Increased Risk for Type 2 Diabetes in Relation to Adiposity in Middle-Aged Black South African Men compared to Women

Abstract

Aims: Despite a higher prevalence of overweight and obesity in black South African women compared to men, the prevalence of type 2 diabetes does not differ. We explored if this could be due to sex differences in insulin sensitivity, clearance and or beta cell function, and also sex-specific associations with total and regional adiposity. Methods: This cross-sectional study included 804 black South African men (n=388) and women (n=416). Dual-energy x ray absorptiometry was used to measure total and regional adiposity. Insulin sensitivity (Matsuda index), secretion (C peptide index) and clearance (C peptide/insulin ratio) were estimated from an oral glucose tolerance test. Results: After adjusting for sex differences in fat mass index, men were less insulin sensitive and had lower beta cell function than women (p<0.001), with the strength of the associations with measures of total and central adiposity being greater in men than women (p<0.001 for interactions). Further, the association between total adiposity and type 2 diabetes risk was also greater in men than women (relative risk ratio (95% confidence interval): 2.05 (1.42 to 2.96), p<0.001 vs. 1.38 (1.03 to 1.85), p=0.031). Conclusion: With increasing adiposity, particularly increased centralisation of body fat linked to decreased insulin sensitivity and beta cell function, Black African men are at greater risk for type 2 diabetes than their female counterparts.

Waist circumference thresholds predicting incident dysglycaemia and type 2 diabetes in Black African men and women

“…25 Further, these discrepant findings may be explained by the stronger association between total and central adiposity and T2D risk in Black SA men compared to Black SA women. 26 WC incorporates both VAT and SAT, and it has been shown in Black SA people and African‐born Black people living in the United States that for the same WC, women have less VAT and more abdominal SAT than men. 26 , 27 Indeed, in the SA cohort, the VAT: SAT ratio was twofold higher in men versus women (0.50 vs. 0.24), 25 whereas in the study in African‐born Black people living in the United States, the VAT: SAT ratio was threefold higher in men than women (~0.91 vs. 0.31).…”

“… 26 WC incorporates both VAT and SAT, and it has been shown in Black SA people and African‐born Black people living in the United States that for the same WC, women have less VAT and more abdominal SAT than men. 26 , 27 Indeed, in the SA cohort, the VAT: SAT ratio was twofold higher in men versus women (0.50 vs. 0.24), 25 whereas in the study in African‐born Black people living in the United States, the VAT: SAT ratio was threefold higher in men than women (~0.91 vs. 0.31). 27 Higher abdominal SAT for every level of VAT explained the higher WC cut‐off point required for predicting insulin resistance in African‐born Black women living in the United States compared to their male counterparts (96 cm vs. 91 cm).…”

“…25 Further, these discrepant findings may be explained by the stronger association between total and central adiposity and T2D risk in Black SA men compared to Black SA women. 26 WC incorporates both VAT and SAT, and it has been shown in Black SA people and African-born Black people living in the United States that for the same WC, women have less VAT and more abdominal SAT than men. 26,27 Indeed, in the SA cohort, the VAT:…”

“…26 WC incorporates both VAT and SAT, and it has been shown in Black SA people and African-born Black people living in the United States that for the same WC, women have less VAT and more abdominal SAT than men. 26,27 Indeed, in the SA cohort, the VAT:…”

Physical behaviours and their association with type 2 diabetes risk in urban South African middle-aged adults: An isotemporal substitution approach

“…This cross–sectional study used data from the Middle-aged Soweto Cohort (MASC) collected between January 2017 and August 2018 (502 men and 527 women), as described previously (26). For this analysis, complete accelerometry (27) and oral glucose tolerance test (OGTT) data were available on 727 participants (n=403 men and n=324 women) (Figure 1).…”