Plasma sterol evidence for decreased absorption and increased synthesis of cholesterol in insulin resistance and obesity.

Background: The rise in LDL with egg feeding in lean insulin-sensitive (LIS) participants is 2- and 3-fold greater than in lean insulin-resistant (LIR) and obese insulin-resistant (OIR) participants, respectively.

Objective: We determined whether differences in cholesterol absorption, synthesis, or both could be responsible for these differences by measuring plasma sterols as indexes of cholesterol absorption and endogenous synthesis.

Design: Plasma sterols were measured by gas chromatography-mass spectrometry in a random subset of 34 LIS, 37 LIR, and 37 OIR participants defined by the insulin sensitivity index (S(I)) and by BMI criteria selected from a parent group of 197 participants.

The SLIM Study: Slo-Niacin® and Atorvastatin Treatment of Lipoproteins and Inflammatory Markers in Combined Hyperlipidemia.

BACKGROUND: The combination of niacin and statin has proven value in hyperlipidemia management and heart disease prevention. However, the efficacy of the non-prescription time-release niacin, Slo-Niacin®, is little studied alone and not at all with atorvastatin. We gave Slo-Niacin® and atorvastatin, singly and together to determine efficacy on the combined abnormalities of triglyceride, LDL and HDL.

Measuring dietary acculturation in Japanese Americans with the use of confirmatory factor analysis of food-frequency data.

Background: Epidemiologic evidence suggests that dietary changes associated with acculturation to a Western diet may increase the risk of type 2 diabetes in Japanese Americans.

Objective: We hypothesized that dietary acculturation patterns could be measured by confirmatory factor analysis (CFA) by using a culturally sensitive food-frequency questionnaire (FFQ). We examined the utility of the estimated factor scores by testing for associations with diabetes and 2 risk factors for diabetes-body mass index (BMI; in kg/m(2)) and C-reactive protein (CRP).

Lipoprotein effects of combined ezetimibe and colesevelam hydrochloride versus ezetimibe alone in hypercholesterolemic subjects: a pilot study.

Two drug classes act in the intestine to lower cholesterol. Ezetimibe inhibits cholesterol absorption, whereas bile acid-binding resins enhance cholesterol excretion via enhanced conversion to bile acids. Combining these 2 classes may be beneficial, but cholestyramine binds ezetimibe, and the combined effect of colesevelam hydrochloride and ezetimibe was little studied.

Sex differences in lipoprotein metabolism and dietary response: basis in hormonal differences and implications for cardiovascular disease.

The transport of fat in the blood stream is approximately twice as fast in women as men. Disease states such as obesity and diabetes are associated with greater lipoprotein abnormalities in women compared with men. A greater increment in cardiovascular disease risk in women is linked to these abnormalities.

A moderate-fat diet for combined hyperlipidemia and metabolic syndrome.

A low-fat diet is recommended for hyperlipidemia. However, low-density lipoprotein (LDL) responses depend on the type of hyperlipidemia (ie, simple hypercholesterolemia or combined hyperlipidemia). In combined hyperlipidemia, which is typical of patients with metabolic syndrome, LDL levels are only one third as responsive to fat and cholesterol as simple hypercholesterolemia.

Impact of differences in fasting glucose and glucose tolerance on the hyperbolic relationship between insulin sensitivity and insulin responses.

Objective: To determine whether the hyperbolic relationship between insulin sensitivity and the acute insulin response to glucose (AIRg) exists in subjects with impaired fasting glucose (IFG) or decreased glucose tolerance.

Research Design And Methods: We studied 219 healthy subjects (88 male and 131 female subjects, aged 26-75 years) with fasting plasma glucose (FPG) <6.11 mmol/l.

Gender differences in lipoprotein metabolism and dietary response: basis in hormonal differences and implications for cardiovascular disease.

The transport of fat in the blood stream is approximately twice as fast in women as men. Disease states such as obesity and diabetes are associated with greater lipoprotein abnormalities in women compared with men. A greater increment in cardiovascular disease risk in women is linked to these abnormalities.

Cholesterol feeding increases C-reactive protein and serum amyloid A levels in lean insulin-sensitive subjects.

Background: Inflammatory markers associated with elevated cardiovascular risk are increased by cholesterol feeding in animal models. However, whether dietary cholesterol increases inflammatory marker levels in humans is not known.

Methods And Results: C-reactive protein (CRP), serum amyloid A (SAA), and lipoprotein levels were compared in 201 healthy subjects on an American Heart Association-National Cholesterol Education Program step 1 diet at baseline and after addition of 4 eggs per day for 4 weeks.

Impact of intra-abdominal fat and age on insulin sensitivity and beta-cell function.

The prevalence of glucose intolerance and type 2 diabetes increases with age. To determine whether the hyperbolic relationship between insulin sensitivity and the insulin response is affected by age and whether the decline in beta-cell function with age is related to increases in intra-abdominal fat or age per se, we studied 220 healthy subjects with fasting glucose <6.1 mmol/l (89 men and 131 women, aged 26-75 years, BMI 18.

Intra-abdominal fat is a major determinant of the National Cholesterol Education Program Adult Treatment Panel III criteria for the metabolic syndrome.

The underlying pathophysiology of the metabolic syndrome is the subject of debate, with both insulin resistance and obesity considered as important factors. We evaluated the differential effects of insulin resistance and central body fat distribution in determining the metabolic syndrome as defined by the National Cholesterol Education Program (NCEP) Adult Treatment Panel III. In addition, we determined which NCEP criteria were associated with insulin resistance and central adiposity.

Effects of insulin resistance and obesity on lipoproteins and sensitivity to egg feeding.

Objective: This study was undertaken to determine if insulin resistance without and with obesity influences LDL response to dietary cholesterol and saturated fat.

Methods And Results: We fed 0, 2, and 4 egg yolks per day to 197 healthy subjects in a 4-week, double-blind, randomized, crossover design. Subjects were dichotomized on body mass index (<27.

Management of patients with diabetic hyperlipidemia.

Hyperlipidemia is commonly observed in patients with type 2 diabetes and is also characteristic of the metabolic syndrome. We discuss the lipoprotein abnormalities in type 2 diabetes and the relation of triglyceride, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol to insulin resistance and diabetes. We also present a case study of a diabetic woman with hyperlipidemia and coronary artery disease.

The atherogenic lipoprotein profile associated with obesity and insulin resistance is largely attributable to intra-abdominal fat.

Obesity and insulin resistance are both associated with an atherogenic lipoprotein profile. We examined the effect of insulin sensitivity and central adiposity on lipoproteins in 196 individuals (75 men and 121 women) with an average age of 52.7 years.

The concurrent accumulation of intra-abdominal and subcutaneous fat explains the association between insulin resistance and plasma leptin concentrations : distinct metabolic effects of two fat compartments.

Obesity is associated with insulin resistance, particularly when body fat has a central distribution. However, insulin resistance also frequently occurs in apparently lean individuals. It has been proposed that these lean insulin-resistant individuals have greater amounts of body fat than lean insulin-sensitive subjects.