Associations of Habitual Micronutrient Intake and New-Onset Prediabetes/Diabetes after Acute Pancreatitis

Abstract

Micronutrients have many roles in human health and metabolism. However, the role of habitual dietary intake of minerals and vitamins in glucose homeostasis in individuals after acute pancreatitis (AP) is yet to be elucidated. The primary aim of this thesis was to investigate the associations of habitual micronutrient intake in individuals after AP: new-onset prediabetes/diabetes after AP (NODAP), pre-existing prediabetes/type 2 diabetes (T2DM), and normoglycaemia after AP (NAP). Associations between habitual intake of minerals and vitamins and glycaemic status were studied, as well as relationships between intake of minerals and vitamins/vitamers and markers of glucose metabolism in individuals after AP. This thesis included two cross-sectional studies. The EPIC-Norfolk food frequency questionnaire was used to determine habitual intake of 13 dietary minerals as well as seven fat-soluble vitamins and seven water-soluble vitamins. ANCOVA as well as multiple linear regression analyses were conducted, and five statistical models were built to adjust for covariates (age, sex, daily energy intake, visceral/subcutaneous fat volume ratio, smoking status, daily alcohol intake, aetiology of AP, number of AP episodes, cholecystectomy, and use of antidiabetic medications). A total of 106 individuals after AP were included in this thesis. In the NODAP group, habitual intake of four minerals were significantly less when compared with the NAP group: iron, nitrogen, phosphorous, and zinc. Glycated haemoglobin (HbA1c) was significantly associated with iodine intake and manganese intake in the NODAP group. Fasting plasma glucose (FPG) was significantly associated with manganese intake in the NODAP group. Habitual intake of one vitamin, vitamin B6, was significantly altered in the NODAP group compared with the NAP group. In the NODAP group, three fat-soluble vitamins/vitamers (α-carotene, β-carotene, and total carotene) were significantly associated with HOMA-β (Homeostasis Model Assessment β-cell function index). One water-soluble vitamin (vitamin B3) was also significantly associated with HOMA-β in the NODAP group. None of the studied vitamins were significantly associated with FPG or HOMA-IR (Homeostasis Model Assessment Insulin Resistance index) in the NODAP group. In conclusion, this thesis provided the first evidence of the associations of habitual micronutrient intake in individuals after AP. Prospective longitudinal studies and randomised controlled trials are now warranted to investigate the associations between micronutrient intake and NODAP are causal and unveil the specific mechanisms underlying their involvement with NODAP.