Associations between pancreatic lipids and β-cell function in black african and white european men with type 2 diabetes

Abstract

Context: Intrapancreatic lipid (IPL) has been linked to b-cell dysfunction. Black populations disproportionately develop type 2 diabetes (T2D) and show distinctions in b-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 b-cell insulin secretory function (ISF). Design, Setting, and Participants: We performed a cross-sectional assessment of 18 WE and 19 BWA middle-agemenwith early T2Das 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- A nd 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 = 20.554, P = 0.026; BWA, r = 20.183, 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.