1
|
Reed RM, Whyte MB, Goff LM. Cardiometabolic disease in Black African and Caribbean populations: an ethnic divergence in pathophysiology? Proc Nutr Soc 2023:1-11. [PMID: 38230432 DOI: 10.1017/s0029665123004895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2024]
Abstract
In the UK, populations of Black African and Caribbean (BAC) ethnicity suffer higher rates of cardiometabolic disease than White Europeans (WE). Obesity, leading to increased visceral adipose tissue (VAT) and intrahepatic lipid (IHL), has long been associated with cardiometabolic risk, driving insulin resistance and defective fatty acid/lipoprotein metabolism. These defects are compounded by a state of chronic low-grade inflammation, driven by dysfunctional adipose tissue. Emerging evidence has highlighted associations between central complement system components and adipose tissue, fatty acid metabolism and inflammation; it may therefore sit at the intersection of various cardiometabolic disease risk factors. However, increasing evidence suggests an ethnic divergence in pathophysiology, whereby current theories fail to explain the high rates of cardiometabolic disease in BAC populations. Lower fasting and postprandial TAG has been reported in BAC, alongside lower VAT and IHL deposition, which are paradoxical to the high rates of cardiometabolic disease exhibited by this ethnic group. Furthermore, BAC have been shown to exhibit a more anti-inflammatory profile, with lower TNF-α and greater IL-10. In contrast, recent evidence has revealed greater complement activation in BAC compared to WE, suggesting its dysregulation may play a greater role in the high rates of cardiometabolic disease experienced by this population. This review outlines the current theories of how obesity is proposed to drive cardiometabolic disease, before discussing evidence for ethnic differences in disease pathophysiology between BAC and WE populations.
Collapse
Affiliation(s)
- Reuben M Reed
- Department of Nutritional Sciences, Faculty of Life Sciences & Medicine, King's College London, London SE1 9NH, UK
| | - Martin B Whyte
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey GU2 7WG, UK
| | - Louise M Goff
- Leicester Diabetes Research Centre, University of Leicester, Leicester, UK
| |
Collapse
|
2
|
Hatano Y, VanWagner LB, Carnethon MR, Bancks MP, Carson AP, Lloyd-Jones DM, Østbye T, Viera AJ, Yano Y. Racial difference in the association between non-alcoholic fatty liver disease and incident type 2 diabetes: findings from the CARDIA study. Diabetologia 2023; 66:1235-1246. [PMID: 36941389 PMCID: PMC10286118 DOI: 10.1007/s00125-023-05903-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2023] [Accepted: 01/31/2023] [Indexed: 03/23/2023]
Abstract
AIMS/HYPOTHESIS Type 2 diabetes and non-alcoholic fatty liver disease (NAFLD) are prevalent diseases of metabolic origin. We examined the association between NAFLD and the development of type 2 diabetes among non-Asian adults, and whether the association differs by race. METHODS We analysed data from the Coronary Artery Risk Development in Young Adults (CARDIA) study, a population-based prospective cohort study. Participants underwent non-contrast abdominal computed tomography (CT) at baseline (2010-2011) and assessment of glucose measures at the follow-up exam (2015-2016). NAFLD was defined as liver attenuation ≤51 Hounsfield units on CT images after exclusion for other liver fat causes. Race was self-reported. We used targeted maximum likelihood estimation (TMLE) with machine-learning algorithms to estimate difference in type 2 diabetes risk between the NAFLD and non-NAFLD groups. RESULTS Of the 1995 participants without type 2 diabetes at baseline (mean age±SD, 50.0±3.6 years; 59% women; 55.0% White and 45.0% Black), 21.7% of White and 16.8% of Black participants had NAFLD at baseline, and 3.7% of White and 8.0% of Black participants developed type 2 diabetes at follow up. After multivariable adjustment, risk difference for type 2 diabetes associated with NAFLD vs no NAFLD was 4.1% (95% CI 0.3%, 7.9%) among White participants and -1.9% (95% CI -5.7%, 2.0%) in Black participants. CONCLUSIONS/INTERPRETATION NAFLD was associated with a higher risk of type 2 diabetes among White participants but not among Black participants. This finding suggests that the effect of liver fat on impaired glucose metabolism may be smaller in Black than in White individuals.
Collapse
Affiliation(s)
- Yu Hatano
- Department of Family Medicine and Community Health, Duke University, Durham, NC, USA.
| | - Lisa B VanWagner
- Division of Digestive Liver Diseases, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Mercedes R Carnethon
- Department of Preventive Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Michael P Bancks
- Department of Epidemiology and Prevention, Wake Forest University School of Medicine, Winston-Salem, NC, USA
| | - April P Carson
- Department of Medicine, University of Mississippi Medical Center, Jackson, MS, USA
| | - Donald M Lloyd-Jones
- Department of Preventive Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Truls Østbye
- Department of Family Medicine and Community Health, Duke University, Durham, NC, USA
| | - Anthony J Viera
- Department of Family Medicine and Community Health, Duke University, Durham, NC, USA
| | - Yuichiro Yano
- Department of Family Medicine and Community Health, Duke University, Durham, NC, USA
| |
Collapse
|
3
|
Meeks KA, Bentley AR, Agyemang C, Galenkamp H, van den Born BJH, Hanssen NM, Doumatey AP, Adeyemo AA, Rotimi CN. Ancestral and environmental patterns in the association between triglycerides and other cardiometabolic risk factors. EBioMedicine 2023; 91:104548. [PMID: 37004336 PMCID: PMC10102222 DOI: 10.1016/j.ebiom.2023.104548] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 03/14/2023] [Accepted: 03/16/2023] [Indexed: 04/03/2023] Open
Abstract
BACKGROUND West Africans and African Americans with substantial (∼80%) West African ancestry are characterized by low levels of triglycerides (TG) compared to East Africans and Europeans. The impact of these varying TG levels on other cardiometabolic risk factors is unclear. We compared the strength of association between TG with hypertension, blood pressure, BMI, waist circumference, type 2 diabetes (T2D), and fasting glucose across West African (WA), East African (EA), and European (EU) ancestry populations residing in three vastly different environmental settings: sub-Saharan Africa, United States, and Europe. METHODS We analysed data from four cross-sectional studies that included WA in sub-Saharan Africa (n = 7201), the U.S. (n = 4390), and Europe (n = 6436), EA in sub-Saharan Africa (n = 781), and EU in the U.S. (n = 8670) and Europe (n = 4541). Linear regression analyses were used to test the association between TG and cardiometabolic risk factors. FINDINGS Higher adjusted regression coefficients were observed in EU compared with WA ancestry for TG on hypertension (EU β [95% CI]: 0.179 [0.156, 0.203], WA β [95% CI]: 0.102 [0.086, 0.118]), BMI (EU β [95% CI]: 0.028 [0.027, 0.030], WA β [95% CI]: 0.015 [0.014, 0.016]), and waist circumference (EU β [95% CI]: 0.013 [0.013, 0.014], WA β [95% CI]: 0.009 [0.008, 0.009) (all ancestry × trait interaction P-values <0.05), irrespective of environmental differences within ancestry groups. Less consistency was observed among EA. Associations of TG with T2D did not follow ancestry patterns, with substantial variation observed between environments. INTERPRETATION TG may not be an equally strong associated with other established cardiometabolic risk factors in West and East Africans in contrast to European ancestry populations. The value of TG for identifying individuals at high risk for developing metabolic disorders needs to be re-evaluated for African ancestry populations. FUNDING National Institutes of Health, European Commission, Dutch Heart Foundation, Netherlands Organization for Health Research and Development, Centers for Disease Control and Prevention.
Collapse
|
4
|
Couch CA, Fowler LA, Goss AM, Gower BA. Associations of renal sinus fat with blood pressure and ectopic fat in a diverse cohort of adults. INTERNATIONAL JOURNAL OF CARDIOLOGY. CARDIOVASCULAR RISK AND PREVENTION 2023; 16:200165. [PMID: 36874041 PMCID: PMC9975207 DOI: 10.1016/j.ijcrp.2022.200165] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 12/04/2022] [Accepted: 12/10/2022] [Indexed: 12/23/2022]
Abstract
Background Renal sinus fat (RSF) is an ectopic fat depot shown to be associated with visceral adiposity and hypertension in predominantly white populations. The purpose of this analysis is to investigate RSF and associations between RSF and blood pressure in a cohort of African American (AA) and European American (EA) adults. A secondary purpose was to explore risk factors associated with RSF. Methods Participants were 116 A A and EA adult men and women. Ectopic fat depots were assessed with MRI: RSF, intraabdominal adipose tissue (IAAT), intermuscular adipose tissue (IMAT), perimuscular adipose tissue (PMAT), and liver fat. Cardiovascular measures included diastolic blood pressure (DBP), systolic blood pressure (SBP), pulse pressure, mean arterial pressure, and flow mediated dilation. Matsuda index was calculated for insulin sensitivity. Pearson correlations were used to investigate associations of RSF with cardiovascular measures. Multiple linear regression was used to evaluate contributions of RSF on SBP and DBP and to explore factors associated with RSF. Results No difference was observed in RSF between AA and EA participants. RSF was positively associated with DBP in AA participants, but this was not independent of age and sex. Age, male sex, and total body fat were positively associated with RSF in AA participants. Insulin sensitivity was inversely and IAAT and PMAT were positively associated with RSF in EA participants. Conclusions Differential associations of RSF with age, insulin sensitivity, and adipose depots among AA and EA adults suggest unique pathophysiological mechanisms influence RSF deposition, which may contribute to chronic disease etiology and progression.
Collapse
Affiliation(s)
- Catharine A. Couch
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Lauren A. Fowler
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Amy M. Goss
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Barbara A. Gower
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, AL, USA
| |
Collapse
|
5
|
Mendham AE, Micklesfield LK, Karpe F, Kengne AP, Chikowore T, Kufe CN, Masemola M, Crowther NJ, Norris SA, Olsson T, Elmståhl S, Fall T, Lind L, Goedecke JH. Targeted proteomics identifies potential biomarkers of dysglycaemia, beta cell function and insulin sensitivity in Black African men and women. Diabetologia 2023; 66:174-189. [PMID: 36114877 DOI: 10.1007/s00125-022-05788-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 06/09/2022] [Indexed: 12/13/2022]
Abstract
AIMS/HYPOTHESIS Using a targeted proteomics approach, we aimed to identify and validate circulating proteins associated with impaired glucose metabolism (IGM) and type 2 diabetes in a Black South African cohort. In addition, we assessed sex-specific associations between the validated proteins and pathophysiological pathways of type 2 diabetes. METHODS This cross-sectional study included Black South African men (n=380) and women (n=375) who were part of the Middle-Aged Soweto Cohort (MASC). Dual-energy x-ray absorptiometry was used to determine fat mass and visceral adipose tissue, and fasting venous blood samples were collected for analysis of glucose, insulin and C-peptide and for targeted proteomics, measuring a total of 184 pre-selected protein biomarkers. An OGTT was performed on participants without diabetes, and peripheral insulin sensitivity (Matsuda index), HOMA-IR, basal insulin clearance, insulin secretion (C-peptide index) and beta cell function (disposition index) were estimated. Participants were classified as having normal glucose tolerance (NGT; n=546), IGM (n=116) or type 2 diabetes (n=93). Proteins associated with dysglycaemia (IGM or type 2 diabetes) in the MASC were validated in the Swedish EpiHealth cohort (NGT, n=1706; impaired fasting glucose, n=550; type 2 diabetes, n=210). RESULTS We identified 73 proteins associated with dysglycaemia in the MASC, of which 34 were validated in the EpiHealth cohort. Among these validated proteins, 11 were associated with various measures of insulin dynamics, with the largest number of proteins being associated with HOMA-IR. In sex-specific analyses, IGF-binding protein 2 (IGFBP2) was associated with lower HOMA-IR in women (coefficient -0.35; 95% CI -0.44, -0.25) and men (coefficient -0.09; 95% CI -0.15, -0.03). Metalloproteinase inhibitor 4 (TIMP4) was associated with higher insulin secretion (coefficient 0.05; 95% CI 0.001, 0.11; p for interaction=0.025) and beta cell function (coefficient 0.06; 95% CI 0.02, 0.09; p for interaction=0.013) in women only. In contrast, a stronger positive association between IGFBP2 and insulin sensitivity determined using an OGTT (coefficient 0.38; 95% CI 0.27, 0.49) was observed in men (p for interaction=0.004). A posteriori analysis showed that the associations between TIMP4 and insulin dynamics were not mediated by adiposity. In contrast, most of the associations between IGFBP2 and insulin dynamics, except for insulin secretion, were mediated by either fat mass index or visceral adipose tissue in men and women. Fat mass index was the strongest mediator between IGFBP2 and insulin sensitivity (total effect mediated 40.7%; 95% CI 37.0, 43.6) and IGFBP2 and HOMA-IR (total effect mediated 39.1%; 95% CI 31.1, 43.5) in men. CONCLUSIONS/INTERPRETATION We validated 34 proteins that were associated with type 2 diabetes, of which 11 were associated with measures of type 2 diabetes pathophysiology such as peripheral insulin sensitivity and beta cell function. This study highlights biomarkers that are similar between cohorts of different ancestry, with different lifestyles and sociodemographic profiles. The African-specific biomarkers identified require validation in African cohorts to identify risk markers and increase our understanding of the pathophysiology of type 2 diabetes in African populations.
Collapse
Affiliation(s)
- Amy E Mendham
- South African Medical Research Council/WITS Developmental Pathways for Health Research Unit, Department of Paediatrics, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
- Health through Physical Activity, Lifestyle and Sport Research Centre, International Federation of Sports Medicine (FIMS), International Collaborating Centre of Sports Medicine, Division of Physiological Sciences, Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.
| | - Lisa K Micklesfield
- South African Medical Research Council/WITS Developmental Pathways for Health Research Unit, Department of Paediatrics, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Fredrik Karpe
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Oxford, UK
- National Institute for Health and Care Research, Oxford Biomedical Research Centre, Oxford University Hospitals Foundation Trust, Oxford, UK
| | - Andre Pascal Kengne
- Biomedical Research and Innovation Platform and Non-Communicable Diseases Research Unit, South African Medical Research Council, Cape Town, South Africa
| | - Tinashe Chikowore
- South African Medical Research Council/WITS Developmental Pathways for Health Research Unit, Department of Paediatrics, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Clement N Kufe
- South African Medical Research Council/WITS Developmental Pathways for Health Research Unit, Department of Paediatrics, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
- Epidemiology and Surveillance Section, National Institute for Occupational Health, National Health Laboratory Service, Johannesburg, South Africa
| | - Maphoko Masemola
- South African Medical Research Council/WITS Developmental Pathways for Health Research Unit, Department of Paediatrics, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Nigel J Crowther
- Department of Chemical Pathology, National Health Laboratory Service and University of the Witwatersrand Faculty of Health Sciences, Johannesburg, South Africa
| | - Shane A Norris
- South African Medical Research Council/WITS Developmental Pathways for Health Research Unit, Department of Paediatrics, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
- School of Human Development and Health, University of Southampton, Southampton, UK
| | - Tommy Olsson
- Department of Public Health and Clinical Medicine, Medicine, Umeå University, Umeå, Sweden
| | - Sölve Elmståhl
- Department of Clinical Sciences in Malmö, Division of Geriatric Medicine, Lund University, Lund, Sweden
- Clinical Research Centre, Skåne University Hospital, Malmö, Sweden
| | - Tove Fall
- Department of Medical Sciences, Molecular Epidemiology and Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Lars Lind
- Department of Medical Sciences, Uppsala University Hospital, Uppsala University, Uppsala, Sweden
| | - Julia H Goedecke
- South African Medical Research Council/WITS Developmental Pathways for Health Research Unit, Department of Paediatrics, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
- Health through Physical Activity, Lifestyle and Sport Research Centre, International Federation of Sports Medicine (FIMS), International Collaborating Centre of Sports Medicine, Division of Physiological Sciences, Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- Biomedical Research and Innovation Platform and Non-Communicable Diseases Research Unit, South African Medical Research Council, Cape Town, South Africa
| |
Collapse
|
6
|
Durdin R, Parsons C, Dennison EM, Williams S, Tillin T, Chaturvedi N, Cooper C, Harvey NC, Ward KA. Inflammatory status, body composition and ethnic differences in bone mineral density: The Southall and Brent Revisited Study. Bone 2022; 155:116286. [PMID: 34890861 PMCID: PMC8755916 DOI: 10.1016/j.bone.2021.116286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 11/19/2021] [Accepted: 12/02/2021] [Indexed: 11/25/2022]
Abstract
Ethnic differences in bone mineral density (BMD) and fracture risk are well-described; the aim of this study was to investigate whether central adiposity or inflammatory status contribute to these ethnic differences in BMD in later life. The Southall and Brent Revisited study (SABRE) is a UK-based tri-ethnic cohort of men and women of European, South Asian or African Caribbean origin. At the most recent SABRE follow-up (2014-2018), in addition to measures of cardiometabolic phenotype, participants had dual-energy X-ray absorptiometry (DXA) bone and body composition scans. Multiple linear regression was used to determine whether markers of body composition, central adiposity or inflammatory status contributed to ethnic differences in BMD. In men and women, age- and height-adjusted BMD at all sites was higher in African Caribbeans compared to Europeans (femoral neck: standardised β (95% confidence interval): men: 1.00SD (0.75, 1.25); women: 0.77SD (0.56, 0.99)). South Asian men had higher BMD than European men at the hip (femoral neck: 0.34SD (95%CI: 0.15, 0.54)). Although adjustment for body mass index (BMI) or lean mass index (LMI) at the lumbar spine reduced the size of the difference in BMD between African Caribbean and European men (age and height adjusted difference: 0.35SD (0.08, 0.62); age and BMI adjusted difference: 0.25SD (-0.02, 0.51)), in both men and women ethnic differences remained after adjustment for measures of central adiposity (estimated visceral adipose tissue mass (VAT mass) and android to gynoid ratio) and inflammation (interleukin-6 (logIL-6) and C-reactive protein (logCRP)). Furthermore, in women, we observed ethnic differences in the relationship between BMI (overall interaction: p = 0.04), LMI (p = 0.04) or VAT mass (p = 0.009) and standardised lumbar spine BMD. In this tri-ethnic cohort, ethnic differences in BMD at the femoral neck, total hip or lumbar spine were not explained by BMI, central adiposity or inflammatory status. Given ethnic differences in fracture incidence, it is important to further investigate why ethnic differences in BMD exist.
Collapse
Affiliation(s)
- Ruth Durdin
- MRC Lifecourse Epidemiology Centre, University of Southampton, Southampton General Hospital, Southampton, UK; National Institute for Health Research Southampton Biomedical Research Centre, University of Southampton and University Hospital Southampton NHS Foundation Trust, Southampton, UK
| | - Camille Parsons
- MRC Lifecourse Epidemiology Centre, University of Southampton, Southampton General Hospital, Southampton, UK
| | - Elaine M Dennison
- MRC Lifecourse Epidemiology Centre, University of Southampton, Southampton General Hospital, Southampton, UK; National Institute for Health Research Southampton Biomedical Research Centre, University of Southampton and University Hospital Southampton NHS Foundation Trust, Southampton, UK
| | - Suzanne Williams
- MRC Unit for Lifelong Health and Ageing, University College London, London, UK
| | - Therese Tillin
- MRC Unit for Lifelong Health and Ageing, University College London, London, UK
| | - Nishi Chaturvedi
- MRC Unit for Lifelong Health and Ageing, University College London, London, UK
| | - Cyrus Cooper
- MRC Lifecourse Epidemiology Centre, University of Southampton, Southampton General Hospital, Southampton, UK; National Institute for Health Research Southampton Biomedical Research Centre, University of Southampton and University Hospital Southampton NHS Foundation Trust, Southampton, UK; Institute of Musculoskeletal Science, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Science, University of Oxford, Oxford, UK
| | - Nicholas C Harvey
- MRC Lifecourse Epidemiology Centre, University of Southampton, Southampton General Hospital, Southampton, UK; National Institute for Health Research Southampton Biomedical Research Centre, University of Southampton and University Hospital Southampton NHS Foundation Trust, Southampton, UK; Institute of Musculoskeletal Science, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Science, University of Oxford, Oxford, UK
| | - Kate A Ward
- MRC Lifecourse Epidemiology Centre, University of Southampton, Southampton General Hospital, Southampton, UK; National Institute for Health Research Southampton Biomedical Research Centre, University of Southampton and University Hospital Southampton NHS Foundation Trust, Southampton, UK.
| |
Collapse
|
7
|
Reed RM, Nevitt SJ, Kemp GJ, Cuthbertson DJ, Whyte MB, Goff LM. Ectopic fat deposition in populations of black African ancestry: A systematic review and meta-analysis. Acta Diabetol 2022; 59:171-187. [PMID: 34518896 PMCID: PMC8841318 DOI: 10.1007/s00592-021-01797-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 09/02/2021] [Indexed: 02/07/2023]
Abstract
AIMS In populations of black African ancestry (BA), a paradox exists whereby lower visceral adipose tissue is found despite their high risk for type 2 diabetes (T2D). This systematic review investigates ethnic differences in other ectopic fat depots (intrahepatic lipid: IHL; intramyocellular lipid: IMCL and intrapancreatic lipid; IPL) to help contextualise their potential contribution to T2D risk. METHODS A systematic literature search was performed in December 2020 to identify studies reporting at least one ectopic fat comparison between BA and one/more other ethnicity. For IHL, a meta-analysis was carried out with studies considered comparable based on the method of measurement. RESULTS Twenty-eight studies were included (IHL: n = 20; IMCL: n = 8; IPL: n = 4). Meta-analysis of 11 studies investigating IHL revealed that it was lower in BA populations vs pooled ethnic comparators (MD -1.35%, 95% CI -1.55 to -1.16, I2 = 85%, P < 0.00001), white European ancestry (MD -0.94%, 95% CI -1.17 to -0.70, I2 = 79%, P < 0.00001), Hispanic ancestry (MD -2.06%, 95% CI -2.49 to -1.63, I2 = 81%, P < 0.00001) and South Asian ancestry comparators (MD -1.92%, 95% CI -3.26 to -0.57, I2 = 78%, P = 0.005). However, heterogeneity was high in all analyses. Most studies found no significant differences in IMCL between BA and WE. Few studies investigated IPL, however, indicated that IPL is lower in BA compared to WE and HIS. CONCLUSION The discordance between ectopic fat and greater risk for T2D in BA populations raises questions around its contribution to T2D pathophysiology in BA.
Collapse
Affiliation(s)
- Reuben M Reed
- Department of Nutritional Sciences, Faculty of Life Sciences & Medicine, King's College London, London, UK
| | - Sarah J Nevitt
- Department of Health Data Science, Institute of Population Health, University of Liverpool, Liverpool, UK
| | - Graham J Kemp
- Department of Musculoskeletal and Ageing Science. Institute of Life Course and Medical Sciences, Liverpool Magnetic Resonance Imaging Centre (LiMRIC), University of Liverpool, Liverpool, UK
| | - Daniel J Cuthbertson
- Department of Cardiovascular and Metabolic Medicine, Institute of Life Course Sciences, University of Liverpool, Liverpool, UK
| | - Martin B Whyte
- Faculty of Health & Medical Sciences, University of Surrey, Guildford, Surrey, UK
| | - Louise M Goff
- Department of Nutritional Sciences, Faculty of Life Sciences & Medicine, King's College London, London, UK.
| |
Collapse
|
8
|
Ladwa M, Bello O, Hakim O, Shojaee-Moradie F, Boselli ML, Charles-Edwards G, Peacock J, Umpleby AM, Amiel SA, Bonadonna RC, Goff LM. Ethnic differences in beta cell function occur independently of insulin sensitivity and pancreatic fat in black and white men. BMJ Open Diabetes Res Care 2021; 9:9/1/e002034. [PMID: 33762314 PMCID: PMC7993168 DOI: 10.1136/bmjdrc-2020-002034] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 01/21/2021] [Accepted: 02/11/2021] [Indexed: 12/12/2022] Open
Abstract
INTRODUCTION It is increasingly recognized that type 2 diabetes (T2D) is a heterogenous disease with ethnic variations. Differences in insulin secretion, insulin resistance and ectopic fat are thought to contribute to these variations. Therefore, we aimed to compare postprandial insulin secretion and the relationships between insulin secretion, insulin sensitivity and pancreatic fat in men of black West African (BA) and white European (WE) ancestry. RESEARCH DESIGN AND METHODS A cross-sectional, observational study in which 23 WE and 23 BA men with normal glucose tolerance, matched for body mass index, underwent a mixed meal tolerance test with C peptide modeling to measure beta cell insulin secretion, an MRI to quantify intrapancreatic lipid (IPL), and a hyperinsulinemic-euglycemic clamp to measure whole-body insulin sensitivity. RESULTS Postprandial insulin secretion was lower in BA versus WE men following adjustment for insulin sensitivity (estimated marginal means, BA vs WE: 40.5 (95% CI 31.8 to 49.2) × 103 vs 56.4 (95% CI 48.9 to 63.8) × 103 pmol/m2 body surface area × 180 min, p=0.008). There was a significantly different relationship by ethnicity between IPL and insulin secretion, with a stronger relationship in WE than in BA (r=0.59 vs r=0.39, interaction p=0.036); however, IPL was not a predictor of insulin secretion in either ethnic group following adjustment for insulin sensitivity. CONCLUSIONS Ethnicity is an independent determinant of beta cell function in black and white men. In response to a meal, healthy BA men exhibit lower insulin secretion compared with their WE counterparts for their given insulin sensitivity. Ethnic differences in beta cell function may contribute to the greater risk of T2D in populations of African ancestry.
Collapse
Affiliation(s)
- Meera Ladwa
- Department of Diabetes, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Oluwatoyosi Bello
- Diabetes and Nutritional Sciences Division, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Olah Hakim
- Diabetes and Nutritional Sciences Division, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | | | | | - Geoff Charles-Edwards
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
| | - Janet Peacock
- Department of Epidemiology, Dartmouth College Geisel School of Medicine, Hanover, New Hampshire, USA
| | - A Margot Umpleby
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, UK
| | - Stephanie A Amiel
- Department of Diabetes, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Riccardo C Bonadonna
- Department of Medicine and Surgery, University of Parma, Parma, Italy
- Endocrinologia e Malattie del Metabolismo, Azienda Ospedaliero-Universitaria di Parma, Parma, Italy
| | - Louise M Goff
- Diabetes and Nutritional Sciences Division, Faculty of Life Sciences and Medicine, King's College London, London, UK
| |
Collapse
|
9
|
Hydes T, Alam U, Cuthbertson DJ. The Impact of Macronutrient Intake on Non-alcoholic Fatty Liver Disease (NAFLD): Too Much Fat, Too Much Carbohydrate, or Just Too Many Calories? Front Nutr 2021; 8:640557. [PMID: 33665203 PMCID: PMC7921724 DOI: 10.3389/fnut.2021.640557] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 01/27/2021] [Indexed: 12/13/2022] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) is a growing epidemic, in parallel with the obesity crisis, rapidly becoming one of the commonest causes of chronic liver disease worldwide. Diet and physical activity are important determinants of liver fat accumulation related to insulin resistance, dysfunctional adipose tissue, and secondary impaired lipid storage and/or increased lipolysis. While it is evident that a hypercaloric diet (an overconsumption of calories) promotes liver fat accumulation, it is also clear that the macronutrient composition can modulate this risk. A number of other baseline factors modify the overfeeding response, which may be genetic or environmental. Although it is difficult to disentangle the effects of excess calories vs. specifically the individual effects of excessive carbohydrates and/or fats, isocaloric, and hypercaloric dietary intervention studies have been implemented to provide insight into the effects of different macronutrients, sub-types and their relative balance, on the regulation of liver fat. What has emerged is that different types of fat and carbohydrates differentially influence liver fat accumulation, even when diets are isocaloric. Furthermore, distinct molecular and metabolic pathways mediate the effects of carbohydrates and fat intake on hepatic steatosis. Fat accumulation appears to act through impairments in lipid storage and/or increased lipolysis, whereas carbohydrate consumption has been shown to promote liver fat accumulation through de novo lipogenesis. Effects differ dependent upon carbohydrate and fat type. Saturated fat and fructose induce the greatest increase in intrahepatic triglycerides (IHTG), insulin resistance, and harmful ceramides compared with unsaturated fats, which have been found to be protective. Decreased intake of saturated fats and avoidance of added sugars are therefore the two most important dietary interventions that can lead to a reduction in IHTG and potentially the associated risk of developing type 2 diabetes. A healthy and balanced diet and regular physical activity must remain the cornerstones of effective lifestyle intervention to prevent the development and progression of NAFLD. Considering the sub-type of each macronutrient, in addition to the quantity, are critical determinants of liver health.
Collapse
Affiliation(s)
- Theresa Hydes
- Department of Metabolic and Cardiovascular Medicine, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, United Kingdom.,Liverpool University Hospitals NHS Foundation Trust, Liverpool, United Kingdom
| | - Uazman Alam
- Department of Metabolic and Cardiovascular Medicine, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, United Kingdom.,Liverpool University Hospitals NHS Foundation Trust, Liverpool, United Kingdom
| | - Daniel J Cuthbertson
- Department of Metabolic and Cardiovascular Medicine, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, United Kingdom.,Liverpool University Hospitals NHS Foundation Trust, Liverpool, United Kingdom
| |
Collapse
|
10
|
Lind L, Salihovic S, Risérus U, Kullberg J, Johansson L, Ahlström H, Eriksson JW, Oscarsson J. The Plasma Metabolomic Profile is Differently Associated with Liver Fat, Visceral Adipose Tissue, and Pancreatic Fat. J Clin Endocrinol Metab 2021; 106:e118-e129. [PMID: 33123723 PMCID: PMC7765636 DOI: 10.1210/clinem/dgaa693] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 08/21/2020] [Indexed: 12/16/2022]
Abstract
CONTEXT Metabolic differences between ectopic fat depots may provide novel insights to obesity-related diseases. OBJECTIVE To investigate the plasma metabolomic profiles in relation to visceral adipose tissue (VAT) volume and liver and pancreas fat percentages. DESIGN Cross-sectional. SETTING Multicenter at academic research laboratories. PATIENTS Magnetic resonance imaging (MRI) was used to assess VAT volume, the percentage of fat in the liver and pancreas (proton density fat fraction [PDFF]) at baseline in 310 individuals with a body mass index ≥ 25 kg/m2 and with serum triglycerides ≥ 1.7 mmol/l and/or type 2 diabetes screened for inclusion in the 2 effect of omega-3 carboxylic acid on liver fat content studies. INTERVENTION None. MAIN OUTCOME MEASURE Metabolomic profiling with mass spectroscopy enabled the determination of 1063 plasma metabolites. RESULTS Thirty metabolites were associated with VAT volume, 31 with liver PDFF, and 2 with pancreas PDFF when adjusting for age, sex, total body fat mass, and fasting glucose. Liver PDFF and VAT shared 4 metabolites, while the 2 metabolites related to pancreas PDFF were unique. The top metabolites associated with liver PDFF were palmitoyl-palmitoleoyl-GPC (16:0/16:1), dihydrosphingomyelin (d18:0/22:0), and betaine. The addition of these metabolites to the Liver Fat Score improved C-statistics significantly (from 0.776 to 0.861, P = 0.0004), regarding discrimination of liver steatosis. CONCLUSION Liver PDFF and VAT adipose tissue shared several metabolic associations, while those were not shared with pancreatic PDFF, indicating partly distinct metabolic profiles associated with different ectopic fat depots. The addition of 3 metabolites to the Liver Fat Score improved the prediction of liver steatosis.
Collapse
Affiliation(s)
- Lars Lind
- Department of Medical Sciences, Uppsala University, Uppsala, Sweden
- Correspondence and Reprint Requests: Lars Lind, MD, Professor, Department of Medical Sciences, Uppsala University, SE-751 85 Uppsala, Sweden.
| | | | - Ulf Risérus
- Department of Public Health and Caring Sciences, Clinical Nutrition and Metabolism, Uppsala University, Uppsala, Sweden
| | - Joel Kullberg
- Antaros Medical AB, Gothenburg, Sweden
- Department of Surgical Sciences, Radiology, Uppsala University, Uppsala, Sweden
| | | | - Håkan Ahlström
- Antaros Medical AB, Gothenburg, Sweden
- Department of Surgical Sciences, Radiology, Uppsala University, Uppsala, Sweden
| | - Jan W Eriksson
- Department of Medical Sciences, Uppsala University, Uppsala, Sweden
| | - Jan Oscarsson
- BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| |
Collapse
|
11
|
Hakim O, Bello O, Ladwa M, Peacock JL, Umpleby AM, Charles-Edwards G, Amiel SA, Goff LM. The Link between Obesity and Inflammatory Markers in the Development of Type 2 Diabetes in Men of Black African and White European Ethnicity. Nutrients 2020; 12:nu12123796. [PMID: 33322261 PMCID: PMC7764810 DOI: 10.3390/nu12123796] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 12/08/2020] [Accepted: 12/09/2020] [Indexed: 12/16/2022] Open
Abstract
In this study, we aimed to assess ethnic differences in visceral (VAT), deep subcutaneous (dSAT), and superficial subcutaneous (sSAT) adipose tissue and their relationships with inflammatory markers between white European (WE) and black West African (BWA) men with normal glucose tolerance (NGT) and type 2 diabetes (T2D). Forty-two WE (23 NGT/19 T2D) and 43 BWA (23 NGT/20 T2D) men underwent assessment of plasma inflammatory markers using immunoassays alongside Dixon magnetic resonance imaging to quantify L4-5 VAT, dSAT and sSAT. Despite no ethnic differences in sSAT and dSAT, BWA men exhibited lower VAT (p = 0.002) and dSAT:sSAT (p = 0.047) than WE men. Adiponectin was inversely associated with sSAT in WE (p = 0.041) but positively associated in BWA (p = 0.031) men with T2D. Interleukin-6 (IL-6) was associated with VAT in WE but not in BWA men with NGT (WE: p = 0.009, BWA: p = 0.137) and T2D (WE: p = 0.070, BWA: p = 0.175). IL-6 was associated with dSAT in only WE men with NGT (WE: p = 0.030, BWA: p = 0.833). The only significant ethnicity interaction present was for the relationship between adiponectin and sSAT (Pinteraction = 0.003). The favourable adipose tissue distribution and the weaker relationships between adiposity and inflammation in BWA men suggest that adipose tissue inflammation may play a lesser role in T2D in BWA than WE men.
Collapse
Affiliation(s)
- Olah Hakim
- Diabetes Research Group, Departments of Diabetes & Nutritional Sciences, School of Life Course Sciences, Faculty of Life Sciences & Medicine, King’s College London, Waterloo Campus, Franklin-Wilkins Building, Room 3.87, London SE1 9NH, UK; (O.H.); (O.B.); (M.L.); (S.A.A.)
| | - Oluwatoyosi Bello
- Diabetes Research Group, Departments of Diabetes & Nutritional Sciences, School of Life Course Sciences, Faculty of Life Sciences & Medicine, King’s College London, Waterloo Campus, Franklin-Wilkins Building, Room 3.87, London SE1 9NH, UK; (O.H.); (O.B.); (M.L.); (S.A.A.)
| | - Meera Ladwa
- Diabetes Research Group, Departments of Diabetes & Nutritional Sciences, School of Life Course Sciences, Faculty of Life Sciences & Medicine, King’s College London, Waterloo Campus, Franklin-Wilkins Building, Room 3.87, London SE1 9NH, UK; (O.H.); (O.B.); (M.L.); (S.A.A.)
| | - Janet L. Peacock
- Department of Epidemiology, Geisel School of Medicine at Dartmouth, Dartmouth College, Hanover, NH 03755-1404, USA;
- School of Population Health and Environmental Sciences, King’s College London, London SE1 7EH, UK
| | - A. Margot Umpleby
- Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7XH, UK;
| | - Geoffrey Charles-Edwards
- Medical Physics, Guy’s & St Thomas’ NHS Foundation Trust, London SE1 7EH, UK;
- School of Biomedical Engineering & Imaging Sciences, King’s College London, London SE1 7EH, UK
| | - Stephanie A. Amiel
- Diabetes Research Group, Departments of Diabetes & Nutritional Sciences, School of Life Course Sciences, Faculty of Life Sciences & Medicine, King’s College London, Waterloo Campus, Franklin-Wilkins Building, Room 3.87, London SE1 9NH, UK; (O.H.); (O.B.); (M.L.); (S.A.A.)
| | - Louise M. Goff
- Diabetes Research Group, Departments of Diabetes & Nutritional Sciences, School of Life Course Sciences, Faculty of Life Sciences & Medicine, King’s College London, Waterloo Campus, Franklin-Wilkins Building, Room 3.87, London SE1 9NH, UK; (O.H.); (O.B.); (M.L.); (S.A.A.)
- Correspondence: ; Tel.: +44-(0)20-7848-6111
| |
Collapse
|
12
|
Ladwa M, Bello O, Hakim O, Shojaee-Moradie F, Boselli L, Charles-Edwards G, Stadler M, Peacock JL, Umpleby AM, Amiel SA, Bonadonna RC, Goff LM. Insulin clearance as the major player in the hyperinsulinaemia of black African men without diabetes. Diabetes Obes Metab 2020; 22:1808-1817. [PMID: 32488928 DOI: 10.1111/dom.14101] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 05/14/2020] [Accepted: 05/27/2020] [Indexed: 12/14/2022]
Abstract
AIM To investigate relationships between insulin clearance, insulin secretion, hepatic fat accumulation and insulin sensitivity in black African (BA) and white European (WE) men. METHODS Twenty-three BA and twenty-three WE men with normal glucose tolerance, matched for age and body mass index, underwent a hyperglycaemic clamp to measure insulin secretion and clearance, hyperinsulinaemic-euglycaemic clamp with stable glucose isotope infusion to measure whole-body and hepatic-specific insulin sensitivity, and magnetic resonance imaging to quantify intrahepatic lipid (IHL). RESULTS BA men had higher glucose-stimulated peripheral insulin levels (48.1 [35.5, 65.2] × 103 vs. 29.9 [23.3, 38.4] × 103 pmol L-1 × min, P = .017) and lower endogeneous insulin clearance (771.6 [227.8] vs. 1381 [534.3] mL m-2 body surface area min -1 , P < .001) compared with WE men. There were no ethnic differences in beta-cell insulin secretion or beta-cell responsivity to glucose, even after adjustment for prevailing insulin sensitivity. In WE men, endogenous insulin clearance was correlated with whole-body insulin sensitivity (r = 0.691, P = .001) and inversely correlated with IHL (r = -0.674, P = .001). These associations were not found in BA men. CONCLUSIONS While normally glucose-tolerant BA men have similar insulin secretory responses to their WE counterparts, they have markedly lower insulin clearance, which does not appear to be explained by either insulin resistance or hepatic fat accumulation. Low insulin clearance may be the primary mechanism of hyperinsulinaemia in populations of African origin.
Collapse
Affiliation(s)
- Meera Ladwa
- Department of Diabetes, School of Life Course Sciences, Faculty of Life Sciences & Medicine, King's College London, London, UK
| | - Oluwatoyosi Bello
- Department of Diabetes, School of Life Course Sciences, Faculty of Life Sciences & Medicine, King's College London, London, UK
| | - Olah Hakim
- Department of Diabetes, School of Life Course Sciences, Faculty of Life Sciences & Medicine, King's College London, London, UK
| | | | - Linda Boselli
- Division of Endocrinology and Metabolic Disease, University of Verona School of Medicine, Verona, Italy
| | - Geoff Charles-Edwards
- School of Biomedical Engineering & Imaging Sciences, King's College London, London, UK
| | - Marietta Stadler
- Department of Diabetes, School of Life Course Sciences, Faculty of Life Sciences & Medicine, King's College London, London, UK
| | - Janet L Peacock
- School of Population Health and Environmental Sciences, King's College London, London, UK
| | | | - Stephanie A Amiel
- Department of Diabetes, School of Life Course Sciences, Faculty of Life Sciences & Medicine, King's College London, London, UK
| | - Riccardo C Bonadonna
- Department of Medicine & Surgery, University of Parma and Azienda Ospedaliera Universitaria di Parma, Parma, Italy
| | - Louise M Goff
- Department of Diabetes, School of Life Course Sciences, Faculty of Life Sciences & Medicine, King's College London, London, UK
| |
Collapse
|
13
|
Rønn PF, Andersen GS, Lauritzen T, Christensen DL, Aadahl M, Carstensen B, Grarup N, Jørgensen ME. Abdominal visceral and subcutaneous adipose tissue and associations with cardiometabolic risk in Inuit, Africans and Europeans: a cross-sectional study. BMJ Open 2020; 10:e038071. [PMID: 32928857 PMCID: PMC7490939 DOI: 10.1136/bmjopen-2020-038071] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
OBJECTIVES Abdominal fat has been identified as a risk marker of cardiometabolic disease independent of overall adiposity. However, it is not clear whether there are ethnic disparities in this risk. We investigated the associations of visceral adipose tissue (VAT) and abdominal subcutaneous adipose tissue (SAT) with cardiometabolic risk factors in three ethnic diverse populations of Inuit, Africans and Europeans. DESIGN Cross-sectional pooled study. SETTING Greenland, Kenya and Denmark. METHODS A total of 5113 participants (2933 Inuit, 1397 Africans and 783 Europeans) from three studies in Greenland, Kenya and Denmark were included. Measurements included abdominal fat distribution assessed by ultrasound, oral glucose tolerance test, hepatic insulin resistance, blood pressure and lipids. The associations were analysed using multiple linear regressions. RESULTS Across ethnic group and gender, an increase in VAT of 1 SD was associated with higher levels of hepatic insulin resistance (ranging from 14% to 28%), triglycerides (8% to 16%) and lower high-density lipoprotein cholesterol (HDL-C, -1.0 to -0.05 mmol/L) independent of body mass index. VAT showed positive associations with most of the other cardiometabolic risk factors in Inuit and Europeans, but not in Africans. In contrast, SAT was mainly associated with the outcomes in Inuit and Africans. Of notice was that higher SAT was associated with higher HDL-C in African men (0.11 mmol/L, 95% CI: 0.03 to 0.18) and with lower HDL-C in Inuit (-0.07 mmol/L, 95% CI: -0.12 to -0.02), but not in European men (-0.02 mmol/L, 95% CI: -0.09 to 0.05). Generally weaker associations were observed for women. Furthermore, the absolute levels of several of the cardiometabolic outcomes differed between the ethnic groups. CONCLUSIONS VAT and SAT were associated with several of the cardiometabolic risk factors beyond overall adiposity. Some of these associations were specific to ethnicity, suggesting that ethnicity plays a role in the pathway from abdominal fat to selected cardiometabolic risk factors.
Collapse
Affiliation(s)
- Pernille Falberg Rønn
- Clinical Epidemiology, Steno Diabetes Center Copenhagen, Gentofte, Denmark
- Department of Public Health, Centre for Arctic Health, Aarhus University, Aarhus, Denmark
| | | | - Torsten Lauritzen
- Department of Public Health, General Practice, Aarhus University, Aarhus, Denmark
| | - Dirk Lund Christensen
- Department of Public Health, Global Health Section, University of Copenhagen, Copenhagen, Denmark
| | - Mette Aadahl
- Center for Clinical Research and Prevention, Frederiksberg and Bispebjerg Hospital, Frederiksberg, Denmark
- Department of Public Health, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Bendix Carstensen
- Clinical Epidemiology, Steno Diabetes Center Copenhagen, Gentofte, Denmark
| | - Niels Grarup
- Novo Nordisk Foundation, Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Kobenhavn, Denmark
| | - Marit Eika Jørgensen
- Clinical Epidemiology, Steno Diabetes Center Copenhagen, Gentofte, Denmark
- National Institute of Public Health, University of Southern Denmark, Copenhagen, Denmark
- Greenland University, Nuuk, Greenland
| |
Collapse
|
14
|
Goedecke JH, Olsson T. Pathogenesis of type 2 diabetes risk in black Africans: a South African perspective. J Intern Med 2020; 288:284-294. [PMID: 32303113 DOI: 10.1111/joim.13083] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 02/25/2020] [Accepted: 03/02/2020] [Indexed: 12/16/2022]
Abstract
The prevalence of type 2 diabetes (T2D) is higher in black Africans than their European counterparts. This review summarizes the research exploring the pathogenesis of T2D in populations of African ancestry compared to white Europeans and shows that the pathogenesis differs by ethnicity. Black Africans present with a phenotype of low insulin sensitivity and hyperinsulinaemia as a result of increased insulin secretion and reduced hepatic insulin clearance. Whether hyperinsulinaemia precedes insulin resistance or is merely a compensatory mechanism is yet to be determined. Black Africans have lower visceral adipose tissue and ectopic fat deposition and greater peripheral (gluteo-femoral) fat deposition than their European counterparts. This suggests that black Africans are more sensitive to the effects of ectopic fat deposition, or alternatively, that ectopic fat is not an important mediator of T2D in black Africans. Importantly, ethnic disparities in T2D risk factors may be confounded by differences in sociocultural and lifestyle factors. Future longitudinal and dietary intervention studies, in combination with genetic analyses, are needed for a better understanding of the pathophysiology of T2D in black Africans. This will be key for effective prevention and management strategies.
Collapse
Affiliation(s)
- J H Goedecke
- From the, Non-Communicable Diseases Research Unit, South African Medical Research Council, Cape Town, South Africa
| | - T Olsson
- Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden
| |
Collapse
|
15
|
Yaghootkar H, Whitcher B, Bell JD, Thomas EL. Ethnic differences in adiposity and diabetes risk - insights from genetic studies. J Intern Med 2020; 288:271-283. [PMID: 32367627 DOI: 10.1111/joim.13082] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Type 2 diabetes is more common in non-Europeans and starts at a younger age and at lower BMI cut-offs. This review discusses the insights from genetic studies about pathophysiological mechanisms which determine risk of disease with a focus on the role of adiposity and body fat distribution in ethnic disparity in risk of type 2 diabetes. During the past decade, genome-wide association studies (GWAS) have identified more than 400 genetic variants associated with the risk of type 2 diabetes. The Eurocentric nature of these genetic studies has made them less effective in identifying mechanisms that make non-Europeans more susceptible to higher risk of disease. One possible mechanism suggested by epidemiological studies is the role of ethnic difference in body fat distribution. Using genetic variants associated with an ability to store extra fat in a safe place, which is subcutaneous adipose tissue, we discuss how different ethnic groups could be genetically less susceptible to type 2 diabetes by developing a more favourable fat distribution.
Collapse
Affiliation(s)
- H Yaghootkar
- From the, Genetics of Complex Traits, University of Exeter Medical School, Royal Devon & Exeter Hospital, Exeter, UK.,School of Life Sciences, College of Liberal Arts and Science, University of Westminster, London, UK.,Division of Medical Sciences, Department of Health Sciences, Luleå University of Technology, Luleå, Sweden
| | - B Whitcher
- School of Life Sciences, College of Liberal Arts and Science, University of Westminster, London, UK
| | - J D Bell
- School of Life Sciences, College of Liberal Arts and Science, University of Westminster, London, UK
| | - E L Thomas
- School of Life Sciences, College of Liberal Arts and Science, University of Westminster, London, UK
| |
Collapse
|