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Insulin clearance as the major player in the hyperinsulinaemia of black African men without diabetes
Author(s) -
Ladwa Meera,
Bello Oluwatoyosi,
Hakim Olah,
ShojaeeMoradie Fariba,
Boselli Linda,
CharlesEdwards Geoff,
Stadler Marietta,
Peacock Janet L.,
Umpleby Anne Margot,
Amiel Stephanie A.,
Bonadonna Riccardo C.,
Goff Louise M.
Publication year - 2020
Publication title -
diabetes, obesity and metabolism
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.445
H-Index - 128
eISSN - 1463-1326
pISSN - 1462-8902
DOI - 10.1111/dom.14101
Subject(s) - medicine , endocrinology , insulin , insulin resistance , diabetes mellitus , chemistry
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] × 10 3 vs. 29.9 [23.3, 38.4] × 10 3 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.