Associations Between Pancreatic Lipids and β-Cell Function in Black African and White European Men With Type 2 Diabetes

• Published in: The journal of clinical endocrinology and metabolism 2019-04, Vol.104 (4), p.1201-1210
• Main Authors: Hakim, Olah, Bonadonna, Riccardo C, Mohandas, Cynthia, Billoo, Zoya, Sunderland, Alexander, Boselli, Linda, Alberti, K George M M, Peacock, Janet L, Umpleby, A Margot, Charles-Edwards, Geoff, Amiel, Stephanie A, Goff, Louise M
• Format: Article
• Language: English
• Subjects: Adipose tissue; African Continental Ancestry Group - statistics & numerical data; Aged; Beta cells; Cross-Sectional Studies; Diabetes; Diabetes mellitus (non-insulin dependent); Diabetes Mellitus, Type 2 - diagnostic imaging; Diabetes Mellitus, Type 2 - ethnology; Diabetes Mellitus, Type 2 - physiopathology; European Continental Ancestry Group - statistics & numerical data; Health Status Disparities; Humans; Insulin; Insulin - metabolism; Insulin-Secreting Cells - metabolism; Intra-Abdominal Fat - diagnostic imaging; Lipids; Lipids - analysis; London; Magnetic Resonance Imaging; Male; Middle Aged; Pancreas; Pancreas - chemistry; Pancreas - diagnostic imaging; Pancreas - physiopathology; Phenotyping
• ISSN: 0021-972X; 1945-7197
• DOI: 10.1210/jc.2018-01809

Abstract Context Intrapancreatic lipid (IPL) has been linked to β-cell dysfunction. Black populations disproportionately develop type 2 diabetes (T2D) and show distinctions in β-cell function compared with white populations. Objective We quantified IPL in white European (WE) and black West African (BWA) men with early T2D and investigated the relationships between IPL and β-cell insulin secretory function (ISF). Design, Setting, and Participants We performed a cross-sectional assessment of 18 WE and 19 BWA middle-age men with early T2D as part of the South London Diabetes and Ethnicity Phenotyping study. Main Outcome Measures The participants underwent Dixon MRI to determine IPL in the pancreatic head, body, and tail and subcutaneous and visceral adipose tissue volumes. Modeled first- and second-phase ISFs were comprehensively determined using C-peptide measurements during a 3-hour meal tolerance test and a 2-hour hyperglycemic clamp test. Results The WE men had greater mean IPL levels compared with BWA men (P = 0.029), mainly owing to greater IPL levels in the pancreatic head (P = 0.009). The mean IPL level was inversely associated with orally stimulated first-phase ISF in WE but not BWA men (WE, r = −0.554, P = 0.026; BWA, r = −0.183, P = 0.468). No association was found with orally stimulated second-phase ISF in either WE or BWA men. No associations were found between the mean IPL level and intravenously stimulated ISF. Conclusions The IPL levels were lower in BWA than WE men with early T2D, and the lack of inverse association with first-phase ISF in BWA men indicates that IPL might be a less important determinant of the development of T2D in BWA than in WE men. We have shown that IPL is associated with orally stimulated β-cell insulin secretory function in WE men but not BWA men with early T2D.