Ethnic differences in the relationship between ectopic fat deposition and insulin sensitivity in Black African and White European men across a spectrum of glucose tolerance.

AIM: To examine the hypothesis that there would be ethnic differences in the relationship between ectopic fat and tissue-specific insulin resistance (IR) across a spectrum of glucose tolerance in Black African (BA) and White European (WE) men. MATERIALS AND METHODS: Fifty-three WE men (23/10/20 normal glucose tolerance [NGT]/impaired glucose tolerance [IGT]/type 2 diabetes [T2D]) and 48 BA men (20/10/18, respectively) underwent a two-step hyperinsulinaemic-euglycaemic clamp with infusion of D-[6,6-2H2]-glucose and [2H5]-glycerol to assess hepatic, peripheral and adipose tissue IR. Magnetic resonance imaging was used to measure subcutaneous adipose tissue, visceral adipose tissue (VAT) and intrahepatic lipid (IHL). Associations between ectopic fat and IR were assessed using linear regression models. RESULTS: There were no differences in tissue-specific IR between ethnic groups at any stage of glucose tolerance. VAT level was consistently lower in the BA population; NGT (p = 0.013), IGT (p = 0.006) and T2D (p = 0.015). IHL was also lower in the BA compared with the WE men (p = 0.013). VAT and IHL levels were significantly associated with hepatic IR in the BA population (p = 0.001) and with peripheral IR in the WE population (p = 0.027). CONCLUSIONS: The present study suggests that BA and WE men exhibit the same degree of IR across a glucose tolerance continuum, but with lower VAT and IHL levels in the BA population, suggesting that IR may be driven by a mechanism other than increased ectopic fat accumulation in BA men.

Ethnic differences in postprandial fatty acid trafficking and utilisation between overweight and obese White European and Black African-Caribbean men.

Black African-Caribbean (BAC) populations are at greater risk of cardiometabolic disease than White Europeans (WE), despite lower fasting triacylglycerol (TAG) concentrations. However, limited data exist regarding postprandial fatty acid metabolism in BAC populations. This study determined the ethnic differences in postprandial fatty acid metabolism between overweight and obese WE and BAC men. WE (n=10) and BAC (n=9) men consumed two consecutive moderate-to-high fat meals; the first labelled with U-13C palmitate. The plasma concentration and appearance of meal-derived fatty acids in very-low density lipoprotein (VLDL)-TAG, chylomicron-TAG, and NEFA were determined over 8-hours. Indirect calorimetry with 13CO2 enrichment determined total and meal-derived fatty acid oxidation rates, and plasma b-hydroxybutyrate (3-OHB) concentration was measured to assess ketogenesis. BAC exhibited lower postprandial TAG (P=0.006) and VLDL-TAG (P=0.002) concentrations than WE. The appearance of meal-derived fatty acids in VLDL-TAG was lower in BAC than WE (P=0.004). Following the second meal, BAC showed a trend for lower chylomicron-TAG concentration (P=0.057). There were no ethnic differences in the appearance of meal-derived fatty acids in chylomicron-TAG. Cumulative fatty acid oxidation and the NEFA:3-OHB ratio were similar in WE and BAC. In conclusion, BAC exhibit lower postprandial TAG concentrations compared with WE men, driven by lower VLDL-TAG concentrations and possibly lower chylomicron-TAG in the late postprandial period. In BAC, the lower VLDL-TAG concentration was partially driven by a lower appearance of meal-derived fatty acids in VLDL-TAG. These findings suggest that postprandial fatty acid trafficking may be a less important determinant of cardiometabolic risk in BAC than WE men.

Co-development of breast cancer health promotion educational materials for ethnically diverse women working with hairdressing and beauty salons: BELONG study.

BACKGROUND: Improved screening uptake is essential for early breast cancer detection, women's health and reducing health disparities. However, minority ethnic and deprived communities often face lower breast cancer screening rates and limited access to culturally tailored educational materials. A recent review found limited culturally tailored materials for breast cancer education. AIM: To investigate the culturally appropriate interfaces and preferences of salon staff in educating their clients about breast cancer METHOD: We used a two-stage approach, following the Double Diamond framework; discover and define phases. Relevant breast cancer materials (i.e., based on cultural appropriateness, English language presentation, and alignment with the UK context) were assessed using the Suitability Assessment of Materials (SAM) toolkit. Interviews with ethnically diverse salon staff provided insights into their needs and preferences for client education materials. Thematic analysis was applied to interview transcripts. RESULTS: Cultural appropriateness was evident in 9/14 (64%) of the materials identified (e.g., targeting black ethnicities with positive representations). Of those, six of them demonstrated an overall SAM rating of 76% ("Superior"). Thematic analysis of interviews identified seven key themes, including the importance of engagement strategies, education and awareness for health promotion, salon staff's role, preferred training methods, supportive materials, inclusivity, representation, and participant satisfaction. CONCLUSION: This study highlights the SAM toolkit's role in selecting suitable educational materials for breast cancer prevention. The research offers prospects for improving breast cancer awareness in ethnically diverse communities and addressing healthcare access disparities, with salon hairdressers emerging as crucial advocates for health promotion.

Waist circumference and cardiometabolic parameters in people of African/Caribbean ancestry with HIV in South London (CKD-AFRICA study).

BACKGROUND: There are no validated waist circumference (WC) cut-offs to define metabolic syndrome in Black people with HIV. METHODS: Cross-sectional analyses within the CKD-AFRICA study. We used Pearson correlation coefficients and receiver operating characteristic (ROC) curves to describe the relationship between WC and cardiometabolic parameters including triglycerides, cholesterol, glucose, glycated haemoglobin (HbA1c), and homeostatic model assessment for insulin resistance (HOMA-IR), and to identify optimal WC cut-offs for each of these outcomes. RESULTS: We included 383 participants (55% female, median age 52 years) with generally well controlled HIV. Female and male participants had similar WC (median 98 vs. 97 cm, p = .16). Generally weak correlations (r2 < 0.2) between WC and other cardiometabolic parameters were observed, with low (<0.7) areas under the ROC curves. The optimal WC cut-offs for constituents of the metabolic syndrome, HbA1c and HOMA-IR ranged from 92 to 101 cm in women and 89-98 cm in men, respectively; these cut-offs had variable sensitivity (52%-100%) and generally poor specificity (28%-72%). CONCLUSIONS: In this cohort of Black people with HIV, WC cut-offs for cardiometabolic risk factors in male participants were in line with the recommended value of 94 cm while in female participants they vastly exceeded the recommended 80 cm for white women.

Associations between social determinants of health and comorbidity and multimorbidity in people of black ethnicities with HIV.

OBJECTIVE: Social determinants of health (SDH) are important determinants of long-term conditions and multimorbidity in the general population. The intersecting relationship between SDH and multimorbidity in people with HIV remains poorly studied. DESIGN: A cross-sectional study investigating the relationships between eight socio-economic parameters and prevalent comorbidities of clinical significance and multimorbidity in adults of African ancestry with HIV aged 18-65 years in South London, UK. METHODS: Multivariable logistic regression analysis was used to evaluate associations between SDH and comorbidities and multimorbidity. RESULTS: Between September 2020 and January 2022, 398 participants (median age 52 years, 55% women) were enrolled; 85% reported at least one SDH and 72% had at least one comorbidity. There were no associations between SDH and diabetes mellitus or kidney disease, few associations between SDH (job and food insecurity) and cardiovascular or lung disease, and multiple associations between SDH (financial, food, housing and job insecurity, low educational level, social isolation, and discrimination) and poor mental health or chronic pain. Associations between SDH and multimorbidity mirrored those for constituent comorbidities. CONCLUSION: We demonstrate strong associations between SDH and poor mental health, chronic pain and multimorbidity in people of black ethnicities living with HIV in the UK. These findings highlight the likely impact of enduring socioeconomic hardship in these communities and underlines the importance of holistic health and social care for people with HIV to address these adverse psychosocial conditions.

Cardiometabolic disease in Black African and Caribbean populations: an ethnic divergence in pathophysiology?

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.