RT Journal Article
SR Electronic
T1 Ethnic differences in beta cell function occur independently of insulin sensitivity and pancreatic fat in black and white men
JF BMJ Open Diabetes Research & Care
JO BMJ Open Diab Res Care
FD American Diabetes Association
SP e002034
DO 10.1136/bmjdrc-2020-002034
VO 9
IS 1
A1 Meera Ladwa
A1 Oluwatoyosi Bello
A1 Olah Hakim
A1 Fariba Shojaee-Moradie
A1 Maria Linda Boselli
A1 Geoff Charles-Edwards
A1 Janet Peacock
A1 A Margot Umpleby
A1 Stephanie A Amiel
A1 Riccardo C Bonadonna
A1 Louise M Goff
YR 2021
UL http://drc.bmj.com/content/9/1/e002034.abstract
AB 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.