethnic differences in lipid levels and low-density lipoprotein (LDL) particle size and subclasses in black and white South African women and to explore the associations with insulin sensitivity (S(I)), body composition, and lifestyle factors. Fasting serum lipids and LDL size and subclasses, body composition (dual-energy x-ray absorptiometry), and S(I) (frequently sampled intravenous glucose tolerance test) were measured in normal-weight (body mass index <25 kg/m(2)) black (n = 15) and white (n = 15), and obese (body mass index >30 kg/m(2)) black (n = 13) and white (n = 13) women. Normal-weight and obese black women had lower triglycerides (0.59 +/- 0.09 and 0.77 +/- 0.10 vs 0.89 +/- 0.09 and 0.93 +/- 0.10 mmol/L, P < .05) and high-density lipoprotein cholesterol (1.2 +/- 0.1 and 1.1 +/- 0.1 vs 1.7 +/- 0.1 and 1.6 +/- 0.3 mmol/L, P < .01) than white women. The LDL particle size was not different, but obese black women had more LDL subclass IV (17.3% +/- 1.0% vs 12.5% +/- 1.0%, P < .01). In white women, triglycerides and LDL particle size correlated with S(I) (P < .01), whereas cholesterol levels correlated with body fat (P < .05). Low socioeconomic status, low dietary protein intake, and injectable contraceptive use were the major determinants of unfavorable lipid profiles in black women. Black women had lower triglyceride and high-density lipoprotein cholesterol levels and more small dense LDL particles than white women. The major determinants of serum lipids in black women were socioeconomic status and lifestyle factors, whereas in white women, S(I) and body composition most closely correlated with serum lipids.
|
|
| 3. |
- Evans, Juliet, et al.
(författare)
-
Depot- and ethnic-specific differences in the relationship between adipose tissue inflammation and insulin sensitivity
- 2011
-
Ingår i: Clinical Endocrinology. - : Wiley. - 0300-0664 .- 1365-2265. ; 74:1, s. 51-59
-
Tidskriftsartikel (refereegranskat)abstract
- Objective It is unclear whether there are differences in inflammatory gene expression between abdominal and gluteal subcutaneous adipose tissue (SAT), and between black and white women. We therefore tested the hypotheses that SAT inflammatory gene expression is greater in the abdominal compared to the gluteal depot, and SAT inflammatory gene expression is associated with differential insulin sensitivity (S(I) ) in black and white women. Design and methods S(I) (frequently sampled intravenous glucose tolerance test) and abdominal SAT and gluteal SAT gene expression levels of 13 inflammatory genes were measured in normal-weight (BMI 18-25 kg/m(2) ) and obese (BMI >30 kg/m(2) ) black (n = 30) and white (n = 26) South African women. Results Black women had higher abdominal and gluteal SAT expression of CCL2, CD68, TNF-α and CSF-1 compared to white women (P < 0·01). Multivariate analysis showed that inflammatory gene expression in the white women explained 56·8% of the variance in S(I) (P < 0·005), compared to 20·9% in black women (P = 0·30). Gluteal SAT had lower expression of adiponectin, but higher expression of inflammatory cytokines, macrophage markers and leptin than abdominal SAT depots (P < 0·05). Conclusions Black South African women had higher inflammatory gene expression levels than white women; however, the relationship between AT inflammation and S(I) was stronger in white compared to black women. Further research is required to explore other factors affecting S(I) in black populations. Contrary to our original hypothesis, gluteal SAT had a greater inflammatory gene expression profile than abdominal SAT depots. The protective nature of gluteo-femoral fat therefore requires further investigation.
|
|
| 4. |
- Goedecke, Julia H, et al.
(författare)
-
Differential effects of abdominal adipose tissue distribution on insulin sensitivity in black and white South African women
- 2009
-
Ingår i: Obesity. - : Wiley. - 1930-7381 .- 1930-739X. ; 17:8, s. 1506-1512
-
Tidskriftsartikel (refereegranskat)abstract
- Black South African women are more insulin resistant than BMI-matched white women. The objective of the study was to characterize the determinants of insulin sensitivity in black and white South African women matched for BMI. A total of 57 normal-weight (BMI 18-25 kg/m(2)) and obese (BMI > 30 kg/m(2)) black and white premenopausal South African women underwent the following measurements: body composition (dual-energy X-ray absorptiometry), body fat distribution (computerized tomography (CT)), insulin sensitivity (S(I), frequently sampled intravenous glucose tolerance test), dietary intake (food frequency questionnaire), physical activity (Global Physical Activity Questionnaire), and socioeconomic status (SES, demographic questionnaire). Black women were less insulin sensitive (4.4 +/- 0.8 vs. 9.5 +/- 0.8 and 3.0 +/- 0.8 vs. 6.0 +/- 0.8 x 10(-5)/min/(pmol/l), for normal-weight and obese women, respectively, P < 0.001), but had less visceral adipose tissue (VAT) (P = 0.051), more abdominal superficial subcutaneous adipose tissue (SAT) (P = 0.003), lower SES (P < 0.001), and higher dietary fat intake (P = 0.001) than white women matched for BMI. S(I) correlated with deep and superficial SAT in both black (R = -0.594, P = 0.002 and R = 0.495, P = 0.012) and white women (R = -0.554, P = 0.005 and R = -0.546, P = 0.004), but with VAT in white women only (R = -0.534, P = 0.005). In conclusion, body fat distribution is differentially associated with insulin sensitivity in black and white women. Therefore, the different abdominal fat depots may have varying metabolic consequences in women of different ethnic origins.
|
|
| 5. |
- Goedecke, Julia H, et al.
(författare)
-
Insulin response in relation to insulin sensitivity : an appropriate beta-cell response in black South African women.
- 2009
-
Ingår i: Diabetes Care. - : American Diabetes Association. - 0149-5992 .- 1935-5548. ; 32:5, s. 860-855
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: The purpose of this study was to characterize differences in the acute insulin response to glucose (AIR(g)) relative to insulin sensitivity (S(I)) in black and white premenopausal normoglycemic South African women matched for body fatness. RESEARCH DESIGN AND METHODS: Cross-sectional analysis including 57 black and white South African women matched for BMI, S(I), AIR(g), and the disposition index (AIR(g) x S(I)) were performed using a frequently sampled intravenous glucose tolerance test with minimal model analysis, and similar measures were analyzed using an oral glucose tolerance test (OGTT). Body composition was assessed by dual-energy X-ray absorptiometry and computed tomography. RESULTS: S(I) was significantly lower (4.4 +/- 0.8 vs. 9.4 +/- 0.8 and 2.9 +/- 0.8 vs. 6.0 +/- 0. 8 x 10(-5) min(-1)/[pmol/l], P < 0.001) and AIR(g) was significantly higher (1,028 +/- 255 vs. 352 +/- 246 and 1,968 +/- 229 vs. 469 +/- 246 pmol/l, P < 0.001), despite similar body fatness (30.9 +/- 1.4 vs. 29.7 +/- 1.3 and 46.8 +/- 1.2 vs. 44.4 +/- 1.3%) in the normal-weight and obese black women compared with their white counterparts, respectively. Disposition index, a marker of beta-cell function, was not different between ethnic groups (3,811 +/- 538 vs. 2,966 +/- 518 and 3,646 +/- 485 vs. 2,353 +/- 518 x 10(-5) min, P = 0.10). Similar results were obtained for the OGTT-derived measures. CONCLUSIONS: Black South African women are more insulin resistant than their white counterparts but compensate by increasing their insulin response to maintain normal glucose levels, suggesting an appropriate beta-cell response for the level of insulin sensitivity.
|
|
| 6. |
- Goedecke, Julia H, et al.
(författare)
-
Reduced gluteal expression of adipogenic and lipogenic genes in black south african women is associated with obesity-related insulin resistance
- 2011
-
Ingår i: Journal of Clinical Endocrinology and Metabolism. - Philadelphia : Lippincott Williams & Wilkins. - 0021-972X .- 1945-7197. ; 96:12, s. E2029-E2033
-
Tidskriftsartikel (refereegranskat)abstract
- Context: Black South African women are less insulin sensitive than their White counterparts, despite less central and greater peripheral fat deposition. We hypothesized that this paradox may be explained, in part, by differences in the adipogenic capacity of sc adipose tissue (SAT). Objective: Our objective was to measure adipogenic and lipogenic gene expression in abdominal and gluteal SAT depots and determine their relationships with insulin sensitivity (S(I)) in South African women. Participants and Design: Fourteen normal-weight [body mass index (BMI) <25 kg/m(2)] Black, 13 normal-weight White, 14 obese (BMI >30 kg/m(2)) Black, and 13 obese White premenopausal South African women participated in this cross-sectional study.Main outcomes:S(I) (frequently sampled iv glucose tolerance test) in relation to expression of adipogenic and lipogenic genes in abdominal and gluteal SAT depots. Results: With increasing BMI, Black women had less visceral fat (P = 0.03) and more abdominal (P = 0.017) and gynoid (P = 0.041) SAT but had lower S(I) (P < 0.01) than White women. The expression of adipogenic and lipogenic genes was proportionately lower with obesity in Black but not White women in the gluteal and deep SAT depots (P < 0.05 for ethnicity × BMI effect). In Black women only, the expression of these genes correlated positively with S(I) (all P < 0.05), independently of age and fat mass. Conclusions: Obese Black women have reduced SAT expression of adipogenic and lipogenic genes compared with White women, which associates with reduced S(I). These findings suggest that obesity in Black women impairs SAT adipogenesis and storage, potentially leading to insulin resistance and increased risk of type 2 diabetes.
|
|
| 7. |
- Jarvis, Erich D., et al.
(författare)
-
Whole-genome analyses resolve early branches in the tree of life of modern birds
- 2014
-
Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 346:6215, s. 1320-1331
-
Tidskriftsartikel (refereegranskat)abstract
- To better determine the history of modern birds, we performed a genome-scale phylogenetic analysis of 48 species representing all orders of Neoaves using phylogenomic methods created to handle genome-scale data. We recovered a highly resolved tree that confirms previously controversial sister or close relationships. We identified the first divergence in Neoaves, two groups we named Passerea and Columbea, representing independent lineages of diverse and convergently evolved land and water bird species. Among Passerea, we infer the common ancestor of core landbirds to have been an apex predator and confirm independent gains of vocal learning. Among Columbea, we identify pigeons and flamingoes as belonging to sister clades. Even with whole genomes, some of the earliest branches in Neoaves proved challenging to resolve, which was best explained by massive protein-coding sequence convergence and high levels of incomplete lineage sorting that occurred during a rapid radiation after the Cretaceous-Paleogene mass extinction event about 66 million years ago.
|
|
