Effects of dietary cholesterol on plasma lipoproteins and their subclasses in IDDM patients

Abstract

Clinical studies have shown that a high cholesterol intake increases the levels of plasma and low density lipoprotein (LDL) cholesterol, even when dietary fat is kept constant [1]. The elevation of LDL cholesterol level is highly variable (4±58 %) [1,2] and this may depend on different factors, such as the type of fat utilized in the diet, dietary cholesterol absorption efficiency, ability to reduce endogenous cholesterol synthesis, regulation of the synthesis of bile acids, amount of intracellular cholesterol, genetic background [1±6].Despite the large number of studies on healthy or hyperlipidaemic individuals [1±7], no data is available Diabetologia (1998) Summary To compare the effects of dietary cholesterol supplementation in insulin-dependent diabetic (IDDM) patients and normal subjects, 10 male IDDM patients in good glycaemic control (HbA 1 c 7.3 ± 0.9 %) (mean ± SD) and normal plasma lipid levels, and 11 control male subjects of similar age, body mass index and lipid plasma levels underwent a double blind, cross-over, sequential study. Cholesterol supplementation of 800 mg/day or placebo were given for consecutive periods of 3 weeks. The concentration of plasma total cholesterol increased significantly with the dietary cholesterol supplementation compared to placebo in IDDM patients by 6 % (p < 0.05) and in control subjects by 9 % (p < 0.05). No changes were observed in the concentration of plasma triglycerides in either group. The LDL cholesterol level increased by 12 % (p < 0.01) in patients and by 7 % (p < 0.05) in control subjects. In patients plasma HDL cholesterol concentration remained the same, while in control subjects it tended to increase after cholesterol supplementation (from 1.14 ± 0.26 to 1.23 ± 0.27 mmol/l, p = 0.06). During the cholesterol intake period the mean concentration of LDL1, LDL2 and LDL3 subclasses in patients showed a significant increase by 21.0 (p < 0.05), 20.4 (p < 0.001) and 11.1 % (p < 0.05), respectively, resulting in an 18.0 % increase in mean total LDL mass (p < 0.001) without major changes in LDL composition. In the control subjects the changes in the concentrations of LDL subclasses during cholesterol intake were less and not significant. In the IDDM patients the cholesterol intake did not affect the concentration or composition of HDL subclasses or total HDL mass. In contrast, in control subjects cholesterol intake increased the mean concentration of HDL2 a by 12.2.% (p < 0.05) and this increase was significantly different if compared to changes obtained in the patients. In conclusion, compared to normal subjects, in IDDM patients, dietary cholesterol intake increased the LDL particle mass significantly and had no positive effect on HDL. [Diabetologia (1998)

Low Synthesis and High Absorption of Cholesterol Characterize Type 1 Diabetes

“…Bile acid malabsorption was responsible for increased cholesterol synthesis despite increased cholesterol absorption. Increased administration of dietary cholesterol under controlled conditions seemed to increase LDL cholesterol more effectively in type 1 diabetic subjects than in matched control subjects (17). On the other hand, reduction of dietary cholesterol with modification of fat intake has been observed to effectively reduce serum cholesterol in type 1 diabetes (18).…”

Egg consumption and cardiovascular disease among diabetic individuals: a systematic review of the literature

“…In the trial conducted by Arora et al, no statistical significant change in serum total cholesterol, HDL, LDL, or triglycerides (TAG) was found within and across the study groups of healthy controls and Type I and II diabetic subjects, after a single dose of 800 mg egg cholesterol 47. The Romano et al trial found a significant increase in LDL and ratio of LDL/HDL in Type I diabetics when fed with 800 mg egg cholesterol over a period of 3 weeks 48. On the contrary, the Pearce et al trial found statistically significant decreases in weight, total cholesterol, TAG, non-HDL-C, apolipoprotein B, HbA1C, FPG, insulin, and BP among T2DM patients after 12 weeks of hypoenergetic high-protein diets with either low or high cholesterol (from egg supplementation) 49.…”

Dietary Cholesterol Affects Plasma Lipid Levels, the Intravascular Processing of Lipoproteins and Reverse Cholesterol Transport without Increasing the Risk for Heart Disease

“…In contrast, in a crossover study, cholesterol supplementation of 800 mg/day during 3 weeks did not result in significant changes on the concentration of HDL subclasses, isolated by density gradient ultracentrifugation, or total HDL mass in insulin-dependent diabetic patients (with normal lipid values) compared with placebo [33]. Conversely, in normal control participants this concentration of dietary cholesterol resulted in a significant increase in the mean concentration of the large HDL2a by 12.2% [33]. This change was significantly different from that observed in the diabetic patients, in whom a similar, but non-significant increase in the mean concentration of HDL2b was observed [33].…”