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Abstract
The obesity epidemic in the USA affects disproportionately women and the ethnic minorities. On the other hand, female sex is traditionally associated with a favorable fat distribution preferentially in the subcutaneous depots of the lower body and with improved endocrine and metabolic function of the adipose tissue. However, these data are derived from predominantly non-Hispanic white populations. This review discusses fat distribution patterns in women of diverse ethnic backgrounds, together with data on the release of adipokines from adipose tissue in these populations. Very little information is available on how the metabolic function of the adipocyte differs depending on ethnicity. Thus, it becomes clear that future clinical and translational research should explicitly discuss and take into account the sex and ethnic background of the populations studied.
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Affiliation(s)
- Kalypso Karastergiou
- Section of Endocrinology, Diabetes & Nutrition, School of Medicine, Boston University, 650 Albany St. EBRC-810, Boston, MA, 02118, USA.
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Ali AT, Chirambo G, Penny C, Paiker JE, Ikram F, Psaras G, Crowther NJ. Ethnic differences in pre-adipocyte intracellular lipid accumulation and alkaline phosphatase activity. Clin Chim Acta 2014; 438:382-7. [PMID: 25281857 DOI: 10.1016/j.cca.2014.09.022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Revised: 09/11/2014] [Accepted: 09/13/2014] [Indexed: 11/28/2022]
Abstract
Alkaline phosphatase (ALP) increases lipid accumulation in human pre-adipocytes. This study was performed to assess whether ethnic differences in the prevalence of obesity in African and European females are related to differences in pre-adipocyte lipid accretion and ALP activity. Pre-adipocytes were isolated from 13 black and 14 white females. Adipogenesis was quantified using the lipid dye, Oil red O, whilst ALP activity was assayed in cell extracts on day zero and 12days after initiating adipogenesis. Lipid levels (OD units/mg protein) were lower in pre-adipocytes from white than black females on day 0 (0.36±0.05 versus 0.44±0.03, respectively; p<0.0005) and day 12 (1.18±0.14 versus 1.80±0.22, respectively; p<0.0005), as was ALP activity (mU/mg protein) on day zero (36.5±5.8 versus 136.4±10.9, respectively; p<0.0005) and day 12 (127±16 versus 278±27, respectively; p<0.0005). Treatment of pre-adipocytes with histidine, an ALP inhibitor, blocked lipid accumulation. Thus, lipid uptake is higher in pre-adipocytes isolated from black compared to white females which parallels the obesity prevalence rates in these population groups. The reason for higher fat accumulation in pre-adipocytes isolated from black females may be related to higher ALP activity.
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Affiliation(s)
- Aus T Ali
- Division of Chemical Pathology, National Health Laboratory Service, Tygerberg Hospital, University of Stellenbosch Medical School, South Africa.
| | - George Chirambo
- Department of Chemical Pathology, National Health Laboratory Service, University of Witwatersrand Medical School, Parktown, South Africa
| | - Clement Penny
- Department of Internal Medicine, University of Witwatersrand Medical School, Parktown, South Africa
| | - Janice E Paiker
- Department of Chemical Pathology, National Health Laboratory Service, University of Witwatersrand Medical School, Parktown, South Africa
| | - Faisel Ikram
- Department of Surgery, University of Witwatersrand Medical School, Parktown, South Africa
| | - George Psaras
- Department of Surgery, University of Witwatersrand Medical School, Parktown, South Africa
| | - Nigel J Crowther
- Department of Chemical Pathology, National Health Laboratory Service, University of Witwatersrand Medical School, Parktown, South Africa
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Crowther NJ, Ferris WF. The impact of insulin resistance, gender, genes, glucocorticoids and ethnicity on body fat distribution. JOURNAL OF ENDOCRINOLOGY, METABOLISM AND DIABETES OF SOUTH AFRICA 2014. [DOI: 10.1080/22201009.2010.10872241] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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Goedecke JH, Levitt NS, Evans J, Ellman N, Hume DJ, Kotze L, Tootla M, Victor H, Keswell D. The role of adipose tissue in insulin resistance in women of African ancestry. J Obes 2013; 2013:952916. [PMID: 23401754 PMCID: PMC3557633 DOI: 10.1155/2013/952916] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Accepted: 12/13/2012] [Indexed: 01/01/2023] Open
Abstract
Women of African ancestry, particularly those living in industrialized countries, experience a disproportionately higher prevalence of type 2 diabetes (T2D) compared to their white counterparts. Similarly, obesity and insulin resistance, which are major risk factors for T2D, are greater in black compared to white women. The exact mechanisms underlying these phenomena are not known. This paper will focus on the role of adipose tissue biology. Firstly, the characteristic body fat distribution of women of African ancestry will be discussed, followed by the depot-specific associations with insulin resistance. Factors involved in adipose tissue biology and their relation to insulin sensitivity will then be explored, including the role of sex hormones, glucocorticoid metabolism, lipolysis and adipogenesis, and their consequent effects on adipose tissue hypoxia, oxidative stress, and inflammation. Finally the role of ectopic fat deposition will be discussed. The paper proposes directions for future research, in particular highlighting the need for longitudinal and/or intervention studies to better understand the mechanisms underlying the high prevalence of insulin resistance and T2D in women of African ancestry.
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Affiliation(s)
- Julia H Goedecke
- UCT/MRC Research Unit for Exercise Science and Sports Medicine, South African Medical Research Council, Parow, Cape Town 7505, South Africa.
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Kursawe R, Eszlinger M, Narayan D, Liu T, Bazuine M, Cali AM, D'Adamo E, Shaw M, Pierpont B, Shulman GI, Cushman SW, Sherman A, Caprio S. Cellularity and adipogenic profile of the abdominal subcutaneous adipose tissue from obese adolescents: association with insulin resistance and hepatic steatosis. Diabetes 2010; 59:2288-96. [PMID: 20805387 PMCID: PMC2927952 DOI: 10.2337/db10-0113] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
OBJECTIVE We explored whether the distribution of adipose cell size, the estimated total number of adipose cells, and the expression of adipogenic genes in subcutaneous adipose tissue are linked to the phenotype of high visceral and low subcutaneous fat depots in obese adolescents. RESEARCH DESIGN AND METHODS A total of 38 adolescents with similar degrees of obesity agreed to have a subcutaneous periumbilical adipose tissue biopsy, in addition to metabolic (oral glucose tolerance test and hyperinsulinemic euglycemic clamp) and imaging studies (MRI, DEXA, (1)H-NMR). Subcutaneous periumbilical adipose cell-size distribution and the estimated total number of subcutaneous adipose cells were obtained from tissue biopsy samples fixed in osmium tetroxide and analyzed by Beckman Coulter Multisizer. The adipogenic capacity was measured by Affymetrix GeneChip and quantitative RT-PCR. RESULTS Subjects were divided into two groups: high versus low ratio of visceral to visceral + subcutaneous fat (VAT/[VAT+SAT]). The cell-size distribution curves were significantly different between the high and low VAT/(VAT+SAT) groups, even after adjusting for age, sex, and ethnicity (MANOVA P = 0.035). Surprisingly, the fraction of large adipocytes was significantly lower (P < 0.01) in the group with high VAT/(VAT+SAT), along with the estimated total number of large adipose cells (P < 0.05), while the mean diameter was increased (P < 0.01). From the microarray analyses emerged a lower expression of lipogenesis/adipogenesis markers (sterol regulatory element binding protein-1, acetyl-CoA carboxylase, fatty acid synthase) in the group with high VAT/(VAT+SAT), which was confirmed by RT-PCR. CONCLUSIONS A reduced lipo-/adipogenic capacity, fraction, and estimated number of large subcutaneous adipocytes may contribute to the abnormal distribution of abdominal fat and hepatic steatosis, as well as to insulin resistance in obese adolescents.
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Affiliation(s)
- Romy Kursawe
- Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut
| | | | - Deepak Narayan
- Department of Plastic Surgery, Yale University School of Medicine, New Haven, Connecticut
| | - Teresa Liu
- Diabetes Branch, NIDDK/National Institutes of Health, Bethesda, Maryland
| | - Merlijn Bazuine
- Diabetes Branch, NIDDK/National Institutes of Health, Bethesda, Maryland
| | - Anna M.G. Cali
- Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut
| | - Ebe D'Adamo
- Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut
| | - Melissa Shaw
- Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut
| | - Bridget Pierpont
- Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut
| | - Gerald I. Shulman
- Department of Internal Medicine and Cellular & Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut
| | - Samuel W. Cushman
- Diabetes Branch, NIDDK/National Institutes of Health, Bethesda, Maryland
| | - Arthur Sherman
- Laboratory of Biological Modeling, NIDDK/National Institutes of Health, Bethesda, Maryland
| | - Sonia Caprio
- Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut
- Corresponding author: Sonia Caprio,
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Abstract
While communicable diseases such as human immunodeficiency virus/acquired immune deficiency syndrome, malaria, and tuberculosis have continued to pose greater threats to the public health system in sub-Saharan Africa (SSA), it is now apparent that non-communicable diseases such as diabetes mellitus are undoubtedly adding to the multiple burdens the peoples in this region suffer. Type 2 diabetes mellitus (T2DM) is the most common form of diabetes (90-95%), exhibiting an alarming prevalence among peoples of this region. Its main risk factors include obesity, rapid urbanization, physical inactivity, ageing, nutrition transitions, and socioeconomic changes. Patients in sub-Saharan Africa also show manifestations of beta-cell dysfunction and insulin resistance. However, because of strained economic resources and a poor health care system, most of the patients are diagnosed only after they have overt symptoms and complications. Microvascular complications are the most prevalent, but metabolic disorders and acute infections cause significant mortality. The high cost of treatment of T2DM and its comorbidities, the increasing prevalence of its risk factors, and the gaps in health care system necessitate that solutions be planned and implemented urgently. Aggressive actions and positive responses from well-informed governments appear to be needed for the conducive interplay of all forces required to curb the threat of T2DM in sub-Saharan Africa. Despite the varied ethnic and transitional factors and the limited population data on T2DM in sub-Saharan Africa, this review provides an extensive discussion of the literature on the epidemiology, risk factors, pathogenesis, complications, treatment, and care challenges of T2DM in this region.
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Affiliation(s)
- Vivian C Tuei
- Department of Molecular Biosciences, Bioengineering University of Hawaii, Honolulu, USA
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Lawrence JC, Gower BA, Garvey WT, Muñoz AJ, Darnell BE, Oster RA, Buchthal SD, Goran MI, Newcomer BR. Relationship between Insulin Sensitivity and Muscle Lipids may Differ with Muscle Group and Ethnicity. ACTA ACUST UNITED AC 2010; 2:137-144. [PMID: 22039395 DOI: 10.2174/1876823701002010137] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Intramyocellular lipid (IMCL) has been inversely associated with insulin sensitivity in some, but not all, studies. This study utilized fast, high-resolution, magnetic resonance spectroscopic imaging (MRSI) to: investigate relationships between muscle lipids (IMCL and extramyocellular lipid (EMCL)) and insulin sensitivity in muscles of varying oxidative capacity, explore ethnic differences in these relationships, and determine whether a eucaloric, low-fat dietary intervention would reduce IMCL and increase insulin sensitivity. Subjects were 30 healthy, African-American (AA; n=14) and European-American (EA; n=16) males, BMI 26.49 (±5.57) kg/m(2), age 21.80 (±7.84) yrs. Soleus and tibialis anterior muscle lipids were quantified using MRSI. Insulin sensitivity was assessed via intravenous glucose tolerance test. A 2-week, eucaloric, low-fat diet intervention was conducted in a sub-group (n=12) subjects with assessments at baseline and post-intervention. Neither IMCL nor EMCL levels differed between ethnicities. In the total group, and within EA (but not AA), both tibialis anterior IMCL and EMCL were inversely associated with insulin sensitivity (P<0.05 for both); soleus muscle lipids were not associated with insulin sensitivity. Soleus, but not tibialis anterior, IMCL declined in both ethnic groups (average 25.3%; p<0.01) following dietary intervention; insulin sensitivity was unchanged. Results suggest that an association of muscle lipids with insulin sensitivity may be influenced by the oxidative capacity of the muscle group studied and may vary with ethnicity.
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Affiliation(s)
- Jeannine C Lawrence
- Department of Human Nutrition, University of Alabama, Tuscaloosa, Alabama, USA
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Fried SK, Tittelbach T, Blumenthal J, Sreenivasan U, Robey L, Yi J, Khan S, Hollender C, Ryan AS, Goldberg AP. Resistance to the antilipolytic effect of insulin in adipocytes of African-American compared to Caucasian postmenopausal women. J Lipid Res 2009; 51:1193-200. [PMID: 19965580 DOI: 10.1194/jlr.p000935] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
High fatty acid (FA) flux is associated with systemic insulin resistance, and African-American (AA) women tend to be more insulin resistant. We assessed possible depot and race difference in the antilipolytic effect of insulin in adipocytes isolated from abdominal (Abd) and gluteal (Glt) subcutaneous (sc) adipose tissue of overweight, postmenopausal AA and Caucasian (C) women. Percent body fat, fasting insulin, visceral adiposity, and adipocyte size was higher in AA women. Disinhibited lipolysis (presence of adenosine deaminase) per unit adipocyte surface area was similar in Abd and Glt and in AA and C. However, rates of 'basal' [submaximal phenylisopropyl adenosine (PIA)-suppressed] and insulin-suppressed lipolysis were higher in Abd of AA compared with C women even after adjustment for percent fat and visceral fat area. The race difference in rates of PIA- and insulin-suppressed lipolysis in AA were correlated with their hyperinsulinemia, but AA race, independent of fasting insulin, was associated with lower responsiveness (percent suppression) to submaximal insulin concentrations, although sensitivity (ED50) was not affected. Overall, these data are consistent with the hypothesis that decreased responsiveness of Abd adipocytes to antilipolytic effectors may contribute to higher FA availability and thereby to racial differences in insulin resistance.
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Affiliation(s)
- Susan K Fried
- Geriatric Research and Education Clinical Center, Baltimore Veterans Administration Medical Center, Baltimore, MD, USA.
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Choukem SP, Sobngwi E, Fetita LS, Boudou P, De Kerviler E, Boirie Y, Hainault I, Vexiau P, Mauvais-Jarvis F, Calvo F, Gautier JF. Multitissue insulin resistance despite near-normoglycemic remission in Africans with ketosis-prone diabetes. Diabetes Care 2008; 31:2332-7. [PMID: 18809633 PMCID: PMC2584191 DOI: 10.2337/dc08-0914] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE To characterize insulin action in Africans with ketosis-prone diabetes (KPD) during remission. RESEARCH DESIGN AND METHODS At Saint-Louis Hospital, Paris, France, 15 African patients with KPD with an average 10.5-month insulin-free near-normoglycemic remission period (mean A1C 6.2%) were compared with 17 control subjects matched for age, sex, BMI, and geographical origin. Insulin stimulation of glucose disposal, and insulin suppression of endogenous glucose production (EGP) and nonesterified fatty acids (NEFAs), was studied using a 200-min two-step (10 mU x m(-2) body surface x min(-1) and 80 mU x m(-2) x min (-1) insulin infusion rates) euglycemic clamp with [6,6-(2)H(2)]glucose as the tracer. Early-phase insulin secretion was determined during an oral glucose tolerance test. RESULTS The total glucose disposal was reduced in patients compared with control subjects (7.5 +/- 0.8 [mean +/- SE] vs. 10.5 +/- 0.9 mg x kg(-1) x min(-1); P = 0.018). EGP rate was higher in patients than control subjects at baseline (4.0 +/- 0.3 vs. 3.0 +/- 0.1 mg x kg(-1) x min(-1); P = 0.001) and after 200-min insulin infusion (10 mU x m(-2) x min(-1): 1.6 +/- 0.2 vs. 0.6 +/- 0.1, P = 0.004; 80 mU x m(-2) x min(-1): 0.3 +/- 0.1 vs. 0 mg x kg(-1) x min(-1), P = 0.007). Basal plasma NEFA concentrations were also higher in patients (1,936.7 +/- 161.4 vs. 1,230.0 +/- 174.1 micromol/l; P = 0.002) and remained higher after 100-min 10 mU x m(-2) x min(-1) insulin infusion (706.6 +/- 96.5 vs. 381.6 +/- 55.9 micromol/l; P = 0.015). CONCLUSIONS The triad hepatic, adipose tissue, and skeletal muscle insulin resistance is observed in patients with KPD during near-normoglycemic remission, suggesting that KPD is a form of type 2 diabetes.
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Affiliation(s)
- Simeon-Pierre Choukem
- Department of Diabetes and Endocrinology, Saint-Louis Hospital, Assistance Publique-Hôpitaux de Paris, University Paris-Diderot Paris 7, Paris, France
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Auvichayapat P, Prapochanung M, Tunkamnerdthai O, Sripanidkulchai BO, Auvichayapat N, Thinkhamrop B, Kunhasura S, Wongpratoom S, Sinawat S, Hongprapas P. Effectiveness of green tea on weight reduction in obese Thais: A randomized, controlled trial. Physiol Behav 2008; 93:486-91. [DOI: 10.1016/j.physbeh.2007.10.009] [Citation(s) in RCA: 118] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2007] [Revised: 09/29/2007] [Accepted: 10/05/2007] [Indexed: 10/22/2022]
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Signorello LB, Schlundt DG, Cohen SS, Steinwandel MD, Buchowski MS, McLaughlin JK, Hargreaves MK, Blot WJ. Comparing diabetes prevalence between African Americans and Whites of similar socioeconomic status. Am J Public Health 2007; 97:2260-7. [PMID: 17971557 DOI: 10.2105/ajph.2006.094482] [Citation(s) in RCA: 134] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
OBJECTIVES We investigated whether racial disparities in the prevalence of type 2 diabetes exist beyond what may be attributable to differences in socioeconomic status (SES) and other modifiable risk factors. METHODS We analyzed data from 34331 African American and 9491 White adults aged 40 to 79 years recruited into the ongoing Southern Community Cohort Study. Participants were enrolled at community health centers and had similar socioeconomic circumstances and risk factor profiles. We used logistic regression to estimate the association between race and prevalence of self-reported diabetes after taking into account age, SES, health insurance coverage, body mass index, physical activity, and hypertension. RESULTS Multivariate analyses accounting for several diabetes risk factors did not provide strong support for higher diabetes prevalence rates among African Americans than among Whites (men: odds ratio [OR]=1.07; 95% confidence interval [CI]=0.95, 1.20); women: OR=1.13, 95% CI=1.04, 1.22). CONCLUSIONS Our findings suggest that major differences in diabetes prevalence between African Americans and Whites may simply reflect differences in established risk factors for the disease, such as SES, that typically vary according to race.
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Affiliation(s)
- Lisa B Signorello
- International Epidemiology Institute, Rockville, MD 20850, USA. lisa.
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Sobngwi E, Effoe V, Boudou P, Njamen D, Gautier JF, Mbanya JC. Waist circumference does not predict circulating adiponectin levels in sub-Saharan women. Cardiovasc Diabetol 2007; 6:31. [PMID: 17939853 PMCID: PMC2098752 DOI: 10.1186/1475-2840-6-31] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2007] [Accepted: 10/16/2007] [Indexed: 11/10/2022] Open
Abstract
Background Because of previously reported ethnic differences in determinants and markers of obesity and related metabolic disorders, we sought to investigate circulating levels of adiponectin and their correlates in a sub-Saharan African (sSA) population. Subjects and Methods We studied 70 non-diabetic volunteers (33M/37F) living in Yaoundé, Cameroon, aged 24–69 yr, with BMI 20–42 kg/m2. In all participants we measured waist circumference and total body fat by bioimpedance, and obtained a fasting venous blood sample for measurement of plasma glucose, serum insulin and adiponectin concentrations. We performed a euglycaemic hyperinsulinaemic clamp in 1/4 subjects, and HOMAIR was used as surrogate of fasting insulin sensitivity index since it best correlates to clamp measurements. Results Males had lower adiponectin levels than females (8.8 ± 4.3 vs. 11.8 ± 5.5 μg/L). There was no significant correlation between adiponectin and total body fat (rs = -0.03; NS), whereas adiponectin was inversely correlated with waist circumference (rs = -0.39; p = 0.001). Adiponectin correlated negatively with insulin resistance (rs = -0.35; p = 0.01). In a regression analysis using fasting adiponectin concentration as the dependent variable, and age, HOMAIR, waist circumference, and fat mass as predictors, waist circumference (β = -3.30; p = 0.002), fat mass (β = -2.68; p = 0.01), and insulin resistance (β = -2.38; p = 0.02) but not age (β = 1.11; p = 0.27) were independent predictors of adiponectin. When considering gender, these relations persisted with the exception of waist circumference in females. Conclusion Adiponectin correlates in this study population are comparable to those observed in Caucasians with the exception of waist circumference in women. The metabolic significance of waist circumference is therefore questioned in sSA women.
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Affiliation(s)
- Eugène Sobngwi
- Department of Medicine and Specialties, Faculty of Medicine and Biomedical Sciences, University of Yaoundé 1, Yaoundé, Cameroon.
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Belhadi L, Chadli A, Bennis L, Ghomari H, Farouqi A. [Ketosis-prone atypical diabetes mellitus: report of two cases]. ANNALES D'ENDOCRINOLOGIE 2007; 68:470-4. [PMID: 17692810 DOI: 10.1016/j.ando.2007.05.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2007] [Revised: 05/21/2007] [Accepted: 05/24/2007] [Indexed: 11/16/2022]
Abstract
An atypical presentation of diabetes mellitus was described in black subjects, initially in adolescents by Winter et al. then, in adult populations. The principal characteristics of "African" diabetes are an acute onset with severe hyperglycemia and ketosis, and a clinical course of type 2 diabetes mellitus. In the subsequent clinical course after initiation of insulin therapy, prolonged remission is often possible with cessation of insulin therapy and maintenance of appropriate metabolic control. In the subsequent clinical course after initiation of insulin therapy, prolonged remission is often possible with cessation of insulin therapy and maintenance of appropriate metabolic control. The molecular mechanisms underlining the insulin secretory dysfunction are still to be understood and may involve glucolipotoxicity processes. The HLA alleles associated with susceptibility to type 1 diabetes were reported of high frequency in some populations with this form of diabetes, in the absence of makers of pancreatic beta cell autoimmunity. The aim of the present review is to discuss two cases of African diabetes and review the specific diagnostic, metabolic, pathogenic and management features of this atypical diabetes.
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Affiliation(s)
- L Belhadi
- Service d'endocrinologie, nutrition et maladies métaboliques, CHU de Ibn-Rochd, Casablanca, Morocco.
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Rush EC, Goedecke JH, Jennings C, Micklesfield L, Dugas L, Lambert EV, Plank LD. BMI, fat and muscle differences in urban women of five ethnicities from two countries. Int J Obes (Lond) 2007; 31:1232-9. [PMID: 17342075 DOI: 10.1038/sj.ijo.0803576] [Citation(s) in RCA: 121] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE To investigate body composition differences, especially the relationship between body mass index (BMI) and percent body fat (%BF), among five ethnic groups. DESIGN Cross-sectional. SUBJECTS Seven hundred and twenty-one apparently healthy women aged 18-60 years (BMI: 17.4-54.0 kg/m(2)) from South Africa (SA, 201 black, 94 European) and New Zealand (NZ, 173 European, 76 Maori, 84 Pacific, 93 Asian Indian). MEASUREMENTS Anthropometry, including waist circumference, and total, central and peripheral body fat, bone mineral content and total appendicular skeletal muscle mass (ASMM) derived from dual X-ray absorptiometry. RESULTS Regression analysis determined that at a BMI of 30 kg/m(2), SA European women had a %BF of 39%, which corresponded to a BMI of 29 for SA black women. For a BMI of 30 kg/m(2) in NZ Europeans, equivalent to 43% body fat, the corresponding BMIs for NZ Maori, Pacific and Asian Indian women were 34, 36 and 26 kg/m(2), respectively. Central fat mass was lower in black SA than in European SA women (P<0.001). In NZ, Pacific women had the lowest central fat mass and highest ASMM, whereas Asian Indian women had the highest central fat mass, but lowest ASMM and bone mineral content. CONCLUSIONS The relationship between %BF and BMI varies with ethnicity and may be due, in part, to differences in central fatness and muscularity. Use of universal BMI or waist cut-points may not be appropriate for comparison of obesity prevalence among differing ethnic groups, as they do not provide a consistent reflection of adiposity and fat distribution across ethnic groups.
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Affiliation(s)
- E C Rush
- Institute of Sport and Recreation Research, Faculty of Health and Environmental Sciences, AUT University, Auckland, New Zealand.
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Kruger HS, Puoane T, Senekal M, van der Merwe MT. Obesity in South Africa: challenges for government and health professionals. Public Health Nutr 2007; 8:491-500. [PMID: 16153330 DOI: 10.1079/phn2005785] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
AbstractObjectivesTo review data on the prevalence, causes and health consequences of obesity in South Africa and propose interventions to prevent and treat obesity and related outcomes.MethodsData from existing literature were reviewed with an emphasis on changing eating and activity patterns, cultural factors, perceptions and beliefs, urbanisation and globalisation. Results of studies on the health consequences of obesity in South Africans are also reviewed.ResultsShifts in dietary intakes and activity patterns to higher fat intakes and lower physical activity are contributing to a higher prevalence of obesity. Few overweight black women view themselves as overweight, and some associate thinness with HIV/AIDS. Glucose and lipid toxicity, associated with insulin resistance, play roles in the pathogenesis of the co-morbid diseases of obesity. Elevated free fatty acids in the black population predispose obese black patients to type 2 diabetes.Conclusion and recommendationsObesity prevention and treatment should be based on education, behaviour change, political support, intersectoral collaboration and community participation, local actions, wide inclusion of the population, adequately resourced programmes, infiltration of existing initiatives, evidence-based planning, and proper monitoring and evaluation. Interventions should have the following components: reasonable weight goals, healthful eating, physical activity and behavioural change. Genes and mutations affecting susceptibility to the development of co-morbidities of obesity and vulnerable periods of life for the development of obesity should be prioritised. Prevention should be managed in community services, identification of high-risk patients in primary healthcare services and treatment of co-morbid diseases in hospital services.
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Affiliation(s)
- H Salome Kruger
- School of Physiology, Nutrition and Consumer Science, North-West University, Potchefstroom, South Africa.
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16
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Abstract
South Africa has not been spared in the rampant global increase in obesity. Throughout Africa, as elsewhere, ethnicity has a major impact on the incidence and pathogenesis of comorbid diseases, particularly diabetes. Combined figures for obesity and overweight (body mass index [BMI] > 25 kg m(-2)) obtained across all ethnic groups in the adult population in 1998, were 57% for women and 29% for men. From the 1960s until the late 1980s, the notion of 'healthy' or 'benign' obesity was propagated in South Africa. Not surprisingly, this led to ignorance around the problem of obesity, and treatment of some of the comorbid diseases was neglected. Fortunately, as an increasing number of seminal studies draw us closer to reality, the misperception of benign obesity is being corrected. This is allowing us to address the real issues underlying the current epidemic, and to recognize and manage the comorbid diseases, in particular type 2 diabetes. A new framework for research is also emerging as we begin to define the factors underlying the impact of ethnicity on obesity.
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Affiliation(s)
- M-T van der Merwe
- University of the Witwatersrand and Johannesburg General Hospital, South Africa.
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Punyadeera C, Crowther NJ, van der Merwe MT, Toman M, Immelman AR, Schlaphoff GP, Gray IP. Metabolic response to a mixed meal in obese and lean women from two South african populations. OBESITY RESEARCH 2002; 10:1207-16. [PMID: 12490664 DOI: 10.1038/oby.2002.165] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
OBJECTIVE Lower lipid and insulin levels are found during a glucose-tolerance test in obese black than obese white South African women. Therefore, beta-cell function and lipid metabolism were compared in these populations during a mixed meal. RESEARCH METHODS AND PROCEDURES Blood concentrations of glucose, free fatty acids (FFAs), insulin, lipograms, and in vivo FFA oxidation were determined at fasting and for 7 hours after oral administration of a mixed emulsion containing glucose-casein-sucrose-lipid and [1-(13)C] palmitic acid in 8 lean black women (LBW), 10 obese black women (OBW), 9 lean white women (LWW), and 10 obese white women (OWW). Subcutaneous and visceral fat mass was assessed by computerized tomography. RESULTS Visceral fat area was higher in OWW (152.7 +/- 17.0 cm(2)) than OBW (80.0 +/- 6.7 cm(2); p < 0.01). In OBW, 30-minute insulin levels were higher (604.3 +/- 117.6 pM) than OWW (311.0 +/- 42.9 pM; p < 0.05). Total triglyceride was higher in OWW (706.7 +/- 96.0 mM x 7 hours) than OBW (465.7 +/- 48.2 mM x 7 hours; p < 0.05) and correlated with visceral fat area (beta = 0.38, p = 0.05). Palmitate oxidation was higher in lean than obese women in both ethnic groups and correlated negatively with fat mass (beta = -0.58, p < 0.005). DISCUSSION The higher 30-minute insulin response in OBW may reflect a higher insulinotropic effect of FFAs or glucose. The elevated triglyceride level of OWW may be due to their higher visceral fat mass and possibly reduced clearance by adipose tissue.
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Affiliation(s)
- Chamindie Punyadeera
- Department of Chemical Pathology, National Health Laboratory Service, University of the Witwatersrand Faculty of Health Sciences, Johannesburg, South Africa
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Sobngwi E, Vexiau P, Levy V, Lepage V, Mauvais-Jarvis F, Leblanc H, Mbanya JC, Gautier JF. Metabolic and immunogenetic prediction of long-term insulin remission in African patients with atypical diabetes. Diabet Med 2002; 19:832-5. [PMID: 12358870 DOI: 10.1046/j.1464-5491.2002.00802.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
AIMS We aimed to characterize a cohort of 'atypical' diabetic patients of sub-Saharan African origin and to analyse possible determinants of long-term remission. METHODS Over 6 years, we studied the clinical and therapeutic profile of 42 consecutive patients undiagnosed or untreated prior to inclusion presenting with cardinal features of diabetes mellitus. We measured insulin secretion and sensitivity at inclusion. Immunogenetic (anti-GAD, anti-ICA and HLA class II) markers of Type 1 diabetes were compared with a 90-non-diabetic unrelated adult African population. RESULTS Twenty-one ketonuric patients (age 42 +/- 9 (sd) years; body mass index (BMI) 26 +/- 3 kg/m2) were initially insulin-treated (IT), and 21 non-ketonuric patients (age 38 +/- 8 years; BMI 26 +/- 5 kg/m2) had oral and/or diet therapy (NIT). Insulin could be discontinued in 47.6% (10/21) IT with adequate glycaemic control (HbA1c 6.7 +/- 1.3%), while insulin was secondarily started in 38.1% (8/21) NIT in expectation of better control. The initial basal (odds ratio (OR) 9.1, 95% confidence interval (CI) 1.3-64.4) and stimulated C-peptide (OR 8.17, 95% CI 1.5-44.1) were independently associated with remission. Insulin resistance was present in all the groups, more marked in the insulin-treated NIT. Anti-GAD antibodies and ICA were rare, but 38.1% IT vs. 1.1% controls had Type 1 diabetes HLA susceptibility haplotypes (P < 0.001) without significant difference between the subgroups. CONCLUSION Prolonged discontinuation of insulin is frequent in African diabetic patients initially presenting with signs of insulinopenia. In our patients, long-term insulin therapy was not associated with immunogenetic markers of Type 1 diabetes. The initial measure of insulin secretion seemed a good predictor of long-term remission.
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Affiliation(s)
- E Sobngwi
- Department of Diabetes and Metabolic Diseases, and Clinical Investigation Centre, Saint-Louis Hospital, Paris, France
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Gray IP, Cooper PA, Cory BJ, Toman M, Crowther NJ. The intrauterine environment is a strong determinant of glucose tolerance during the neonatal period, even in prematurity. J Clin Endocrinol Metab 2002; 87:4252-6. [PMID: 12213880 DOI: 10.1210/jc.2001-011961] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
The aim of this study was to determine the contribution of birth weight and gestational age to glucose tolerance in premature neonates. The study group consisted of 100 premature and/or small-for-gestational age infants. Anthropometric measurements were performed both at birth and at the time of a standardized milk feed carried out at 19.6 +/- 12.1 d (range, 1-65 d) after birth. Fasting and postprandial glucose and insulin levels were measured. Birth weight, as a proxy mirror of the intrauterine environment, was found to influence the glucose concentration following a standardized milk feed (beta = -0.46; P = 0.01 for birth weight z-score with 60-min glucose level), whereas gestational age did not. Small-for-gestational age neonates had higher 60-min insulin levels than appropriate-for-gestational age neonates (115.4 +/- 9.5 vs. 68.4 +/- 14.2; P < 0.05) despite similar glucose levels. Neonates born of mothers who were on antihypertensive treatment were smaller and had a higher insulin secretory response than neonates from normotensive mothers. Postnatal growth velocity (kilograms per day) correlated with birth weight (beta = -0.65; P < 0.0001) and insulin resistance (beta = -0.31; P = 0.0004), independently of each other. This study shows that glucose tolerance of the neonate is determined by weight attained at birth irrespective of gestational age and that maternal blood pressure may influence insulin sensitivity of the newborn. Furthermore, catch-up growth in neonates is determined by birth weight and insulin sensitivity.
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Affiliation(s)
- I P Gray
- Department of Chemical Pathology, University of the Witwatersrand and National Health Laboratory Service, Johannesburg, South Africa
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Punyadeera C, van der Merwe MT, Crowther NJ, Toman M, Immelman AR, Schlaphoff GP, Gray IP. Weight-related differences in glucose metabolism and free fatty acid production in two South African population groups. Int J Obes (Lond) 2001; 25:1196-205. [PMID: 11477505 DOI: 10.1038/sj.ijo.0801660] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2000] [Revised: 01/31/2001] [Accepted: 02/02/2001] [Indexed: 01/02/2023]
Abstract
OBJECTIVE The effects of free fatty acids (FFA), leptin, tumour necrosis factor (TNF) alpha and body fat distribution on in vivo oxidation of a glucose load were studied in two South African ethnic groups. DESIGN AND MEASUREMENTS Anthropometric and various metabolic indices were measured at fasting and during a 7 h oral glucose tolerance test (OGTT). Body composition was measured using bioelectrical impedance analysis and subcutaneous and visceral fat mass was assessed using a five- and two-level CT-scan respectively. Glucose oxidation was evaluated by measuring the ratio of (13)CO(2) to (12)CO(2) in breath following ingestion of 1-(13)C-labelled glucose. SUBJECTS Ten lean black women (LBW), ten obese black women (OBW), nine lean white women (LWW) and nine obese white women (OWW) were investigated after an overnight fast. RESULTS Visceral fat levels were significantly higher (P<0.01) in obese white than black women, despite similar body mass indexes (BMIs). There were no ethnic differences in glucose oxidation however; in the lean subjects of both ethnic groups the area under the curve (AUC) was higher than in obese subjects (P<0.05 for both) and was found to correlate negatively with weight (r=-0.69, P<0.01) after correcting for age. Basal TNF alpha concentrations were similar in all groups. Percentage suppression of FFAs at 30 min of the OGTT was 24+/-12% in OWW and -38+/-23% (P<0.05) in OBW, ie the 30 min FFA level was higher than the fasting level in the latter group. AUC for FFAs during the late postprandial period (120--420 min) was significantly higher in OWW than OBW (P<0.01) and LWW (P<0.01) and correlated positively with visceral fat mass independent of age (r=0.78, P<0.05) in the OWW only. Leptin levels were higher (P<0.01) both at fasting and during the course of the OGTT in obese women from both ethnic groups compared to the lean women. CONCLUSIONS Glucose oxidation is reduced in obese subjects of both ethnic groups; inter- and intra-ethnic differences were observed in visceral fat mass and FFA production and it is possible that such differences may play a role in the differing prevalences of obesity-related disorders that have been reported in these two populations.
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Affiliation(s)
- C Punyadeera
- Department of Chemical Pathology, University of the Witwatersrand Faculty of Health Sciences, Johannesburg, South Africa
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Punyadeera C, van der Merwe MT, Crowther N, Toman M, Schlaphoff G, Gray I. Ethnic differences in lipid metabolism in two groups of obese South African women. J Lipid Res 2001. [DOI: 10.1016/s0022-2275(20)31638-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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van der Merwe MT, Crowther NJ, Schlaphoff GP, Gray IP, Joffe BI, Lönnroth PN. Evidence for insulin resistance in black women from South Africa. Int J Obes (Lond) 2000; 24:1340-6. [PMID: 11093297 DOI: 10.1038/sj.ijo.0801416] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVE The rate of glucose disposal was determined in 10 black and 10 white obese nondiabetic urban women from South Africa to assess insulin resistance. DESIGN AND METHODS Euglycemic hyperinsulinemic clamp and body composition analysis. RESULTS Age, body mass index (BMI), anthropometric measurements and body composition were similar in both groups of women. A five-level computed tomography (CT) scan showed a similar mean subcutaneous fat mass in both groups of women (black obese women 555 +/- 9.0 vs white obese women 532 +/- 6.0 cm2), but less visceral fat in black obese women (90 +/- 3.0 vs 121 +/- 3.1 cm2; P< 0.05). Black obese women had higher fasting free fatty acid (997 +/- 69 vs 678 +/- 93 micromol/l; P < 0.05) and lactate concentrations (1,462 +/- 94 vs 1,038 +/- 39 micromol/l; P < 0.05), but lower fasting insulin levels (87 +/- 12 vs 155 +/- 9 pmol/l; P < 0.001). Black obese women also had a more favorable HDL: total cholesterol ratio (30.5% vs 23.0%; P< 0.04). The mean glucose disposal rate (M) and disposal expressed as glucose sensitivity index (M/I) were reduced in the black obese women vs white obese women (M: 7.1 +/- 0.8 vs 13.7 +/- 1.0 mmol/kg min(-1) x 100; P< 0.01, and M/I: 0.12 +/- 0.01 vs 0.24 +/- 0.02 mmol/kg x min(-1)/pmol/1 x 1,000; P < 0.01). Only black obese women showed a significant decrease in C-peptide levels during the clamp (2.9 +/- 0.22 vs 1.2 +/- 0.12 nmol/l; P<0.001). During the euglycemic period, the black obese women had higher lactate levels at all time points, but only the white obese women had increased lactate levels (918 +/- 66 to 1,300 +/- 53 micromol/l; P< 0.05). CONCLUSION Black obese women demonstrate a higher degree of insulin resistance, despite less visceral fat and a higher HDL: total-cholesterol ratio. In addition, endogenous beta-cell secretory function in black obese women appears to be more sensitive to the suppressive effect of exogenous insulin administration. The significant increase in lactate levels in white obese women confirms that they are more insulin sensitive.
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Affiliation(s)
- M T van der Merwe
- Carbohydrate and Lipid Metabolism Research Group, University of Witwatersrand Medical School, Johannesburg, South Africa.
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