Effect of the inflammation, chronic hyperglycemia, or malabsorption on theapolipoprotein A-IV concentration in type 1 diabetes mellitus and in diabetes secondary to chronic pancreatitis

The metabolism of apolipoprotein (apo) A-IV in diabetes mellitus (DM) is Po orly understood. Several factors, such as dietary fat intake, fat malabsorp tion, acute inflammation, and hormonal dysregulation can disturb the plasma apo A-IV concentration. We have compared the plasma apo A-IV concentration s in patients with type 1 DM and DM secondary to chronic pancreatitis to de termine the effects of combinations of these factors. We examined 4 groups of male patients with chronic pancreatitis without diabetes (ND-CP) (n = 12 ), diabetes secondary to chronic pancreatitis and insulin-treated (CP-DM) ( n = 32), type I diabetes (n = 25), and controls (n = 20). Plasma apo A-IV w as significantly lower in the chronic pancreatitis patients (ND-CP and CP-D M) than in the other patients, Inflammatory proteins (fibrinogen, cerulopla smin, and haptoglobin) were significantly elevated in the 2 chronic pancrea titis groups. The apo A-IV concentration was positively correlated with hem oglobin A(1c) (HbA(1c)) percentage in each group of diabetic patients (CP-D M, r = .35; P = .046; type 1 DM, r = .53; P = .010), in both groups of diab etic patients (r = .472; P < .0001) and negatively correlated with cerulopl asmin concentration in each group of diabetic patients (CP-DM, r = -.48; P = .0052; type 1 DM, r = -.66; P = .003), in both groups of diabetic patient s (r = -.561; P < .0001), and in the whole population (r = -.463; P < .0001 ). Apo A-IV was also negatively correlated with haptoglobin in type 1 DM pa tients (r = -.434, P = .0435), in the both groups of diabetic patients (r = -.349; P = .0154), and in the whole population (r = -.351; P = .0019). Mul tiple linear regression analysis revealed that only HbA(1c) and ceruloplasm in were independent explanatory variables. Plasma apo A-IV is positively co rrelated with HbA(1c) suggesting that hyperglycemia per se selectively affe cts apo A-IV metabolism. The correlation between the concentrations of infl ammatory protein and apo A-IV suggest a link between chronic inflammation a nd apo A-IV synthesis or catabolism. As apo A-IV is involved in reverse cho lesterol transport, its low level in CP-DM may contribute to the accelerate d development of atherosclerosis in these patients. Copyright (C) 2001 by W .B. Saunders Company.